X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Futils_cache.c;h=9f7e3b686e52083f37871afc4f69391d1dd191bc;hb=ff8390d53b08dd36f8b0c5f4e530fe7ea9f21b90;hp=20d4deb65db31a3ee83f17fe9c0f75b57a2a08e0;hpb=fbcda5ac431bbb293157bf00e204310dcb65afd3;p=collectd.git

diff --git a/src/utils_cache.c b/src/utils_cache.c
index 20d4deb6..69ea864b 100644
--- a/src/utils_cache.c
+++ b/src/utils_cache.c
@@ -1,6 +1,6 @@
 /**
  * collectd - src/utils_cache.c
- * Copyright (C) 2007  Florian octo Forster
+ * Copyright (C) 2007,2008  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
@@ -23,6 +23,9 @@
 #include "common.h"
 #include "plugin.h"
 #include "utils_avltree.h"
+#include "utils_cache.h"
+#include "utils_threshold.h"
+#include "meta_data.h"
 
 #include <assert.h>
 #include <pthread.h>
@@ -32,7 +35,7 @@ typedef struct cache_entry_s
 	char name[6 * DATA_MAX_NAME_LEN];
 	int        values_num;
 	gauge_t   *values_gauge;
-	counter_t *values_counter;
+	value_t   *values_raw;
 	/* Time contained in the package
 	 * (for calculating rates) */
 	time_t last_time;
@@ -42,9 +45,26 @@ typedef struct cache_entry_s
 	/* Interval in which the data is collected
 	 * (for purding old entries) */
 	int interval;
+	int state;
+	int hits;
+
+	/*
+	 * +-----+-----+-----+-----+-----+-----+-----+-----+-----+----
+	 * !  0  !  1  !  2  !  3  !  4  !  5  !  6  !  7  !  8  ! ...
+	 * +-----+-----+-----+-----+-----+-----+-----+-----+-----+----
+	 * ! ds0 ! ds1 ! ds2 ! ds0 ! ds1 ! ds2 ! ds0 ! ds1 ! ds2 ! ...
+	 * +-----+-----+-----+-----+-----+-----+-----+-----+-----+----
+	 * !      t = 0      !      t = 1      !      t = 2      ! ...
+	 * +-----------------+-----------------+-----------------+----
+	 */
+	gauge_t *history;
+	size_t   history_index; /* points to the next position to write to. */
+	size_t   history_length;
+
+	meta_data_t *meta;
 } cache_entry_t;
 
-static avl_tree_t     *cache_tree = NULL;
+static c_avl_tree_t   *cache_tree = NULL;
 static pthread_mutex_t cache_lock = PTHREAD_MUTEX_INITIALIZER;
 
 static int cache_compare (const cache_entry_t *a, const cache_entry_t *b)
@@ -53,6 +73,53 @@ static int cache_compare (const cache_entry_t *a, const cache_entry_t *b)
   return (strcmp (a->name, b->name));
 } /* int cache_compare */
 
+static cache_entry_t *cache_alloc (int values_num)
+{
+  cache_entry_t *ce;
+
+  ce = (cache_entry_t *) malloc (sizeof (cache_entry_t));
+  if (ce == NULL)
+  {
+    ERROR ("utils_cache: cache_alloc: malloc failed.");
+    return (NULL);
+  }
+  memset (ce, '\0', sizeof (cache_entry_t));
+  ce->values_num = values_num;
+
+  ce->values_gauge = calloc (values_num, sizeof (*ce->values_gauge));
+  ce->values_raw   = calloc (values_num, sizeof (*ce->values_raw));
+  if ((ce->values_gauge == NULL) || (ce->values_raw == NULL))
+  {
+    sfree (ce->values_gauge);
+    sfree (ce->values_raw);
+    sfree (ce);
+    ERROR ("utils_cache: cache_alloc: calloc failed.");
+    return (NULL);
+  }
+
+  ce->history = NULL;
+  ce->history_length = 0;
+  ce->meta = NULL;
+
+  return (ce);
+} /* cache_entry_t *cache_alloc */
+
+static void cache_free (cache_entry_t *ce)
+{
+  if (ce == NULL)
+    return;
+
+  sfree (ce->values_gauge);
+  sfree (ce->values_raw);
+  sfree (ce->history);
+  if (ce->meta != NULL)
+  {
+    meta_data_destroy (ce->meta);
+    ce->meta = NULL;
+  }
+  sfree (ce);
+} /* void cache_free */
+
 static int uc_send_notification (const char *name)
 {
   cache_entry_t *ce = NULL;
@@ -67,8 +134,6 @@ static int uc_send_notification (const char *name)
 
   notification_t n;
 
-  memset (&n, '\0', sizeof (n));
-
   name_copy = strdup (name);
   if (name_copy == NULL)
   {
@@ -85,18 +150,23 @@ static int uc_send_notification (const char *name)
     return (-1);
   }
 
-  n.severity = NOTIF_FAILURE;
-  strncpy (n.host, host, sizeof (n.host));
-  n.host[sizeof (n.host) - 1] = '\0';
+  /* Copy the associative members */
+  notification_init (&n, NOTIF_FAILURE, /* host = */ NULL,
+      host, plugin, plugin_instance, type, type_instance);
 
   sfree (name_copy);
   name_copy = host = plugin = plugin_instance = type = type_instance = NULL;
 
   pthread_mutex_lock (&cache_lock);
 
+  /*
+   * Set the time _after_ getting the lock because we don't know how long
+   * acquiring the lock takes and we will use this time later to decide
+   * whether or not the state is OKAY.
+   */
   n.time = time (NULL);
 
-  status = avl_get (cache_tree, name, (void *) &ce);
+  status = c_avl_get (cache_tree, name, (void *) &ce);
   if (status != 0)
   {
     pthread_mutex_unlock (&cache_lock);
@@ -105,29 +175,124 @@ static int uc_send_notification (const char *name)
   }
     
   /* Check if the entry has been updated in the meantime */
-  if ((n.time - ce->last_update) <= (2 * ce->interval))
+  if ((n.time - ce->last_update) < (2 * ce->interval))
   {
+    ce->state = STATE_OKAY;
     pthread_mutex_unlock (&cache_lock);
     sfree (name_copy);
     return (-1);
   }
 
-  snprintf (n.message, sizeof (n.message),
+  ssnprintf (n.message, sizeof (n.message),
       "%s has not been updated for %i seconds.", name,
-      (int) (ce->last_update - n.time));
+      (int) (n.time - ce->last_update));
 
   pthread_mutex_unlock (&cache_lock);
 
-  n.message[sizeof (n.message) - 1] = '\0';
   plugin_dispatch_notification (&n);
 
   return (0);
 } /* int uc_send_notification */
 
+static void uc_check_range (const data_set_t *ds, cache_entry_t *ce)
+{
+  int i;
+
+  for (i = 0; i < ds->ds_num; i++)
+  {
+    if (isnan (ce->values_gauge[i]))
+      continue;
+    else if (ce->values_gauge[i] < ds->ds[i].min)
+      ce->values_gauge[i] = NAN;
+    else if (ce->values_gauge[i] > ds->ds[i].max)
+      ce->values_gauge[i] = NAN;
+  }
+} /* void uc_check_range */
+
+static int uc_insert (const data_set_t *ds, const value_list_t *vl,
+    const char *key)
+{
+  int i;
+  char *key_copy;
+  cache_entry_t *ce;
+
+  /* `cache_lock' has been locked by `uc_update' */
+
+  key_copy = strdup (key);
+  if (key_copy == NULL)
+  {
+    ERROR ("uc_insert: strdup failed.");
+    return (-1);
+  }
+
+  ce = cache_alloc (ds->ds_num);
+  if (ce == NULL)
+  {
+    sfree (key_copy);
+    ERROR ("uc_insert: cache_alloc (%i) failed.", ds->ds_num);
+    return (-1);
+  }
+
+  sstrncpy (ce->name, key, sizeof (ce->name));
+
+  for (i = 0; i < ds->ds_num; i++)
+  {
+    switch (ds->ds[i].type)
+    {
+      case DS_TYPE_COUNTER:
+	ce->values_gauge[i] = NAN;
+	ce->values_raw[i].counter = vl->values[i].counter;
+	break;
+
+      case DS_TYPE_GAUGE:
+	ce->values_gauge[i] = vl->values[i].gauge;
+	ce->values_raw[i].gauge = vl->values[i].gauge;
+	break;
+
+      case DS_TYPE_DERIVE:
+	ce->values_gauge[i] = NAN;
+	ce->values_raw[i].derive = vl->values[i].derive;
+	break;
+
+      case DS_TYPE_ABSOLUTE:
+	ce->values_gauge[i] = NAN;
+	if (vl->interval > 0)
+	  ce->values_gauge[i] = ((double) vl->values[i].absolute)
+	    / ((double) vl->interval);
+	ce->values_raw[i].absolute = vl->values[i].absolute;
+	break;
+	
+      default:
+	/* This shouldn't happen. */
+	ERROR ("uc_insert: Don't know how to handle data source type %i.",
+	    ds->ds[i].type);
+	return (-1);
+    } /* switch (ds->ds[i].type) */
+  } /* for (i) */
+
+  /* Prune invalid gauge data */
+  uc_check_range (ds, ce);
+
+  ce->last_time = vl->time;
+  ce->last_update = time (NULL);
+  ce->interval = vl->interval;
+  ce->state = STATE_OKAY;
+
+  if (c_avl_insert (cache_tree, key_copy, ce) != 0)
+  {
+    sfree (key_copy);
+    ERROR ("uc_insert: c_avl_insert failed.");
+    return (-1);
+  }
+
+  DEBUG ("uc_insert: Added %s to the cache.", key);
+  return (0);
+} /* int uc_insert */
+
 int uc_init (void)
 {
   if (cache_tree == NULL)
-    cache_tree = avl_create ((int (*) (const void *, const void *))
+    cache_tree = c_avl_create ((int (*) (const void *, const void *))
 	cache_compare);
 
   return (0);
@@ -142,7 +307,7 @@ int uc_check_timeout (void)
   int keys_len = 0;
 
   char *key;
-  avl_iterator_t *iter;
+  c_avl_iterator_t *iter;
   int i;
   
   pthread_mutex_lock (&cache_lock);
@@ -150,11 +315,11 @@ int uc_check_timeout (void)
   now = time (NULL);
 
   /* Build a list of entries to be flushed */
-  iter = avl_get_iterator (cache_tree);
-  while (avl_iterator_next (iter, (void *) &key, (void *) &ce) == 0)
+  iter = c_avl_get_iterator (cache_tree);
+  while (c_avl_iterator_next (iter, (void *) &key, (void *) &ce) == 0)
   {
     /* If entry has not been updated, add to `keys' array */
-    if ((now - ce->last_update) > (2 * ce->interval))
+    if ((now - ce->last_update) >= (timeout_g * ce->interval))
     {
       char **tmp;
 
@@ -162,8 +327,10 @@ int uc_check_timeout (void)
 	  (keys_len + 1) * sizeof (char *));
       if (tmp == NULL)
       {
-	ERROR ("uc_purge: realloc failed.");
-	avl_iterator_destroy (iter);
+	ERROR ("uc_check_timeout: realloc failed.");
+	c_avl_iterator_destroy (iter);
+	sfree (keys);
+	pthread_mutex_unlock (&cache_lock);
 	return (-1);
       }
 
@@ -176,34 +343,97 @@ int uc_check_timeout (void)
       }
       keys_len++;
     }
-  } /* while (avl_iterator_next) */
+  } /* while (c_avl_iterator_next) */
+
+  ce = NULL;
 
   for (i = 0; i < keys_len; i++)
   {
     int status;
 
-    /* TODO: Check if value interesting:
-     * - Not interesting: Remove value from cache and shut up
-     * - Interesting:     Don't remove value from cache but send a
-     *                    notification.
-     */
-    status = avl_remove (cache_tree, keys[i], (void *) &key, (void *) &ce);
-    if (status != 0)
+    status = ut_check_interesting (keys[i]);
+
+    if (status < 0)
     {
-      ERROR ("uc_check_timeout: avl_remove (%s) failed.", keys[i]);
+      ERROR ("uc_check_timeout: ut_check_interesting failed.");
+      sfree (keys[i]);
+      continue;
+    }
+    else if (status == 0) /* ``service'' is uninteresting */
+    {
+      DEBUG ("uc_check_timeout: %s is missing but ``uninteresting''",
+	  keys[i]);
+      ce = NULL;
+      status = c_avl_remove (cache_tree, keys[i],
+	  (void *) &key, (void *) &ce);
+      if (status != 0)
+      {
+	ERROR ("uc_check_timeout: c_avl_remove (%s) failed.", keys[i]);
+      }
+      sfree (keys[i]);
+      sfree (key);
+      if (ce != NULL)
+        cache_free (ce);
       continue;
     }
 
-    sfree (key);
-    sfree (ce);
-  }
+    /* If we get here, the value is ``interesting''. Query the record from the
+     * cache and update the state field. */
+    if (c_avl_get (cache_tree, keys[i], (void *) &ce) != 0)
+    {
+      ERROR ("uc_check_timeout: cannot get data for %s from cache", keys[i]);
+      /* Do not free `keys[i]' so a notification is sent further down. */
+      continue;
+    }
+    assert (ce != NULL);
+
+    if (status == 2) /* persist */
+    {
+      DEBUG ("uc_check_timeout: %s is missing, sending notification.",
+	  keys[i]);
+      ce->state = STATE_MISSING;
+      /* Do not free `keys[i]' so a notification is sent further down. */
+    }
+    else if (status == 1) /* do not persist */
+    {
+      if (ce->state == STATE_MISSING)
+      {
+	DEBUG ("uc_check_timeout: %s is missing but "
+	    "notification has already been sent.",
+	    keys[i]);
+	/* Set `keys[i]' to NULL to no notification is sent. */
+	sfree (keys[i]);
+      }
+      else /* (ce->state != STATE_MISSING) */
+      {
+	DEBUG ("uc_check_timeout: %s is missing, sending one notification.",
+	    keys[i]);
+	ce->state = STATE_MISSING;
+	/* Do not free `keys[i]' so a notification is sent further down. */
+      }
+    }
+    else
+    {
+      WARNING ("uc_check_timeout: ut_check_interesting (%s) returned "
+	  "invalid status %i.",
+	  keys[i], status);
+      sfree (keys[i]);
+    }
 
-  avl_iterator_destroy (iter);
+    /* Make really sure the next iteration doesn't work with this pointer.
+     * There have been too many bugs in the past.. :/  -- octo */
+    ce = NULL;
+  } /* for (keys[i]) */
+
+  c_avl_iterator_destroy (iter);
 
   pthread_mutex_unlock (&cache_lock);
 
   for (i = 0; i < keys_len; i++)
   {
+    if (keys[i] == NULL)
+      continue;
+
     uc_send_notification (keys[i]);
     sfree (keys[i]);
   }
@@ -217,169 +447,638 @@ int uc_update (const data_set_t *ds, const value_list_t *vl)
 {
   char name[6 * DATA_MAX_NAME_LEN];
   cache_entry_t *ce = NULL;
+  int send_okay_notification = 0;
+  time_t update_delay = 0;
+  notification_t n;
+  int status;
+  int i;
 
-  if (FORMAT_VL (name, sizeof (name), vl, ds) != 0)
+  if (FORMAT_VL (name, sizeof (name), vl) != 0)
   {
-    ERROR ("uc_insert: FORMAT_VL failed.");
+    ERROR ("uc_update: FORMAT_VL failed.");
     return (-1);
   }
 
   pthread_mutex_lock (&cache_lock);
 
-  if (avl_get (cache_tree, name, (void *) &ce) == 0)
+  status = c_avl_get (cache_tree, name, (void *) &ce);
+  if (status != 0) /* entry does not yet exist */
   {
-    int i;
+    status = uc_insert (ds, vl, name);
+    pthread_mutex_unlock (&cache_lock);
+    return (status);
+  }
 
-    assert (ce != NULL);
-    assert (ce->values_num == ds->ds_num);
+  assert (ce != NULL);
+  assert (ce->values_num == ds->ds_num);
 
-    if (ce->last_time >= vl->time)
-    {
-      pthread_mutex_unlock (&cache_lock);
-      NOTICE ("uc_insert: Value too old: name = %s; value time = %u; "
-	  "last cache update = %u;",
-	  name, (unsigned int) vl->time, (unsigned int) ce->last_time);
-      return (-1);
-    }
+  if (ce->last_time >= vl->time)
+  {
+    pthread_mutex_unlock (&cache_lock);
+    NOTICE ("uc_update: Value too old: name = %s; value time = %u; "
+	"last cache update = %u;",
+	name, (unsigned int) vl->time, (unsigned int) ce->last_time);
+    return (-1);
+  }
 
-    if ((ce->last_time + ce->interval) < vl->time)
-    {
-      /* TODO: Implement a `real' okay notification. Watch out for locking
-       * issues, though! */
-      NOTICE ("uc_insert: Okay notification for %s", name);
-    }
+  /* Send a notification (after the lock has been released) if we switch the
+   * state from something else to `okay'. */
+  if (ce->state == STATE_MISSING)
+  {
+    send_okay_notification = 1;
+    ce->state = STATE_OKAY;
+    update_delay = time (NULL) - ce->last_update;
+  }
 
-    for (i = 0; i < ds->ds_num; i++)
+  for (i = 0; i < ds->ds_num; i++)
+  {
+    switch (ds->ds[i].type)
     {
-      if (ds->ds[i].type == DS_TYPE_COUNTER)
-      {
-	counter_t diff;
-
-	/* check if the counter has wrapped around */
-	if (vl->values[i].counter < ce->values_counter[i])
+      case DS_TYPE_COUNTER:
 	{
-	  if (ce->values_counter[i] <= 4294967295U)
-	    diff = (4294967295U - ce->values_counter[i])
-	      + vl->values[i].counter;
-	  else
-	    diff = (18446744073709551615ULL - ce->values_counter[i])
-	      + vl->values[i].counter;
+	  counter_t diff;
+
+	  /* check if the counter has wrapped around */
+	  if (vl->values[i].counter < ce->values_raw[i].counter)
+	  {
+	    if (ce->values_raw[i].counter <= 4294967295U)
+	      diff = (4294967295U - ce->values_raw[i].counter)
+		+ vl->values[i].counter;
+	    else
+	      diff = (18446744073709551615ULL - ce->values_raw[i].counter)
+		+ vl->values[i].counter;
+	  }
+	  else /* counter has NOT wrapped around */
+	  {
+	    diff = vl->values[i].counter - ce->values_raw[i].counter;
+	  }
+
+	  ce->values_gauge[i] = ((double) diff)
+	    / ((double) (vl->time - ce->last_time));
+	  ce->values_raw[i].counter = vl->values[i].counter;
 	}
-	else /* counter has NOT wrapped around */
+	break;
+
+      case DS_TYPE_GAUGE:
+	ce->values_raw[i].gauge = vl->values[i].gauge;
+	ce->values_gauge[i] = vl->values[i].gauge;
+	break;
+
+      case DS_TYPE_DERIVE:
 	{
-	  diff = vl->values[i].counter - ce->values_counter[i];
+	  derive_t diff;
+
+	  diff = vl->values[i].derive - ce->values_raw[i].derive;
+
+	  ce->values_gauge[i] = ((double) diff)
+	    / ((double) (vl->time - ce->last_time));
+	  ce->values_raw[i].derive = vl->values[i].derive;
 	}
+	break;
 
-	ce->values_gauge[i] = ((double) diff)
+      case DS_TYPE_ABSOLUTE:
+	ce->values_gauge[i] = ((double) vl->values[i].absolute)
 	  / ((double) (vl->time - ce->last_time));
-	ce->values_counter[i] = vl->values[i].counter;
-      }
-      else /* if (ds->ds[i].type == DS_TYPE_GAUGE) */
-      {
-	ce->values_gauge[i] = vl->values[i].gauge;
-      }
-      DEBUG ("uc_insert: %s: ds[%i] = %lf", name, i, ce->values_gauge[i]);
-    } /* for (i) */
+	ce->values_raw[i].absolute = vl->values[i].absolute;
+	break;
+
+      default:
+	/* This shouldn't happen. */
+	pthread_mutex_unlock (&cache_lock);
+	ERROR ("uc_update: Don't know how to handle data source type %i.",
+	    ds->ds[i].type);
+	return (-1);
+    } /* switch (ds->ds[i].type) */
 
-    ce->last_time = vl->time;
-    ce->last_update = time (NULL);
-    ce->interval = vl->interval;
-  }
-  else /* key is not found */
+    DEBUG ("uc_update: %s: ds[%i] = %lf", name, i, ce->values_gauge[i]);
+  } /* for (i) */
+
+  /* Update the history if it exists. */
+  if (ce->history != NULL)
   {
-    int i;
-    size_t ce_size = sizeof (cache_entry_t)
-      + ds->ds_num * (sizeof (counter_t) + sizeof (gauge_t));
-    char *key;
-    
-    key = strdup (name);
-    if (key == NULL)
+    assert (ce->history_index < ce->history_length);
+    for (i = 0; i < ce->values_num; i++)
     {
-      pthread_mutex_unlock (&cache_lock);
-      ERROR ("uc_insert: strdup failed.");
-      return (-1);
+      size_t hist_idx = (ce->values_num * ce->history_index) + i;
+      ce->history[hist_idx] = ce->values_gauge[i];
     }
 
-    ce = (cache_entry_t *) malloc (ce_size);
-    if (ce == NULL)
-    {
-      pthread_mutex_unlock (&cache_lock);
-      ERROR ("uc_insert: malloc (%u) failed.", (unsigned int) ce_size);
-      return (-1);
-    }
+    assert (ce->history_length > 0);
+    ce->history_index = (ce->history_index + 1) % ce->history_length;
+  }
+
+  /* Prune invalid gauge data */
+  uc_check_range (ds, ce);
 
-    memset (ce, '\0', ce_size);
+  ce->last_time = vl->time;
+  ce->last_update = time (NULL);
+  ce->interval = vl->interval;
+
+  pthread_mutex_unlock (&cache_lock);
 
-    strncpy (ce->name, name, sizeof (ce->name));
-    ce->name[sizeof (ce->name) - 1] = '\0';
+  if (send_okay_notification == 0)
+    return (0);
 
-    ce->values_num = ds->ds_num;
-    ce->values_gauge = (gauge_t *) (ce + 1);
-    ce->values_counter = (counter_t *) (ce->values_gauge + ce->values_num);
+  /* Do not send okay notifications for uninteresting values, i. e. values for
+   * which no threshold is configured. */
+  status = ut_check_interesting (name);
+  if (status <= 0)
+    return (0);
 
-    for (i = 0; i < ds->ds_num; i++)
+  /* Initialize the notification */
+  memset (&n, '\0', sizeof (n));
+  NOTIFICATION_INIT_VL (&n, vl, ds);
+
+  n.severity = NOTIF_OKAY;
+  n.time = vl->time;
+
+  ssnprintf (n.message, sizeof (n.message),
+      "Received a value for %s. It was missing for %u seconds.",
+      name, (unsigned int) update_delay);
+
+  plugin_dispatch_notification (&n);
+
+  return (0);
+} /* int uc_update */
+
+int uc_get_rate_by_name (const char *name, gauge_t **ret_values, size_t *ret_values_num)
+{
+  gauge_t *ret = NULL;
+  size_t ret_num = 0;
+  cache_entry_t *ce = NULL;
+  int status = 0;
+
+  pthread_mutex_lock (&cache_lock);
+
+  if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
+  {
+    assert (ce != NULL);
+
+    /* remove missing values from getval */
+    if (ce->state == STATE_MISSING)
     {
-      if (ds->ds[i].type == DS_TYPE_COUNTER)
+      status = -1;
+    }
+    else
+    {
+      ret_num = ce->values_num;
+      ret = (gauge_t *) malloc (ret_num * sizeof (gauge_t));
+      if (ret == NULL)
       {
-	ce->values_gauge[i] = NAN;
-	ce->values_counter[i] = vl->values[i].counter;
+        ERROR ("utils_cache: uc_get_rate_by_name: malloc failed.");
+        status = -1;
       }
-      else /* if (ds->ds[i].type == DS_TYPE_GAUGE) */
+      else
       {
-	ce->values_gauge[i] = vl->values[i].gauge;
+        memcpy (ret, ce->values_gauge, ret_num * sizeof (gauge_t));
       }
-    } /* for (i) */
+    }
+  }
+  else
+  {
+    DEBUG ("utils_cache: uc_get_rate_by_name: No such value: %s", name);
+    status = -1;
+  }
 
-    ce->last_time = vl->time;
+  pthread_mutex_unlock (&cache_lock);
 
-    if (avl_insert (cache_tree, key, ce) != 0)
+  if (status == 0)
+  {
+    *ret_values = ret;
+    *ret_values_num = ret_num;
+  }
+
+  return (status);
+} /* gauge_t *uc_get_rate_by_name */
+
+gauge_t *uc_get_rate (const data_set_t *ds, const value_list_t *vl)
+{
+  char name[6 * DATA_MAX_NAME_LEN];
+  gauge_t *ret = NULL;
+  size_t ret_num = 0;
+  int status;
+
+  if (FORMAT_VL (name, sizeof (name), vl) != 0)
+  {
+    ERROR ("utils_cache: uc_get_rate: FORMAT_VL failed.");
+    return (NULL);
+  }
+
+  status = uc_get_rate_by_name (name, &ret, &ret_num);
+  if (status != 0)
+    return (NULL);
+
+  /* This is important - the caller has no other way of knowing how many
+   * values are returned. */
+  if (ret_num != (size_t) ds->ds_num)
+  {
+    ERROR ("utils_cache: uc_get_rate: ds[%s] has %i values, "
+	"but uc_get_rate_by_name returned %zu.",
+	ds->type, ds->ds_num, ret_num);
+    sfree (ret);
+    return (NULL);
+  }
+
+  return (ret);
+} /* gauge_t *uc_get_rate */
+
+int uc_get_names (char ***ret_names, time_t **ret_times, size_t *ret_number)
+{
+  c_avl_iterator_t *iter;
+  char *key;
+  cache_entry_t *value;
+
+  char **names = NULL;
+  time_t *times = NULL;
+  size_t number = 0;
+
+  int status = 0;
+
+  if ((ret_names == NULL) || (ret_number == NULL))
+    return (-1);
+
+  pthread_mutex_lock (&cache_lock);
+
+  iter = c_avl_get_iterator (cache_tree);
+  while (c_avl_iterator_next (iter, (void *) &key, (void *) &value) == 0)
+  {
+    char **temp;
+
+    /* remove missing values when list values */
+    if (value->state == STATE_MISSING)
+      continue;
+
+    if (ret_times != NULL)
     {
-      pthread_mutex_unlock (&cache_lock);
-      ERROR ("uc_insert: avl_insert failed.");
-      return (-1);
+      time_t *tmp_times;
+
+      tmp_times = (time_t *) realloc (times, sizeof (time_t) * (number + 1));
+      if (tmp_times == NULL)
+      {
+	status = -1;
+	break;
+      }
+      times = tmp_times;
+      times[number] = value->last_time;
     }
 
-    DEBUG ("uc_insert: Added %s to the cache.", name);
-  } /* if (key is not found) */
+    temp = (char **) realloc (names, sizeof (char *) * (number + 1));
+    if (temp == NULL)
+    {
+      status = -1;
+      break;
+    }
+    names = temp;
+    names[number] = strdup (key);
+    if (names[number] == NULL)
+    {
+      status = -1;
+      break;
+    }
+    number++;
+  } /* while (c_avl_iterator_next) */
 
+  c_avl_iterator_destroy (iter);
   pthread_mutex_unlock (&cache_lock);
 
+  if (status != 0)
+  {
+    size_t i;
+    
+    for (i = 0; i < number; i++)
+    {
+      sfree (names[i]);
+    }
+    sfree (names);
+
+    return (-1);
+  }
+
+  *ret_names = names;
+  if (ret_times != NULL)
+    *ret_times = times;
+  *ret_number = number;
+
   return (0);
-} /* int uc_insert */
+} /* int uc_get_names */
 
-gauge_t *uc_get_rate (const data_set_t *ds, const value_list_t *vl)
+int uc_get_state (const data_set_t *ds, const value_list_t *vl)
 {
   char name[6 * DATA_MAX_NAME_LEN];
-  gauge_t *ret = NULL;
   cache_entry_t *ce = NULL;
+  int ret = STATE_ERROR;
 
-  if (FORMAT_VL (name, sizeof (name), vl, ds) != 0)
+  if (FORMAT_VL (name, sizeof (name), vl) != 0)
   {
-    ERROR ("uc_insert: FORMAT_VL failed.");
-    return (NULL);
+    ERROR ("uc_get_state: FORMAT_VL failed.");
+    return (STATE_ERROR);
   }
 
   pthread_mutex_lock (&cache_lock);
 
-  if (avl_get (cache_tree, name, (void *) &ce) == 0)
+  if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
   {
     assert (ce != NULL);
-    assert (ce->values_num == ds->ds_num);
+    ret = ce->state;
+  }
 
-    ret = (gauge_t *) malloc (ce->values_num * sizeof (gauge_t));
-    if (ret == NULL)
+  pthread_mutex_unlock (&cache_lock);
+
+  return (ret);
+} /* int uc_get_state */
+
+int uc_set_state (const data_set_t *ds, const value_list_t *vl, int state)
+{
+  char name[6 * DATA_MAX_NAME_LEN];
+  cache_entry_t *ce = NULL;
+  int ret = -1;
+
+  if (FORMAT_VL (name, sizeof (name), vl) != 0)
+  {
+    ERROR ("uc_get_state: FORMAT_VL failed.");
+    return (STATE_ERROR);
+  }
+
+  pthread_mutex_lock (&cache_lock);
+
+  if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
+  {
+    assert (ce != NULL);
+    ret = ce->state;
+    ce->state = state;
+  }
+
+  pthread_mutex_unlock (&cache_lock);
+
+  return (ret);
+} /* int uc_set_state */
+
+int uc_get_history_by_name (const char *name,
+    gauge_t *ret_history, size_t num_steps, size_t num_ds)
+{
+  cache_entry_t *ce = NULL;
+  size_t i;
+  int status = 0;
+
+  pthread_mutex_lock (&cache_lock);
+
+  status = c_avl_get (cache_tree, name, (void *) &ce);
+  if (status != 0)
+  {
+    pthread_mutex_unlock (&cache_lock);
+    return (-ENOENT);
+  }
+
+  if (((size_t) ce->values_num) != num_ds)
+  {
+    pthread_mutex_unlock (&cache_lock);
+    return (-EINVAL);
+  }
+
+  /* Check if there are enough values available. If not, increase the buffer
+   * size. */
+  if (ce->history_length < num_steps)
+  {
+    gauge_t *tmp;
+    size_t i;
+
+    tmp = realloc (ce->history, sizeof (*ce->history)
+	* num_steps * ce->values_num);
+    if (tmp == NULL)
     {
-      ERROR ("uc_get_rate: malloc failed.");
+      pthread_mutex_unlock (&cache_lock);
+      return (-ENOMEM);
     }
+
+    for (i = ce->history_length * ce->values_num;
+	i < (num_steps * ce->values_num);
+	i++)
+      tmp[i] = NAN;
+
+    ce->history = tmp;
+    ce->history_length = num_steps;
+  } /* if (ce->history_length < num_steps) */
+
+  /* Copy the values to the output buffer. */
+  for (i = 0; i < num_steps; i++)
+  {
+    size_t src_index;
+    size_t dst_index;
+
+    if (i < ce->history_index)
+      src_index = ce->history_index - (i + 1);
     else
-    {
-      memcpy (ret, ce->values_gauge, ce->values_num * sizeof (gauge_t));
-    }
+      src_index = ce->history_length + ce->history_index - (i + 1);
+    src_index = src_index * num_ds;
+
+    dst_index = i * num_ds;
+
+    memcpy (ret_history + dst_index, ce->history + src_index,
+	sizeof (*ret_history) * num_ds);
+  }
+
+  pthread_mutex_unlock (&cache_lock);
+
+  return (0);
+} /* int uc_get_history_by_name */
+
+int uc_get_history (const data_set_t *ds, const value_list_t *vl,
+    gauge_t *ret_history, size_t num_steps, size_t num_ds)
+{
+  char name[6 * DATA_MAX_NAME_LEN];
+
+  if (FORMAT_VL (name, sizeof (name), vl) != 0)
+  {
+    ERROR ("utils_cache: uc_get_history: FORMAT_VL failed.");
+    return (-1);
+  }
+
+  return (uc_get_history_by_name (name, ret_history, num_steps, num_ds));
+} /* int uc_get_history */
+
+int uc_get_hits (const data_set_t *ds, const value_list_t *vl)
+{
+  char name[6 * DATA_MAX_NAME_LEN];
+  cache_entry_t *ce = NULL;
+  int ret = STATE_ERROR;
+
+  if (FORMAT_VL (name, sizeof (name), vl) != 0)
+  {
+    ERROR ("uc_get_state: FORMAT_VL failed.");
+    return (STATE_ERROR);
+  }
+
+  pthread_mutex_lock (&cache_lock);
+
+  if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
+  {
+    assert (ce != NULL);
+    ret = ce->hits;
   }
 
   pthread_mutex_unlock (&cache_lock);
 
   return (ret);
-} /* gauge_t *uc_get_rate */
+} /* int uc_get_hits */
+
+int uc_set_hits (const data_set_t *ds, const value_list_t *vl, int hits)
+{
+  char name[6 * DATA_MAX_NAME_LEN];
+  cache_entry_t *ce = NULL;
+  int ret = -1;
+
+  if (FORMAT_VL (name, sizeof (name), vl) != 0)
+  {
+    ERROR ("uc_get_state: FORMAT_VL failed.");
+    return (STATE_ERROR);
+  }
+
+  pthread_mutex_lock (&cache_lock);
+
+  if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
+  {
+    assert (ce != NULL);
+    ret = ce->hits;
+    ce->hits = hits;
+  }
+
+  pthread_mutex_unlock (&cache_lock);
+
+  return (ret);
+} /* int uc_set_hits */
+
+int uc_inc_hits (const data_set_t *ds, const value_list_t *vl, int step)
+{
+  char name[6 * DATA_MAX_NAME_LEN];
+  cache_entry_t *ce = NULL;
+  int ret = -1;
+
+  if (FORMAT_VL (name, sizeof (name), vl) != 0)
+  {
+    ERROR ("uc_get_state: FORMAT_VL failed.");
+    return (STATE_ERROR);
+  }
+
+  pthread_mutex_lock (&cache_lock);
+
+  if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
+  {
+    assert (ce != NULL);
+    ret = ce->hits;
+    ce->hits = ret + step;
+  }
+
+  pthread_mutex_unlock (&cache_lock);
+
+  return (ret);
+} /* int uc_inc_hits */
+
+/*
+ * Meta data interface
+ */
+/* XXX: This function will acquire `cache_lock' but will not free it! */
+static meta_data_t *uc_get_meta (const value_list_t *vl) /* {{{ */
+{
+  char name[6 * DATA_MAX_NAME_LEN];
+  cache_entry_t *ce = NULL;
+  int status;
+
+  status = FORMAT_VL (name, sizeof (name), vl);
+  if (status != 0)
+  {
+    ERROR ("utils_cache: uc_get_meta: FORMAT_VL failed.");
+    return (NULL);
+  }
+
+  pthread_mutex_lock (&cache_lock);
+
+  status = c_avl_get (cache_tree, name, (void *) &ce);
+  if (status != 0)
+  {
+    pthread_mutex_unlock (&cache_lock);
+    return (NULL);
+  }
+  assert (ce != NULL);
+
+  if (ce->meta == NULL)
+    ce->meta = meta_data_create ();
+
+  if (ce->meta == NULL)
+    pthread_mutex_unlock (&cache_lock);
+
+  return (ce->meta);
+} /* }}} meta_data_t *uc_get_meta */
+
+/* Sorry about this preprocessor magic, but it really makes this file much
+ * shorter.. */
+#define UC_WRAP(wrap_function) { \
+  meta_data_t *meta; \
+  int status; \
+  meta = uc_get_meta (vl); \
+  if (meta == NULL) return (-1); \
+  status = wrap_function (meta, key); \
+  pthread_mutex_unlock (&cache_lock); \
+  return (status); \
+}
+int uc_meta_data_exists (const value_list_t *vl, const char *key)
+  UC_WRAP (meta_data_exists)
+
+int uc_meta_data_delete (const value_list_t *vl, const char *key)
+  UC_WRAP (meta_data_delete)
+#undef UC_WRAP
+
+/* We need a new version of this macro because the following functions take
+ * two argumetns. */
+#define UC_WRAP(wrap_function) { \
+  meta_data_t *meta; \
+  int status; \
+  meta = uc_get_meta (vl); \
+  if (meta == NULL) return (-1); \
+  status = wrap_function (meta, key, value); \
+  pthread_mutex_unlock (&cache_lock); \
+  return (status); \
+}
+int uc_meta_data_add_string (const value_list_t *vl,
+    const char *key,
+    const char *value)
+  UC_WRAP(meta_data_add_string)
+int uc_meta_data_add_signed_int (const value_list_t *vl,
+    const char *key,
+    int64_t value)
+  UC_WRAP(meta_data_add_signed_int)
+int uc_meta_data_add_unsigned_int (const value_list_t *vl,
+    const char *key,
+    uint64_t value)
+  UC_WRAP(meta_data_add_unsigned_int)
+int uc_meta_data_add_double (const value_list_t *vl,
+    const char *key,
+    double value)
+  UC_WRAP(meta_data_add_double)
+int uc_meta_data_add_boolean (const value_list_t *vl,
+    const char *key,
+    _Bool value)
+  UC_WRAP(meta_data_add_boolean)
+
+int uc_meta_data_get_string (const value_list_t *vl,
+    const char *key,
+    char **value)
+  UC_WRAP(meta_data_get_string)
+int uc_meta_data_get_signed_int (const value_list_t *vl,
+    const char *key,
+    int64_t *value)
+  UC_WRAP(meta_data_get_signed_int)
+int uc_meta_data_get_unsigned_int (const value_list_t *vl,
+    const char *key,
+    uint64_t *value)
+  UC_WRAP(meta_data_get_unsigned_int)
+int uc_meta_data_get_double (const value_list_t *vl,
+    const char *key,
+    double *value)
+  UC_WRAP(meta_data_get_double)
+int uc_meta_data_get_boolean (const value_list_t *vl,
+    const char *key,
+    _Bool *value)
+  UC_WRAP(meta_data_get_boolean)
+#undef UC_WRAP
 
 /* vim: set sw=2 ts=8 sts=2 tw=78 : */