dbi plugin: Put the row handling logic in an extra module.

The `utils_db_query' module now handles config parsing and row handling.
This unifies basically all of the <Query> blocks, so that the `dbi' and
`oracle' plugins behave exactly alike. Porting the `postgresql' plugin
should be possible, too, so that all three database plugins are in line.

diff --git a/src/Makefile.am b/src/Makefile.am
index 500b389566d72fe33d599c02002abd9e4207de96..58d7dde99eba1b9cc20ea24b3cc140688ee271da 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -203,7 +203,8 @@ endif
 
 if BUILD_PLUGIN_DBI
 pkglib_LTLIBRARIES += dbi.la
-dbi_la_SOURCES = dbi.c
+dbi_la_SOURCES = dbi.c \
+                utils_db_query.c utils_db_query.h
 dbi_la_CPPFLAGS = $(AM_CPPFLAGS) $(BUILD_WITH_LIBDBI_CPPFLAGS)
 dbi_la_LDFLAGS = -module -avoid-version $(BUILD_WITH_LIBDBI_LDFLAGS)
 dbi_la_LIBADD = $(BUILD_WITH_LIBDBI_LIBS)

diff --git a/src/collectd.conf.in b/src/collectd.conf.in
index 15ae7f7cc4e3a2716b5ae0bbf7d06b7267481d4f..b241c9b6d8700279c552d93da49c363d782d9f7a 100644 (file)
--- a/src/collectd.conf.in
+++ b/src/collectd.conf.in
@@ -140,7 +140,7 @@ FQDNLookup   true
 #                      Type "gauge"
 #                      InstancesFrom "c_key"
 #                      ValuesFrom "c_value"
-#              <Result>
+#              </Result>
 #      </Query>
 #      <Database "customers_db">
 #              Driver "mysql"

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index 67fe3b631415bc654ce4f3614309c69a1ce8b521..9b72b437ffb95cc8e4aa0b31d5ee8d82d5f63f10 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -356,6 +356,7 @@ than those of other plugins. It usually looks something like this:
       Statement "SELECT category, COUNT(*) AS value FROM products WHERE in_stock = 0 GROUP BY category"
       <Result>
         Type "gauge"
+       InstancePrefix "out_of_stock"
         InstancesFrom "category"
         ValuesFrom "value"
       </Result>
@@ -400,6 +401,7 @@ Example:
     Statement "select station, temperature, humidity from environment"
     <Result>
       Type "temperature"
+      # InstancePrefix "foo"
       InstancesFrom "station"
       ValuesFrom "temperature"
     </Result>
@@ -444,6 +446,11 @@ setting below.
 
 There must be exactly one B<Type> option inside each B<Result> block.
 
+=item B<InstancePrefix> I<prefix>
+
+Prepends I<prefix> followed by a dash I<("-")> to the type instance. See
+B<InstancesFrom> on how the rest of the type instance is built.
+
 =item B<InstancesFrom> I<column0> [I<column1> ...]
 
 Specifies the columns whose values will be used to create the "TypeInstance"

diff --git a/src/dbi.c b/src/dbi.c
index 9e4f446fe3b879db4ae30eda492f1c2b021f28e6..ee43602309e55cbc8ec6749fb4fe974021c8e5b8 100644 (file)
--- a/src/dbi.c
+++ b/src/dbi.c
@@ -23,42 +23,21 @@
 #include "common.h"
 #include "plugin.h"
 #include "configfile.h"
+#include "utils_db_query.h"
 
 #include <dbi/dbi.h>
 
 /*
  * Data types
  */
-struct cdbi_driver_option_s
+struct cdbi_driver_option_s /* {{{ */
 {
   char *key;
   char *value;
 };
-typedef struct cdbi_driver_option_s cdbi_driver_option_t;
+typedef struct cdbi_driver_option_s cdbi_driver_option_t; /* }}} */
 
-struct cdbi_result_s;
-typedef struct cdbi_result_s cdbi_result_t;
-struct cdbi_result_s
-{
-  char    *type;
-  char   **instances;
-  size_t   instances_num;
-  char   **values;
-  size_t   values_num;
-
-  cdbi_result_t *next;
-};
-
-struct cdbi_query_s
-{
-  char    *name;
-  char    *statement;
-
-  cdbi_result_t *results;
-};
-typedef struct cdbi_query_s cdbi_query_t;
-
-struct cdbi_database_s
+struct cdbi_database_s /* {{{ */
 {
   char *name;
   char *select_db;
@@ -67,17 +46,17 @@ struct cdbi_database_s
   cdbi_driver_option_t *driver_options;
   size_t driver_options_num;
 
-  cdbi_query_t **queries;
-  size_t      queries_num;
+  udb_query_t **queries;
+  size_t        queries_num;
 
   dbi_conn connection;
 };
-typedef struct cdbi_database_s cdbi_database_t;
+typedef struct cdbi_database_s cdbi_database_t; /* }}} */
 
 /*
  * Global variables
  */
-static cdbi_query_t    **queries       = NULL;
+static udb_query_t     **queries       = NULL;
 static size_t            queries_num   = 0;
 static cdbi_database_t **databases     = NULL;
 static size_t            databases_num = 0;
@@ -109,19 +88,9 @@ static const char *cdbi_strerror (dbi_conn conn, /* {{{ */
 } /* }}} const char *cdbi_conn_error */
 
 static int cdbi_result_get_field (dbi_result res, /* {{{ */
-    const char *name, int dst_type, value_t *ret_value)
+    unsigned int index, char *buffer, size_t buffer_size)
 {
-  value_t value;
-  unsigned int index;
   unsigned short src_type;
-  dbi_conn connection;
-
-  index = dbi_result_get_field_idx (res, name);
-  if (index < 1)
-  {
-    ERROR ("dbi plugin: cdbi_result_get: No such column: %s.", name);
-    return (-1);
-  }
 
   src_type = dbi_result_get_field_type_idx (res, index);
   if (src_type == DBI_TYPE_ERROR)
@@ -131,44 +100,31 @@ static int cdbi_result_get_field (dbi_result res, /* {{{ */
     return (-1);
   }
 
-  if ((dst_type != DS_TYPE_COUNTER) && (dst_type != DS_TYPE_GAUGE))
-  {
-    ERROR ("dbi plugin: cdbi_result_get: Don't know how to handle "
-        "destination type %i.", dst_type);
-    return (-1);
-  }
-
   if (src_type == DBI_TYPE_INTEGER)
   {
-    if (dst_type == DS_TYPE_COUNTER)
-      value.counter = dbi_result_get_ulonglong_idx (res, index);
-    else
-      value.gauge = (gauge_t) dbi_result_get_longlong_idx (res, index);
+    long long value;
+
+    value = dbi_result_get_longlong_idx (res, index);
+    ssnprintf (buffer, buffer_size, "%lli", value);
   }
   else if (src_type == DBI_TYPE_DECIMAL)
   {
-    value.gauge = dbi_result_get_double_idx (res, index);
-    if (dst_type == DS_TYPE_COUNTER)
-      value.counter = (counter_t) round (value.gauge);
+    double value;
+
+    value = dbi_result_get_double_idx (res, index);
+    ssnprintf (buffer, buffer_size, "%63.15g", value);
   }
   else if (src_type == DBI_TYPE_STRING)
   {
-    const char *string = dbi_result_get_string_idx (res, index);
-    char *endptr = NULL;
-
-    if (string == NULL)
-      value.gauge = NAN;
-    else if (dst_type == DS_TYPE_COUNTER)
-      value.counter = (counter_t) strtoll (string, &endptr, 0);
-    else
-      value.gauge = (gauge_t) strtod (string, &endptr);
-
-    if (string == endptr)
-    {
-      ERROR ("dbi plugin: cdbi_result_get: Can't parse string as number: %s.",
-          string);
+    const char *value;
+    
+    value = dbi_result_get_string_idx (res, index);
+    if (value == NULL)
+      sstrncpy (buffer, "", buffer_size);
+    else if (strcmp ("ERROR", value) == 0)
       return (-1);
-    }
+    else
+      sstrncpy (buffer, value, buffer_size);
   }
   else
   {
@@ -177,54 +133,9 @@ static int cdbi_result_get_field (dbi_result res, /* {{{ */
     return (-1);
   }
 
-  connection = dbi_result_get_conn (res);
-  if (dbi_conn_error (connection, NULL) != 0)
-  {
-    char errbuf[1024];
-    ERROR ("dbi plugin: cdbi_result_get: dbi_result_get_*_idx failed: %s.",
-        cdbi_strerror (connection, errbuf, sizeof (errbuf)));
-    return (-1);
-  }
-
-  *ret_value = value;
   return (0);
 } /* }}} int cdbi_result_get_field */
 
-static void cdbi_result_free (cdbi_result_t *r) /* {{{ */
-{
-  size_t i;
-
-  if (r == NULL)
-    return;
-
-  sfree (r->type);
-
-  for (i = 0; i < r->instances_num; i++)
-    sfree (r->instances[i]);
-  sfree (r->instances);
-
-  for (i = 0; i < r->values_num; i++)
-    sfree (r->values[i]);
-  sfree (r->values);
-
-  cdbi_result_free (r->next);
-
-  sfree (r);
-} /* }}} void cdbi_result_free */
-
-static void cdbi_query_free (cdbi_query_t *q) /* {{{ */
-{
-  if (q == NULL)
-    return;
-
-  sfree (q->name);
-  sfree (q->statement);
-
-  cdbi_result_free (q->results);
-
-  sfree (q);
-} /* }}} void cdbi_query_free */
-
 static void cdbi_database_free (cdbi_database_t *db) /* {{{ */
 {
   size_t i;
@@ -245,25 +156,6 @@ static void cdbi_database_free (cdbi_database_t *db) /* {{{ */
   sfree (db);
 } /* }}} void cdbi_database_free */
 
-static void cdbi_submit (cdbi_database_t *db, cdbi_result_t *r, /* {{{ */
-    char **instances, value_t *values)
-{
-  value_list_t vl = VALUE_LIST_INIT;
-
-  vl.values = values;
-  vl.values_len = (int) r->values_num;
-  vl.time = time (NULL);
-  sstrncpy (vl.host, hostname_g, sizeof (vl.host));
-  sstrncpy (vl.plugin, "dbi", sizeof (vl.plugin));
-  sstrncpy (vl.plugin_instance, db->name, sizeof (vl.type_instance));
-  sstrncpy (vl.type, r->type, sizeof (vl.type));
-  strjoin (vl.type_instance, sizeof (vl.type_instance),
-      instances, r->instances_num, "-");
-  vl.type_instance[sizeof (vl.type_instance) - 1] = 0;
-
-  plugin_dispatch_values (&vl);
-} /* }}} void cdbi_submit */
-
 /* Configuration handling functions {{{
  *
  * <Plugin dbi>
@@ -313,253 +205,6 @@ static int cdbi_config_set_string (char **ret_string, /* {{{ */
   return (0);
 } /* }}} int cdbi_config_set_string */
 
-static int cdbi_config_add_string (char ***ret_array, /* {{{ */
-    size_t *ret_array_len, oconfig_item_t *ci)
-{
-  char **array;
-  size_t array_len;
-  int i;
-
-  if (ci->values_num < 1)
-  {
-    WARNING ("dbi plugin: The `%s' config option "
-        "needs at least one argument.", ci->key);
-    return (-1);
-  }
-
-  for (i = 0; i < ci->values_num; i++)
-  {
-    if (ci->values[i].type != OCONFIG_TYPE_STRING)
-    {
-      WARNING ("dbi plugin: Argument %i to the `%s' option "
-          "is not a string.", i + 1, ci->key);
-      return (-1);
-    }
-  }
-
-  array_len = *ret_array_len;
-  array = (char **) realloc (*ret_array,
-      sizeof (char *) * (array_len + ci->values_num));
-  if (array == NULL)
-  {
-    ERROR ("dbi plugin: realloc failed.");
-    return (-1);
-  }
-  *ret_array = array;
-
-  for (i = 0; i < ci->values_num; i++)
-  {
-    array[array_len] = strdup (ci->values[i].value.string);
-    if (array[array_len] == NULL)
-    {
-      ERROR ("dbi plugin: strdup failed.");
-      *ret_array_len = array_len;
-      return (-1);
-    }
-    array_len++;
-  }
-
-  *ret_array_len = array_len;
-  return (0);
-} /* }}} int cdbi_config_add_string */
-
-static int cdbi_config_add_query_result (cdbi_query_t *q, /* {{{ */
-    oconfig_item_t *ci)
-{
-  cdbi_result_t *r;
-  int status;
-  int i;
-
-  if (ci->values_num != 0)
-  {
-    WARNING ("dbi plugin: The `Result' block doesn't accept any arguments. "
-        "Ignoring %i argument%s.",
-        ci->values_num, (ci->values_num == 1) ? "" : "s");
-  }
-
-  r = (cdbi_result_t *) malloc (sizeof (*r));
-  if (r == NULL)
-  {
-    ERROR ("dbi plugin: malloc failed.");
-    return (-1);
-  }
-  memset (r, 0, sizeof (*r));
-  r->type = NULL;
-  r->instances = NULL;
-  r->values = NULL;
-  r->next = NULL;
-
-  /* Fill the `cdbi_result_t' structure.. */
-  for (i = 0; i < ci->children_num; i++)
-  {
-    oconfig_item_t *child = ci->children + i;
-
-    if (strcasecmp ("Type", child->key) == 0)
-      status = cdbi_config_set_string (&r->type, child);
-    else if (strcasecmp ("InstancesFrom", child->key) == 0)
-      status = cdbi_config_add_string (&r->instances, &r->instances_num, child);
-    else if (strcasecmp ("ValuesFrom", child->key) == 0)
-      status = cdbi_config_add_string (&r->values, &r->values_num, child);
-    else
-    {
-      WARNING ("dbi plugin: Option `%s' not allowed here.", child->key);
-      status = -1;
-    }
-
-    if (status != 0)
-      break;
-  }
-
-  /* Check that all necessary options have been given. */
-  while (status == 0)
-  {
-    if (r->type == NULL)
-    {
-      WARNING ("dbi plugin: `Type' not given for "
-          "result in query `%s'", q->name);
-      status = -1;
-    }
-    if (r->instances == NULL)
-    {
-      WARNING ("dbi plugin: `InstancesFrom' not given for "
-          "result in query `%s'", q->name);
-      status = -1;
-    }
-    if (r->values == NULL)
-    {
-      WARNING ("dbi plugin: `ValuesFrom' not given for "
-          "result in query `%s'", q->name);
-      status = -1;
-    }
-
-    break;
-  } /* while (status == 0) */
-
-  /* If all went well, add this result to the list of results within the
-   * query structure. */
-  if (status == 0)
-  {
-    if (q->results == NULL)
-    {
-      q->results = r;
-    }
-    else
-    {
-      cdbi_result_t *last;
-
-      last = q->results;
-      while (last->next != NULL)
-        last = last->next;
-
-      last->next = r;
-    }
-  }
-
-  if (status != 0)
-  {
-    cdbi_result_free (r);
-    return (-1);
-  }
-
-  return (0);
-} /* }}} int cdbi_config_add_query_result */
-
-static int cdbi_config_add_query (oconfig_item_t *ci) /* {{{ */
-{
-  cdbi_query_t *q;
-  int status;
-  int i;
-
-  if ((ci->values_num != 1)
-      || (ci->values[0].type != OCONFIG_TYPE_STRING))
-  {
-    WARNING ("dbi plugin: The `Query' block "
-        "needs exactly one string argument.");
-    return (-1);
-  }
-
-  q = (cdbi_query_t *) malloc (sizeof (*q));
-  if (q == NULL)
-  {
-    ERROR ("dbi plugin: malloc failed.");
-    return (-1);
-  }
-  memset (q, 0, sizeof (*q));
-
-  status = cdbi_config_set_string (&q->name, ci);
-  if (status != 0)
-  {
-    sfree (q);
-    return (status);
-  }
-
-  /* Fill the `cdbi_query_t' structure.. */
-  for (i = 0; i < ci->children_num; i++)
-  {
-    oconfig_item_t *child = ci->children + i;
-
-    if (strcasecmp ("Statement", child->key) == 0)
-      status = cdbi_config_set_string (&q->statement, child);
-    else if (strcasecmp ("Result", child->key) == 0)
-      status = cdbi_config_add_query_result (q, child);
-    else
-    {
-      WARNING ("dbi plugin: Option `%s' not allowed here.", child->key);
-      status = -1;
-    }
-
-    if (status != 0)
-      break;
-  }
-
-  /* Check that all necessary options have been given. */
-  while (status == 0)
-  {
-    if (q->statement == NULL)
-    {
-      WARNING ("dbi plugin: `Statement' not given for query `%s'", q->name);
-      status = -1;
-    }
-    if (q->results == NULL)
-    {
-      WARNING ("dbi plugin: No (valid) `Result' block given for query `%s'",
-          q->name);
-      status = -1;
-    }
-
-    break;
-  } /* while (status == 0) */
-
-  /* If all went well, add this query to the list of queries within the
-   * database structure. */
-  if (status == 0)
-  {
-    cdbi_query_t **temp;
-
-    temp = (cdbi_query_t **) realloc (queries,
-        sizeof (*queries) * (queries_num + 1));
-    if (temp == NULL)
-    {
-      ERROR ("dbi plugin: realloc failed");
-      status = -1;
-    }
-    else
-    {
-      queries = temp;
-      queries[queries_num] = q;
-      queries_num++;
-    }
-  }
-
-  if (status != 0)
-  {
-    cdbi_query_free (q);
-    return (-1);
-  }
-
-  return (0);
-} /* }}} int cdbi_config_add_query */
-
 static int cdbi_config_add_database_driver_option (cdbi_database_t *db, /* {{{ */
     oconfig_item_t *ci)
 {
@@ -604,58 +249,6 @@ static int cdbi_config_add_database_driver_option (cdbi_database_t *db, /* {{{ *
   return (0);
 } /* }}} int cdbi_config_add_database_driver_option */
 
-static int cdbi_config_add_database_query (cdbi_database_t *db, /* {{{ */
-    oconfig_item_t *ci)
-{
-  cdbi_query_t *q;
-  cdbi_query_t **temp;
-  size_t i;
-
-  if ((ci->values_num != 1)
-      || (ci->values[0].type != OCONFIG_TYPE_STRING))
-  {
-    WARNING ("dbi plugin: The `Query' config option "
-        "needs exactly one string argument.");
-    return (-1);
-  }
-
-  q = NULL;
-  for (i = 0; i < queries_num; i++)
-  {
-    if (strcasecmp (queries[i]->name, ci->values[0].value.string) == 0)
-    {
-      q = queries[i];
-      break;
-    }
-  }
-
-  if (q == NULL)
-  {
-    WARNING ("dbi plugin: Database `%s': Unknown query `%s'. "
-        "Please make sure that the <Query \"%s\"> block comes before "
-        "the <Database \"%s\"> block.",
-        db->name, ci->values[0].value.string,
-        ci->values[0].value.string, db->name);
-    return (-1);
-  }
-
-  temp = (cdbi_query_t **) realloc (db->queries,
-      sizeof (*db->queries) * (db->queries_num + 1));
-  if (temp == NULL)
-  {
-    ERROR ("dbi plugin: realloc failed");
-    return (-1);
-  }
-  else
-  {
-    db->queries = temp;
-    db->queries[db->queries_num] = q;
-    db->queries_num++;
-  }
-
-  return (0);
-} /* }}} int cdbi_config_add_database_query */
-
 static int cdbi_config_add_database (oconfig_item_t *ci) /* {{{ */
 {
   cdbi_database_t *db;
@@ -697,7 +290,8 @@ static int cdbi_config_add_database (oconfig_item_t *ci) /* {{{ */
     else if (strcasecmp ("SelectDB", child->key) == 0)
       status = cdbi_config_set_string (&db->select_db, child);
     else if (strcasecmp ("Query", child->key) == 0)
-      status = cdbi_config_add_database_query (db, child);
+      status = udb_query_pick_from_list (child, queries, queries_num,
+          &db->queries, &db->queries_num);
     else
     {
       WARNING ("dbi plugin: Option `%s' not allowed here.", child->key);
@@ -762,7 +356,7 @@ static int cdbi_config (oconfig_item_t *ci) /* {{{ */
   {
     oconfig_item_t *child = ci->children + i;
     if (strcasecmp ("Query", child->key) == 0)
-      cdbi_config_add_query (child);
+      udb_query_create (&queries, &queries_num, child);
     else if (strcasecmp ("Database", child->key) == 0)
       cdbi_config_add_database (child);
     else
@@ -818,176 +412,167 @@ static int cdbi_init (void) /* {{{ */
 } /* }}} int cdbi_init */
 
 static int cdbi_read_database_query (cdbi_database_t *db, /* {{{ */
-    cdbi_query_t *q)
+    udb_query_t *q)
 {
+  const char *statement;
   dbi_result res;
+  size_t column_num;
+  char **column_names;
+  char **column_values;
   int status;
+  size_t i;
 
   /* Macro that cleans up dynamically allocated memory and returns the
    * specified status. */
 #define BAIL_OUT(status) \
+  if (column_names != NULL) { sfree (column_names[0]); sfree (column_names); } \
+  if (column_values != NULL) { sfree (column_values[0]); sfree (column_values); } \
   if (res != NULL) { dbi_result_free (res); res = NULL; } \
   return (status)
 
-  res = dbi_conn_query (db->connection, q->statement);
+  column_names = NULL;
+  column_values = NULL;
+  res = NULL;
+
+  statement = udb_query_get_statement (q);
+  assert (statement != NULL);
+
+  res = dbi_conn_query (db->connection, statement);
   if (res == NULL)
   {
     char errbuf[1024];
     ERROR ("dbi plugin: cdbi_read_database_query (%s, %s): "
         "dbi_conn_query failed: %s",
-        db->name, q->name,
+        db->name, udb_query_get_name (q),
         cdbi_strerror (db->connection, errbuf, sizeof (errbuf)));
     BAIL_OUT (-1);
   }
+  else /* Get the number of columns */
+  {
+    unsigned int db_status;
+
+    db_status = dbi_result_get_numfields (res);
+    if (db_status == DBI_FIELD_ERROR)
+    {
+      char errbuf[1024];
+      ERROR ("dbi plugin: cdbi_read_database_query (%s, %s): "
+          "dbi_result_get_numfields failed: %s",
+          db->name, udb_query_get_name (q),
+          cdbi_strerror (db->connection, errbuf, sizeof (errbuf)));
+      BAIL_OUT (-1);
+    }
+
+    column_num = (size_t) db_status;
+    DEBUG ("cdbi_read_database_query (%s, %s): There are %zu columns.",
+        db->name, udb_query_get_name (q), column_num);
+  }
+
+  /* Allocate `column_names' and `column_values'. {{{ */
+  column_names = (char **) calloc (column_num, sizeof (char *));
+  if (column_names == NULL)
+  {
+    ERROR ("dbi plugin: malloc failed.");
+    BAIL_OUT (-1);
+  }
+
+  column_names[0] = (char *) calloc (column_num,
+      DATA_MAX_NAME_LEN * sizeof (char));
+  if (column_names[0] == NULL)
+  {
+    ERROR ("dbi plugin: malloc failed.");
+    BAIL_OUT (-1);
+  }
+  for (i = 1; i < column_num; i++)
+    column_names[i] = column_names[i - 1] + DATA_MAX_NAME_LEN;
+
+  column_values = (char **) calloc (column_num, sizeof (char *));
+  if (column_values == NULL)
+  {
+    ERROR ("dbi plugin: malloc failed.");
+    BAIL_OUT (-1);
+  }
+
+  column_values[0] = (char *) calloc (column_num,
+      DATA_MAX_NAME_LEN * sizeof (char));
+  if (column_values[0] == NULL)
+  {
+    ERROR ("dbi plugin: malloc failed.");
+    BAIL_OUT (-1);
+  }
+  for (i = 1; i < column_num; i++)
+    column_values[i] = column_values[i - 1] + DATA_MAX_NAME_LEN;
+  /* }}} */
+
+  /* Copy the field names to `column_names' */
+  for (i = 0; i < column_num; i++) /* {{{ */
+  {
+    const char *column_name;
+
+    column_name = dbi_result_get_field_name (res, (unsigned int) (i + 1));
+    if (column_name == NULL)
+    {
+      ERROR ("dbi plugin: cdbi_read_database_query (%s, %s): "
+          "Cannot retrieve name of field %zu.",
+          db->name, udb_query_get_name (q), i + 1);
+      BAIL_OUT (-1);
+    }
+
+    sstrncpy (column_names[i], column_name, DATA_MAX_NAME_LEN);
+  } /* }}} for (i = 0; i < column_num; i++) */
+
+  udb_query_prepare_result (q, hostname_g, /* plugin = */ "dbi", db->name,
+      column_names, column_num);
 
   /* 0 = error; 1 = success; */
-  status = dbi_result_first_row (res);
+  status = dbi_result_first_row (res); /* {{{ */
   if (status != 1)
   {
     char errbuf[1024];
     ERROR ("dbi plugin: cdbi_read_database_query (%s, %s): "
         "dbi_result_first_row failed: %s. Maybe the statement didn't "
         "return any rows?",
-        db->name, q->name, 
+        db->name, udb_query_get_name (q),
         cdbi_strerror (db->connection, errbuf, sizeof (errbuf)));
+    udb_query_finish_result (q);
     BAIL_OUT (-1);
-  }
+  } /* }}} */
 
-  /* Iterate over all rows and use every result with each row. */
+  /* Iterate over all rows and call `udb_query_handle_result' with each list of
+   * values. */
   while (42) /* {{{ */
   {
-    cdbi_result_t *r;
-
-    /* Iterate over all results, get the appropriate data_set, allocate memory
-     * for the instance(s) and value(s), copy the values and finally call
-     * `cdbi_submit' to create and dispatch a value_list. */
-    for (r = q->results; r != NULL; r = r->next) /* {{{ */
+    status = 0;
+    /* Copy the value of the columns to `column_values' */
+    for (i = 0; i < column_num; i++) /* {{{ */
     {
-      const data_set_t *ds;
-      char **instances;
-      value_t *values;
-      size_t i;
-
-      instances = NULL;
-      values = NULL;
-
-      /* Macro to clean up dynamically allocated memory and continue with the
-       * next iteration of the containing loop, i. e. the `for' loop iterating
-       * over all `Result' sets. */
-#define BAIL_OUT_CONTINUE \
-      if (instances != NULL) { sfree (instances[0]); sfree (instances); } \
-      sfree (values); \
-      continue
-
-      /* Read `ds' and check number of values {{{ */
-      ds = plugin_get_ds (r->type);
-      if (ds == NULL)
-      {
-        ERROR ("dbi plugin: cdbi_read_database_query: Query `%s': Type `%s' is not "
-            "known by the daemon. See types.db(5) for details.",
-            q->name, r->type);
-        BAIL_OUT_CONTINUE;
-      }
-
-      if (((size_t) ds->ds_num) != r->values_num)
-      {
-        ERROR ("dbi plugin: cdbi_read_database_query: Query `%s': The type `%s' "
-            "requires exactly %i value%s, but the configuration specifies %zu.",
-            q->name, r->type,
-            ds->ds_num, (ds->ds_num == 1) ? "" : "s",
-            r->values_num);
-        BAIL_OUT_CONTINUE;
-      }
-      /* }}} */
-
-      /* Allocate `instances' and `values' {{{ */
-      instances = (char **) malloc (sizeof (*instances) * r->instances_num);
-      if (instances == NULL)
-      {
-        ERROR ("dbi plugin: malloc failed.");
-        BAIL_OUT_CONTINUE;
-      }
-
-      instances[0] = (char *) malloc (r->instances_num * DATA_MAX_NAME_LEN);
-      if (instances[0] == NULL)
-      {
-        ERROR ("dbi plugin: malloc failed.");
-        BAIL_OUT_CONTINUE;
-      }
-      for (i = 1; i < r->instances_num; i++)
-        instances[i] = instances[i - 1] + DATA_MAX_NAME_LEN;
-
-      values = (value_t *) malloc (sizeof (*values) * r->values_num);
-      if (values == NULL)
-      {
-        ERROR ("dbi plugin: malloc failed.");
-        BAIL_OUT_CONTINUE;
-      }
-      /* }}} */
-
-      /* Get instance names and values from the result: */
-      for (i = 0; i < r->instances_num; i++) /* {{{ */
-      {
-        const char *inst;
-
-        inst = dbi_result_get_string (res, r->instances[i]);
-        if (dbi_conn_error (db->connection, NULL) != 0)
-        {
-          char errbuf[1024];
-          ERROR ("dbi plugin: cdbi_read_database_query (%s, %s): "
-              "dbi_result_get_string (%s) failed: %s",
-              db->name, q->name, r->instances[i],
-              cdbi_strerror (db->connection, errbuf, sizeof (errbuf)));
-          status = -1;
-          break;
-        }
-
-        sstrncpy (instances[i], (inst == NULL) ? "" : inst, DATA_MAX_NAME_LEN);
-        DEBUG ("dbi plugin: cdbi_read_database_query (%s, %s): "
-            "instances[%zu] = %s;",
-            db->name, q->name, i, instances[i]);
-      } /* }}} for (i = 0; i < q->instances_num; i++) */
+      status = cdbi_result_get_field (res, (unsigned int) (i + 1),
+          column_values[i], DATA_MAX_NAME_LEN);
 
       if (status != 0)
       {
-        BAIL_OUT_CONTINUE;
+        ERROR ("dbi plugin: cdbi_read_database_query (%s, %s): "
+            "cdbi_result_get_field (%zu) failed.",
+            db->name, udb_query_get_name (q), i + 1);
+        status = -1;
+        break;
       }
+    } /* }}} for (i = 0; i < column_num; i++) */
 
-      for (i = 0; i < r->values_num; i++) /* {{{ */
-      {
-        status = cdbi_result_get_field (res, r->values[i], ds->ds[i].type,
-            values + i);
-        if (status != 0)
-        {
-          break;
-        }
-
-        if (ds->ds[i].type == DS_TYPE_COUNTER)
-        {
-          DEBUG ("dbi plugin: cdbi_read_database_query (%s, %s): values[%zu] = %llu;",
-              db->name, q->name, i, values[i].counter);
-        }
-        else
-        {
-          DEBUG ("dbi plugin: cdbi_read_database_query (%s, %s): values[%zu] = %g;",
-              db->name, q->name, i, values[i].gauge);
-        }
-      } /* }}} for (i = 0; i < q->values_num; i++) */
-
+    /* If all values were copied successfully, call `udb_query_handle_result'
+     * to dispatch the row to the daemon. */
+    if (status == 0) /* {{{ */
+    {
+      status = udb_query_handle_result (q, column_values);
       if (status != 0)
       {
-        BAIL_OUT_CONTINUE;
+        ERROR ("dbi plugin: cdbi_read_database_query (%s, %s): "
+            "udb_query_handle_result failed.",
+            db->name, udb_query_get_name (q));
       }
-
-      /* Dispatch this row to the daemon. */
-      cdbi_submit (db, r, instances, values);
-
-      BAIL_OUT_CONTINUE;
-#undef BAIL_OUT_CONTINUE
-    } /* }}} for (r = q->results; r != NULL; r = r->next) */
+    } /* }}} */
 
     /* Get the next row from the database. */
-    status = dbi_result_next_row (res);
+    status = dbi_result_next_row (res); /* {{{ */
     if (status != 1)
     {
       if (dbi_conn_error (db->connection, NULL) != 0)
@@ -995,13 +580,16 @@ static int cdbi_read_database_query (cdbi_database_t *db, /* {{{ */
         char errbuf[1024];
         WARNING ("dbi plugin: cdbi_read_database_query (%s, %s): "
             "dbi_result_next_row failed: %s.",
-            db->name, q->name,
+            db->name, udb_query_get_name (q),
             cdbi_strerror (db->connection, errbuf, sizeof (errbuf)));
       }
       break;
-    }
+    } /* }}} */
   } /* }}} while (42) */
 
+  /* Tell the db query interface that we're done with this query. */
+  udb_query_finish_result (q);
+
   /* Clean up and return `status = 0' (success) */
   BAIL_OUT (0);
 #undef BAIL_OUT
@@ -1185,9 +773,8 @@ static int cdbi_shutdown (void) /* {{{ */
   sfree (databases);
   databases_num = 0;
 
-  for (i = 0; i < queries_num; i++)
-    cdbi_query_free (queries[i]);
-  sfree (queries);
+  udb_query_free (queries, queries_num);
+  queries = NULL;
   queries_num = 0;
 
   return (0);

diff --git a/src/utils_db_query.c b/src/utils_db_query.c
new file mode 100644 (file)
index 0000000..87f36d2
--- /dev/null
+++ b/src/utils_db_query.c
@@ -0,0 +1,845 @@
+/**
+ * collectd - src/utils_db_query.c
+ * Copyright (C) 2008,2009  Florian octo Forster
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * Authors:
+ *   Florian octo Forster <octo at verplant.org>
+ **/
+
+#include "collectd.h"
+#include "common.h"
+#include "plugin.h"
+#include "configfile.h"
+#include "utils_db_query.h"
+
+/*
+ * Data types
+ */
+struct udb_result_s; /* {{{ */
+typedef struct udb_result_s udb_result_t;
+struct udb_result_s
+{
+  char    *type;
+  char    *instance_prefix;
+  char   **instances;
+  size_t   instances_num;
+  char   **values;
+  size_t   values_num;
+
+  /* Preparation area */
+  const   data_set_t *ds;
+  size_t *instances_pos;
+  size_t *values_pos;
+  char  **instances_buffer;
+  char  **values_buffer;
+
+  udb_result_t *next;
+}; /* }}} */
+
+struct udb_query_s /* {{{ */
+{
+  char *name;
+  char *statement;
+  void *user_data;
+
+  /* Preparation area */
+  size_t column_num;
+  char *host;
+  char *plugin;
+  char *db_name;
+
+  udb_result_t *results;
+}; /* }}} */
+
+/*
+ * Config Private functions
+ */
+static int udb_config_set_string (char **ret_string, /* {{{ */
+    oconfig_item_t *ci)
+{
+  char *string;
+
+  if ((ci->values_num != 1)
+      || (ci->values[0].type != OCONFIG_TYPE_STRING))
+  {
+    WARNING ("db query utils: The `%s' config option "
+        "needs exactly one string argument.", ci->key);
+    return (-1);
+  }
+
+  string = strdup (ci->values[0].value.string);
+  if (string == NULL)
+  {
+    ERROR ("db query utils: strdup failed.");
+    return (-1);
+  }
+
+  if (*ret_string != NULL)
+    free (*ret_string);
+  *ret_string = string;
+
+  return (0);
+} /* }}} int udb_config_set_string */
+
+static int udb_config_add_string (char ***ret_array, /* {{{ */
+    size_t *ret_array_len, oconfig_item_t *ci)
+{
+  char **array;
+  size_t array_len;
+  int i;
+
+  if (ci->values_num < 1)
+  {
+    WARNING ("db query utils: The `%s' config option "
+        "needs at least one argument.", ci->key);
+    return (-1);
+  }
+
+  for (i = 0; i < ci->values_num; i++)
+  {
+    if (ci->values[i].type != OCONFIG_TYPE_STRING)
+    {
+      WARNING ("db query utils: Argument %i to the `%s' option "
+          "is not a string.", i + 1, ci->key);
+      return (-1);
+    }
+  }
+
+  array_len = *ret_array_len;
+  array = (char **) realloc (*ret_array,
+      sizeof (char *) * (array_len + ci->values_num));
+  if (array == NULL)
+  {
+    ERROR ("db query utils: realloc failed.");
+    return (-1);
+  }
+  *ret_array = array;
+
+  for (i = 0; i < ci->values_num; i++)
+  {
+    array[array_len] = strdup (ci->values[i].value.string);
+    if (array[array_len] == NULL)
+    {
+      ERROR ("db query utils: strdup failed.");
+      *ret_array_len = array_len;
+      return (-1);
+    }
+    array_len++;
+  }
+
+  *ret_array_len = array_len;
+  return (0);
+} /* }}} int udb_config_add_string */
+
+/*
+ * Result private functions
+ */
+static void udb_result_submit (udb_result_t *r, udb_query_t *q) /* {{{ */
+{
+  value_list_t vl = VALUE_LIST_INIT;
+  size_t i;
+
+  assert (((size_t) r->ds->ds_num) == r->values_num);
+
+  DEBUG ("db query utils: udb_result_submit: r->instance_prefix = %s;",
+      (r->instance_prefix == NULL) ? "NULL" : r->instance_prefix);
+  for (i = 0; i < r->instances_num; i++)
+  {
+    DEBUG ("db query utils: udb_result_submit: r->instances_buffer[%zu] = %s;",
+        i, r->instances_buffer[i]);
+  }
+
+  vl.values = (value_t *) calloc (r->ds->ds_num, sizeof (value_t));
+  if (vl.values == NULL)
+  {
+    ERROR ("db query utils: malloc failed.");
+    return;
+  }
+  vl.values_len = r->ds->ds_num;
+
+  for (i = 0; i < r->values_num; i++)
+  {
+    char *endptr;
+
+    endptr = NULL;
+    errno = 0;
+    if (r->ds->ds[i].type == DS_TYPE_COUNTER)
+      vl.values[i].counter = (counter_t) strtoll (r->values_buffer[i],
+          &endptr, /* base = */ 0);
+    else if (r->ds->ds[i].type == DS_TYPE_GAUGE)
+      vl.values[i].gauge = (gauge_t) strtod (r->values_buffer[i], &endptr);
+    else
+      errno = EINVAL;
+
+    if ((endptr == r->values_buffer[i]) || (errno != 0))
+    {
+      WARNING ("db query utils: udb_result_submit: Parsing `%s' as %s failed.",
+          r->values_buffer[i],
+          (r->ds->ds[i].type == DS_TYPE_COUNTER) ? "counter" : "gauge");
+      vl.values[i].gauge = NAN;
+    }
+  }
+
+  vl.time = time (NULL);
+  sstrncpy (vl.host, q->host, sizeof (vl.host));
+  sstrncpy (vl.plugin, q->plugin, sizeof (vl.plugin));
+  sstrncpy (vl.plugin_instance, q->db_name, sizeof (vl.type_instance));
+  sstrncpy (vl.type, r->type, sizeof (vl.type));
+
+  if (r->instance_prefix == NULL)
+  {
+    strjoin (vl.type_instance, sizeof (vl.type_instance),
+        r->instances_buffer, r->instances_num, "-");
+  }
+  else
+  {
+    char tmp[DATA_MAX_NAME_LEN];
+
+    strjoin (tmp, sizeof (tmp), r->instances_buffer, r->instances_num, "-");
+    tmp[sizeof (tmp) - 1] = 0;
+
+    snprintf (vl.type_instance, sizeof (vl.type_instance), "%s-%s",
+        r->instance_prefix, tmp);
+  }
+  vl.type_instance[sizeof (vl.type_instance) - 1] = 0;
+
+  plugin_dispatch_values (&vl);
+
+  sfree (vl.values);
+} /* }}} void udb_result_submit */
+
+static void udb_result_finish_result (udb_result_t *r) /* {{{ */
+{
+  if (r == NULL)
+    return;
+
+  r->ds = NULL;
+  sfree (r->instances_pos);
+  sfree (r->values_pos);
+  sfree (r->instances_buffer);
+  sfree (r->values_buffer);
+} /* }}} void udb_result_finish_result */
+
+static int udb_result_handle_result (udb_result_t *r, /* {{{ */
+    udb_query_t *q, char **column_values)
+{
+  size_t i;
+
+  for (i = 0; i < r->instances_num; i++)
+    r->instances_buffer[i] = column_values[r->instances_pos[i]];
+
+  for (i = 0; i < r->values_num; i++)
+    r->values_buffer[i] = column_values[r->values_pos[i]];
+
+  udb_result_submit (r, q);
+
+  return (0);
+} /* }}} int udb_result_handle_result */
+
+static int udb_result_prepare_result (udb_result_t *r, /* {{{ */
+    char **column_names, size_t column_num)
+{
+  size_t i;
+
+  if (r == NULL)
+    return (-EINVAL);
+
+#define BAIL_OUT(status) \
+  r->ds = NULL; \
+  sfree (r->instances_pos); \
+  sfree (r->values_pos); \
+  sfree (r->instances_buffer); \
+  sfree (r->values_buffer); \
+  return (status)
+
+  /* Make sure previous preparations are cleaned up. */
+  udb_result_finish_result (r);
+  r->instances_pos = NULL;
+  r->values_pos = NULL;
+
+  /* Read `ds' and check number of values {{{ */
+  r->ds = plugin_get_ds (r->type);
+  if (r->ds == NULL)
+  {
+    ERROR ("db query utils: udb_result_prepare_result: Type `%s' is not "
+        "known by the daemon. See types.db(5) for details.",
+        r->type);
+    BAIL_OUT (-1);
+  }
+
+  if (((size_t) r->ds->ds_num) != r->values_num)
+  {
+    ERROR ("db query utils: udb_result_prepare_result: The type `%s' "
+        "requires exactly %i value%s, but the configuration specifies %zu.",
+        r->type,
+        r->ds->ds_num, (r->ds->ds_num == 1) ? "" : "s",
+        r->values_num);
+    BAIL_OUT (-1);
+  }
+  /* }}} */
+
+  /* Allocate r->instances_pos, r->values_pos, r->instances_buffer, and
+   * r->values_buffer {{{ */
+  r->instances_pos = (size_t *) calloc (r->instances_num, sizeof (size_t));
+  if (r->instances_pos == NULL)
+  {
+    ERROR ("db query utils: udb_result_prepare_result: malloc failed.");
+    BAIL_OUT (-ENOMEM);
+  }
+
+  r->values_pos = (size_t *) calloc (r->values_num, sizeof (size_t));
+  if (r->values_pos == NULL)
+  {
+    ERROR ("db query utils: udb_result_prepare_result: malloc failed.");
+    BAIL_OUT (-ENOMEM);
+  }
+
+  r->instances_buffer = (char **) calloc (r->instances_num, sizeof (char *));
+  if (r->instances_buffer == NULL)
+  {
+    ERROR ("db query utils: udb_result_prepare_result: malloc failed.");
+    BAIL_OUT (-ENOMEM);
+  }
+
+  r->values_buffer = (char **) calloc (r->values_num, sizeof (char *));
+  if (r->values_buffer == NULL)
+  {
+    ERROR ("db query utils: udb_result_prepare_result: malloc failed.");
+    BAIL_OUT (-ENOMEM);
+  }
+  /* }}} */
+
+  /* Determine the position of the instance columns {{{ */
+  for (i = 0; i < r->instances_num; i++)
+  {
+    size_t j;
+
+    for (j = 0; j < column_num; j++)
+    {
+      if (strcasecmp (r->instances[i], column_names[j]) == 0)
+      {
+        r->instances_pos[i] = j;
+        break;
+      }
+    }
+
+    if (j >= column_num)
+    {
+      ERROR ("db query utils: udb_result_prepare_result: "
+          "Column `%s' could not be found.",
+          r->instances[i]);
+      BAIL_OUT (-ENOENT);
+    }
+  } /* }}} for (i = 0; i < r->instances_num; i++) */
+
+  /* Determine the position of the value columns {{{ */
+  for (i = 0; i < r->values_num; i++)
+  {
+    size_t j;
+
+    for (j = 0; j < column_num; j++)
+    {
+      if (strcasecmp (r->values[i], column_names[j]) == 0)
+      {
+        r->values_pos[i] = j;
+        break;
+      }
+    }
+
+    if (j >= column_num)
+    {
+      ERROR ("db query utils: udb_result_prepare_result: "
+          "Column `%s' could not be found.",
+          r->values[i]);
+      BAIL_OUT (-ENOENT);
+    }
+  } /* }}} for (i = 0; i < r->values_num; i++) */
+
+#undef BAIL_OUT
+  return (0);
+} /* }}} int udb_result_prepare_result */
+
+static void udb_result_free (udb_result_t *r) /* {{{ */
+{
+  size_t i;
+
+  if (r == NULL)
+    return;
+
+  sfree (r->type);
+
+  for (i = 0; i < r->instances_num; i++)
+    sfree (r->instances[i]);
+  sfree (r->instances);
+
+  for (i = 0; i < r->values_num; i++)
+    sfree (r->values[i]);
+  sfree (r->values);
+
+  udb_result_free (r->next);
+
+  sfree (r);
+} /* }}} void udb_result_free */
+
+static int udb_result_create (const char *query_name, /* {{{ */
+    udb_result_t **r_head, oconfig_item_t *ci)
+{
+  udb_result_t *r;
+  int status;
+  int i;
+
+  if (ci->values_num != 0)
+  {
+    WARNING ("db query utils: The `Result' block doesn't accept "
+        "any arguments. Ignoring %i argument%s.",
+        ci->values_num, (ci->values_num == 1) ? "" : "s");
+  }
+
+  r = (udb_result_t *) malloc (sizeof (*r));
+  if (r == NULL)
+  {
+    ERROR ("db query utils: malloc failed.");
+    return (-1);
+  }
+  memset (r, 0, sizeof (*r));
+  r->type = NULL;
+  r->instance_prefix = NULL;
+  r->instances = NULL;
+  r->values = NULL;
+  r->next = NULL;
+
+  /* Fill the `udb_result_t' structure.. */
+  status = 0;
+  for (i = 0; i < ci->children_num; i++)
+  {
+    oconfig_item_t *child = ci->children + i;
+
+    if (strcasecmp ("Type", child->key) == 0)
+      status = udb_config_set_string (&r->type, child);
+    else if (strcasecmp ("InstancePrefix", child->key) == 0)
+      status = udb_config_set_string (&r->instance_prefix, child);
+    else if (strcasecmp ("InstancesFrom", child->key) == 0)
+      status = udb_config_add_string (&r->instances, &r->instances_num, child);
+    else if (strcasecmp ("ValuesFrom", child->key) == 0)
+      status = udb_config_add_string (&r->values, &r->values_num, child);
+    else
+    {
+      WARNING ("db query utils: Query `%s': Option `%s' not allowed here.",
+          query_name, child->key);
+      status = -1;
+    }
+
+    if (status != 0)
+      break;
+  }
+
+  /* Check that all necessary options have been given. */
+  while (status == 0)
+  {
+    if (r->type == NULL)
+    {
+      WARNING ("db query utils: `Type' not given for "
+          "result in query `%s'", query_name);
+      status = -1;
+    }
+    if (r->instances == NULL)
+    {
+      WARNING ("db query utils: `InstancesFrom' not given for "
+          "result in query `%s'", query_name);
+      status = -1;
+    }
+    if (r->values == NULL)
+    {
+      WARNING ("db query utils: `ValuesFrom' not given for "
+          "result in query `%s'", query_name);
+      status = -1;
+    }
+
+    break;
+  } /* while (status == 0) */
+
+  if (status != 0)
+  {
+    udb_result_free (r);
+    return (-1);
+  }
+
+  /* If all went well, add this result to the list of results. */
+  if (*r_head == NULL)
+  {
+    *r_head = r;
+  }
+  else
+  {
+    udb_result_t *last;
+
+    last = *r_head;
+    while (last->next != NULL)
+      last = last->next;
+
+    last->next = r;
+  }
+
+  return (0);
+} /* }}} int udb_result_create */
+
+/*
+ * Query private functions
+ */
+void udb_query_free_one (udb_query_t *q) /* {{{ */
+{
+  if (q == NULL)
+    return;
+
+  sfree (q->name);
+  sfree (q->statement);
+
+  udb_result_free (q->results);
+
+  sfree (q);
+} /* }}} void udb_query_free_one */
+
+/*
+ * Query public functions
+ */
+int udb_query_create (udb_query_t ***ret_query_list, /* {{{ */
+    size_t *ret_query_list_len, oconfig_item_t *ci)
+{
+  udb_query_t **query_list;
+  size_t        query_list_len;
+
+  udb_query_t *q;
+  int status;
+  int i;
+
+  if ((ret_query_list == NULL) || (ret_query_list_len == NULL))
+    return (-EINVAL);
+  query_list     = *ret_query_list;
+  query_list_len = *ret_query_list_len;
+
+  if ((ci->values_num != 1)
+      || (ci->values[0].type != OCONFIG_TYPE_STRING))
+  {
+    WARNING ("db query utils: The `Query' block "
+        "needs exactly one string argument.");
+    return (-1);
+  }
+
+  q = (udb_query_t *) malloc (sizeof (*q));
+  if (q == NULL)
+  {
+    ERROR ("db query utils: malloc failed.");
+    return (-1);
+  }
+  memset (q, 0, sizeof (*q));
+
+  status = udb_config_set_string (&q->name, ci);
+  if (status != 0)
+  {
+    sfree (q);
+    return (status);
+  }
+
+  /* Fill the `udb_query_t' structure.. */
+  for (i = 0; i < ci->children_num; i++)
+  {
+    oconfig_item_t *child = ci->children + i;
+
+    if (strcasecmp ("Statement", child->key) == 0)
+      status = udb_config_set_string (&q->statement, child);
+    else if (strcasecmp ("Result", child->key) == 0)
+      status = udb_result_create (q->name, &q->results, child);
+    else
+    {
+      WARNING ("db query utils: Query `%s': Option `%s' not allowed here.",
+          q->name, child->key);
+      status = -1;
+    }
+
+    if (status != 0)
+      break;
+  }
+
+  /* Check that all necessary options have been given. */
+  if (status == 0)
+  {
+    if (q->statement == NULL)
+    {
+      WARNING ("db query utils: Query `%s': No `Statement' given.", q->name);
+      status = -1;
+    }
+    if (q->results == NULL)
+    {
+      WARNING ("db query utils: Query `%s': No (valid) `Result' block given.",
+          q->name);
+      status = -1;
+    }
+  } /* if (status == 0) */
+
+  /* If all went well, add this query to the list of queries within the
+   * database structure. */
+  if (status == 0)
+  {
+    udb_query_t **temp;
+
+    temp = (udb_query_t **) realloc (query_list,
+        sizeof (*query_list) * (query_list_len + 1));
+    if (temp == NULL)
+    {
+      ERROR ("db query utils: realloc failed");
+      status = -1;
+    }
+    else
+    {
+      query_list = temp;
+      query_list[query_list_len] = q;
+      query_list_len++;
+    }
+  }
+
+  if (status != 0)
+  {
+    udb_query_free_one (q);
+    return (-1);
+  }
+
+  *ret_query_list     = query_list;
+  *ret_query_list_len = query_list_len;
+
+  return (0);
+} /* }}} int udb_query_create */
+
+void udb_query_free (udb_query_t **query_list, size_t query_list_len) /* {{{ */
+{
+  size_t i;
+
+  if (query_list == NULL)
+    return;
+
+  for (i = 0; i < query_list_len; i++)
+    udb_query_free_one (query_list[i]);
+
+  sfree (query_list);
+} /* }}} void udb_query_free */
+
+int udb_query_pick_from_list (oconfig_item_t *ci, /* {{{ */
+    udb_query_t **src_list, size_t src_list_len,
+    udb_query_t ***dst_list, size_t *dst_list_len)
+{
+  const char *name;
+  udb_query_t *q;
+  udb_query_t **tmp_list;
+  size_t tmp_list_len;
+  size_t i;
+
+  if ((ci == NULL) || (src_list == NULL) || (dst_list == NULL)
+      || (dst_list_len == NULL))
+  {
+    ERROR ("db query utils: Invalid argument.");
+    return (-EINVAL);
+  }
+
+  if ((ci->values_num != 1)
+      || (ci->values[0].type != OCONFIG_TYPE_STRING))
+  {
+    ERROR ("db query utils: The `%s' config option "
+        "needs exactly one string argument.", ci->key);
+    return (-1);
+  }
+  name = ci->values[0].value.string;
+
+  q = NULL;
+  for (i = 0; i < src_list_len; i++)
+    if (strcasecmp (name, src_list[i]->name) == 0)
+    {
+      q = src_list[i];
+      break;
+    }
+
+  if (q == NULL)
+  {
+    ERROR ("db query utils: Cannot find query `%s'. Make sure the <%s> "
+        "block is above the database definition!",
+        name, ci->key);
+    return (-ENOENT);
+  }
+
+  tmp_list_len = *dst_list_len;
+  tmp_list = (udb_query_t **) realloc (*dst_list, (tmp_list_len + 1)
+      * sizeof (udb_query_t *));
+  if (tmp_list == NULL)
+  {
+    ERROR ("db query utils: realloc failed.");
+    return (-ENOMEM);
+  }
+  tmp_list[tmp_list_len] = q;
+  tmp_list_len++;
+
+  *dst_list = tmp_list;
+  *dst_list_len = tmp_list_len;
+
+  return (0);
+} /* }}} int udb_query_pick_from_list */
+
+const char *udb_query_get_name (udb_query_t *q) /* {{{ */
+{
+  if (q == NULL)
+    return (NULL);
+
+  return (q->name);
+} /* }}} const char *udb_query_get_name */
+
+const char *udb_query_get_statement (udb_query_t *q) /* {{{ */
+{
+  if (q == NULL)
+    return (NULL);
+
+  return (q->statement);
+} /* }}} const char *udb_query_get_statement */
+
+void udb_query_set_user_data (udb_query_t *q, void *user_data) /* {{{ */
+{
+  if (q == NULL)
+    return;
+
+  q->user_data = user_data;
+} /* }}} void udb_query_set_user_data */
+
+void *udb_query_get_user_data (udb_query_t *q) /* {{{ */
+{
+  if (q == NULL)
+    return (NULL);
+
+  return (q->statement);
+} /* }}} void *udb_query_get_user_data */
+
+void udb_query_finish_result (udb_query_t *q) /* {{{ */
+{
+  udb_result_t *r;
+
+  if (q == NULL)
+    return;
+
+  q->column_num = 0;
+  sfree (q->host);
+  sfree (q->plugin);
+  sfree (q->db_name);
+
+  for (r = q->results; r != NULL; r = r->next)
+    udb_result_finish_result (r);
+} /* }}} void udb_query_finish_result */
+
+int udb_query_handle_result (udb_query_t *q, char **column_values) /* {{{ */
+{
+  udb_result_t *r;
+  int success;
+  int status;
+
+  if (q == NULL)
+    return (-EINVAL);
+
+  if ((q->column_num < 1) || (q->host == NULL) || (q->plugin == NULL)
+      || (q->db_name == NULL))
+  {
+    ERROR ("db query utils: Query `%s': Query is not prepared; "
+        "can't handle result.", q->name);
+    return (-EINVAL);
+  }
+
+#if defined(COLLECT_DEBUG) && COLLECT_DEBUG /* {{{ */
+  do
+  {
+    size_t i;
+
+    for (i = 0; i < q->column_num; i++)
+    {
+      DEBUG ("db query utils: udb_query_handle_result (%s, %s): "
+          "column[%zu] = %s;",
+          q->db_name, q->name, i, column_values[i]);
+    }
+  } while (0);
+#endif /* }}} */
+
+  success = 0;
+  for (r = q->results; r != NULL; r = r->next)
+  {
+    status = udb_result_handle_result (r, q, column_values);
+    if (status == 0)
+      success++;
+  }
+
+  if (success == 0)
+  {
+    ERROR ("db query utils: udb_query_handle_result (%s, %s): "
+        "All results failed.", q->db_name, q->name);
+    return (-1);
+  }
+
+  return (0);
+} /* }}} int udb_query_handle_result */
+
+int udb_query_prepare_result (udb_query_t *q, /* {{{ */
+    const char *host, const char *plugin, const char *db_name,
+    char **column_names, size_t column_num)
+{
+  udb_result_t *r;
+  int status;
+
+  if (q == NULL)
+    return (-EINVAL);
+
+  udb_query_finish_result (q);
+
+  q->column_num = column_num;
+  q->host = strdup (host);
+  q->plugin = strdup (plugin);
+  q->db_name = strdup (db_name);
+
+  if ((q->host == NULL) || (q->plugin == NULL) || (q->db_name == NULL))
+  {
+    ERROR ("db query utils: Query `%s': Prepare failed: Out of memory.", q->name);
+    udb_query_finish_result (q);
+    return (-ENOMEM);
+  }
+
+#if defined(COLLECT_DEBUG) && COLLECT_DEBUG
+  do
+  {
+    size_t i;
+
+    for (i = 0; i < column_num; i++)
+    {
+      DEBUG ("db query utils: udb_query_prepare_result: "
+          "query = %s; column[%zu] = %s;",
+          q->name, i, column_names[i]);
+    }
+  } while (0);
+#endif
+
+  for (r = q->results; r != NULL; r = r->next)
+  {
+    status = udb_result_prepare_result (r, column_names, column_num);
+    if (status != 0)
+    {
+      udb_query_finish_result (q);
+      return (status);
+    }
+  }
+
+  return (0);
+} /* }}} int udb_query_prepare_result */
+
+/* vim: set sw=2 sts=2 et fdm=marker : */

diff --git a/src/utils_db_query.h b/src/utils_db_query.h
new file mode 100644 (file)
index 0000000..87c3e4e
--- /dev/null
+++ b/src/utils_db_query.h
@@ -0,0 +1,57 @@
+/**
+ * collectd - src/utils_db_query.h
+ * Copyright (C) 2008,2009  Florian octo Forster
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * Authors:
+ *   Florian octo Forster <octo at verplant.org>
+ **/
+
+#ifndef UTILS_DB_QUERY_H
+#define UTILS_DB_QUERY_H 1
+
+#include "configfile.h"
+
+/*
+ * Data types
+ */
+struct udb_query_s;
+typedef struct udb_query_s udb_query_t;
+
+/* 
+ * Public functions
+ */
+int udb_query_create (udb_query_t ***ret_query_list,
+    size_t *ret_query_list_len, oconfig_item_t *ci);
+void udb_query_free (udb_query_t **query_list, size_t query_list_len);
+
+int udb_query_pick_from_list (oconfig_item_t *ci,
+    udb_query_t **src_list, size_t src_list_len,
+    udb_query_t ***dst_list, size_t *dst_list_len);
+
+const char *udb_query_get_name (udb_query_t *q);
+const char *udb_query_get_statement (udb_query_t *q);
+
+void  udb_query_set_user_data (udb_query_t *q, void *user_data);
+void *udb_query_get_user_data (udb_query_t *q);
+
+int udb_query_prepare_result (udb_query_t *q,
+    const char *host, const char *plugin, const char *db_name,
+    char **column_names, size_t column_num);
+int udb_query_handle_result (udb_query_t *q, char **column_values);
+void udb_query_finish_result (udb_query_t *q);
+
+#endif /* UTILS_DB_QUERY_H */
+/* vim: set sw=2 sts=2 et : */