extending datacache API with function to return random element, implemented (only) in heap plugin right now

3 files changed, 86 insertions, 33 deletions

diff --git a/src/include/gnunet_container_lib.h b/src/include/gnunet_container_lib.h
index 125bc81b2..1ecf4f52a 100644
--- a/src/include/gnunet_container_lib.h
+++ b/src/include/gnunet_container_lib.h
@@ -854,6 +854,22 @@ GNUNET_CONTAINER_multihashmap_get_multiple (const struct GNUNET_CONTAINER_MultiH
                                             void *it_cls);
 
 
+/**
+ * @ingroup hashmap
+ * Call @a it on a random value from the map, or not at all
+ * if the map is empty.
+ *
+ * @param map the map
+ * @param it function to call on a random entry
+ * @param it_cls extra argument to @a it
+ * @return the number of key value pairs processed, zero or one.
+ */
+unsigned int
+GNUNET_CONTAINER_multihashmap_get_random (const struct GNUNET_CONTAINER_MultiHashMap *map,
+                                          GNUNET_CONTAINER_HashMapIterator it,
+                                          void *it_cls);
+
+
 /* ***************** Version of Multihashmap for peer identities ****************** */
 
 /**
diff --git a/src/include/gnunet_datacache_lib.h b/src/include/gnunet_datacache_lib.h
index 5e2ad1c1d..f3761bd89 100644
--- a/src/include/gnunet_datacache_lib.h
+++ b/src/include/gnunet_datacache_lib.h
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet
-     Copyright (C) 2006, 2009 Christian Grothoff (and other contributing authors)
+     Copyright (C) 2006, 2009, 2015 Christian Grothoff (and other contributing authors)
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
@@ -75,21 +75,23 @@ GNUNET_DATACACHE_destroy (struct GNUNET_DATACACHE_Handle *h);
  *
  * @param cls closure
  * @param key key for the content
- * @param size number of bytes in data
+ * @param data_size number of bytes in @a data
  * @param data content stored
  * @param type type of the content
  * @param exp when will the content expire?
- * @param path_info_len number of entries in 'path_info'
+ * @param path_info_len number of entries in @a path_info
  * @param path_info a path through the network
- * @return GNUNET_OK to continue iterating, GNUNET_SYSERR to abort
+ * @return #GNUNET_OK to continue iterating, #GNUNET_SYSERR to abort
  */
-typedef int (*GNUNET_DATACACHE_Iterator) (void *cls,
-                                          const struct GNUNET_HashCode *key,
-                                          size_t size, const char *data,
-                                          enum GNUNET_BLOCK_Type type,
-                                          struct GNUNET_TIME_Absolute exp,
-                                          unsigned int path_info_len,
-                                          const struct GNUNET_PeerIdentity *path_info);
+typedef int
+(*GNUNET_DATACACHE_Iterator) (void *cls,
+                              const struct GNUNET_HashCode *key,
+                              size_t data_size,
+                              const char *data,
+                              enum GNUNET_BLOCK_Type type,
+                              struct GNUNET_TIME_Absolute exp,
+                              unsigned int path_info_len,
+                              const struct GNUNET_PeerIdentity *path_info);
 
 
 /**
@@ -97,18 +99,20 @@ typedef int (*GNUNET_DATACACHE_Iterator) (void *cls,
  *
  * @param h handle to the datacache
  * @param key key to store data under
- * @param size number of bytes in data
+ * @param data_size number of bytes in @a data
  * @param data data to store
  * @param type type of the value
  * @param discard_time when to discard the value in any case
- * @param path_info_len number of entries in 'path_info'
+ * @param path_info_len number of entries in @a path_info
  * @param path_info a path through the network
- * @return GNUNET_OK on success, GNUNET_SYSERR on error, GNUNET_NO if duplicate
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on error, #GNUNET_NO if duplicate
  */
 int
 GNUNET_DATACACHE_put (struct GNUNET_DATACACHE_Handle *h,
-                      const struct GNUNET_HashCode * key, size_t size,
-                      const char *data, enum GNUNET_BLOCK_Type type,
+                      const struct GNUNET_HashCode *key,
+                      size_t data_size,
+                      const char *data,
+                      enum GNUNET_BLOCK_Type type,
                       struct GNUNET_TIME_Absolute discard_time,
                       unsigned int path_info_len,
                       const struct GNUNET_PeerIdentity *path_info);
@@ -122,15 +126,32 @@ GNUNET_DATACACHE_put (struct GNUNET_DATACACHE_Handle *h,
  * @param key what to look up
  * @param type entries of which type are relevant?
  * @param iter maybe NULL (to just count)
- * @param iter_cls closure for iter
+ * @param iter_cls closure for @a iter
  * @return the number of results found
  */
 unsigned int
 GNUNET_DATACACHE_get (struct GNUNET_DATACACHE_Handle *h,
-                      const struct GNUNET_HashCode * key, enum GNUNET_BLOCK_Type type,
+                      const struct GNUNET_HashCode *key,
+                      enum GNUNET_BLOCK_Type type,
                       GNUNET_DATACACHE_Iterator iter, void *iter_cls);
 
 
+/**
+ * Obtain a random element from the datacache.
+ *
+ * @param h handle to the datacache
+ * @param iter maybe NULL (to just count)
+ * @param iter_cls closure for @a iter
+ * @return the number of results found (zero or 1)
+ */
+unsigned int
+GNUNET_DATACACHE_get_random (struct GNUNET_DATACACHE_Handle *h,
+                             GNUNET_DATACACHE_Iterator iter,
+                             void *iter_cls);
+
+
+
+
 #if 0                           /* keep Emacsens' auto-indent happy */
 {
 #endif
diff --git a/src/include/gnunet_datacache_plugin.h b/src/include/gnunet_datacache_plugin.h
index 347ed9a59..34cf8fecc 100644
--- a/src/include/gnunet_datacache_plugin.h
+++ b/src/include/gnunet_datacache_plugin.h
@@ -45,9 +45,10 @@ extern "C"
  * @param key key of the content that was deleted
  * @param size number of bytes that were made available
  */
-typedef void (*GNUNET_DATACACHE_DeleteNotifyCallback) (void *cls,
-                                                       const struct GNUNET_HashCode *
-                                                       key, size_t size);
+typedef void
+(*GNUNET_DATACACHE_DeleteNotifyCallback) (void *cls,
+                                          const struct GNUNET_HashCode *key,
+                                          size_t size);
 
 
 /**
@@ -58,7 +59,6 @@ typedef void (*GNUNET_DATACACHE_DeleteNotifyCallback) (void *cls,
 struct GNUNET_DATACACHE_PluginEnvironment
 {
 
-
   /**
    * Configuration to use.
    */
@@ -103,46 +103,62 @@ struct GNUNET_DATACACHE_PluginFunctions
    * Store an item in the datastore.
    *
    * @param cls closure (internal context for the plugin)
-   * @param size number of bytes in data
+   * @param key key to store the value under
+   * @param size number of bytes in @a data
    * @param data data to store
    * @param type type of the value
    * @param discard_time when to discard the value in any case
-   * @param path_info_len number of entries in 'path_info'
+   * @param path_info_len number of entries in @a path_info
    * @param path_info a path through the network
    * @return 0 if duplicate, -1 on error, number of bytes used otherwise
    */
-  ssize_t (*put) (void *cls, const struct GNUNET_HashCode * key, size_t size,
-                  const char *data, enum GNUNET_BLOCK_Type type,
+  ssize_t (*put) (void *cls,
+                  const struct GNUNET_HashCode *key,
+                  size_t size,
+                  const char *data,
+                  enum GNUNET_BLOCK_Type type,
                   struct GNUNET_TIME_Absolute discard_time,
                   unsigned int path_info_len,
                   const struct GNUNET_PeerIdentity *path_info);
 
-
   /**
    * Iterate over the results for a particular key
    * in the datastore.
    *
    * @param cls closure (internal context for the plugin)
-   * @param key
+   * @param key key to look for
    * @param type entries of which type are relevant?
    * @param iter maybe NULL (to just count)
-   * @param iter_cls closure for iter
+   * @param iter_cls closure for @a iter
    * @return the number of results found
    */
-  unsigned int (*get) (void *cls, const struct GNUNET_HashCode * key,
+  unsigned int (*get) (void *cls,
+                       const struct GNUNET_HashCode * key,
                        enum GNUNET_BLOCK_Type type,
-                       GNUNET_DATACACHE_Iterator iter, void *iter_cls);
-
+                       GNUNET_DATACACHE_Iterator iter,
+                       void *iter_cls);
 
   /**
    * Delete the entry with the lowest expiration value
    * from the datacache right now.
    *
    * @param cls closure (internal context for the plugin)
-   * @return GNUNET_OK on success, GNUNET_SYSERR on error
+   * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
    */
   int (*del) (void *cls);
 
+  /**
+   * Return a random value from the datastore.
+   *
+   * @param cls closure (internal context for the plugin)
+   * @param iter maybe NULL (to just count)
+   * @param iter_cls closure for @a iter
+   * @return the number of results found (zero or one)
+   */
+  unsigned int (*get_random) (void *cls,
+                              GNUNET_DATACACHE_Iterator iter,
+                              void *iter_cls);
+
 
 };