From 3402ebca4425ea0dbb8ccb1c438d0b8d23735067 Mon Sep 17 00:00:00 2001
From: Vincent Bernat <bernat@luffy.cx>
Date: Sat, 12 Oct 2013 22:38:57 +0200
Subject: [PATCH] dbi plugin: register one read callback for each database
 block

By using a distinct read callback for each database block, collectd
will be able to query several databases in parallel. This is useful if
the plugin should handle many queries. This lets the user split them in
chunks and speed up the retrieval.
---
 src/dbi.c | 44 +++++++++++++++++++-------------------------
 1 file changed, 19 insertions(+), 25 deletions(-)

diff --git a/src/dbi.c b/src/dbi.c
index 45e0d31d..779c723f 100644
--- a/src/dbi.c
+++ b/src/dbi.c
@@ -68,6 +68,8 @@ static size_t            queries_num   = 0;
 static cdbi_database_t **databases     = NULL;
 static size_t            databases_num = 0;
 
+static int cdbi_read_database (user_data_t *ud);
+
 /*
  * Functions
  */
@@ -369,9 +371,24 @@ static int cdbi_config_add_database (oconfig_item_t *ci) /* {{{ */
     }
     else
     {
+      user_data_t ud;
+      char *name = NULL;
+
       databases = temp;
       databases[databases_num] = db;
       databases_num++;
+
+      memset (&ud, 0, sizeof (ud));
+      ud.data = (void *) db;
+      ud.free_func = NULL;
+      name = ssnprintf_alloc("dbi:%s", db->name);
+
+      plugin_register_complex_read (/* group = */ NULL,
+          /* name = */ name ? name : db->name,
+          /* callback = */ cdbi_read_database,
+          /* interval = */ NULL,
+          /* user_data = */ &ud);
+      free (name);
     }
   }
 
@@ -758,8 +775,9 @@ static int cdbi_connect_database (cdbi_database_t *db) /* {{{ */
   return (0);
 } /* }}} int cdbi_connect_database */
 
-static int cdbi_read_database (cdbi_database_t *db) /* {{{ */
+static int cdbi_read_database (user_data_t *ud) /* {{{ */
 {
+  cdbi_database_t *db = (cdbi_database_t *) ud->data;
   size_t i;
   int success;
   int status;
@@ -798,29 +816,6 @@ static int cdbi_read_database (cdbi_database_t *db) /* {{{ */
   return (0);
 } /* }}} int cdbi_read_database */
 
-static int cdbi_read (void) /* {{{ */
-{
-  size_t i;
-  int success = 0;
-  int status;
-
-  for (i = 0; i < databases_num; i++)
-  {
-    status = cdbi_read_database (databases[i]);
-    if (status == 0)
-      success++;
-  }
-
-  if (success == 0)
-  {
-    ERROR ("dbi plugin: No database could be read. Will return an error so "
-        "the plugin will be delayed.");
-    return (-1);
-  }
-
-  return (0);
-} /* }}} int cdbi_read */
-
 static int cdbi_shutdown (void) /* {{{ */
 {
   size_t i;
@@ -848,7 +843,6 @@ void module_register (void) /* {{{ */
 {
   plugin_register_complex_config ("dbi", cdbi_config);
   plugin_register_init ("dbi", cdbi_init);
-  plugin_register_read ("dbi", cdbi_read);
   plugin_register_shutdown ("dbi", cdbi_shutdown);
 } /* }}} void module_register */
 
-- 
2.11.0