timeseries: Add data-structures and helpers to manage timeseries information.

Currently, timeseries information objects provide the names of data sources.

diff --git a/src/core/timeseries.c b/src/core/timeseries.c
index 2c5537dbc5838528ec60b15994c4a029777f1ecd..01854aa5779778f42e4bbdaf45bbad536a4e40d9 100644 (file)
--- a/src/core/timeseries.c
+++ b/src/core/timeseries.c
@@ -1,6 +1,6 @@
 /*
  * SysDB - src/core/timeseries.c
- * Copyright (C) 2014 Sebastian 'tokkee' Harl <sh@tokkee.org>
+ * Copyright (C) 2014-2016 Sebastian 'tokkee' Harl <sh@tokkee.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -36,10 +36,74 @@
 #include <string.h>
 #include <math.h>
 
+static int
+copy_strings(char ***out, size_t *out_len,
+               const char * const *in, size_t in_len)
+{
+       size_t i;
+
+       *out = calloc(in_len, sizeof(**out));
+       if (! *out)
+               return -1;
+
+       *out_len = in_len;
+       for (i = 0; i < in_len; ++i) {
+               (*out)[i] = strdup(in[i]);
+               if (! (*out)[i])
+                       return -1;
+       }
+       return 0;
+} /* copy_strings */
+
+static void
+free_strings(char ***strings, size_t *strings_len)
+{
+       size_t i;
+
+       if (*strings) {
+               for (i = 0; i < *strings_len; ++i) {
+                       if ((*strings)[i])
+                               free((*strings)[i]);
+                       (*strings)[i] = NULL;
+               }
+               free(*strings);
+       }
+
+       *strings = NULL;
+       *strings_len = 0;
+} /* free_strings */
+
 /*
  * public API
  */
 
+sdb_timeseries_info_t *
+sdb_timeseries_info_create(size_t data_names_len, const char * const *data_names)
+{
+       sdb_timeseries_info_t *ts_info;
+
+       ts_info = calloc(1, sizeof(*ts_info));
+       if (! ts_info)
+               return NULL;
+
+       if (copy_strings(&ts_info->data_names, &ts_info->data_names_len,
+                               data_names, data_names_len)) {
+               sdb_timeseries_info_destroy(ts_info);
+               return NULL;
+       }
+       return ts_info;
+} /* sdb_timeseries_info_create */
+
+void
+sdb_timeseries_info_destroy(sdb_timeseries_info_t *ts_info)
+{
+       if (! ts_info)
+               return;
+
+       free_strings(&ts_info->data_names, &ts_info->data_names_len);
+       free(ts_info);
+} /* sdb_timeseries_info_destroy */
+
 sdb_timeseries_t *
 sdb_timeseries_create(size_t data_names_len, const char * const *data_names,
                size_t data_len)
@@ -51,12 +115,17 @@ sdb_timeseries_create(size_t data_names_len, const char * const *data_names,
        if (! ts)
                return NULL;
 
+       if (copy_strings(&ts->data_names, &ts->data_names_len,
+                               data_names, data_names_len)) {
+               sdb_timeseries_destroy(ts);
+               return NULL;
+       }
+
        ts->data = calloc(data_names_len, sizeof(*ts->data));
        if (! ts->data) {
                sdb_timeseries_destroy(ts);
                return NULL;
        }
-       ts->data_names_len = data_names_len;
        for (i = 0; i < data_names_len; ++i) {
                ts->data[i] = calloc(data_len, sizeof(**ts->data));
                if (! ts->data[i]) {
@@ -65,19 +134,6 @@ sdb_timeseries_create(size_t data_names_len, const char * const *data_names,
                }
        }
        ts->data_len = data_len;
-
-       ts->data_names = calloc(data_names_len, sizeof(*ts->data_names));
-       if (! ts->data_names) {
-               sdb_timeseries_destroy(ts);
-               return NULL;
-       }
-       for (i = 0; i < data_names_len; ++i) {
-               ts->data_names[i] = strdup(data_names[i]);
-               if (! ts->data_names[i]) {
-                       sdb_timeseries_destroy(ts);
-                       return NULL;
-               }
-       }
        return ts;
 } /* sdb_timeseries_create */
 
@@ -100,16 +156,7 @@ sdb_timeseries_destroy(sdb_timeseries_t *ts)
        ts->data = NULL;
        ts->data_len = 0;
 
-       if (ts->data_names) {
-               for (i = 0; i < ts->data_names_len; ++i) {
-                       if (ts->data_names[i])
-                               free(ts->data_names[i]);
-                       ts->data_names[i] = NULL;
-               }
-               free(ts->data_names);
-       }
-       ts->data_names = NULL;
-       ts->data_names_len = 0;
+       free_strings(&ts->data_names, &ts->data_names_len);
        free(ts);
 } /* sdb_timeseries_destroy */
 
@@ -166,5 +213,6 @@ sdb_timeseries_tojson(sdb_timeseries_t *ts, sdb_strbuf_t *buf)
        sdb_strbuf_append(buf, "}}");
        return 0;
 } /* sdb_timeseries_tojson */
+
 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 

diff --git a/src/include/core/timeseries.h b/src/include/core/timeseries.h
index b19625d1ca21166e5eb75bcb65571f06c8286051..ce4f0d24c974d89f8e7f6af8fa41ac4c5dac4821 100644 (file)
--- a/src/include/core/timeseries.h
+++ b/src/include/core/timeseries.h
@@ -36,6 +36,33 @@
 extern "C" {
 #endif
 
+/*
+ * sdb_timeseries_info_t:
+ * Information about a timeseries.
+ */
+typedef struct {
+       char **data_names;
+       size_t data_names_len;
+} sdb_timeseries_info_t;
+
+/*
+ * sdb_timeseries_info_create:
+ * Allocate a timeseries information object.
+ *
+ * Returns:
+ *  - a newly allocated timeseries info object on success
+ *  - NULL else
+ */
+sdb_timeseries_info_t *
+sdb_timeseries_info_create(size_t data_names_len, const char * const *data_names);
+
+/*
+ * sdb_timeseries_info_destroy:
+ * Destroy a timeseries info object, freeing all of its memory.
+ */
+void
+sdb_timeseries_info_destroy(sdb_timeseries_info_t *ts_info);
+
 /*
  * A data-point describes a datum at a certain point of time.
  */

diff --git a/t/unit/core/timeseries_test.c b/t/unit/core/timeseries_test.c
index dff1b53a7fb28a5bb32fc6c53d2c71462a44a993..093257d4f8d145ed49f541be0cc5ed2f2ead83c1 100644 (file)
--- a/t/unit/core/timeseries_test.c
+++ b/t/unit/core/timeseries_test.c
@@ -37,6 +37,17 @@
 #define TS "1970-01-01 00:00:00 +0000"
 #define V "0.000000"
 
+START_TEST(timeseries_info)
+{
+       const char * const data_names[] = {"abc", "xyz"};
+       sdb_timeseries_info_t *ts_info = sdb_timeseries_info_create(2, data_names);
+
+       fail_unless(ts_info != NULL,
+                       "sdb_timeseries_info_create(2, {\"abc\", \"xyz\"}) = NULL; expected: <ts_info>");
+       sdb_timeseries_info_destroy(ts_info);
+}
+END_TEST
+
 START_TEST(timeseries)
 {
        const char * const data_names[] = {"abc", "xyz"};
@@ -53,7 +64,7 @@ START_TEST(timeseries)
                "}}";
 
        fail_unless(ts != NULL,
-                       "sdb_timeseries_create(2, {\"abc\", \"xyz\"}, 3) = NULL; expected: <ts>");
+                       "sdb_timeseries_create(2, {\"abc\", \"xyz\"}, 2) = NULL; expected: <ts>");
 
        test = sdb_timeseries_tojson(ts, buf);
        fail_unless(test == 0,
@@ -69,6 +80,7 @@ END_TEST
 TEST_MAIN("core::timeseries")
 {
        TCase *tc = tcase_create("core");
+       tcase_add_test(tc, timeseries_info);
        tcase_add_test(tc, timeseries);
        ADD_TCASE(tc);
 }