porting xdht to new service API, major code de-duplication effort

1 files changed, 175 insertions, 18 deletions

diff --git a/src/dht/gnunet-service-dht_datacache.c b/src/dht/gnunet-service-dht_datacache.c
index 12c79764d..9b4dace67 100644
--- a/src/dht/gnunet-service-dht_datacache.c
+++ b/src/dht/gnunet-service-dht_datacache.c
@@ -31,6 +31,11 @@
 
 #define LOG(kind,...) GNUNET_log_from (kind, "dht-dhtcache",__VA_ARGS__)
 
+/**
+ * How many "closest" results to we return for migration when
+ * asked (at most)?
+ */
+#define NUM_CLOSEST 42
 
 /**
  * Handle to the datacache service (for inserting/retrieving data)
@@ -127,6 +132,17 @@ struct GetRequestContext
    * Return value to give back.
    */
   enum GNUNET_BLOCK_EvaluationResult eval;
+
+  /**
+   * Function to call on results.
+   */
+  GDS_DATACACHE_GetCallback gc;
+
+  /**
+   * Closure for @e gc.
+   */
+  void *gc_cls;
+
 };
 
 
@@ -136,7 +152,7 @@ struct GetRequestContext
  * @param cls closure for iterator, a `struct GetRequestContext`
  * @param exp when does this value expire?
  * @param key the key this data is stored under
- * @param size the size of the data identified by key
+ * @param data_size the size of the data identified by key
  * @param data the actual data
  * @param type the type of the @a data
  * @param put_path_length number of peers in @a put_path
@@ -147,7 +163,7 @@ struct GetRequestContext
 static int
 datacache_get_iterator (void *cls,
                         const struct GNUNET_HashCode *key,
-                        size_t size,
+                        size_t data_size,
                         const char *data,
                         enum GNUNET_BLOCK_Type type,
                         struct GNUNET_TIME_Absolute exp,
@@ -157,8 +173,8 @@ datacache_get_iterator (void *cls,
   struct GetRequestContext *ctx = cls;
   enum GNUNET_BLOCK_EvaluationResult eval;
 
-  eval =
-      GNUNET_BLOCK_evaluate (GDS_block_context,
+  eval
+    = GNUNET_BLOCK_evaluate (GDS_block_context,
                              type,
                              GNUNET_BLOCK_EO_LOCAL_SKIP_CRYPTO,
                              key,
@@ -167,7 +183,7 @@ datacache_get_iterator (void *cls,
                              ctx->xquery,
                              ctx->xquery_size,
                              data,
-                             size);
+                             data_size);
   LOG (GNUNET_ERROR_TYPE_DEBUG,
        "Found reply for query %s in datacache, evaluation result is %d\n",
        GNUNET_h2s (key),
@@ -182,18 +198,13 @@ datacache_get_iterator (void *cls,
                               gettext_noop
                               ("# Good RESULTS found in datacache"), 1,
                               GNUNET_NO);
-    GDS_CLIENTS_handle_reply (exp, key,
-                              0, NULL,
-                              put_path_length, put_path,
-                              type,
-                              size, data);
-    /* forward to other peers */
-    GDS_ROUTING_process (type,
-                         exp,
-                         key,
-                         put_path_length, put_path,
-                         0, NULL,
-                         data, size);
+    ctx->gc (ctx->gc_cls,
+             type,
+             exp,
+             key,
+             put_path_length, put_path,
+             0, NULL,
+             data, data_size);
     break;
   case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
     GNUNET_STATISTICS_update (GDS_stats,
@@ -242,6 +253,8 @@ datacache_get_iterator (void *cls,
  * @param xquery_size number of bytes in @a xquery
  * @param reply_bf where the reply bf is (to be) stored, possibly updated, can be NULL
  * @param reply_bf_mutator mutation value for @a reply_bf
+ * @param gc function to call on the results
+ * @param gc_cls closure for @a gc
  * @return evaluation result for the local replies
  */
 enum GNUNET_BLOCK_EvaluationResult
@@ -250,7 +263,9 @@ GDS_DATACACHE_handle_get (const struct GNUNET_HashCode *key,
                           const void *xquery,
                           size_t xquery_size,
                           struct GNUNET_CONTAINER_BloomFilter **reply_bf,
-                          uint32_t reply_bf_mutator)
+                          uint32_t reply_bf_mutator,
+                          GDS_DATACACHE_GetCallback gc,
+                          void *gc_cls)
 {
   struct GetRequestContext ctx;
   unsigned int r;
@@ -267,6 +282,8 @@ GDS_DATACACHE_handle_get (const struct GNUNET_HashCode *key,
   ctx.xquery_size = xquery_size;
   ctx.reply_bf = reply_bf;
   ctx.reply_bf_mutator = reply_bf_mutator;
+  ctx.gc = gc;
+  ctx.gc_cls = gc_cls;
   r = GNUNET_DATACACHE_get (datacache,
                             key,
                             type,
@@ -282,6 +299,146 @@ GDS_DATACACHE_handle_get (const struct GNUNET_HashCode *key,
 
 
 /**
+ * Function called with a random element from the datacache.
+ * Stores the key in the closure.
+ *
+ * @param cls a `struct GNUNET_HashCode *`, where to store the @a key
+ * @param key key for the content
+ * @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 @a path_info
+ * @param path_info a path through the network
+ * @return #GNUNET_OK to continue iterating, #GNUNET_SYSERR to abort
+ */
+static int
+datacache_random_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)
+{
+  struct GNUNET_HashCode *dest = cls;
+
+  *dest = *key;
+  return GNUNET_OK; /* should actually not matter which we return */
+}
+
+
+/**
+ * Obtain a random key from the datacache.
+ * Used by Whanau for load-balancing.
+ *
+ * @param[out] key where to store the key of a random element,
+ *             randomized by PRNG if datacache is empty
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if the datacache is empty
+ */
+int
+GDS_DATACACHE_get_random_key (struct GNUNET_HashCode *key)
+{
+  if (0 ==
+      GNUNET_DATACACHE_get_random (datacache,
+                                   &datacache_random_iterator,
+                                   key))
+  {
+    /* randomize key in this case */
+    GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE,
+                                      key);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Closure for #datacache_get_successors_iterator().
+ */
+struct SuccContext
+{
+  /**
+   * Function to call on the result
+   */
+  GDS_DATACACHE_SuccessorCallback cb;
+
+  /**
+   * Closure for @e cb.
+   */
+  void *cb_cls;
+};
+
+
+/**
+ * Iterator for local get request results,
+ *
+ * @param cls closure with the `struct GNUNET_HashCode *` with the trail ID
+ * @param key the key this data is stored under
+ * @param size the size of the data identified by key
+ * @param data the actual data
+ * @param type the type of the data
+ * @param exp when does this value expire?
+ * @param put_path_length number of peers in @a put_path
+ * @param put_path path the reply took on put
+ * @return #GNUNET_OK to continue iteration, anything else
+ * to stop iteration.
+ */
+static int
+datacache_get_successors_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 put_path_length,
+                                   const struct GNUNET_PeerIdentity *put_path)
+{
+  const struct SuccContext *sc = cls;
+
+  /* NOTE: The datacache currently does not store the RO from
+     the original 'put', so we don't know the 'correct' option
+     at this point anymore.  Thus, we conservatively assume
+     that recording is desired (for now). */
+  sc->cb (sc->cb_cls,
+          GNUNET_DHT_RO_RECORD_ROUTE,
+          key,
+          type,
+          put_path_length, put_path,
+          exp,
+          data,
+          size);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Handle a request for data close to a key that we have received from
+ * another peer.
+ *
+ * @param key the location at which the peer is looking for data that is close
+ * @param cb function to call with the result
+ * @param cb_cls closure for @a cb
+ */
+void
+GDS_DATACACHE_get_successors (const struct GNUNET_HashCode *key,
+                              GDS_DATACACHE_SuccessorCallback cb,
+                              void *cb_cls)
+{
+  struct SuccContext sc;
+
+  sc.cb = cb;
+  sc.cb_cls = cb_cls;
+  (void) GNUNET_DATACACHE_get_closest (datacache,
+                                       key,
+                                       NUM_CLOSEST,
+                                       &datacache_get_successors_iterator,
+                                       &sc);
+}
+
+
+/**
  * Initialize datacache subsystem.
  */
 void