Code

Refactored rrd_update code in preparation of finding the HW update
authoroetiker <oetiker@a5681a0c-68f1-0310-ab6d-d61299d08faa>
Mon, 13 Aug 2007 20:06:10 +0000 (20:06 +0000)
committeroetiker <oetiker@a5681a0c-68f1-0310-ab6d-d61299d08faa>
Mon, 13 Aug 2007 20:06:10 +0000 (20:06 +0000)
problem -- Evan Miller

git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk@1191 a5681a0c-68f1-0310-ab6d-d61299d08faa

program/src/rrd_update.c

index 1e5397935ec9f4b5f76c245321caa579a7f6e7a7..45f635bfaa46774f533e2453fb5f31dc17e32b30 100644 (file)
@@ -57,6 +57,128 @@ static int gettimeofday(
 }
 
 #endif
+
+/* FUNCTION PROTOTYPES */
+
+int       rrd_update_r(
+    const char *filename,
+    const char *tmplt,
+    int argc,
+    const char **argv);
+int       _rrd_update(
+    const char *filename,
+    const char *tmplt,
+    int argc,
+    const char **argv,
+    info_t *);
+
+static int allocate_data_structures(
+    rrd_t *rrd, char ***updvals, rrd_value_t **pdp_temp,
+    const char *tmplt, long **tmpl_idx, unsigned long *tmpl_cnt, 
+    unsigned long **rra_step_cnt, rrd_value_t **pdp_new);
+
+static int parse_template(rrd_t *rrd, const char *tmplt,
+    unsigned long *tmpl_cnt, long *tmpl_idx);
+
+static int process_arg(
+    char          *step_start, 
+    rrd_t         *rrd, 
+    rrd_file_t    *rrd_file, 
+    unsigned long  rra_begin,
+    unsigned long *rra_current,
+    time_t        *current_time,
+    unsigned long *current_time_usec,
+    rrd_value_t   *pdp_temp,
+    rrd_value_t   *pdp_new,
+    unsigned long *rra_step_cnt,
+    char         **updvals,
+    long          *tmpl_idx,
+    unsigned long  tmpl_cnt,
+    info_t       **pcdp_summary,
+    int            version,
+    int           *schedule_smooth);
+
+static int parse_ds(rrd_t *rrd, char **updvals, long *tmpl_idx, char *input,
+    unsigned long tmpl_cnt, time_t *current_time, unsigned long *current_time_usec, 
+    int version);
+
+static int get_time_from_reading(rrd_t *rrd, char timesyntax, char **updvals, 
+    time_t *current_time, unsigned long *current_time_usec, int version);
+
+static int update_pdp_prep(rrd_t *rrd, char **updvals, 
+    rrd_value_t *pdp_new, double interval);
+
+static int calculate_elapsed_steps(rrd_t *rrd, 
+    unsigned long current_time, unsigned long current_time_usec,
+    double interval, double *pre_int, double *post_int, 
+    unsigned long *proc_pdp_cnt);
+
+static void simple_update(rrd_t *rrd, double interval, rrd_value_t *pdp_new);
+
+static int process_all_pdp_st(rrd_t *rrd, double interval, 
+    double pre_int, double post_int, unsigned long elapsed_pdp_st, 
+    rrd_value_t *pdp_new, rrd_value_t *pdp_temp);
+
+static int process_pdp_st(rrd_t *rrd, unsigned long ds_idx, double interval, 
+    double pre_int, double post_int, long diff_pdp_st, rrd_value_t *pdp_new, 
+    rrd_value_t *pdp_temp);
+
+static int update_all_cdp_prep(
+    rrd_t *rrd, unsigned long *rra_step_cnt, unsigned long rra_begin, 
+    rrd_file_t *rrd_file, unsigned long elapsed_pdp_st, unsigned long proc_pdp_cnt,
+    rrd_value_t **last_seasonal_coef, rrd_value_t **seasonal_coef,
+    rrd_value_t *pdp_temp, unsigned long *rra_current, int *schedule_smooth);
+
+static int do_schedule_smooth(rrd_t *rrd, unsigned long rra_idx, 
+    unsigned long elapsed_pdp_st);
+
+static int update_cdp_prep(rrd_t *rrd, unsigned long elapsed_pdp_st, 
+    unsigned long start_pdp_offset, unsigned long *rra_step_cnt, 
+    int rra_idx, rrd_value_t *pdp_temp, rrd_value_t *last_seasonal_coef, 
+    rrd_value_t *seasonal_coef, int current_cf);
+
+static void update_cdp(unival *scratch, int current_cf, 
+    rrd_value_t pdp_temp_val, unsigned long rra_step_cnt, 
+    unsigned long elapsed_pdp_st, unsigned long start_pdp_offset, 
+    unsigned long pdp_cnt, rrd_value_t xff, int i, int ii);
+
+static void initialize_cdp_val(unival *scratch, int current_cf,
+    rrd_value_t pdp_temp_val, unsigned long elapsed_pdp_st, 
+    unsigned long start_pdp_offset, unsigned long pdp_cnt);
+
+static void reset_cdp(rrd_t *rrd, unsigned long elapsed_pdp_st, 
+    rrd_value_t *pdp_temp, rrd_value_t *last_seasonal_coef, 
+    rrd_value_t *seasonal_coef, 
+    int rra_idx, int ds_idx, int cdp_idx, enum cf_en current_cf);
+
+static rrd_value_t initialize_average_carry_over(rrd_value_t pdp_temp_val,
+    unsigned long elapsed_pdp_st, unsigned long start_pdp_offset, 
+    unsigned long pdp_cnt);
+
+static rrd_value_t calculate_cdp_val(
+    rrd_value_t cdp_val, rrd_value_t pdp_temp_val,
+    unsigned long elapsed_pdp_st, int current_cf, int i, int ii);
+
+static int update_aberrant_cdps(rrd_t *rrd, rrd_file_t *rrd_file, 
+    unsigned long rra_begin, unsigned long *rra_current, 
+    unsigned long elapsed_pdp_st, rrd_value_t *pdp_temp, rrd_value_t **seasonal_coef);
+
+static int write_to_rras(rrd_t *rrd, rrd_file_t *rrd_file, 
+    unsigned long *rra_step_cnt, unsigned long rra_begin, 
+    unsigned long *rra_current, time_t current_time, info_t **pcdp_summary);
+
+static int write_RRA_row(rrd_file_t *rrd_file, rrd_t *rrd, unsigned long rra_idx,
+    unsigned long *rra_current, unsigned short CDP_scratch_idx, info_t **pcdp_summary,
+    time_t *rra_time);
+
+static int smooth_all_rras(rrd_t *rrd, rrd_file_t *rrd_file, 
+    unsigned long rra_begin);
+
+#ifndef HAVE_MMAP
+static int write_changes_to_disk(rrd_t *rrd, rrd_file_t *rrd_file, 
+    int version);
+#endif
+
 /*
  * normalize time as returned by gettimeofday. usec part must
  * be always >= 0
@@ -66,70 +188,32 @@ static inline void normalize_time(
 {
     if (t->tv_usec < 0) {
         t->tv_sec--;
-        t->tv_usec += 1000000L;
+        t->tv_usec += 1e6L;
     }
 }
 
-static inline info_t *write_RRA_row(
-    rrd_file_t *rrd_file,
-    rrd_t *rrd,
-    unsigned long rra_idx,
-    unsigned long *rra_current,
-    unsigned short CDP_scratch_idx,
-    info_t *pcdp_summary,
-    time_t *rra_time)
+/*
+ * Sets current_time and current_time_usec based on the current time.
+ * current_time_usec is set to 0 if the version number is 1 or 2.
+ */
+static inline void initialize_time(
+    time_t *current_time, unsigned long *current_time_usec,
+    int version) 
 {
-    unsigned long ds_idx, cdp_idx;
-    infoval   iv;
+    struct timeval tmp_time;    /* used for time conversion */
 
-    for (ds_idx = 0; ds_idx < rrd->stat_head->ds_cnt; ds_idx++) {
-        /* compute the cdp index */
-        cdp_idx = rra_idx * (rrd->stat_head->ds_cnt) + ds_idx;
-#ifdef DEBUG
-        fprintf(stderr, "  -- RRA WRITE VALUE %e, at %ld CF:%s\n",
-                rrd->cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val,
-                rrd_file->pos, rrd->rra_def[rra_idx].cf_nam);
-#endif
-        if (pcdp_summary != NULL) {
-            iv.u_val = rrd->cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val;
-            /* append info to the return hash */
-            pcdp_summary = info_push(pcdp_summary,
-                                     sprintf_alloc("[%d]RRA[%s][%lu]DS[%s]",
-                                                   *rra_time,
-                                                   rrd->rra_def[rra_idx].
-                                                   cf_nam,
-                                                   rrd->rra_def[rra_idx].
-                                                   pdp_cnt,
-                                                   rrd->ds_def[ds_idx].
-                                                   ds_nam), RD_I_VAL, iv);
-        }
-        if (rrd_write
-            (rrd_file,
-             &(rrd->cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val),
-             sizeof(rrd_value_t)) != sizeof(rrd_value_t)) {
-            rrd_set_error("writing rrd: %s", rrd_strerror(errno));
-            return 0;
-        }
-        *rra_current += sizeof(rrd_value_t);
+    gettimeofday(&tmp_time, 0);
+    normalize_time(&tmp_time);
+    *current_time = tmp_time.tv_sec;
+    if (version >= 3) {
+        *current_time_usec = tmp_time.tv_usec;
+    } else {
+        *current_time_usec = 0;
     }
-    return (pcdp_summary);
 }
 
-int       rrd_update_r(
-    const char *filename,
-    const char *tmplt,
-    int argc,
-    const char **argv);
-int       _rrd_update(
-    const char *filename,
-    const char *tmplt,
-    int argc,
-    const char **argv,
-    info_t *);
-
 #define IFDNAN(X,Y) (isnan(X) ? (Y) : (X));
 
-
 info_t   *rrd_update_v(
     int argc,
     char **argv)
@@ -244,78 +328,33 @@ int _rrd_update(
     info_t *pcdp_summary)
 {
 
-    int       arg_i = 2;
-    short     j;
-    unsigned long i, ii, iii = 1;
+    int           arg_i = 2;
 
     unsigned long rra_begin;    /* byte pointer to the rra
                                  * area in the rrd file.  this
                                  * pointer never changes value */
-    unsigned long rra_start;    /* byte pointer to the rra
-                                 * area in the rrd file.  this
-                                 * pointer changes as each rrd is
-                                 * processed. */
     unsigned long rra_current;  /* byte pointer to the current write
                                  * spot in the rrd file. */
-    unsigned long rra_pos_tmp;  /* temporary byte pointer. */
-    double    interval, pre_int, post_int;  /* interval between this and
-                                             * the last run */
-    unsigned long proc_pdp_st;  /* which pdp_st was the last
-                                 * to be processed */
-    unsigned long occu_pdp_st;  /* when was the pdp_st
-                                 * before the last update
-                                 * time */
-    unsigned long proc_pdp_age; /* how old was the data in
-                                 * the pdp prep area when it
-                                 * was last updated */
-    unsigned long occu_pdp_age; /* how long ago was the last
-                                 * pdp_step time */
-    rrd_value_t *pdp_new;   /* prepare the incoming data
-                             * to be added the the
-                             * existing entry */
-    rrd_value_t *pdp_temp;  /* prepare the pdp values
-                             * to be added the the
-                             * cdp values */
-
-    long     *tmpl_idx; /* index representing the settings
-                           transported by the tmplt index */
-    unsigned long tmpl_cnt = 2; /* time and data */
+    rrd_value_t   *pdp_new;     /* prepare the incoming data to be added 
+                                 * to the existing entry */
+    rrd_value_t   *pdp_temp;    /* prepare the pdp values to be added 
+                                 * to the cdp values */
 
-    rrd_t     rrd;
-    time_t    current_time = 0;
-    time_t    rra_time = 0; /* time of update for a RRA */
+    long          *tmpl_idx;    /* index representing the settings
+                                 * transported by the tmplt index */
+    unsigned long tmpl_cnt = 2; /* time and data */
+    rrd_t         rrd;
+    time_t        current_time = 0;
     unsigned long current_time_usec = 0;    /* microseconds part of current time */
-    struct timeval tmp_time;    /* used for time conversion */
-
-    char    **updvals;
-    int       schedule_smooth = 0;
-    rrd_value_t *seasonal_coef = NULL, *last_seasonal_coef = NULL;
-
-    /* a vector of future Holt-Winters seasonal coefs */
-    unsigned long elapsed_pdp_st;
+    char        **updvals;
+    int           schedule_smooth = 0;
 
     /* number of elapsed PDP steps since last update */
     unsigned long *rra_step_cnt = NULL;
 
-    /* number of rows to be updated in an RRA for a data
-     * value. */
-    unsigned long start_pdp_offset;
-
-    /* number of PDP steps since the last update that
-     * are assigned to the first CDP to be generated
-     * since the last update. */
-    unsigned short scratch_idx;
-
-    /* index into the CDP scratch array */
-    enum cf_en current_cf;
-
-    /* numeric id of the current consolidation function */
-    rpnstack_t rpnstack;    /* used for COMPUTE DS */
-    int       version;  /* rrd version */
-    char     *endptr;   /* used in the conversion */
-    rrd_file_t *rrd_file;
-
-    rpnstack_init(&rpnstack);
+    int            version;     /* rrd version */
+    rrd_file_t    *rrd_file;
+    char          *arg_copy;    /* for processing the argv */
 
     /* need at least 1 arguments: data. */
     if (argc < 1) {
@@ -323,23 +362,15 @@ int _rrd_update(
         goto err_out;
     }
 
-    rrd_file = rrd_open(filename, &rrd, RRD_READWRITE);
-    if (rrd_file == NULL) {
+    if ((rrd_file = rrd_open(filename, &rrd, RRD_READWRITE)) == NULL) {
         goto err_free;
     }
     /* We are now at the beginning of the rra's */
-    rra_current = rra_start = rra_begin = rrd_file->header_len;
+    rra_current = rra_begin = rrd_file->header_len;
 
-    /* initialize time */
     version = atoi(rrd.stat_head->version);
-    gettimeofday(&tmp_time, 0);
-    normalize_time(&tmp_time);
-    current_time = tmp_time.tv_sec;
-    if (version >= 3) {
-        current_time_usec = tmp_time.tv_usec;
-    } else {
-        current_time_usec = 0;
-    }
+
+    initialize_time(&current_time, &current_time_usec, version);
 
     /* get exclusive lock to whole file.
      * lock gets removed when we close the file.
@@ -349,1191 +380,1494 @@ int _rrd_update(
         goto err_close;
     }
 
-    if ((updvals =
-         malloc(sizeof(char *) * (rrd.stat_head->ds_cnt + 1))) == NULL) {
-        rrd_set_error("allocating updvals pointer array");
+    if (allocate_data_structures(&rrd, &updvals, 
+                    &pdp_temp, tmplt, &tmpl_idx, &tmpl_cnt,
+                    &rra_step_cnt, &pdp_new) == -1) {
         goto err_close;
     }
 
-    if ((pdp_temp = malloc(sizeof(rrd_value_t)
-                           * rrd.stat_head->ds_cnt)) == NULL) {
+    /* loop through the arguments. */
+    for (arg_i = 0; arg_i < argc; arg_i++) {
+        if ((arg_copy = strdup(argv[arg_i])) == NULL) {
+            rrd_set_error("failed duplication argv entry");
+            break;
+        }
+        if (process_arg(arg_copy, &rrd, rrd_file, rra_begin, &rra_current, 
+                        &current_time, &current_time_usec, pdp_temp, pdp_new,
+                        rra_step_cnt, updvals, tmpl_idx, tmpl_cnt, &pcdp_summary, 
+                        version, &schedule_smooth) == -1) {
+            free(arg_copy);
+            break;
+        }
+        free(arg_copy);
+    }
+
+    free(rra_step_cnt);
+
+    /* if we got here and if there is an error and if the file has not been
+     * written to, then close things up and return. */
+    if (rrd_test_error()) {
+        goto err_free_structures;
+    }
+
+#ifndef HAVE_MMAP
+    if (write_changes_to_disk(&rrd, rrd_file, version) == -1) {
+        goto err_free_structures;
+    }
+#endif
+
+    /* calling the smoothing code here guarantees at most one smoothing
+     * operation per rrd_update call. Unfortunately, it is possible with bulk
+     * updates, or a long-delayed update for smoothing to occur off-schedule.
+     * This really isn't critical except during the burn-in cycles. */
+    if (schedule_smooth) {
+        smooth_all_rras(&rrd, rrd_file, rra_begin);
+    }
+
+/*    rrd_dontneed(rrd_file,&rrd); */
+    rrd_free(&rrd);
+    rrd_close(rrd_file);
+
+    free(pdp_new);
+    free(tmpl_idx);
+    free(pdp_temp);
+    free(updvals);
+    return 0;
+
+  err_free_structures:
+    free(pdp_new);
+    free(tmpl_idx);
+    free(pdp_temp);
+    free(updvals);
+  err_close:
+    rrd_close(rrd_file);
+  err_free:
+    rrd_free(&rrd);
+  err_out:
+    return -1;
+}
+
+/*
+ * get exclusive lock to whole file.
+ * lock gets removed when we close the file
+ *
+ * returns 0 on success
+ */
+int LockRRD(
+    int in_file)
+{
+    int       rcstat;
+
+    {
+#if defined(_WIN32) && !defined(__CYGWIN__) && !defined(__CYGWIN32__)
+        struct _stat st;
+
+        if (_fstat(in_file, &st) == 0) {
+            rcstat = _locking(in_file, _LK_NBLCK, st.st_size);
+        } else {
+            rcstat = -1;
+        }
+#else
+        struct flock lock;
+
+        lock.l_type = F_WRLCK;  /* exclusive write lock */
+        lock.l_len = 0; /* whole file */
+        lock.l_start = 0;   /* start of file */
+        lock.l_whence = SEEK_SET;   /* end of file */
+
+        rcstat = fcntl(in_file, F_SETLK, &lock);
+#endif
+    }
+
+    return (rcstat);
+}
+
+/*
+ * Allocate some important arrays used, and initialize the template.
+ *
+ * When it returns, either all of the structures are allocated
+ * or none of them are.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int allocate_data_structures(
+    rrd_t *rrd, char ***updvals, rrd_value_t **pdp_temp, const char *tmplt, 
+    long **tmpl_idx, unsigned long *tmpl_cnt, unsigned long **rra_step_cnt, 
+    rrd_value_t **pdp_new) 
+{
+    unsigned i, ii;
+    if ((*updvals = (char **)malloc(sizeof(char *) 
+                           * (rrd->stat_head->ds_cnt + 1))) == NULL) {
+        rrd_set_error("allocating updvals pointer array");
+        return -1;
+    }
+
+    if ((*pdp_temp = (rrd_value_t *)malloc(sizeof(rrd_value_t)
+                           * rrd->stat_head->ds_cnt)) == NULL) {
         rrd_set_error("allocating pdp_temp ...");
         goto err_free_updvals;
     }
 
-    if ((tmpl_idx = malloc(sizeof(unsigned long)
-                           * (rrd.stat_head->ds_cnt + 1))) == NULL) {
+    if ((*tmpl_idx = (long *)malloc(sizeof(unsigned long)
+                           * (rrd->stat_head->ds_cnt + 1))) == NULL) {
         rrd_set_error("allocating tmpl_idx ...");
         goto err_free_pdp_temp;
     }
+    if ((*rra_step_cnt = (unsigned long *)malloc(sizeof(unsigned long) 
+                           * (rrd->stat_head->rra_cnt))) == NULL) {
+        rrd_set_error("allocating rra_step_cnt...");
+        goto err_free_tmpl_idx;
+    }
+
     /* initialize tmplt redirector */
     /* default config example (assume DS 1 is a CDEF DS)
        tmpl_idx[0] -> 0; (time)
        tmpl_idx[1] -> 1; (DS 0)
        tmpl_idx[2] -> 3; (DS 2)
        tmpl_idx[3] -> 4; (DS 3) */
-    tmpl_idx[0] = 0;    /* time */
-    for (i = 1, ii = 1; i <= rrd.stat_head->ds_cnt; i++) {
-        if (dst_conv(rrd.ds_def[i - 1].dst) != DST_CDEF)
-            tmpl_idx[ii++] = i;
+    (*tmpl_idx)[0] = 0;    /* time */
+    for (i = 1, ii = 1; i <= rrd->stat_head->ds_cnt; i++) {
+        if (dst_conv(rrd->ds_def[i-1].dst) != DST_CDEF)
+            (*tmpl_idx)[ii++] = i;
     }
-    tmpl_cnt = ii;
-
-    if (tmplt) {
-        /* we should work on a writeable copy here */
-        char     *dsname;
-        unsigned int tmpl_len;
-        char     *tmplt_copy = strdup(tmplt);
-
-        dsname = tmplt_copy;
-        tmpl_cnt = 1;   /* the first entry is the time */
-        tmpl_len = strlen(tmplt_copy);
-        for (i = 0; i <= tmpl_len; i++) {
-            if (tmplt_copy[i] == ':' || tmplt_copy[i] == '\0') {
-                tmplt_copy[i] = '\0';
-                if (tmpl_cnt > rrd.stat_head->ds_cnt) {
-                    rrd_set_error
-                        ("tmplt contains more DS definitions than RRD");
-                    goto err_free_tmpl_idx;
-                }
-                if ((tmpl_idx[tmpl_cnt++] = ds_match(&rrd, dsname)) == -1) {
-                    rrd_set_error("unknown DS name '%s'", dsname);
-                    goto err_free_tmpl_idx;
-                } else {
-                    /* the first element is always the time */
-                    tmpl_idx[tmpl_cnt - 1]++;
-                    /* go to the next entry on the tmplt_copy */
-                    dsname = &tmplt_copy[i + 1];
-                    /* fix the damage we did before */
-                    if (i < tmpl_len) {
-                        tmplt_copy[i] = ':';
-                    }
+    *tmpl_cnt = ii;
 
-                }
-            }
+    if (tmplt != NULL) {
+        if (parse_template(rrd, tmplt, tmpl_cnt, *tmpl_idx) == -1) {
+            goto err_free_tmpl_idx;
         }
-        free(tmplt_copy);
     }
-    if ((pdp_new = malloc(sizeof(rrd_value_t)
-                          * rrd.stat_head->ds_cnt)) == NULL) {
+
+    if ((*pdp_new = (rrd_value_t *)malloc(sizeof(rrd_value_t)
+                          * rrd->stat_head->ds_cnt)) == NULL) {
         rrd_set_error("allocating pdp_new ...");
         goto err_free_tmpl_idx;
     }
-    /* loop through the arguments. */
-    for (arg_i = 0; arg_i < argc; arg_i++) {
-        char     *stepper = strdup(argv[arg_i]);
-        char     *step_start = stepper;
-        char     *p;
-        char     *parsetime_error = NULL;
-        enum { atstyle, normal } timesyntax;
-        struct rrd_time_value ds_tv;
-
-        if (stepper == NULL) {
-            rrd_set_error("failed duplication argv entry");
-            free(step_start);
-            goto err_free_pdp_new;
-        }
-        /* initialize all ds input to unknown except the first one
-           which has always got to be set */
-        for (ii = 1; ii <= rrd.stat_head->ds_cnt; ii++)
-            updvals[ii] = "U";
-        updvals[0] = stepper;
-        /* separate all ds elements; first must be examined separately
-           due to alternate time syntax */
-        if ((p = strchr(stepper, '@')) != NULL) {
-            timesyntax = atstyle;
-            *p = '\0';
-            stepper = p + 1;
-        } else if ((p = strchr(stepper, ':')) != NULL) {
-            timesyntax = normal;
-            *p = '\0';
-            stepper = p + 1;
-        } else {
-            rrd_set_error
-                ("expected timestamp not found in data source from %s",
-                 argv[arg_i]);
-            free(step_start);
-            break;
-        }
-        ii = 1;
-        updvals[tmpl_idx[ii]] = stepper;
-        while (*stepper) {
-            if (*stepper == ':') {
-                *stepper = '\0';
-                ii++;
-                if (ii < tmpl_cnt) {
-                    updvals[tmpl_idx[ii]] = stepper + 1;
-                }
-            }
-            stepper++;
-        }
 
-        if (ii != tmpl_cnt - 1) {
-            rrd_set_error
-                ("expected %lu data source readings (got %lu) from %s",
-                 tmpl_cnt - 1, ii, argv[arg_i]);
-            free(step_start);
-            break;
-        }
+    return 0;
 
-        /* get the time from the reading ... handle N */
-        if (timesyntax == atstyle) {
-            if ((parsetime_error = parsetime(updvals[0], &ds_tv))) {
-                rrd_set_error("ds time: %s: %s", updvals[0], parsetime_error);
-                free(step_start);
-                break;
-            }
-            if (ds_tv.type == RELATIVE_TO_END_TIME ||
-                ds_tv.type == RELATIVE_TO_START_TIME) {
-                rrd_set_error("specifying time relative to the 'start' "
-                              "or 'end' makes no sense here: %s", updvals[0]);
-                free(step_start);
-                break;
-            }
+err_free_tmpl_idx:
+    free(*tmpl_idx);
+err_free_pdp_temp:
+    free(*pdp_temp);
+err_free_updvals:
+    free(*updvals);
+    return -1;
+}
 
-            current_time = mktime(&ds_tv.tm) + ds_tv.offset;
+/*
+ * Parses tmplt and puts an ordered list of DS's into tmpl_idx.
+ *
+ * Returns 0 on success.
+ */
+static int parse_template(
+    rrd_t *rrd, const char *tmplt, 
+    unsigned long *tmpl_cnt, long *tmpl_idx)
+{
+    char          *dsname, *tmplt_copy;
+    unsigned int   tmpl_len, i;
 
-            current_time_usec = 0;  /* FIXME: how to handle usecs here ? */
+    *tmpl_cnt = 1;   /* the first entry is the time */
 
-        } else if (strcmp(updvals[0], "N") == 0) {
-            gettimeofday(&tmp_time, 0);
-            normalize_time(&tmp_time);
-            current_time = tmp_time.tv_sec;
-            current_time_usec = tmp_time.tv_usec;
-        } else {
-            double    tmp;
-            char     *old_locale;
-
-            old_locale = setlocale(LC_NUMERIC, "C");
-            tmp = strtod(updvals[0], 0);
-            setlocale(LC_NUMERIC, old_locale);
-            current_time = floor(tmp);
-            current_time_usec =
-                (long) ((tmp - (double) current_time) * 1000000.0);
-        }
-        /* dont do any correction for old version RRDs */
-        if (version < 3)
-            current_time_usec = 0;
-
-        if (current_time < rrd.live_head->last_up ||
-            (current_time == rrd.live_head->last_up &&
-             (long) current_time_usec <=
-             (long) rrd.live_head->last_up_usec)) {
-            rrd_set_error("illegal attempt to update using time %ld when "
-                          "last update time is %ld (minimum one second step)",
-                          current_time, rrd.live_head->last_up);
-            free(step_start);
-            break;
-        }
+    /* we should work on a writeable copy here */
+    if ((tmplt_copy = strdup(tmplt)) == NULL) {
+        rrd_set_error("error copying tmplt '%s'", tmplt);
+        return -1;
+    }
 
-        /* seek to the beginning of the rra's */
-        if (rra_current != rra_begin) {
-#ifndef HAVE_MMAP
-            if (rrd_seek(rrd_file, rra_begin, SEEK_SET) != 0) {
-                rrd_set_error("seek error in rrd");
-                free(step_start);
-                break;
+    dsname = tmplt_copy;
+    tmpl_len = strlen(tmplt_copy);
+    for (i = 0; i <= tmpl_len; i++) {
+        if (tmplt_copy[i] == ':' || tmplt_copy[i] == '\0') {
+            tmplt_copy[i] = '\0';
+            if (*tmpl_cnt > rrd->stat_head->ds_cnt) {
+                rrd_set_error("tmplt contains more DS definitions than RRD");
+                free(tmplt_copy);
+                return -1;
             }
-#endif
-            rra_current = rra_begin;
-        }
-        rra_start = rra_begin;
-
-        /* when was the current pdp started */
-        proc_pdp_age = rrd.live_head->last_up % rrd.stat_head->pdp_step;
-        proc_pdp_st = rrd.live_head->last_up - proc_pdp_age;
-
-        /* when did the last pdp_st occur */
-        occu_pdp_age = current_time % rrd.stat_head->pdp_step;
-        occu_pdp_st = current_time - occu_pdp_age;
-
-        /* interval = current_time - rrd.live_head->last_up; */
-        interval = (double) (current_time - rrd.live_head->last_up)
-            + (double) ((long) current_time_usec -
-                        (long) rrd.live_head->last_up_usec) / 1000000.0;
-
-        if (occu_pdp_st > proc_pdp_st) {
-            /* OK we passed the pdp_st moment */
-            pre_int = (long) occu_pdp_st - rrd.live_head->last_up;  /* how much of the input data
-                                                                     * occurred before the latest
-                                                                     * pdp_st moment*/
-            pre_int -= ((double) rrd.live_head->last_up_usec) / 1000000.0;  /* adjust usecs */
-            post_int = occu_pdp_age;    /* how much after it */
-            post_int += ((double) current_time_usec) / 1000000.0;   /* adjust usecs */
-        } else {
-            pre_int = interval;
-            post_int = 0;
+            if ((tmpl_idx[(*tmpl_cnt)++] = ds_match(rrd, dsname)+1) == 0) {
+                rrd_set_error("unknown DS name '%s'", dsname);
+                free(tmplt_copy);
+                return -1;
+            } 
+            /* go to the next entry on the tmplt_copy */
+            if (i < tmpl_len)
+                dsname = &tmplt_copy[i+1];
         }
+    }
+    free(tmplt_copy);
+    return 0;
+}
 
-#ifdef DEBUG
-        printf("proc_pdp_age %lu\t"
-               "proc_pdp_st %lu\t"
-               "occu_pfp_age %lu\t"
-               "occu_pdp_st %lu\t"
-               "int %lf\t"
-               "pre_int %lf\t"
-               "post_int %lf\n", proc_pdp_age, proc_pdp_st,
-               occu_pdp_age, occu_pdp_st, interval, pre_int, post_int);
-#endif
-
-        /* process the data sources and update the pdp_prep 
-         * area accordingly */
-        for (i = 0; i < rrd.stat_head->ds_cnt; i++) {
-            enum dst_en dst_idx;
+/*
+ * Parse an update string, updates the primary data points (PDPs)
+ * and consolidated data points (CDPs), and writes changes to the RRAs.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int process_arg(
+    char           *step_start, 
+    rrd_t          *rrd, 
+    rrd_file_t     *rrd_file, 
+    unsigned long  rra_begin,
+    unsigned long *rra_current,
+    time_t        *current_time,
+    unsigned long *current_time_usec,
+    rrd_value_t   *pdp_temp,
+    rrd_value_t   *pdp_new,
+    unsigned long *rra_step_cnt,
+    char         **updvals,
+    long          *tmpl_idx,
+    unsigned long  tmpl_cnt,
+    info_t       **pcdp_summary,
+    int            version,
+    int           *schedule_smooth)
+{
+    rrd_value_t *seasonal_coef = NULL, *last_seasonal_coef = NULL;
 
-            dst_idx = dst_conv(rrd.ds_def[i].dst);
+    /* a vector of future Holt-Winters seasonal coefs */
+    unsigned long elapsed_pdp_st;
 
-            /* make sure we do not build diffs with old last_ds values */
-            if (rrd.ds_def[i].par[DS_mrhb_cnt].u_cnt < interval) {
-                strncpy(rrd.pdp_prep[i].last_ds, "U", LAST_DS_LEN - 1);
-                rrd.pdp_prep[i].last_ds[LAST_DS_LEN - 1] = '\0';
-            }
+    double    interval, pre_int, post_int;  /* interval between this and
+                                             * the last run */
+    unsigned long proc_pdp_cnt;
+    unsigned long rra_start;
 
-            /* NOTE: DST_CDEF should never enter this if block, because
-             * updvals[i+1][0] is initialized to 'U'; unless the caller
-             * accidently specified a value for the DST_CDEF. To handle
-             * this case, an extra check is required. */
-
-            if ((updvals[i + 1][0] != 'U') &&
-                (dst_idx != DST_CDEF) &&
-                rrd.ds_def[i].par[DS_mrhb_cnt].u_cnt >= interval) {
-                double    rate = DNAN;
-                char     *old_locale;
-
-                /* the data source type defines how to process the data */
-                /* pdp_new contains rate * time ... eg the bytes
-                 * transferred during the interval. Doing it this way saves
-                 * a lot of math operations */
-                switch (dst_idx) {
-                case DST_COUNTER:
-                case DST_DERIVE:
-                    for (ii = 0; updvals[i + 1][ii] != '\0'; ii++) {
-                        if ((updvals[i + 1][ii] < '0'
-                             || updvals[i + 1][ii] > '9') && (ii != 0
-                                                              && updvals[i
-                                                                         + 1]
-                                                              [ii] != '-')) {
-                            rrd_set_error("not a simple integer: '%s'",
-                                          updvals[i + 1]);
+    if (parse_ds(rrd, updvals, tmpl_idx, step_start, tmpl_cnt, 
+            current_time, current_time_usec, version) == -1) {
+        return -1;
+    }
+    /* seek to the beginning of the rra's */
+    if (*rra_current != rra_begin) {
+#ifndef HAVE_MMAP
+        if (rrd_seek(rrd_file, rra_begin, SEEK_SET) != 0) {
+            rrd_set_error("seek error in rrd");
+            return -1;
+        }
+#endif
+        *rra_current = rra_begin;
+    }
+    rra_start = rra_begin;
+
+    interval = (double) (*current_time - rrd->live_head->last_up)
+            + (double) ((long) *current_time_usec -
+                            (long) rrd->live_head->last_up_usec) / 1e6f;
+
+    /* process the data sources and update the pdp_prep 
+     * area accordingly */
+    if (update_pdp_prep(rrd, updvals, pdp_new, interval) == -1) {
+        return -1;
+    }
+
+    elapsed_pdp_st = calculate_elapsed_steps(rrd, 
+                    *current_time, *current_time_usec, 
+                    interval, &pre_int, &post_int,
+                    &proc_pdp_cnt);
+
+    /* has a pdp_st moment occurred since the last run ? */
+    if (elapsed_pdp_st == 0) {
+        /* no we have not passed a pdp_st moment. therefore update is simple */
+        simple_update(rrd, interval, pdp_new);
+    } else {
+        /* an pdp_st has occurred. */
+        if (process_all_pdp_st(rrd, interval, 
+                               pre_int, post_int,
+                               elapsed_pdp_st, 
+                               pdp_new, pdp_temp) == -1) 
+        {
+            return -1;
+        }
+        if (update_all_cdp_prep(rrd, rra_step_cnt, 
+                                rra_begin, rrd_file,
+                                elapsed_pdp_st,
+                                proc_pdp_cnt,
+                                &last_seasonal_coef,
+                                &seasonal_coef,
+                                pdp_temp, rra_current,
+                                schedule_smooth) == -1)
+        {
+            goto err_free_coefficients;
+        }
+        if (update_aberrant_cdps(rrd, rrd_file, rra_begin, rra_current, 
+                elapsed_pdp_st, pdp_temp, &seasonal_coef) == -1)
+        {
+            goto err_free_coefficients;
+        }
+        if (write_to_rras(rrd, rrd_file, 
+                rra_step_cnt, rra_begin, rra_current, 
+                *current_time, pcdp_summary) == -1)
+        {
+            goto err_free_coefficients;
+        }
+    }               /* endif a pdp_st has occurred */
+    rrd->live_head->last_up = *current_time;
+    rrd->live_head->last_up_usec = *current_time_usec;
+
+    free(seasonal_coef);
+    free(last_seasonal_coef);
+    return 0;
+
+err_free_coefficients:
+    free(seasonal_coef);
+    free(last_seasonal_coef);
+    return -1;
+}
+
+/*
+ * Parse a DS string (time + colon-separated values), storing the
+ * results in current_time, current_time_usec, and updvals.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int parse_ds(
+    rrd_t *rrd, char **updvals, long *tmpl_idx, char *input,
+    unsigned long tmpl_cnt, time_t *current_time,
+    unsigned long *current_time_usec, int version)
+{
+    char *p;
+    unsigned long i;
+    char timesyntax;
+
+    updvals[0] = input;
+    /* initialize all ds input to unknown except the first one
+       which has always got to be set */
+    for (i = 1; i <= rrd->stat_head->ds_cnt; i++)
+        updvals[i] = "U";
+
+    /* separate all ds elements; first must be examined separately
+       due to alternate time syntax */
+    if ((p = strchr(input, '@')) != NULL) {
+        timesyntax = '@';
+    } else if ((p = strchr(input, ':')) != NULL) {
+        timesyntax = ':';
+    } else {
+        rrd_set_error("expected timestamp not found in data source from %s",
+                 input);
+        return -1;
+    }
+    *p = '\0';
+    i = 1;
+    updvals[tmpl_idx[i++]] = p+1;
+    while (*(++p)) {
+        if (*p == ':') {
+            *p = '\0';
+            if (i < tmpl_cnt) {
+                updvals[tmpl_idx[i++]] = p+1;
+            }
+        }
+    }
+
+    if (i != tmpl_cnt) {
+        rrd_set_error("expected %lu data source readings (got %lu) from %s",
+                 tmpl_cnt - 1, i, input);
+        return -1;
+    }
+
+    if (get_time_from_reading(rrd, timesyntax, updvals, 
+                            current_time, current_time_usec, 
+                            version) == -1) {
+        return -1;
+    }
+    return 0;
+}
+
+/*
+ * Parse the time in a DS string, store it in current_time and 
+ * current_time_usec and verify that it's later than the last
+ * update for this DS.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int get_time_from_reading(
+    rrd_t *rrd, char timesyntax, char **updvals, 
+    time_t *current_time, unsigned long *current_time_usec,
+    int version)
+{
+    double    tmp;
+    char     *parsetime_error = NULL;
+    char     *old_locale;
+    struct rrd_time_value ds_tv;
+    struct timeval tmp_time;    /* used for time conversion */
+
+    /* get the time from the reading ... handle N */
+    if (timesyntax == '@') { /* at-style */
+        if ((parsetime_error = parsetime(updvals[0], &ds_tv))) {
+            rrd_set_error("ds time: %s: %s", updvals[0], parsetime_error);
+            return -1;
+        }
+        if (ds_tv.type == RELATIVE_TO_END_TIME ||
+                        ds_tv.type == RELATIVE_TO_START_TIME) {
+            rrd_set_error("specifying time relative to the 'start' "
+                            "or 'end' makes no sense here: %s", updvals[0]);
+            return -1;
+        }
+        *current_time = mktime(&ds_tv.tm) + ds_tv.offset;
+        *current_time_usec = 0;  /* FIXME: how to handle usecs here ? */
+    } else if (strcmp(updvals[0], "N") == 0) {
+        gettimeofday(&tmp_time, 0);
+        normalize_time(&tmp_time);
+        *current_time = tmp_time.tv_sec;
+        *current_time_usec = tmp_time.tv_usec;
+    } else {
+        old_locale = setlocale(LC_NUMERIC, "C");
+        tmp = strtod(updvals[0], 0);
+        setlocale(LC_NUMERIC, old_locale);
+        *current_time = floor(tmp);
+        *current_time_usec = (long) ((tmp - (double) *current_time) * 1e6f);
+    }
+    /* dont do any correction for old version RRDs */
+    if (version < 3)
+        *current_time_usec = 0;
+
+    if (*current_time < rrd->live_head->last_up ||
+                    (*current_time == rrd->live_head->last_up &&
+                     (long) *current_time_usec <=
+                     (long) rrd->live_head->last_up_usec)) {
+        rrd_set_error("illegal attempt to update using time %ld when "
+                          "last update time is %ld (minimum one second step)",
+                          *current_time, rrd->live_head->last_up);
+        return -1;
+    }
+    return 0;
+}
+
+/*
+ * Update pdp_new by interpreting the updvals according to the DS type
+ * (COUNTER, GAUGE, etc.).
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int update_pdp_prep(
+    rrd_t *rrd, char **updvals, 
+    rrd_value_t *pdp_new, double interval) 
+{
+    unsigned long ds_idx; 
+    int ii;
+    char     *endptr;   /* used in the conversion */
+    double rate;
+    char     *old_locale;
+    enum dst_en dst_idx;
+
+    for (ds_idx = 0; ds_idx < rrd->stat_head->ds_cnt; ds_idx++) {
+        dst_idx = dst_conv(rrd->ds_def[ds_idx].dst);
+
+        /* make sure we do not build diffs with old last_ds values */
+        if (rrd->ds_def[ds_idx].par[DS_mrhb_cnt].u_cnt < interval) {
+            strncpy(rrd->pdp_prep[ds_idx].last_ds, "U", LAST_DS_LEN - 1);
+            rrd->pdp_prep[ds_idx].last_ds[LAST_DS_LEN - 1] = '\0';
+        }
+
+        /* NOTE: DST_CDEF should never enter this if block, because
+         * updvals[ds_idx+1][0] is initialized to 'U'; unless the caller
+         * accidently specified a value for the DST_CDEF. To handle this case,
+         * an extra check is required. */
+
+        if ((updvals[ds_idx+1][0] != 'U') &&
+                        (dst_idx != DST_CDEF) &&
+                        rrd->ds_def[ds_idx].par[DS_mrhb_cnt].u_cnt >= interval) {
+            rate = DNAN;
+
+            /* pdp_new contains rate * time ... eg the bytes transferred during
+             * the interval. Doing it this way saves a lot of math operations
+             */
+            switch (dst_idx) {
+                    case DST_COUNTER:
+                    case DST_DERIVE:
+                            for (ii = 0; updvals[ds_idx + 1][ii] != '\0'; ii++) {
+                                if ((updvals[ds_idx + 1][ii] < '0' || updvals[ds_idx + 1][ii] > '9') 
+                                                && (ii != 0 && updvals[ds_idx + 1][ii] != '-')) {
+                                    rrd_set_error("not a simple integer: '%s'", updvals[ds_idx + 1]);
+                                    return -1;
+                                }
+                            }
+                            if (rrd->pdp_prep[ds_idx].last_ds[0] != 'U') {
+                                pdp_new[ds_idx] = rrd_diff(updvals[ds_idx+1], rrd->pdp_prep[ds_idx].last_ds);
+                                if (dst_idx == DST_COUNTER) {
+                                    /* simple overflow catcher. This will fail
+                                     * terribly for non 32 or 64 bit counters
+                                     * ... are there any others in SNMP land?
+                                     */
+                                    if (pdp_new[ds_idx] < (double) 0.0)
+                                        pdp_new[ds_idx] += (double) 4294967296.0; /* 2^32 */
+                                    if (pdp_new[ds_idx] < (double) 0.0)
+                                        pdp_new[ds_idx] += (double) 18446744069414584320.0; /* 2^64-2^32 */
+                                }
+                                rate = pdp_new[ds_idx] / interval;
+                            } else {
+                                pdp_new[ds_idx] = DNAN;
+                            }
                             break;
-                        }
-                    }
-                    if (rrd_test_error()) {
-                        break;
-                    }
-                    if (rrd.pdp_prep[i].last_ds[0] != 'U') {
-                        pdp_new[i] =
-                            rrd_diff(updvals[i + 1], rrd.pdp_prep[i].last_ds);
-                        if (dst_idx == DST_COUNTER) {
-                            /* simple overflow catcher suggested by Andres Kroonmaa */
-                            /* this will fail terribly for non 32 or 64 bit counters ... */
-                            /* are there any others in SNMP land ? */
-                            if (pdp_new[i] < (double) 0.0)
-                                pdp_new[i] += (double) 4294967296.0;    /* 2^32 */
-                            if (pdp_new[i] < (double) 0.0)
-                                pdp_new[i] += (double) 18446744069414584320.0;
-                            /* 2^64-2^32 */ ;
-                        }
-                        rate = pdp_new[i] / interval;
-                    } else {
-                        pdp_new[i] = DNAN;
-                    }
-                    break;
-                case DST_ABSOLUTE:
-                    old_locale = setlocale(LC_NUMERIC, "C");
-                    errno = 0;
-                    pdp_new[i] = strtod(updvals[i + 1], &endptr);
-                    setlocale(LC_NUMERIC, old_locale);
-                    if (errno > 0) {
-                        rrd_set_error("converting '%s' to float: %s",
-                                      updvals[i + 1], rrd_strerror(errno));
-                        break;
-                    };
-                    if (endptr[0] != '\0') {
-                        rrd_set_error
-                            ("conversion of '%s' to float not complete: tail '%s'",
-                             updvals[i + 1], endptr);
-                        break;
-                    }
-                    rate = pdp_new[i] / interval;
-                    break;
-                case DST_GAUGE:
-                    errno = 0;
-                    old_locale = setlocale(LC_NUMERIC, "C");
-                    pdp_new[i] = strtod(updvals[i + 1], &endptr) * interval;
-                    setlocale(LC_NUMERIC, old_locale);
-                    if (errno > 0) {
-                        rrd_set_error("converting '%s' to float: %s",
-                                      updvals[i + 1], rrd_strerror(errno));
-                        break;
-                    };
-                    if (endptr[0] != '\0') {
-                        rrd_set_error
-                            ("conversion of '%s' to float not complete: tail '%s'",
-                             updvals[i + 1], endptr);
-                        break;
-                    }
-                    rate = pdp_new[i] / interval;
-                    break;
-                default:
-                    rrd_set_error("rrd contains unknown DS type : '%s'",
-                                  rrd.ds_def[i].dst);
-                    break;
-                }
-                /* break out of this for loop if the error string is set */
-                if (rrd_test_error()) {
-                    break;
-                }
-                /* make sure pdp_temp is neither too large or too small
-                 * if any of these occur it becomes unknown ...
-                 * sorry folks ... */
-                if (!isnan(rate) &&
-                    ((!isnan(rrd.ds_def[i].par[DS_max_val].u_val) &&
-                      rate > rrd.ds_def[i].par[DS_max_val].u_val) ||
-                     (!isnan(rrd.ds_def[i].par[DS_min_val].u_val) &&
-                      rate < rrd.ds_def[i].par[DS_min_val].u_val))) {
-                    pdp_new[i] = DNAN;
-                }
-            } else {
-                /* no news is news all the same */
-                pdp_new[i] = DNAN;
+                    case DST_ABSOLUTE:
+                            old_locale = setlocale(LC_NUMERIC, "C");
+                            errno = 0;
+                            pdp_new[ds_idx] = strtod(updvals[ds_idx + 1], &endptr);
+                            setlocale(LC_NUMERIC, old_locale);
+                            if (errno > 0) {
+                                rrd_set_error("converting '%s' to float: %s",
+                                                updvals[ds_idx + 1], rrd_strerror(errno));
+                                return -1;
+                            };
+                            if (endptr[0] != '\0') {
+                                rrd_set_error("conversion of '%s' to float not complete: tail '%s'",
+                                         updvals[ds_idx + 1], endptr);
+                                return -1;
+                            }
+                            rate = pdp_new[ds_idx] / interval;
+                            break;
+                    case DST_GAUGE:
+                            errno = 0;
+                            old_locale = setlocale(LC_NUMERIC, "C");
+                            pdp_new[ds_idx] = strtod(updvals[ds_idx + 1], &endptr) * interval;
+                            setlocale(LC_NUMERIC, old_locale);
+                            if (errno) {
+                                rrd_set_error("converting '%s' to float: %s",
+                                                updvals[ds_idx + 1], rrd_strerror(errno));
+                                return -1;
+                            };
+                            if (endptr[0] != '\0') {
+                                rrd_set_error("conversion of '%s' to float not complete: tail '%s'",
+                                         updvals[ds_idx + 1], endptr);
+                                return -1;
+                            }
+                            rate = pdp_new[ds_idx] / interval;
+                            break;
+                    default:
+                            rrd_set_error("rrd contains unknown DS type : '%s'",
+                                            rrd->ds_def[ds_idx].dst);
+                            return -1;
+            }
+            /* break out of this for loop if the error string is set */
+            if (rrd_test_error()) {
+                return -1;
+            }
+            /* make sure pdp_temp is neither too large or too small
+             * if any of these occur it becomes unknown ...
+             * sorry folks ... */
+            if (!isnan(rate) &&
+                            ((!isnan(rrd->ds_def[ds_idx].par[DS_max_val].u_val) &&
+                              rate > rrd->ds_def[ds_idx].par[DS_max_val].u_val) ||
+                             (!isnan(rrd->ds_def[ds_idx].par[DS_min_val].u_val) &&
+                              rate < rrd->ds_def[ds_idx].par[DS_min_val].u_val))) {
+                pdp_new[ds_idx] = DNAN;
             }
+        } else {
+            /* no news is news all the same */
+            pdp_new[ds_idx] = DNAN;
+        }
 
 
-            /* make a copy of the command line argument for the next run */
+        /* make a copy of the command line argument for the next run */
 #ifdef DEBUG
-            fprintf(stderr,
-                    "prep ds[%lu]\t"
-                    "last_arg '%s'\t"
-                    "this_arg '%s'\t"
-                    "pdp_new %10.2f\n",
-                    i, rrd.pdp_prep[i].last_ds, updvals[i + 1], pdp_new[i]);
+        fprintf(stderr, "prep ds[%lu]\t"
+                        "last_arg '%s'\t"
+                        "this_arg '%s'\t"
+                        "pdp_new %10.2f\n",
+                        ds_idx, rrd->pdp_prep[ds_idx].last_ds, updvals[ds_idx+1], pdp_new[ds_idx]);
 #endif
-            strncpy(rrd.pdp_prep[i].last_ds, updvals[i + 1], LAST_DS_LEN - 1);
-            rrd.pdp_prep[i].last_ds[LAST_DS_LEN - 1] = '\0';
-        }
-        /* break out of the argument parsing loop if the error_string is set */
-        if (rrd_test_error()) {
-            free(step_start);
-            break;
+        strncpy(rrd->pdp_prep[ds_idx].last_ds, updvals[ds_idx+1], LAST_DS_LEN - 1);
+        rrd->pdp_prep[ds_idx].last_ds[LAST_DS_LEN-1] = '\0';
+    }
+    return 0;
+}
+
+/*
+ * How many PDP steps have elapsed since the last update? Returns the answer,
+ * and stores the time between the last update and the last PDP in pre_time,
+ * and the time between the last PDP and the current time in post_int.
+ */
+static int calculate_elapsed_steps(
+    rrd_t *rrd, 
+    unsigned long current_time, 
+    unsigned long current_time_usec,
+    double interval,
+    double *pre_int,
+    double *post_int,
+    unsigned long *proc_pdp_cnt) 
+{
+
+    unsigned long proc_pdp_st;  /* which pdp_st was the last
+                                 * to be processed */
+    unsigned long occu_pdp_st;  /* when was the pdp_st
+                                 * before the last update
+                                 * time */
+    unsigned long proc_pdp_age; /* how old was the data in
+                                 * the pdp prep area when it
+                                 * was last updated */
+    unsigned long occu_pdp_age; /* how long ago was the last
+                                 * pdp_step time */
+
+    /* when was the current pdp started */
+    proc_pdp_age = rrd->live_head->last_up % rrd->stat_head->pdp_step;
+    proc_pdp_st = rrd->live_head->last_up - proc_pdp_age;
+
+    /* when did the last pdp_st occur */
+    occu_pdp_age = current_time % rrd->stat_head->pdp_step;
+    occu_pdp_st = current_time - occu_pdp_age;
+
+    if (occu_pdp_st > proc_pdp_st) {
+        /* OK we passed the pdp_st moment */
+        *pre_int = (long) occu_pdp_st - rrd->live_head->last_up;  /* how much of the input data
+                                                                 * occurred before the latest
+                                                                 * pdp_st moment*/
+        *pre_int -= ((double) rrd->live_head->last_up_usec) / 1e6f;  /* adjust usecs */
+        *post_int = occu_pdp_age;    /* how much after it */
+        *post_int += ((double) current_time_usec) / 1e6f;   /* adjust usecs */
+    } else {
+        *pre_int = interval;
+        *post_int = 0;
+    }
+
+    *proc_pdp_cnt = proc_pdp_st / rrd->stat_head->pdp_step;
+
+#ifdef DEBUG
+    printf("proc_pdp_age %lu\t"
+                    "proc_pdp_st %lu\t"
+                    "occu_pfp_age %lu\t"
+                    "occu_pdp_st %lu\t"
+                    "int %lf\t"
+                    "pre_int %lf\t"
+                    "post_int %lf\n", proc_pdp_age, proc_pdp_st,
+                    occu_pdp_age, occu_pdp_st, interval, *pre_int, *post_int);
+#endif
+
+    /* compute the number of elapsed pdp_st moments */
+    return (occu_pdp_st - proc_pdp_st) / rrd->stat_head->pdp_step;
+}
+
+/*
+ * Increment the PDP values by the values in pdp_new, or else initialize them.
+ */
+static void simple_update(
+    rrd_t *rrd, double interval, rrd_value_t *pdp_new) 
+{
+    int i;
+    for (i = 0; i < (signed)rrd->stat_head->ds_cnt; i++) {
+        if (isnan(pdp_new[i])) {
+            /* this is not really accurate if we use subsecond data arrival time
+               should have thought of it when going subsecond resolution ...
+               sorry next format change we will have it! */
+            rrd->pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt += floor(interval);
+        } else {
+            if (isnan(rrd->pdp_prep[i].scratch[PDP_val].u_val)) {
+                rrd->pdp_prep[i].scratch[PDP_val].u_val = pdp_new[i];
+            } else {
+                rrd->pdp_prep[i].scratch[PDP_val].u_val += pdp_new[i];
+            }
         }
-        /* has a pdp_st moment occurred since the last run ? */
-
-        if (proc_pdp_st == occu_pdp_st) {
-            /* no we have not passed a pdp_st moment. therefore update is simple */
-
-            for (i = 0; i < rrd.stat_head->ds_cnt; i++) {
-                if (isnan(pdp_new[i])) {
-                    /* this is not realy accurate if we use subsecond data arival time
-                       should have thought of it when going subsecond resolution ...
-                       sorry next format change we will have it! */
-                    rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt +=
-                        floor(interval);
-                } else {
-                    if (isnan(rrd.pdp_prep[i].scratch[PDP_val].u_val)) {
-                        rrd.pdp_prep[i].scratch[PDP_val].u_val = pdp_new[i];
-                    } else {
-                        rrd.pdp_prep[i].scratch[PDP_val].u_val += pdp_new[i];
-                    }
-                }
 #ifdef DEBUG
-                fprintf(stderr,
-                        "NO PDP  ds[%lu]\t"
+        fprintf(stderr,
+                        "NO PDP  ds[%i]\t"
                         "value %10.2f\t"
                         "unkn_sec %5lu\n",
                         i,
-                        rrd.pdp_prep[i].scratch[PDP_val].u_val,
-                        rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt);
+                        rrd->pdp_prep[i].scratch[PDP_val].u_val,
+                        rrd->pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt);
 #endif
-            }
-        } else {
-            /* an pdp_st has occurred. */
-
-            /* in pdp_prep[].scratch[PDP_val].u_val we have collected
-               rate*seconds which occurred up to the last run.
-               pdp_new[] contains rate*seconds from the latest run.
-               pdp_temp[] will contain the rate for cdp */
-
-            for (i = 0; i < rrd.stat_head->ds_cnt; i++) {
-                /* update pdp_prep to the current pdp_st. */
-                double    pre_unknown = 0.0;
-
-                if (isnan(pdp_new[i])) {
-                    /* a final bit of unkonwn to be added bevore calculation
-                       we use a temporary variable for this so that we
-                       don't have to turn integer lines before using the value */
-                    pre_unknown = pre_int;
-                } else {
-                    if (isnan(rrd.pdp_prep[i].scratch[PDP_val].u_val)) {
-                        rrd.pdp_prep[i].scratch[PDP_val].u_val =
-                            pdp_new[i] / interval * pre_int;
-                    } else {
-                        rrd.pdp_prep[i].scratch[PDP_val].u_val +=
-                            pdp_new[i] / interval * pre_int;
-                    }
-                }
-
-
-                /* if too much of the pdp_prep is unknown we dump it */
-                if (
-                       /* removed because this does not agree with the
-                          definition that a heartbeat can be unknown */
-                       /* (rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt
-                          > rrd.ds_def[i].par[DS_mrhb_cnt].u_cnt) || */
-                       /* if the interval is larger thatn mrhb we get NAN */
-                       (interval > rrd.ds_def[i].par[DS_mrhb_cnt].u_cnt) ||
-                       (occu_pdp_st - proc_pdp_st <=
-                        rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt)) {
-                    pdp_temp[i] = DNAN;
-                } else {
-                    pdp_temp[i] = rrd.pdp_prep[i].scratch[PDP_val].u_val
-                        / ((double) (occu_pdp_st - proc_pdp_st
-                                     -
-                                     rrd.pdp_prep[i].
-                                     scratch[PDP_unkn_sec_cnt].u_cnt)
-                           - pre_unknown);
-                }
-
-                /* process CDEF data sources; remember each CDEF DS can
-                 * only reference other DS with a lower index number */
-                if (dst_conv(rrd.ds_def[i].dst) == DST_CDEF) {
-                    rpnp_t   *rpnp;
-
-                    rpnp =
-                        rpn_expand((rpn_cdefds_t *) &
-                                   (rrd.ds_def[i].par[DS_cdef]));
-                    /* substitue data values for OP_VARIABLE nodes */
-                    for (ii = 0; rpnp[ii].op != OP_END; ii++) {
-                        if (rpnp[ii].op == OP_VARIABLE) {
-                            rpnp[ii].op = OP_NUMBER;
-                            rpnp[ii].val = pdp_temp[rpnp[ii].ptr];
-                        }
-                    }
-                    /* run the rpn calculator */
-                    if (rpn_calc(rpnp, &rpnstack, 0, pdp_temp, i) == -1) {
-                        free(rpnp);
-                        break;  /* exits the data sources pdp_temp loop */
-                    }
-                }
+    }
+}
 
-                /* make pdp_prep ready for the next run */
-                if (isnan(pdp_new[i])) {
-                    /* this is not realy accurate if we use subsecond data arival time
-                       should have thought of it when going subsecond resolution ...
-                       sorry next format change we will have it! */
-                    rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt =
-                        floor(post_int);
-                    rrd.pdp_prep[i].scratch[PDP_val].u_val = DNAN;
-                } else {
-                    rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt = 0;
-                    rrd.pdp_prep[i].scratch[PDP_val].u_val =
-                        pdp_new[i] / interval * post_int;
-                }
+/*
+ * Call process_pdp_st for each DS.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int process_all_pdp_st(
+    rrd_t *rrd, double interval, double pre_int, double post_int, 
+    unsigned long elapsed_pdp_st, rrd_value_t *pdp_new, rrd_value_t *pdp_temp) 
+{
+    unsigned long ds_idx;
+    /* in pdp_prep[].scratch[PDP_val].u_val we have collected
+       rate*seconds which occurred up to the last run.
+       pdp_new[] contains rate*seconds from the latest run.
+       pdp_temp[] will contain the rate for cdp */
 
+    for (ds_idx = 0; ds_idx < rrd->stat_head->ds_cnt; ds_idx++) {
+        if (process_pdp_st(rrd, ds_idx, interval, pre_int, post_int,
+                                elapsed_pdp_st * rrd->stat_head->pdp_step, 
+                                pdp_new, pdp_temp) == -1) {
+            return -1;
+        }
 #ifdef DEBUG
-                fprintf(stderr,
-                        "PDP UPD ds[%lu]\t"
+        fprintf(stderr, "PDP UPD ds[%lu]\t"
                         "pdp_temp %10.2f\t"
                         "new_prep %10.2f\t"
                         "new_unkn_sec %5lu\n",
-                        i, pdp_temp[i],
-                        rrd.pdp_prep[i].scratch[PDP_val].u_val,
-                        rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt);
+                        ds_idx, pdp_temp[ds_idx],
+                        rrd->pdp_prep[ds_idx].scratch[PDP_val].u_val,
+                        rrd->pdp_prep[ds_idx].scratch[PDP_unkn_sec_cnt].u_cnt);
 #endif
-            }
+    }
+    return 0;
+}
 
-            /* if there were errors during the last loop, bail out here */
-            if (rrd_test_error()) {
-                free(step_start);
-                break;
+/*
+ * Process an update that occurs after one of the PDP moments.
+ * Increments the PDP value, sets NAN if time greater than the
+ * heartbeats have elapsed, processes CDEFs.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int process_pdp_st(rrd_t *rrd, unsigned long ds_idx, double interval, 
+    double pre_int, double post_int, long diff_pdp_st, 
+    rrd_value_t *pdp_new, rrd_value_t *pdp_temp) 
+{
+    int i;
+    /* update pdp_prep to the current pdp_st. */
+    double    pre_unknown = 0.0;
+    unival *scratch = rrd->pdp_prep[ds_idx].scratch;
+    unsigned long mrhb = rrd->ds_def[ds_idx].par[DS_mrhb_cnt].u_cnt;
+
+    rpnstack_t     rpnstack;    /* used for COMPUTE DS */
+    rpnstack_init(&rpnstack);
+
+
+    if (isnan(pdp_new[ds_idx])) {
+        /* a final bit of unknown to be added bevore calculation
+           we use a temporary variable for this so that we
+           don't have to turn integer lines before using the value */
+        pre_unknown = pre_int;
+    } else {
+        if (isnan(scratch[PDP_val].u_val)) {
+            scratch[PDP_val].u_val = 0;
+        } 
+        scratch[PDP_val].u_val += pdp_new[ds_idx] / interval * pre_int;
+    }
+
+    /* if too much of the pdp_prep is unknown we dump it */
+    /* if the interval is larger thatn mrhb we get NAN */
+    if ((interval > mrhb) ||
+                    (diff_pdp_st <= (signed)scratch[PDP_unkn_sec_cnt].u_cnt)) {
+        pdp_temp[ds_idx] = DNAN;
+    } else {
+        pdp_temp[ds_idx] = scratch[PDP_val].u_val / 
+                ((double) (diff_pdp_st - scratch[PDP_unkn_sec_cnt].u_cnt) - pre_unknown);
+    }
+
+    /* process CDEF data sources; remember each CDEF DS can
+     * only reference other DS with a lower index number */
+    if (dst_conv(rrd->ds_def[ds_idx].dst) == DST_CDEF) {
+        rpnp_t   *rpnp;
+
+        rpnp = rpn_expand((rpn_cdefds_t *)&(rrd->ds_def[ds_idx].par[DS_cdef]));
+        /* substitute data values for OP_VARIABLE nodes */
+        for (i = 0; rpnp[i].op != OP_END; i++) {
+            if (rpnp[i].op == OP_VARIABLE) {
+                rpnp[i].op = OP_NUMBER;
+                rpnp[i].val = pdp_temp[rpnp[i].ptr];
             }
+        }
+        /* run the rpn calculator */
+        if (rpn_calc(rpnp, &rpnstack, 0, pdp_temp, ds_idx) == -1) {
+            free(rpnp);
+            rpnstack_free(&rpnstack);
+            return -1;
+        }
+    }
 
-            /* compute the number of elapsed pdp_st moments */
-            elapsed_pdp_st =
-                (occu_pdp_st - proc_pdp_st) / rrd.stat_head->pdp_step;
+    /* make pdp_prep ready for the next run */
+    if (isnan(pdp_new[ds_idx])) {
+        /* this is not realy accurate if we use subsecond data arival time
+           should have thought of it when going subsecond resolution ...
+           sorry next format change we will have it! */
+        scratch[PDP_unkn_sec_cnt].u_cnt = floor(post_int);
+        scratch[PDP_val].u_val = DNAN;
+    } else {
+        scratch[PDP_unkn_sec_cnt].u_cnt = 0;
+        scratch[PDP_val].u_val = pdp_new[ds_idx] / interval * post_int;
+    }
+    rpnstack_free(&rpnstack);
+    return 0;
+}
+
+/*
+ * Iterate over all the RRAs for a given DS and:
+ * 1. Decide whether to schedule a smooth later
+ * 2. Shift the seasonal array if it's a bulk update
+ * 3. Update the CDP
+ *
+ * Returns 0 on success, -1 on error
+ */
+static int update_all_cdp_prep(
+    rrd_t *rrd, unsigned long *rra_step_cnt, unsigned long rra_begin, 
+    rrd_file_t *rrd_file, unsigned long elapsed_pdp_st, unsigned long proc_pdp_cnt,
+    rrd_value_t  **last_seasonal_coef, rrd_value_t  **seasonal_coef,
+    rrd_value_t *pdp_temp, unsigned long *rra_current, int *schedule_smooth) 
+{
+    unsigned long rra_idx;
+    /* index into the CDP scratch array */
+    enum cf_en current_cf;
+    unsigned long rra_start;
+    /* number of rows to be updated in an RRA for a data value. */
+    unsigned long start_pdp_offset;
+
+    rra_start = rra_begin;
+    for (rra_idx = 0; rra_idx < rrd->stat_head->rra_cnt; rra_idx++) {
+        current_cf = cf_conv(rrd->rra_def[rra_idx].cf_nam);
+        start_pdp_offset = rrd->rra_def[rra_idx].pdp_cnt - proc_pdp_cnt % rrd->rra_def[rra_idx].pdp_cnt;
+        if (start_pdp_offset <= elapsed_pdp_st) {
+            rra_step_cnt[rra_idx] = (elapsed_pdp_st - start_pdp_offset) /
+                    rrd->rra_def[rra_idx].pdp_cnt + 1;
+        } else {
+            rra_step_cnt[rra_idx] = 0;
+        }
+
+        if (current_cf == CF_SEASONAL || current_cf == CF_DEVSEASONAL) {
+            /* If this is a bulk update, we need to skip ahead in the seasonal arrays
+             * so that they will be correct for the next observed value; note that for
+             * the bulk update itself, no update will occur to DEVSEASONAL or SEASONAL;
+             * futhermore, HWPREDICT and DEVPREDICT will be set to DNAN. */
+            if (rra_step_cnt[rra_idx] > 2) {
+                /* skip update by resetting rra_step_cnt[rra_idx], note that this is not data
+                 * source specific; this is due to the bulk update, not a DNAN value
+                 * for the specific data source. */
+                rra_step_cnt[rra_idx] = 0;
+                lookup_seasonal(rrd, rra_idx, rra_start, rrd_file,
+                                elapsed_pdp_st, last_seasonal_coef);
+                lookup_seasonal(rrd, rra_idx, rra_start, rrd_file,
+                                elapsed_pdp_st + 1, seasonal_coef);
+            }
+            /* periodically run a smoother for seasonal effects */
+            if (do_schedule_smooth(rrd, rra_idx, elapsed_pdp_st)) {
 #ifdef DEBUG
-            fprintf(stderr, "elapsed PDP steps: %lu\n", elapsed_pdp_st);
+                fprintf(stderr, "schedule_smooth: cur_row %lu, elapsed_pdp_st %lu, smooth idx %lu\n",
+                                rrd->rra_ptr[rra_idx].cur_row, elapsed_pdp_st, 
+                                rrd->rra_def[rra_idx].par[RRA_seasonal_smooth_idx].u_cnt);
 #endif
-            if (rra_step_cnt == NULL) {
-                rra_step_cnt = (unsigned long *)
-                    malloc((rrd.stat_head->rra_cnt) * sizeof(unsigned long));
+                *schedule_smooth = 1;
             }
+            *rra_current = rrd_tell(rrd_file);
+        }
+        /* if cf is DEVSEASONAL or SEASONAL */
+        if (rrd_test_error())
+            return -1;
+
+        if (update_cdp_prep(rrd, elapsed_pdp_st, start_pdp_offset, rra_step_cnt, 
+                                rra_idx, pdp_temp, *last_seasonal_coef, *seasonal_coef, 
+                                current_cf) == -1) {
+            return -1;
+        }
+        rra_start += rrd->rra_def[rra_idx].row_cnt * rrd->stat_head->ds_cnt * sizeof(rrd_value_t);
+    }
+    return 0;
+}
 
-            for (i = 0, rra_start = rra_begin;
-                 i < rrd.stat_head->rra_cnt;
-                 rra_start +=
-                 rrd.rra_def[i].row_cnt * rrd.stat_head->ds_cnt *
-                 sizeof(rrd_value_t), i++) {
-                current_cf = cf_conv(rrd.rra_def[i].cf_nam);
-                start_pdp_offset = rrd.rra_def[i].pdp_cnt -
-                    (proc_pdp_st / rrd.stat_head->pdp_step) %
-                    rrd.rra_def[i].pdp_cnt;
-                if (start_pdp_offset <= elapsed_pdp_st) {
-                    rra_step_cnt[i] = (elapsed_pdp_st - start_pdp_offset) /
-                        rrd.rra_def[i].pdp_cnt + 1;
-                } else {
-                    rra_step_cnt[i] = 0;
-                }
+/* 
+ * Are we due for a smooth? Also increments our position in the burn-in cycle.
+ */
+static int do_schedule_smooth(
+    rrd_t *rrd, unsigned long rra_idx,
+    unsigned long elapsed_pdp_st)
+{
+    unsigned long cdp_idx = rra_idx * (rrd->stat_head->ds_cnt);
+    unsigned long cur_row = rrd->rra_ptr[rra_idx].cur_row;
+    unsigned long row_cnt = rrd->rra_def[rra_idx].row_cnt;
+    unsigned long seasonal_smooth_idx = rrd->rra_def[rra_idx].par[RRA_seasonal_smooth_idx].u_cnt;
+    unsigned long *init_seasonal = &(rrd->cdp_prep[cdp_idx].scratch[CDP_init_seasonal].u_cnt);
+
+    /* Need to use first cdp parameter buffer to track burnin (burnin requires
+     * a specific smoothing schedule).  The CDP_init_seasonal parameter is
+     * really an RRA level, not a data source within RRA level parameter, but
+     * the rra_def is read only for rrd_update (not flushed to disk). */
+    if (*init_seasonal > BURNIN_CYCLES) {
+        /* someone has no doubt invented a trick to deal with this wrap around,
+         * but at least this code is clear. */
+        if (seasonal_smooth_idx > cur_row) {
+            /* here elapsed_pdp_st = rra_step_cnt[rra_idx] because of 1-1 mapping
+             * between PDP and CDP */
+            return (cur_row + elapsed_pdp_st >= seasonal_smooth_idx);
+        } 
+        /* can't rely on negative numbers because we are working with
+         * unsigned values */
+        return (cur_row + elapsed_pdp_st >= row_cnt
+                        && cur_row + elapsed_pdp_st >= row_cnt + seasonal_smooth_idx);
+    } 
+    /* mark off one of the burn-in cycles */
+    return (cur_row + elapsed_pdp_st >= row_cnt && ++(*init_seasonal));
+}
 
-                if (current_cf == CF_SEASONAL || current_cf == CF_DEVSEASONAL) {
-                    /* If this is a bulk update, we need to skip ahead in
-                       the seasonal arrays so that they will be correct for
-                       the next observed value;
-                       note that for the bulk update itself, no update will
-                       occur to DEVSEASONAL or SEASONAL; futhermore, HWPREDICT
-                       and DEVPREDICT will be set to DNAN. */
-                    if (rra_step_cnt[i] > 2) {
-                        /* skip update by resetting rra_step_cnt[i],
-                           note that this is not data source specific; this is
-                           due to the bulk update, not a DNAN value for the
-                           specific data source. */
-                        rra_step_cnt[i] = 0;
-                        lookup_seasonal(&rrd, i, rra_start, rrd_file,
-                                        elapsed_pdp_st, &last_seasonal_coef);
-                        lookup_seasonal(&rrd, i, rra_start, rrd_file,
-                                        elapsed_pdp_st + 1, &seasonal_coef);
-                    }
+/*
+ * For a given RRA, iterate over the data sources and call the appropriate
+ * consolidation function.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int update_cdp_prep(
+    rrd_t *rrd, 
+    unsigned long elapsed_pdp_st, 
+    unsigned long start_pdp_offset, 
+    unsigned long *rra_step_cnt, 
+    int rra_idx, 
+    rrd_value_t *pdp_temp, 
+    rrd_value_t *last_seasonal_coef, 
+    rrd_value_t *seasonal_coef, 
+    int current_cf) 
+{
+    unsigned long ds_idx, cdp_idx;
+    /* update CDP_PREP areas */
+    /* loop over data soures within each RRA */
+    for (ds_idx = 0; ds_idx < rrd->stat_head->ds_cnt; ds_idx++) {
 
-                    /* periodically run a smoother for seasonal effects */
-                    /* Need to use first cdp parameter buffer to track
-                     * burnin (burnin requires a specific smoothing schedule).
-                     * The CDP_init_seasonal parameter is really an RRA level,
-                     * not a data source within RRA level parameter, but the rra_def
-                     * is read only for rrd_update (not flushed to disk). */
-                    iii = i * (rrd.stat_head->ds_cnt);
-                    if (rrd.cdp_prep[iii].scratch[CDP_init_seasonal].u_cnt
-                        <= BURNIN_CYCLES) {
-                        if (rrd.rra_ptr[i].cur_row + elapsed_pdp_st
-                            > rrd.rra_def[i].row_cnt - 1) {
-                            /* mark off one of the burnin cycles */
-                            ++(rrd.cdp_prep[iii].scratch[CDP_init_seasonal].
-                               u_cnt);
-                            schedule_smooth = 1;
-                        }
-                    } else {
-                        /* someone has no doubt invented a trick to deal with this
-                         * wrap around, but at least this code is clear. */
-                        if (rrd.rra_def[i].par[RRA_seasonal_smooth_idx].
-                            u_cnt > rrd.rra_ptr[i].cur_row) {
-                            /* here elapsed_pdp_st = rra_step_cnt[i] because of 1-1
-                             * mapping between PDP and CDP */
-                            if (rrd.rra_ptr[i].cur_row + elapsed_pdp_st
-                                >=
-                                rrd.rra_def[i].par[RRA_seasonal_smooth_idx].
-                                u_cnt) {
-#ifdef DEBUG
-                                fprintf(stderr,
-                                        "schedule_smooth 1: cur_row %lu, elapsed_pdp_st %lu, smooth idx %lu\n",
-                                        rrd.rra_ptr[i].cur_row,
-                                        elapsed_pdp_st,
-                                        rrd.rra_def[i].
-                                        par[RRA_seasonal_smooth_idx].u_cnt);
-#endif
-                                schedule_smooth = 1;
-                            }
-                        } else {
-                            /* can't rely on negative numbers because we are working with
-                             * unsigned values */
-                            /* Don't need modulus here. If we've wrapped more than once, only
-                             * one smooth is executed at the end. */
-                            if (rrd.rra_ptr[i].cur_row + elapsed_pdp_st >=
-                                rrd.rra_def[i].row_cnt
-                                && rrd.rra_ptr[i].cur_row + elapsed_pdp_st -
-                                rrd.rra_def[i].row_cnt >=
-                                rrd.rra_def[i].par[RRA_seasonal_smooth_idx].
-                                u_cnt) {
-#ifdef DEBUG
-                                fprintf(stderr,
-                                        "schedule_smooth 2: cur_row %lu, elapsed_pdp_st %lu, smooth idx %lu\n",
-                                        rrd.rra_ptr[i].cur_row,
-                                        elapsed_pdp_st,
-                                        rrd.rra_def[i].
-                                        par[RRA_seasonal_smooth_idx].u_cnt);
-#endif
-                                schedule_smooth = 1;
-                            }
-                        }
-                    }
+        cdp_idx = rra_idx * rrd->stat_head->ds_cnt + ds_idx;
+
+        if (rrd->rra_def[rra_idx].pdp_cnt > 1) {
+            update_cdp(rrd->cdp_prep[cdp_idx].scratch, current_cf, 
+                            pdp_temp[ds_idx], rra_step_cnt[rra_idx],
+                            elapsed_pdp_st, start_pdp_offset,
+                            rrd->rra_def[rra_idx].pdp_cnt,
+                            rrd->rra_def[rra_idx].par[RRA_cdp_xff_val].u_val, rra_idx, ds_idx);
+        } else { 
+            /* Nothing to consolidate if there's one PDP per CDP. However, if
+             * we've missed some PDPs, let's update null counters etc. */
+            if (elapsed_pdp_st > 2) {
+                reset_cdp(rrd, elapsed_pdp_st, pdp_temp, last_seasonal_coef, seasonal_coef, 
+                                rra_idx, ds_idx, cdp_idx, current_cf);
+            }
+        }
 
-                    rra_current = rrd_tell(rrd_file);
-                }
-                /* if cf is DEVSEASONAL or SEASONAL */
-                if (rrd_test_error())
-                    break;
+        if (rrd_test_error())
+            return -1;
+    }       /* endif data sources loop */
+    return 0;
+}
 
-                /* update CDP_PREP areas */
-                /* loop over data soures within each RRA */
-                for (ii = 0; ii < rrd.stat_head->ds_cnt; ii++) {
-
-                    /* iii indexes the CDP prep area for this data source within the RRA */
-                    iii = i * rrd.stat_head->ds_cnt + ii;
-
-                    if (rrd.rra_def[i].pdp_cnt > 1) {
-
-                        if (rra_step_cnt[i] > 0) {
-                            /* If we are in this block, as least 1 CDP value will be written to
-                             * disk, this is the CDP_primary_val entry. If more than 1 value needs
-                             * to be written, then the "fill in" value is the CDP_secondary_val
-                             * entry. */
-                            if (isnan(pdp_temp[ii])) {
-                                rrd.cdp_prep[iii].scratch[CDP_unkn_pdp_cnt].
-                                    u_cnt += start_pdp_offset;
-                                rrd.cdp_prep[iii].scratch[CDP_secondary_val].
-                                    u_val = DNAN;
-                            } else {
-                                /* CDP_secondary value is the RRA "fill in" value for intermediary
-                                 * CDP data entries. No matter the CF, the value is the same because
-                                 * the average, max, min, and last of a list of identical values is
-                                 * the same, namely, the value itself. */
-                                rrd.cdp_prep[iii].scratch[CDP_secondary_val].
-                                    u_val = pdp_temp[ii];
-                            }
+/*
+ * Given the new reading (pdp_temp_val), update or initialize the CDP value,
+ * primary value, secondary value, and # of unknowns.
+ */
+static void update_cdp(
+    unival *scratch,
+    int current_cf,
+    rrd_value_t pdp_temp_val,
+    unsigned long rra_step_cnt,
+    unsigned long elapsed_pdp_st,
+    unsigned long start_pdp_offset,
+    unsigned long pdp_cnt,
+    rrd_value_t xff,
+    int i, int ii)
+{
+    /* shorthand variables */
+    rrd_value_t            *cdp_val = &scratch[CDP_val].u_val;
+    rrd_value_t    *cdp_primary_val = &scratch[CDP_primary_val].u_val;
+    rrd_value_t  *cdp_secondary_val = &scratch[CDP_secondary_val].u_val;
+    unsigned long *cdp_unkn_pdp_cnt = &scratch[CDP_unkn_pdp_cnt].u_cnt;
+
+    if (rra_step_cnt) {
+        /* If we are in this block, as least 1 CDP value will be written to
+         * disk, this is the CDP_primary_val entry. If more than 1 value needs
+         * to be written, then the "fill in" value is the CDP_secondary_val
+         * entry. */
+        if (isnan(pdp_temp_val)) {
+            *cdp_unkn_pdp_cnt += start_pdp_offset;
+            *cdp_secondary_val = DNAN;
+        } else {
+            /* CDP_secondary value is the RRA "fill in" value for intermediary
+             * CDP data entries. No matter the CF, the value is the same because
+             * the average, max, min, and last of a list of identical values is
+             * the same, namely, the value itself. */
+            *cdp_secondary_val = pdp_temp_val;
+        }
+
+        if (*cdp_unkn_pdp_cnt > pdp_cnt * xff) {
+            *cdp_primary_val = DNAN;
+            if (current_cf == CF_AVERAGE) {
+                *cdp_val = initialize_average_carry_over(pdp_temp_val, elapsed_pdp_st,
+                                start_pdp_offset, pdp_cnt);
+            } else {
+                *cdp_val = pdp_temp_val;
+            }
+        } else {
+            initialize_cdp_val(scratch, current_cf, pdp_temp_val, 
+                            elapsed_pdp_st, start_pdp_offset, pdp_cnt);
+        }   /* endif meets xff value requirement for a valid value */
+        /* initialize carry over CDP_unkn_pdp_cnt, this must after CDP_primary_val
+         * is set because CDP_unkn_pdp_cnt is required to compute that value. */
+        if (isnan(pdp_temp_val))
+            *cdp_unkn_pdp_cnt = (elapsed_pdp_st - start_pdp_offset) % pdp_cnt;
+        else
+            *cdp_unkn_pdp_cnt = 0;
+    } else {    /* rra_step_cnt[i]  == 0 */
 
-                            if (rrd.cdp_prep[iii].scratch[CDP_unkn_pdp_cnt].
-                                u_cnt >
-                                rrd.rra_def[i].pdp_cnt *
-                                rrd.rra_def[i].par[RRA_cdp_xff_val].u_val) {
-                                rrd.cdp_prep[iii].scratch[CDP_primary_val].
-                                    u_val = DNAN;
-                                /* initialize carry over */
-                                if (current_cf == CF_AVERAGE) {
-                                    if (isnan(pdp_temp[ii])) {
-                                        rrd.cdp_prep[iii].scratch[CDP_val].
-                                            u_val = DNAN;
-                                    } else {
-                                        rrd.cdp_prep[iii].scratch[CDP_val].
-                                            u_val =
-                                            pdp_temp[ii] *
-                                            ((elapsed_pdp_st -
-                                              start_pdp_offset) %
-                                             rrd.rra_def[i].pdp_cnt);
-                                    }
-                                } else {
-                                    rrd.cdp_prep[iii].scratch[CDP_val].u_val =
-                                        pdp_temp[ii];
-                                }
-                            } else {
-                                rrd_value_t cum_val, cur_val;
-
-                                switch (current_cf) {
-                                case CF_AVERAGE:
-                                    cum_val =
-                                        IFDNAN(rrd.cdp_prep[iii].
-                                               scratch[CDP_val].u_val, 0.0);
-                                    cur_val = IFDNAN(pdp_temp[ii], 0.0);
-                                    rrd.cdp_prep[iii].
-                                        scratch[CDP_primary_val].u_val =
-                                        (cum_val +
-                                         cur_val * start_pdp_offset) /
-                                        (rrd.rra_def[i].pdp_cnt -
-                                         rrd.cdp_prep[iii].
-                                         scratch[CDP_unkn_pdp_cnt].u_cnt);
-                                    /* initialize carry over value */
-                                    if (isnan(pdp_temp[ii])) {
-                                        rrd.cdp_prep[iii].scratch[CDP_val].
-                                            u_val = DNAN;
-                                    } else {
-                                        rrd.cdp_prep[iii].scratch[CDP_val].
-                                            u_val =
-                                            pdp_temp[ii] *
-                                            ((elapsed_pdp_st -
-                                              start_pdp_offset) %
-                                             rrd.rra_def[i].pdp_cnt);
-                                    }
-                                    break;
-                                case CF_MAXIMUM:
-                                    cum_val =
-                                        IFDNAN(rrd.cdp_prep[iii].
-                                               scratch[CDP_val].u_val, -DINF);
-                                    cur_val = IFDNAN(pdp_temp[ii], -DINF);
 #ifdef DEBUG
-                                    if (isnan
-                                        (rrd.cdp_prep[iii].scratch[CDP_val].
-                                         u_val) && isnan(pdp_temp[ii])) {
-                                        fprintf(stderr,
-                                                "RRA %lu, DS %lu, both CDP_val and pdp_temp are DNAN!",
-                                                i, ii);
-                                        exit(-1);
-                                    }
+        if (isnan(*cdp_val)) {
+            fprintf(stderr, "schedule CDP_val update, RRA %d DS %d, DNAN\n",
+                            i, ii);
+        } else {
+            fprintf(stderr, "schedule CDP_val update, RRA %d DS %d, %10.2f\n",
+                            i, ii, *cdp_val);
+        }
 #endif
-                                    if (cur_val > cum_val)
-                                        rrd.cdp_prep[iii].
-                                            scratch[CDP_primary_val].u_val =
-                                            cur_val;
-                                    else
-                                        rrd.cdp_prep[iii].
-                                            scratch[CDP_primary_val].u_val =
-                                            cum_val;
-                                    /* initialize carry over value */
-                                    rrd.cdp_prep[iii].scratch[CDP_val].u_val =
-                                        pdp_temp[ii];
-                                    break;
-                                case CF_MINIMUM:
-                                    cum_val =
-                                        IFDNAN(rrd.cdp_prep[iii].
-                                               scratch[CDP_val].u_val, DINF);
-                                    cur_val = IFDNAN(pdp_temp[ii], DINF);
+        if (isnan(pdp_temp_val)) {
+            *cdp_unkn_pdp_cnt += elapsed_pdp_st;
+        } else {
+            *cdp_val = calculate_cdp_val(*cdp_val, pdp_temp_val, elapsed_pdp_st, current_cf, i, ii);
+        }
+    }
+}
+
+/*
+ * Set the CDP_primary_val and CDP_val to the appropriate initial value based
+ * on the type of consolidation function.
+ */
+static void initialize_cdp_val(
+    unival *scratch, 
+    int current_cf,
+    rrd_value_t pdp_temp_val,
+    unsigned long elapsed_pdp_st, 
+    unsigned long start_pdp_offset,
+    unsigned long pdp_cnt) 
+{
+    rrd_value_t cum_val, cur_val;
+
+    switch (current_cf) {
+            case CF_AVERAGE:
+                    cum_val = IFDNAN(scratch[CDP_val].u_val, 0.0);
+                    cur_val = IFDNAN(pdp_temp_val, 0.0);
+                    scratch[CDP_primary_val].u_val =
+                            (cum_val + cur_val * start_pdp_offset) /
+                            (pdp_cnt - scratch[CDP_unkn_pdp_cnt].u_cnt);
+                    scratch[CDP_val].u_val = initialize_average_carry_over(
+                                    pdp_temp_val, elapsed_pdp_st, start_pdp_offset, pdp_cnt);
+                    break;
+            case CF_MAXIMUM:
+                    cum_val = IFDNAN(scratch[CDP_val].u_val, -DINF);
+                    cur_val = IFDNAN(pdp_temp_val, -DINF);
+#if 0
 #ifdef DEBUG
-                                    if (isnan
-                                        (rrd.cdp_prep[iii].scratch[CDP_val].
-                                         u_val) && isnan(pdp_temp[ii])) {
-                                        fprintf(stderr,
-                                                "RRA %lu, DS %lu, both CDP_val and pdp_temp are DNAN!",
-                                                i, ii);
-                                        exit(-1);
-                                    }
+                    if (isnan(scratch[CDP_val].u_val) && isnan(pdp_temp)) {
+                        fprintf(stderr,
+                                        "RRA %lu, DS %lu, both CDP_val and pdp_temp are DNAN!",
+                                        i, ii);
+                        exit(-1);
+                    }
 #endif
-                                    if (cur_val < cum_val)
-                                        rrd.cdp_prep[iii].
-                                            scratch[CDP_primary_val].u_val =
-                                            cur_val;
-                                    else
-                                        rrd.cdp_prep[iii].
-                                            scratch[CDP_primary_val].u_val =
-                                            cum_val;
-                                    /* initialize carry over value */
-                                    rrd.cdp_prep[iii].scratch[CDP_val].u_val =
-                                        pdp_temp[ii];
-                                    break;
-                                case CF_LAST:
-                                default:
-                                    rrd.cdp_prep[iii].
-                                        scratch[CDP_primary_val].u_val =
-                                        pdp_temp[ii];
-                                    /* initialize carry over value */
-                                    rrd.cdp_prep[iii].scratch[CDP_val].u_val =
-                                        pdp_temp[ii];
-                                    break;
-                                }
-                            }   /* endif meets xff value requirement for a valid value */
-                            /* initialize carry over CDP_unkn_pdp_cnt, this must after CDP_primary_val
-                             * is set because CDP_unkn_pdp_cnt is required to compute that value. */
-                            if (isnan(pdp_temp[ii]))
-                                rrd.cdp_prep[iii].scratch[CDP_unkn_pdp_cnt].
-                                    u_cnt =
-                                    (elapsed_pdp_st -
-                                     start_pdp_offset) %
-                                    rrd.rra_def[i].pdp_cnt;
-                            else
-                                rrd.cdp_prep[iii].scratch[CDP_unkn_pdp_cnt].
-                                    u_cnt = 0;
-                        } else {    /* rra_step_cnt[i]  == 0 */
-
+#endif
+                    if (cur_val > cum_val)
+                        scratch[CDP_primary_val].u_val = cur_val;
+                    else
+                        scratch[CDP_primary_val].u_val = cum_val;
+                    /* initialize carry over value */
+                    scratch[CDP_val].u_val = pdp_temp_val;
+                    break;
+            case CF_MINIMUM:
+                    cum_val = IFDNAN(scratch[CDP_val].u_val, DINF);
+                    cur_val = IFDNAN(pdp_temp_val, DINF);
+#if 0
 #ifdef DEBUG
-                            if (isnan
-                                (rrd.cdp_prep[iii].scratch[CDP_val].u_val)) {
-                                fprintf(stderr,
-                                        "schedule CDP_val update, RRA %lu DS %lu, DNAN\n",
+                    if (isnan(scratch[CDP_val].u_val) && isnan(pdp_temp)) {
+                        fprintf(stderr, "RRA %lu, DS %lu, both CDP_val and pdp_temp are DNAN!",
                                         i, ii);
-                            } else {
-                                fprintf(stderr,
-                                        "schedule CDP_val update, RRA %lu DS %lu, %10.2f\n",
-                                        i, ii,
-                                        rrd.cdp_prep[iii].scratch[CDP_val].
-                                        u_val);
-                            }
+                        exit(-1);
+                    }
 #endif
-                            if (isnan(pdp_temp[ii])) {
-                                rrd.cdp_prep[iii].scratch[CDP_unkn_pdp_cnt].
-                                    u_cnt += elapsed_pdp_st;
-                            } else
-                                if (isnan
-                                    (rrd.cdp_prep[iii].scratch[CDP_val].
-                                     u_val)) {
-                                if (current_cf == CF_AVERAGE) {
-                                    rrd.cdp_prep[iii].scratch[CDP_val].u_val =
-                                        pdp_temp[ii] * elapsed_pdp_st;
-                                } else {
-                                    rrd.cdp_prep[iii].scratch[CDP_val].u_val =
-                                        pdp_temp[ii];
-                                }
+#endif
+                    if (cur_val < cum_val)
+                        scratch[CDP_primary_val].u_val = cur_val;
+                    else
+                        scratch[CDP_primary_val].u_val = cum_val;
+                    /* initialize carry over value */
+                    scratch[CDP_val].u_val = pdp_temp_val;
+                    break;
+            case CF_LAST:
+            default:
+                    scratch[CDP_primary_val].u_val = pdp_temp_val;
+                    /* initialize carry over value */
+                    scratch[CDP_val].u_val = pdp_temp_val;
+                    break;
+    }
+}
+
+/*
+ * Update the consolidation function for Holt-Winters functions as
+ * well as other functions that don't actually consolidate multiple
+ * PDPs.
+ */
+static void reset_cdp(
+    rrd_t *rrd,
+    unsigned long elapsed_pdp_st, 
+    rrd_value_t *pdp_temp,
+    rrd_value_t *last_seasonal_coef,
+    rrd_value_t *seasonal_coef,
+    int rra_idx, int ds_idx, int cdp_idx, 
+    enum cf_en current_cf)
+{
+    unival *scratch = rrd->cdp_prep[cdp_idx].scratch;
+
+    switch (current_cf) {
+            case CF_AVERAGE:
+            default:
+                    scratch[CDP_primary_val].u_val = pdp_temp[ds_idx];
+                    scratch[CDP_secondary_val].u_val = pdp_temp[ds_idx];
+                    break;
+            case CF_SEASONAL:
+            case CF_DEVSEASONAL:
+                    /* need to update cached seasonal values, so they are consistent
+                     * with the bulk update */
+                    /* WARNING: code relies on the fact that CDP_hw_last_seasonal and
+                     * CDP_last_deviation are the same. */
+                    scratch[CDP_hw_last_seasonal].u_val = last_seasonal_coef[ds_idx];
+                    scratch[CDP_hw_seasonal].u_val = seasonal_coef[ds_idx];
+                    break;
+            case CF_HWPREDICT:
+            case CF_MHWPREDICT:
+                    /* need to update the null_count and last_null_count.
+                     * even do this for non-DNAN pdp_temp because the
+                     * algorithm is not learning from batch updates. */
+                    scratch[CDP_null_count].u_cnt += elapsed_pdp_st;
+                    scratch[CDP_last_null_count].u_cnt += elapsed_pdp_st - 1;
+                    /* fall through */
+            case CF_DEVPREDICT:
+                    scratch[CDP_primary_val].u_val = DNAN;
+                    scratch[CDP_secondary_val].u_val = DNAN;
+                    break;
+            case CF_FAILURES:
+                    /* do not count missed bulk values as failures */
+                    scratch[CDP_primary_val].u_val = 0;
+                    scratch[CDP_secondary_val].u_val = 0;
+                    /* need to reset violations buffer.
+                     * could do this more carefully, but for now, just
+                     * assume a bulk update wipes away all violations. */
+                    erase_violations(rrd, cdp_idx, rra_idx);
+                    break;
+    }
+}
+
+static rrd_value_t initialize_average_carry_over(
+    rrd_value_t pdp_temp_val, 
+    unsigned long elapsed_pdp_st,
+    unsigned long start_pdp_offset,
+    unsigned long pdp_cnt)
+{
+    /* initialize carry over value */
+    if (isnan(pdp_temp_val)) {
+        return DNAN;
+    } 
+    return pdp_temp_val * ((elapsed_pdp_st - start_pdp_offset) % pdp_cnt);
+}
+
+/*
+ * Update or initialize a CDP value based on the consolidation
+ * function.
+ *
+ * Returns the new value.
+ */
+static rrd_value_t calculate_cdp_val(
+    rrd_value_t cdp_val,
+    rrd_value_t pdp_temp_val,
+    unsigned long elapsed_pdp_st,
+    int current_cf, int i, int ii)
+{
+    if (isnan(cdp_val)) {
+        if (current_cf == CF_AVERAGE) {
+            pdp_temp_val *= elapsed_pdp_st;
+        }
 #ifdef DEBUG
-                                fprintf(stderr,
-                                        "Initialize CDP_val for RRA %lu DS %lu: %10.2f\n",
-                                        i, ii,
-                                        rrd.cdp_prep[iii].scratch[CDP_val].
-                                        u_val);
+        fprintf(stderr, "Initialize CDP_val for RRA %d DS %d: %10.2f\n",
+                        i, ii, pdp_temp_val);
 #endif
-                            } else {
-                                switch (current_cf) {
-                                case CF_AVERAGE:
-                                    rrd.cdp_prep[iii].scratch[CDP_val].
-                                        u_val +=
-                                        pdp_temp[ii] * elapsed_pdp_st;
-                                    break;
-                                case CF_MINIMUM:
-                                    if (pdp_temp[ii] <
-                                        rrd.cdp_prep[iii].scratch[CDP_val].
-                                        u_val)
-                                        rrd.cdp_prep[iii].scratch[CDP_val].
-                                            u_val = pdp_temp[ii];
-                                    break;
-                                case CF_MAXIMUM:
-                                    if (pdp_temp[ii] >
-                                        rrd.cdp_prep[iii].scratch[CDP_val].
-                                        u_val)
-                                        rrd.cdp_prep[iii].scratch[CDP_val].
-                                            u_val = pdp_temp[ii];
-                                    break;
-                                case CF_LAST:
-                                default:
-                                    rrd.cdp_prep[iii].scratch[CDP_val].u_val =
-                                        pdp_temp[ii];
-                                    break;
-                                }
-                            }
-                        }
-                    } else {    /* rrd.rra_def[i].pdp_cnt == 1 */
-                        if (elapsed_pdp_st > 2) {
-                            switch (current_cf) {
-                            case CF_AVERAGE:
-                            default:
-                                rrd.cdp_prep[iii].scratch[CDP_primary_val].
-                                    u_val = pdp_temp[ii];
-                                rrd.cdp_prep[iii].scratch[CDP_secondary_val].
-                                    u_val = pdp_temp[ii];
-                                break;
-                            case CF_SEASONAL:
-                            case CF_DEVSEASONAL:
-                                /* need to update cached seasonal values, so they are consistent
-                                 * with the bulk update */
-                                /* WARNING: code relies on the fact that CDP_hw_last_seasonal and
-                                 * CDP_last_deviation are the same. */
-                                rrd.cdp_prep[iii].
-                                    scratch[CDP_hw_last_seasonal].u_val =
-                                    last_seasonal_coef[ii];
-                                rrd.cdp_prep[iii].scratch[CDP_hw_seasonal].
-                                    u_val = seasonal_coef[ii];
-                                break;
-                            case CF_HWPREDICT:
-                            case CF_MHWPREDICT:
-                                /* need to update the null_count and last_null_count.
-                                 * even do this for non-DNAN pdp_temp because the
-                                 * algorithm is not learning from batch updates. */
-                                rrd.cdp_prep[iii].scratch[CDP_null_count].
-                                    u_cnt += elapsed_pdp_st;
-                                rrd.cdp_prep[iii].
-                                    scratch[CDP_last_null_count].u_cnt +=
-                                    elapsed_pdp_st - 1;
-                                /* fall through */
-                            case CF_DEVPREDICT:
-                                rrd.cdp_prep[iii].scratch[CDP_primary_val].
-                                    u_val = DNAN;
-                                rrd.cdp_prep[iii].scratch[CDP_secondary_val].
-                                    u_val = DNAN;
-                                break;
-                            case CF_FAILURES:
-                                /* do not count missed bulk values as failures */
-                                rrd.cdp_prep[iii].scratch[CDP_primary_val].
-                                    u_val = 0;
-                                rrd.cdp_prep[iii].scratch[CDP_secondary_val].
-                                    u_val = 0;
-                                /* need to reset violations buffer.
-                                 * could do this more carefully, but for now, just
-                                 * assume a bulk update wipes away all violations. */
-                                erase_violations(&rrd, iii, i);
-                                break;
-                            }
-                        }
-                    }   /* endif rrd.rra_def[i].pdp_cnt == 1 */
-
-                    if (rrd_test_error())
-                        break;
-
-                }       /* endif data sources loop */
-            }           /* end RRA Loop */
-
-            /* this loop is only entered if elapsed_pdp_st < 3 */
-            for (j = elapsed_pdp_st, scratch_idx = CDP_primary_val;
-                 j > 0 && j < 3; j--, scratch_idx = CDP_secondary_val) {
-                for (i = 0, rra_start = rra_begin;
-                     i < rrd.stat_head->rra_cnt;
-                     rra_start +=
-                     rrd.rra_def[i].row_cnt * rrd.stat_head->ds_cnt *
-                     sizeof(rrd_value_t), i++) {
-                    if (rrd.rra_def[i].pdp_cnt > 1)
-                        continue;
-
-                    current_cf = cf_conv(rrd.rra_def[i].cf_nam);
-                    if (current_cf == CF_SEASONAL
-                        || current_cf == CF_DEVSEASONAL) {
-                        lookup_seasonal(&rrd, i, rra_start, rrd_file,
-                                        elapsed_pdp_st + (scratch_idx ==
-                                                          CDP_primary_val ? 1
-                                                          : 2),
-                                        &seasonal_coef);
-                        rra_current = rrd_tell(rrd_file);
-                    }
-                    if (rrd_test_error())
-                        break;
-                    /* loop over data soures within each RRA */
-                    for (ii = 0; ii < rrd.stat_head->ds_cnt; ii++) {
-                        update_aberrant_CF(&rrd, pdp_temp[ii], current_cf,
-                                           i * (rrd.stat_head->ds_cnt) + ii,
-                                           i, ii, scratch_idx, seasonal_coef);
+        return pdp_temp_val;
+    } 
+    if (current_cf == CF_AVERAGE) 
+        return cdp_val + pdp_temp_val * elapsed_pdp_st;
+    if (current_cf == CF_MINIMUM)
+        return (pdp_temp_val < cdp_val) ? pdp_temp_val : cdp_val;
+    if (current_cf == CF_MAXIMUM)
+        return (pdp_temp_val > cdp_val) ? pdp_temp_val : cdp_val;
+
+    return pdp_temp_val;
+}
+
+/*
+ * For each RRA, update the seasonal values and then call update_aberrant_CF
+ * for each data source.
+ *
+ * Return 0 on success, -1 on error.
+ */
+static int update_aberrant_cdps(
+    rrd_t *rrd, rrd_file_t *rrd_file, unsigned long rra_begin,
+    unsigned long *rra_current, unsigned long elapsed_pdp_st, 
+    rrd_value_t *pdp_temp, rrd_value_t  **seasonal_coef) 
+{
+    unsigned long rra_idx, ds_idx, j;
+
+    /* number of PDP steps since the last update that
+     * are assigned to the first CDP to be generated
+     * since the last update. */
+    unsigned short scratch_idx;
+    unsigned long  rra_start;
+    enum cf_en     current_cf;
+
+    /* this loop is only entered if elapsed_pdp_st < 3 */
+    for (j = elapsed_pdp_st, scratch_idx = CDP_primary_val;
+                    j > 0 && j < 3; j--, scratch_idx = CDP_secondary_val) {
+        rra_start = rra_begin;
+        for (rra_idx = 0; rra_idx < rrd->stat_head->rra_cnt; rra_idx++) {
+            if (rrd->rra_def[rra_idx].pdp_cnt == 1) {
+                current_cf = cf_conv(rrd->rra_def[rra_idx].cf_nam);
+                if (current_cf == CF_SEASONAL || current_cf == CF_DEVSEASONAL) {
+                    if (scratch_idx == CDP_primary_val) {
+                        lookup_seasonal(rrd, rra_idx, rra_start, rrd_file,
+                                        elapsed_pdp_st + 1, seasonal_coef);
+                    } else {
+                        lookup_seasonal(rrd, rra_idx, rra_start, rrd_file,
+                                        elapsed_pdp_st + 2, seasonal_coef);
                     }
-                }       /* end RRA Loop */
+                    *rra_current = rrd_tell(rrd_file);
+                }
                 if (rrd_test_error())
-                    break;
-            }           /* end elapsed_pdp_st loop */
+                    return -1;
+                /* loop over data soures within each RRA */
+                for (ds_idx = 0; ds_idx < rrd->stat_head->ds_cnt; ds_idx++) {
+                    update_aberrant_CF(rrd, pdp_temp[ds_idx], current_cf,
+                                    rra_idx * (rrd->stat_head->ds_cnt) + ds_idx,
+                                    rra_idx, ds_idx, scratch_idx, *seasonal_coef);
+                }
+            }
+            rra_start += rrd->rra_def[rra_idx].row_cnt 
+                    * rrd->stat_head->ds_cnt 
+                    * sizeof(rrd_value_t);
+        }
+    }
+    return 0;
+}
 
-            if (rrd_test_error())
-                break;
-
-            /* Ready to write to disk */
-            /* Move sequentially through the file, writing one RRA at a time.
-             * Note this architecture divorces the computation of CDP with
-             * flushing updated RRA entries to disk. */
-            for (i = 0, rra_start = rra_begin;
-                 i < rrd.stat_head->rra_cnt;
-                 rra_start +=
-                 rrd.rra_def[i].row_cnt * rrd.stat_head->ds_cnt *
-                 sizeof(rrd_value_t), i++) {
-                /* is th5Aere anything to write for this RRA? If not, continue. */
-                if (rra_step_cnt[i] == 0)
-                    continue;
-
-                /* write the first row */
+/* 
+ * Move sequentially through the file, writing one RRA at a time.  Note this
+ * architecture divorces the computation of CDP with flushing updated RRA
+ * entries to disk.
+ *
+ * Return 0 on success, -1 on error.
+ */
+static int write_to_rras(
+    rrd_t *rrd, 
+    rrd_file_t *rrd_file, 
+    unsigned long *rra_step_cnt,
+    unsigned long rra_begin, 
+    unsigned long *rra_current,
+    time_t current_time,
+    info_t **pcdp_summary)
+{
+    unsigned long rra_idx;
+    unsigned long rra_start;    
+    unsigned long rra_pos_tmp;  /* temporary byte pointer. */
+    /* number of PDP steps since the last update that
+     * are assigned to the first CDP to be generated
+     * since the last update. */
+    unsigned short scratch_idx;
+    time_t    rra_time = 0; /* time of update for a RRA */
+
+    /* Ready to write to disk */
+    rra_start = rra_begin;
+    for (rra_idx = 0; rra_idx < rrd->stat_head->rra_cnt; rra_idx++) {
+        /* skip unless there's something to write */
+        if (rra_step_cnt[rra_idx]) {
+            /* write the first row */
 #ifdef DEBUG
-                fprintf(stderr, "  -- RRA Preseek %ld\n", rrd_file->pos);
+            fprintf(stderr, "  -- RRA Preseek %ld\n", rrd_file->pos);
 #endif
-                rrd.rra_ptr[i].cur_row++;
-                if (rrd.rra_ptr[i].cur_row >= rrd.rra_def[i].row_cnt)
-                    rrd.rra_ptr[i].cur_row = 0; /* wrap around */
-                /* positition on the first row */
-                rra_pos_tmp = rra_start +
-                    (rrd.stat_head->ds_cnt) * (rrd.rra_ptr[i].cur_row) *
+            rrd->rra_ptr[rra_idx].cur_row++;
+            if (rrd->rra_ptr[rra_idx].cur_row >= rrd->rra_def[rra_idx].row_cnt)
+                rrd->rra_ptr[rra_idx].cur_row = 0; /* wrap around */
+            /* positition on the first row */
+            rra_pos_tmp = rra_start +
+                    (rrd->stat_head->ds_cnt) * (rrd->rra_ptr[rra_idx].cur_row) *
                     sizeof(rrd_value_t);
-                if (rra_pos_tmp != rra_current) {
-                    if (rrd_seek(rrd_file, rra_pos_tmp, SEEK_SET) != 0) {
-                        rrd_set_error("seek error in rrd");
-                        break;
-                    }
-                    rra_current = rra_pos_tmp;
+            if (rra_pos_tmp != *rra_current) {
+                if (rrd_seek(rrd_file, rra_pos_tmp, SEEK_SET) != 0) {
+                    rrd_set_error("seek error in rrd");
+                    return -1;
                 }
+                *rra_current = rra_pos_tmp;
+            }
 #ifdef DEBUG
-                fprintf(stderr, "  -- RRA Postseek %ld\n", rrd_file->pos);
+            fprintf(stderr, "  -- RRA Postseek %ld\n", rrd_file->pos);
 #endif
-                scratch_idx = CDP_primary_val;
-                if (pcdp_summary != NULL) {
-                    rra_time = (current_time - current_time
-                                % (rrd.rra_def[i].pdp_cnt *
-                                   rrd.stat_head->pdp_step))
-                        -
-                        ((rra_step_cnt[i] -
-                          1) * rrd.rra_def[i].pdp_cnt *
-                         rrd.stat_head->pdp_step);
-                }
-                pcdp_summary =
-                    write_RRA_row(rrd_file, &rrd, i, &rra_current,
-                                  scratch_idx, pcdp_summary, &rra_time);
-                if (rrd_test_error())
-                    break;
+            scratch_idx = CDP_primary_val;
+            if (*pcdp_summary != NULL) {
+                rra_time = (current_time - current_time
+                                % (rrd->rra_def[rra_idx].pdp_cnt *
+                                        rrd->stat_head->pdp_step))
+                        - ((rra_step_cnt[rra_idx] - 1) * rrd->rra_def[rra_idx].pdp_cnt *
+                                        rrd->stat_head->pdp_step);
+            }
+            if (write_RRA_row(rrd_file, rrd, rra_idx, rra_current, scratch_idx, 
+                                    pcdp_summary, &rra_time) == -1)
+                return -1;
+            if (rrd_test_error())
+                return -1;
 
-                /* write other rows of the bulk update, if any */
-                scratch_idx = CDP_secondary_val;
-                for (; rra_step_cnt[i] > 1; rra_step_cnt[i]--) {
-                    if (++rrd.rra_ptr[i].cur_row == rrd.rra_def[i].row_cnt) {
+            /* write other rows of the bulk update, if any */
+            scratch_idx = CDP_secondary_val;
+            for (; rra_step_cnt[rra_idx] > 1; rra_step_cnt[rra_idx]--) {
+                if (++rrd->rra_ptr[rra_idx].cur_row == rrd->rra_def[rra_idx].row_cnt) {
 #ifdef DEBUG
-                        fprintf(stderr,
-                                "Wraparound for RRA %s, %lu updates left\n",
-                                rrd.rra_def[i].cf_nam, rra_step_cnt[i] - 1);
+                    fprintf(stderr,
+                                    "Wraparound for RRA %s, %lu updates left\n",
+                                    rrd->rra_def[rra_idx].cf_nam, rra_step_cnt[rra_idx] - 1);
 #endif
-                        /* wrap */
-                        rrd.rra_ptr[i].cur_row = 0;
-                        /* seek back to beginning of current rra */
-                        if (rrd_seek(rrd_file, rra_start, SEEK_SET) != 0) {
-                            rrd_set_error("seek error in rrd");
-                            break;
-                        }
+                    /* wrap */
+                    rrd->rra_ptr[rra_idx].cur_row = 0;
+                    /* seek back to beginning of current rra */
+                    if (rrd_seek(rrd_file, rra_start, SEEK_SET) != 0) {
+                        rrd_set_error("seek error in rrd");
+                        return -1;
+                    }
 #ifdef DEBUG
-                        fprintf(stderr, "  -- Wraparound Postseek %ld\n",
-                                rrd_file->pos);
+                    fprintf(stderr, "  -- Wraparound Postseek %ld\n",
+                                    rrd_file->pos);
 #endif
-                        rra_current = rra_start;
-                    }
-                    if (pcdp_summary != NULL) {
-                        rra_time = (current_time - current_time
-                                    % (rrd.rra_def[i].pdp_cnt *
-                                       rrd.stat_head->pdp_step))
+                    *rra_current = rra_start;
+                }
+                if (*pcdp_summary != NULL) {
+                    rra_time = (current_time - current_time
+                                    % (rrd->rra_def[rra_idx].pdp_cnt *
+                                            rrd->stat_head->pdp_step))
                             -
-                            ((rra_step_cnt[i] -
-                              2) * rrd.rra_def[i].pdp_cnt *
-                             rrd.stat_head->pdp_step);
-                    }
-                    pcdp_summary =
-                        write_RRA_row(rrd_file, &rrd, i, &rra_current,
-                                      scratch_idx, pcdp_summary, &rra_time);
+                            ((rra_step_cnt[rra_idx] - 2) * rrd->rra_def[rra_idx].pdp_cnt *
+                             rrd->stat_head->pdp_step);
                 }
+                if (write_RRA_row(rrd_file, rrd, rra_idx, rra_current,
+                                        scratch_idx, pcdp_summary, &rra_time) == -1)
+                    return -1;
+            }
 
-                if (rrd_test_error())
-                    break;
-            }           /* RRA LOOP */
+            if (rrd_test_error())
+                return -1;
+        }
+        rra_start += rrd->rra_def[rra_idx].row_cnt * rrd->stat_head->ds_cnt *
+                sizeof(rrd_value_t);
+    }           /* RRA LOOP */
 
-            /* break out of the argument parsing loop if error_string is set */
-            if (rrd_test_error()) {
-                free(step_start);
-                break;
-            }
+    return 0;
+}
 
-        }               /* endif a pdp_st has occurred */
-        rrd.live_head->last_up = current_time;
-        rrd.live_head->last_up_usec = current_time_usec;
-        free(step_start);
-    }                   /* function argument loop */
-
-    if (seasonal_coef != NULL)
-        free(seasonal_coef);
-    if (last_seasonal_coef != NULL)
-        free(last_seasonal_coef);
-    if (rra_step_cnt != NULL)
-        free(rra_step_cnt);
-    rpnstack_free(&rpnstack);
+/*
+ * Write out one row of values (one value per DS) to the archive.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int write_RRA_row(
+    rrd_file_t *rrd_file,
+    rrd_t *rrd,
+    unsigned long rra_idx,
+    unsigned long *rra_current,
+    unsigned short CDP_scratch_idx,
+    info_t **pcdp_summary,
+    time_t *rra_time)
+{
+    unsigned long ds_idx, cdp_idx;
+    infoval   iv;
 
-#if 0
-    //rrd_flush(rrd_file);    //XXX: really needed?
+    for (ds_idx = 0; ds_idx < rrd->stat_head->ds_cnt; ds_idx++) {
+        /* compute the cdp index */
+        cdp_idx = rra_idx * (rrd->stat_head->ds_cnt) + ds_idx;
+#ifdef DEBUG
+        fprintf(stderr, "  -- RRA WRITE VALUE %e, at %ld CF:%s\n",
+                rrd->cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val,
+                rrd_file->pos, rrd->rra_def[rra_idx].cf_nam);
 #endif
-    /* if we got here and if there is an error and if the file has not been
-     * written to, then close things up and return. */
-    if (rrd_test_error()) {
-        goto err_free_pdp_new;
+        if (pcdp_summary != NULL) {
+            iv.u_val = rrd->cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val;
+            /* append info to the return hash */
+            *pcdp_summary = info_push(*pcdp_summary,
+                     sprintf_alloc("[%d]RRA[%s][%lu]DS[%s]", *rra_time,
+                           rrd->rra_def[rra_idx].cf_nam,
+                           rrd->rra_def[rra_idx].pdp_cnt,
+                           rrd->ds_def[ds_idx].ds_nam), RD_I_VAL, iv);
+        }
+        if (rrd_write(rrd_file,
+             &(rrd->cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val),
+             sizeof(rrd_value_t)) != sizeof(rrd_value_t)) {
+            rrd_set_error("writing rrd: %s", rrd_strerror(errno));
+            return -1;
+        }
+        *rra_current += sizeof(rrd_value_t);
     }
+    return 0;
+}
 
-    /* aargh ... that was tough ... so many loops ... anyway, its done.
-     * we just need to write back the live header portion now*/
+/*
+ * Call apply_smoother for all DEVSEASONAL and SEASONAL RRAs.
+ *
+ * Returns 0 on success, -1 otherwise
+ */
+static int smooth_all_rras(
+    rrd_t *rrd, 
+    rrd_file_t *rrd_file, 
+    unsigned long rra_begin) 
+{
+    unsigned long rra_start = rra_begin;
+    unsigned long rra_idx;
+    for (rra_idx = 0; rra_idx < rrd->stat_head->rra_cnt; ++rra_idx) {
+        if (cf_conv(rrd->rra_def[rra_idx].cf_nam) == CF_DEVSEASONAL ||
+                        cf_conv(rrd->rra_def[rra_idx].cf_nam) == CF_SEASONAL) {
+#ifdef DEBUG
+            fprintf(stderr, "Running smoother for rra %lu\n", rra_idx);
+#endif
+            apply_smoother(rrd, rra_idx, rra_start, rrd_file);
+            if (rrd_test_error())
+                return -1;
+        }
+        rra_start += rrd->rra_def[rra_idx].row_cnt
+                * rrd->stat_head->ds_cnt * sizeof(rrd_value_t);
+    }
+    return 0;
+}
 
+#ifndef HAVE_MMAP
+/*
+ * Flush changes to disk (unless we're using mmap)
+ *
+ * Returns 0 on success, -1 otherwise
+ */
+static int write_changes_to_disk(
+    rrd_t *rrd, rrd_file_t *rrd_file, int version) 
+{
+    /* we just need to write back the live header portion now*/
     if (rrd_seek(rrd_file, (sizeof(stat_head_t)
-                            + sizeof(ds_def_t) * rrd.stat_head->ds_cnt
-                            + sizeof(rra_def_t) * rrd.stat_head->rra_cnt),
+                            + sizeof(ds_def_t) * rrd->stat_head->ds_cnt
+                            + sizeof(rra_def_t) * rrd->stat_head->rra_cnt),
                  SEEK_SET) != 0) {
         rrd_set_error("seek rrd for live header writeback");
-        goto err_free_pdp_new;
+        return -1;
     }
-    /* for mmap, we did already write to the underlying mapping, so we do
-       not need to write again.  */
-#ifndef HAVE_MMAP
     if (version >= 3) {
-        if (rrd_write(rrd_file, rrd.live_head,
+        if (rrd_write(rrd_file, rrd->live_head,
                       sizeof(live_head_t) * 1) != sizeof(live_head_t) * 1) {
             rrd_set_error("rrd_write live_head to rrd");
-            goto err_free_pdp_new;
+            return -1;
         }
     } else {
-        if (rrd_write(rrd_file, &rrd.live_head->last_up,
+        if (rrd_write(rrd_file, &rrd->live_head->last_up,
                       sizeof(time_t) * 1) != sizeof(time_t) * 1) {
             rrd_set_error("rrd_write live_head to rrd");
-            goto err_free_pdp_new;
+            return -1;
         }
     }
 
 
-    if (rrd_write(rrd_file, rrd.pdp_prep,
-                  sizeof(pdp_prep_t) * rrd.stat_head->ds_cnt)
-        != (ssize_t) (sizeof(pdp_prep_t) * rrd.stat_head->ds_cnt)) {
+    if (rrd_write(rrd_file, rrd->pdp_prep,
+                  sizeof(pdp_prep_t) * rrd->stat_head->ds_cnt)
+        != (ssize_t) (sizeof(pdp_prep_t) * rrd->stat_head->ds_cnt)) {
         rrd_set_error("rrd_write pdp_prep to rrd");
-        goto err_free_pdp_new;
+        return -1;
     }
 
-    if (rrd_write(rrd_file, rrd.cdp_prep,
-                  sizeof(cdp_prep_t) * rrd.stat_head->rra_cnt *
-                  rrd.stat_head->ds_cnt)
-        != (ssize_t) (sizeof(cdp_prep_t) * rrd.stat_head->rra_cnt *
-                      rrd.stat_head->ds_cnt)) {
+    if (rrd_write(rrd_file, rrd->cdp_prep,
+                  sizeof(cdp_prep_t) * rrd->stat_head->rra_cnt *
+                  rrd->stat_head->ds_cnt)
+        != (ssize_t) (sizeof(cdp_prep_t) * rrd->stat_head->rra_cnt *
+                      rrd->stat_head->ds_cnt)) {
 
         rrd_set_error("rrd_write cdp_prep to rrd");
-        goto err_free_pdp_new;
+        return -1;
     }
 
-    if (rrd_write(rrd_file, rrd.rra_ptr,
-                  sizeof(rra_ptr_t) * rrd.stat_head->rra_cnt)
-        != (ssize_t) (sizeof(rra_ptr_t) * rrd.stat_head->rra_cnt)) {
+    if (rrd_write(rrd_file, rrd->rra_ptr,
+                  sizeof(rra_ptr_t) * rrd->stat_head->rra_cnt)
+        != (ssize_t) (sizeof(rra_ptr_t) * rrd->stat_head->rra_cnt)) {
         rrd_set_error("rrd_write rra_ptr to rrd");
-        goto err_free_pdp_new;
-    }
-#endif
-
-    /* rrd_flush(rrd_file); */
-
-    /* calling the smoothing code here guarantees at most
-     * one smoothing operation per rrd_update call. Unfortunately,
-     * it is possible with bulk updates, or a long-delayed update
-     * for smoothing to occur off-schedule. This really isn't
-     * critical except during the burning cycles. */
-    if (schedule_smooth) {
-
-        rra_start = rra_begin;
-        for (i = 0; i < rrd.stat_head->rra_cnt; ++i) {
-            if (cf_conv(rrd.rra_def[i].cf_nam) == CF_DEVSEASONAL ||
-                cf_conv(rrd.rra_def[i].cf_nam) == CF_SEASONAL) {
-#ifdef DEBUG
-                fprintf(stderr, "Running smoother for rra %ld\n", i);
-#endif
-                apply_smoother(&rrd, i, rra_start, rrd_file);
-                if (rrd_test_error())
-                    break;
-            }
-            rra_start += rrd.rra_def[i].row_cnt
-                * rrd.stat_head->ds_cnt * sizeof(rrd_value_t);
-        }
+        return -1;
     }
-
-/*    rrd_dontneed(rrd_file,&rrd); */
-    rrd_free(&rrd);
-    rrd_close(rrd_file);
-
-    free(pdp_new);
-    free(tmpl_idx);
-    free(pdp_temp);
-    free(updvals);
-    return (0);
-
-  err_free_pdp_new:
-    free(pdp_new);
-  err_free_tmpl_idx:
-    free(tmpl_idx);
-  err_free_pdp_temp:
-    free(pdp_temp);
-  err_free_updvals:
-    free(updvals);
-  err_close:
-    rrd_close(rrd_file);
-  err_free:
-    rrd_free(&rrd);
-  err_out:
-    return (-1);
+    return 0;
 }
-
-/*
- * get exclusive lock to whole file.
- * lock gets removed when we close the file
- *
- * returns 0 on success
- */
-int LockRRD(
-    int in_file)
-{
-    int       rcstat;
-
-    {
-#if defined(_WIN32) && !defined(__CYGWIN__) && !defined(__CYGWIN32__)
-        struct _stat st;
-
-        if (_fstat(in_file, &st) == 0) {
-            rcstat = _locking(in_file, _LK_NBLCK, st.st_size);
-        } else {
-            rcstat = -1;
-        }
-#else
-        struct flock lock;
-
-        lock.l_type = F_WRLCK;  /* exclusive write lock */
-        lock.l_len = 0; /* whole file */
-        lock.l_start = 0;   /* start of file */
-        lock.l_whence = SEEK_SET;   /* end of file */
-
-        rcstat = fcntl(in_file, F_SETLK, &lock);
 #endif
-    }
-
-    return (rcstat);
-}