completed big block refactoring in preparation for SET-BLOCK integration

5 files changed, 259 insertions, 124 deletions

diff --git a/src/block/Makefile.am b/src/block/Makefile.am
index 4a6d8e71e..da1d8257c 100644
--- a/src/block/Makefile.am
+++ b/src/block/Makefile.am
@@ -26,7 +26,7 @@ noinst_LTLIBRARIES = \
 libgnunet_plugin_block_template_la_SOURCES = \
   plugin_block_template.c
 libgnunet_plugin_block_template_la_LIBADD = \
-  libgnunetblock.la \
+  libgnunetblockgroup.la \
   $(top_builddir)/src/util/libgnunetutil.la \
   $(LTLIBINTL)
 libgnunet_plugin_block_template_la_LDFLAGS = \
@@ -35,8 +35,8 @@ libgnunet_plugin_block_template_la_LDFLAGS = \
 libgnunet_plugin_block_test_la_SOURCES = \
   plugin_block_test.c
 libgnunet_plugin_block_test_la_LIBADD = \
-  libgnunetblock.la \
-  $(top_builddir)/src/util/libgnunetutil.la  \
+  libgnunetblockgroup.la \
+$(top_builddir)/src/util/libgnunetutil.la  \
   $(LTLIBINTL)
 libgnunet_plugin_block_test_la_LDFLAGS = \
  $(GN_PLUGIN_LDFLAGS)
diff --git a/src/block/bg_bf.c b/src/block/bg_bf.c
index f03ae5247..9c4dc9060 100644
--- a/src/block/bg_bf.c
+++ b/src/block/bg_bf.c
@@ -56,6 +56,7 @@ struct BfGroupInternals
  * Serialize state of a block group.
  *
  * @param bg group to serialize
+ * @param[out] nonce set to the nonce of the @a bg
  * @param[out] raw_data set to the serialized state
  * @param[out] raw_data_size set to the number of bytes in @a raw_data
  * @return #GNUNET_OK on success, #GNUNET_NO if serialization is not
@@ -63,6 +64,7 @@ struct BfGroupInternals
  */
 static int
 bf_group_serialize_cb (struct GNUNET_BLOCK_Group *bg,
+                       uint32_t *nonce,
                        void **raw_data,
                        size_t *raw_data_size)
 {
@@ -78,6 +80,7 @@ bf_group_serialize_cb (struct GNUNET_BLOCK_Group *bg,
     GNUNET_break (0);
     return GNUNET_SYSERR;
   }
+  *nonce = gi->bf_mutator;
   *raw_data = raw;
   *raw_data_size = gi->bf_size;
   return GNUNET_OK;
@@ -85,6 +88,60 @@ bf_group_serialize_cb (struct GNUNET_BLOCK_Group *bg,
 
 
 /**
+ * Mark elements as "seen" using a hash of the element. Not supported
+ * by all block plugins.
+ *
+ * @param bg group to update
+ * @param seen_results results already seen
+ * @param seen_results_count number of entries in @a seen_results
+ */
+static void
+bf_group_mark_seen_cb (struct GNUNET_BLOCK_Group *bg,
+                       const struct GNUNET_HashCode *seen_results,
+                       unsigned int seen_results_count)
+{
+  struct BfGroupInternals *gi = bg->internal_cls;
+
+  for (unsigned int i=0;i<seen_results_count;i++)
+  {
+    struct GNUNET_HashCode mhash;
+
+    GNUNET_BLOCK_mingle_hash (&seen_results[i],
+                              gi->bf_mutator,
+                              &mhash);
+    GNUNET_CONTAINER_bloomfilter_add (gi->bf,
+                                      &mhash);
+  }
+}
+
+
+/**
+ * Merge two groups, if possible. Not supported by all block plugins,
+ * can also fail if the nonces were different.
+ *
+ * @param bg1 group to update
+ * @param bg2 group to merge into @a bg1
+ * @return #GNUNET_OK on success, #GNUNET_NO if the nonces were different and thus
+ *         we failed.
+ */
+static int
+bf_group_merge_cb (struct GNUNET_BLOCK_Group *bg1,
+                   const struct GNUNET_BLOCK_Group *bg2)
+{
+  struct BfGroupInternals *gi1 = bg1->internal_cls;
+  struct BfGroupInternals *gi2 = bg2->internal_cls;
+
+  if (gi1->bf_mutator != gi2->bf_mutator)
+    return GNUNET_NO;
+  if (gi1->bf_size != gi2->bf_size)
+    return GNUNET_NO;
+  GNUNET_CONTAINER_bloomfilter_or2 (gi1->bf,
+                                    gi2->bf);
+  return GNUNET_OK;
+}
+
+
+/**
  * Destroy resources used by a block group.
  *
  * @param bg group to destroy, NULL is allowed
@@ -134,6 +191,8 @@ GNUNET_BLOCK_GROUP_bf_create (void *cls,
   bg = GNUNET_new (struct GNUNET_BLOCK_Group);
   bg->type = type;
   bg->serialize_cb = &bf_group_serialize_cb;
+  bg->mark_seen_cb = &bf_group_mark_seen_cb;
+  bg->merge_cb = &bf_group_merge_cb;
   bg->destroy_cb = &bf_group_destroy_cb;
   bg->internal_cls = gi;
   return bg;
@@ -154,9 +213,12 @@ int
 GNUNET_BLOCK_GROUP_bf_test_and_set (struct GNUNET_BLOCK_Group *bg,
                                     const struct GNUNET_HashCode *hc)
 {
-  struct BfGroupInternals *gi = bg->internal_cls;
+  struct BfGroupInternals *gi;
   struct GNUNET_HashCode mhash;
 
+  if (NULL == bg)
+    return GNUNET_NO;
+  gi = bg->internal_cls;
   GNUNET_BLOCK_mingle_hash (hc,
                             gi->bf_mutator,
                             &mhash);
diff --git a/src/block/block.c b/src/block/block.c
index d4f5462dd..b7a19ae90 100644
--- a/src/block/block.c
+++ b/src/block/block.c
@@ -162,6 +162,7 @@ GNUNET_BLOCK_context_destroy (struct GNUNET_BLOCK_Context *ctx)
  * Serialize state of a block group.
  *
  * @param bg group to serialize
+ * @param[out] nonce set to the nonce of the @a bg
  * @param[out] raw_data set to the serialized state
  * @param[out] raw_data_size set to the number of bytes in @a raw_data
  * @return #GNUNET_OK on success, #GNUNET_NO if serialization is not
@@ -169,9 +170,11 @@ GNUNET_BLOCK_context_destroy (struct GNUNET_BLOCK_Context *ctx)
  */
 int
 GNUNET_BLOCK_group_serialize (struct GNUNET_BLOCK_Group *bg,
+                              uint32_t *nonce,
                               void **raw_data,
                               size_t *raw_data_size)
 {
+  *nonce = 0;
   *raw_data = NULL;
   *raw_data_size = 0;
   if (NULL == bg)
@@ -179,6 +182,7 @@ GNUNET_BLOCK_group_serialize (struct GNUNET_BLOCK_Group *bg,
   if (NULL == bg->serialize_cb)
     return GNUNET_NO;
   return bg->serialize_cb (bg,
+                           nonce,
                            raw_data,
                            raw_data_size);
 }
@@ -199,6 +203,41 @@ GNUNET_BLOCK_group_destroy (struct GNUNET_BLOCK_Group *bg)
 
 
 /**
+ * Try merging two block groups.  Afterwards, @a bg1 should remain
+ * valid and contain the rules from both @a bg1 and @bg2, and
+ * @a bg2 should be destroyed (as part of this call).  The latter
+ * should happen even if merging is not supported.
+ *
+ * @param[in,out] bg1 first group to merge, is updated
+ * @param bg2 second group to merge, is destroyed
+ * @return #GNUNET_OK on success,
+ *         #GNUNET_NO if merge failed due to different nonce
+ *         #GNUNET_SYSERR if merging is not supported
+ */
+int
+GNUNET_BLOCK_group_merge (struct GNUNET_BLOCK_Group *bg1,
+                          struct GNUNET_BLOCK_Group *bg2)
+{
+  int ret;
+
+  if (NULL == bg2)
+    return GNUNET_OK;
+  if (NULL == bg1)
+  {
+    bg2->destroy_cb (bg2);
+    return GNUNET_OK;
+  }
+  if (NULL == bg1->merge_cb)
+    return GNUNET_SYSERR;
+  GNUNET_assert (bg1->merge_cb == bg1->merge_cb);
+  ret = bg1->merge_cb (bg1,
+                       bg2);
+  bg2->destroy_cb (bg2);
+  return ret;
+}
+
+
+/**
  * Find a plugin for the given type.
  *
  * @param ctx context to search
@@ -244,19 +283,26 @@ GNUNET_BLOCK_group_create (struct GNUNET_BLOCK_Context *ctx,
                            enum GNUNET_BLOCK_Type type,
                            uint32_t nonce,
                            const void *raw_data,
-                           size_t raw_data_size)
+                           size_t raw_data_size,
+                           ...)
 {
   struct GNUNET_BLOCK_PluginFunctions *plugin;
+  struct GNUNET_BLOCK_Group *bg;
+  va_list ap;
 
   plugin = find_plugin (ctx,
                         type);
   if (NULL == plugin->create_group)
     return NULL;
-  return plugin->create_group (plugin->cls,
-                               type,
-                               nonce,
-                               raw_data,
-                               raw_data_size);
+  va_start (ap, raw_data_size);
+  bg = plugin->create_group (plugin->cls,
+                             type,
+                             nonce,
+                             raw_data,
+                             raw_data_size,
+                             ap);
+  va_end (ap);
+  return bg;
 }
 
 
@@ -269,10 +315,9 @@ GNUNET_BLOCK_group_create (struct GNUNET_BLOCK_Context *ctx,
  *
  * @param ctx block contxt
  * @param type block type
+ * @param block block group to use
  * @param eo control flags
  * @param query original query (hash)
- * @param bf pointer to bloom filter associated with query; possibly updated (!)
- * @param bf_mutator mutation value for @a bf
  * @param xquery extended query data (can be NULL, depending on type)
  * @param xquery_size number of bytes in @a xquery
  * @param reply_block response to validate
@@ -282,25 +327,24 @@ GNUNET_BLOCK_group_create (struct GNUNET_BLOCK_Context *ctx,
 enum GNUNET_BLOCK_EvaluationResult
 GNUNET_BLOCK_evaluate (struct GNUNET_BLOCK_Context *ctx,
                        enum GNUNET_BLOCK_Type type,
+                       struct GNUNET_BLOCK_Group *group,
                        enum GNUNET_BLOCK_EvaluationOptions eo,
                        const struct GNUNET_HashCode *query,
-                       struct GNUNET_CONTAINER_BloomFilter **bf,
-                       int32_t bf_mutator,
                        const void *xquery,
                        size_t xquery_size,
                        const void *reply_block,
                        size_t reply_block_size)
 {
-  struct GNUNET_BLOCK_PluginFunctions *plugin = find_plugin (ctx, type);
+  struct GNUNET_BLOCK_PluginFunctions *plugin = find_plugin (ctx,
+                                                             type);
 
-  if (plugin == NULL)
+  if (NULL == plugin)
     return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
   return plugin->evaluate (plugin->cls,
                            type,
+                           group,
                            eo,
                            query,
-                           bf,
-                           bf_mutator,
                            xquery,
                            xquery_size,
                            reply_block,
@@ -326,7 +370,8 @@ GNUNET_BLOCK_get_key (struct GNUNET_BLOCK_Context *ctx,
                       size_t block_size,
                       struct GNUNET_HashCode *key)
 {
-  struct GNUNET_BLOCK_PluginFunctions *plugin = find_plugin (ctx, type);
+  struct GNUNET_BLOCK_PluginFunctions *plugin = find_plugin (ctx,
+                                                             type);
 
   if (plugin == NULL)
     return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
@@ -335,65 +380,29 @@ GNUNET_BLOCK_get_key (struct GNUNET_BLOCK_Context *ctx,
 
 
 /**
- * How many bytes should a bloomfilter be if we have already seen
- * entry_count responses?  Note that #GNUNET_CONSTANTS_BLOOMFILTER_K
- * gives us the number of bits set per entry.  Furthermore, we should
- * not re-size the filter too often (to keep it cheap).
- *
- * Since other peers will also add entries but not resize the filter,
- * we should generally pick a slightly larger size than what the
- * strict math would suggest.
- *
- * @param entry_count expected number of entries in the Bloom filter
- * @return must be a power of two and smaller or equal to 2^15.
- */
-static size_t
-compute_bloomfilter_size (unsigned int entry_count)
-{
-  size_t size;
-  unsigned int ideal = (entry_count * GNUNET_CONSTANTS_BLOOMFILTER_K) / 4;
-  uint16_t max = 1 << 15;
-
-  if (entry_count > max)
-    return max;
-  size = 8;
-  while ((size < max) && (size < ideal))
-    size *= 2;
-  if (size > max)
-    return max;
-  return size;
-}
-
-
-/**
- * Construct a bloom filter that would filter out the given
- * results.
+ * Update block group to filter out the given results.  Note that the
+ * use of a hash for seen results implies that the caller magically
+ * knows how the specific block engine hashes for filtering
+ * duplicates, so this API may not always apply.
  *
  * @param bf_mutator mutation value to use
  * @param seen_results results already seen
  * @param seen_results_count number of entries in @a seen_results
- * @return NULL if seen_results_count is 0, otherwise a BF
- *         that would match the given results.
+ * @return #GNUNET_SYSERR if not supported, #GNUNET_OK on success
  */
-struct GNUNET_CONTAINER_BloomFilter *
-GNUNET_BLOCK_construct_bloomfilter (int32_t bf_mutator,
-                                    const struct GNUNET_HashCode *seen_results,
-                                    unsigned int seen_results_count)
+int
+GNUNET_BLOCK_group_set_seen (struct GNUNET_BLOCK_Group *bg,
+                             const struct GNUNET_HashCode *seen_results,
+                             unsigned int seen_results_count)
 {
-  struct GNUNET_CONTAINER_BloomFilter *bf;
-  struct GNUNET_HashCode mhash;
-  unsigned int i;
-  size_t nsize;
-
-  nsize = compute_bloomfilter_size (seen_results_count);
-  bf = GNUNET_CONTAINER_bloomfilter_init (NULL, nsize,
-                                          GNUNET_CONSTANTS_BLOOMFILTER_K);
-  for (i = 0; i < seen_results_count; i++)
-  {
-    GNUNET_BLOCK_mingle_hash (&seen_results[i], bf_mutator, &mhash);
-    GNUNET_CONTAINER_bloomfilter_add (bf, &mhash);
-  }
-  return bf;
+  if (NULL == bg)
+    return GNUNET_OK;
+  if (NULL == bg->mark_seen_cb)
+    return GNUNET_SYSERR;
+  bg->mark_seen_cb (bg,
+                    seen_results,
+                    seen_results_count);
+  return GNUNET_OK;
 }
 
 
diff --git a/src/block/plugin_block_template.c b/src/block/plugin_block_template.c
index 6cb69ef5f..0e8107af2 100644
--- a/src/block/plugin_block_template.c
+++ b/src/block/plugin_block_template.c
@@ -26,9 +26,52 @@
 
 #include "platform.h"
 #include "gnunet_block_plugin.h"
+#include "gnunet_block_group_lib.h"
 
 #define DEBUG_TEMPLATE GNUNET_EXTRA_LOGGING
 
+/**
+ * Number of bits we set per entry in the bloomfilter.
+ * Do not change!
+ */
+#define BLOOMFILTER_K 16
+
+
+/**
+ * How big is the BF we use for DHT blocks?
+ */
+#define TEMPLATE_BF_SIZE 8
+
+
+/**
+ * Create a new block group.
+ *
+ * @param ctx block context in which the block group is created
+ * @param type type of the block for which we are creating the group
+ * @param nonce random value used to seed the group creation
+ * @param raw_data optional serialized prior state of the group, NULL if unavailable/fresh
+ * @param raw_data_size number of bytes in @a raw_data, 0 if unavailable/fresh
+ * @param va variable arguments specific to @a type
+ * @return block group handle, NULL if block groups are not supported
+ *         by this @a type of block (this is not an error)
+ */
+static struct GNUNET_BLOCK_Group *
+block_plugin_template_create_group (void *cls,
+                                    enum GNUNET_BLOCK_Type type,
+                                    uint32_t nonce,
+                                    const void *raw_data,
+                                    size_t raw_data_size,
+                                    va_list va)
+{
+  return GNUNET_BLOCK_GROUP_bf_create (cls,
+                                       TEMPLATE_BF_SIZE,
+                                       BLOOMFILTER_K,
+                                       type,
+                                       nonce,
+                                       raw_data,
+                                       raw_data_size);
+}
+
 
 /**
  * Function called to validate a reply or a request.  For
@@ -36,10 +79,9 @@
  *
  * @param cls closure
  * @param type block type
+ * @param group block group to use
  * @param eo control flags
  * @param query original query (hash)
- * @param bf pointer to bloom filter associated with query; possibly updated (!)
- * @param bf_mutator mutation value for bf
  * @param xquery extrended query data (can be NULL, depending on type)
  * @param xquery_size number of bytes in xquery
  * @param reply_block response to validate
@@ -49,36 +91,25 @@
 static enum GNUNET_BLOCK_EvaluationResult
 block_plugin_template_evaluate (void *cls,
                                 enum GNUNET_BLOCK_Type type,
+                                struct GNUNET_BLOCK_Group *group,
                                 enum GNUNET_BLOCK_EvaluationOptions eo,
                                 const struct GNUNET_HashCode *query,
-                                struct GNUNET_CONTAINER_BloomFilter **bf,
-                                int32_t bf_mutator,
                                 const void *xquery,
                                 size_t xquery_size,
                                 const void *reply_block,
                                 size_t reply_block_size)
 {
   struct GNUNET_HashCode chash;
-  struct GNUNET_HashCode mhash;
-  /* FIXME: check validity first... */
 
-  /* mandatory duplicate-detection code... */
-  if (NULL != bf)
-  {
-    GNUNET_CRYPTO_hash (reply_block, reply_block_size, &chash);
-    GNUNET_BLOCK_mingle_hash (&chash, bf_mutator, &mhash);
-    if (NULL != *bf)
-    {
-      if (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (*bf, &mhash))
-        return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
-    }
-    else
-    {
-      *bf = GNUNET_CONTAINER_bloomfilter_init (NULL, 8, 64 /* BLOOMFILTER_K */);
-    }
-    GNUNET_CONTAINER_bloomfilter_add (*bf, &mhash);
-  }
-  /* FIXME: other stuff here... */
+  if (NULL == reply_block)
+    return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
+  GNUNET_CRYPTO_hash (reply_block,
+                      reply_block_size,
+                      &chash);
+  if (GNUNET_YES ==
+      GNUNET_BLOCK_GROUP_bf_test_and_set (group,
+                                          &chash))
+    return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
   return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
 }
 
@@ -91,13 +122,15 @@ block_plugin_template_evaluate (void *cls,
  * @param block block to get the key for
  * @param block_size number of bytes in block
  * @param key set to the key (query) for the given block
- * @return GNUNET_OK on success, GNUNET_SYSERR if type not supported
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if type not supported
  *         (or if extracting a key from a block of this type does not work)
  */
 static int
-block_plugin_template_get_key (void *cls, enum GNUNET_BLOCK_Type type,
-                               const void *block, size_t block_size,
-                               struct GNUNET_HashCode * key)
+block_plugin_template_get_key (void *cls,
+                               enum GNUNET_BLOCK_Type type,
+                               const void *block,
+                               size_t block_size,
+                               struct GNUNET_HashCode *key)
 {
   return GNUNET_SYSERR;
 }
@@ -119,6 +152,7 @@ libgnunet_plugin_block_template_init (void *cls)
   api = GNUNET_new (struct GNUNET_BLOCK_PluginFunctions);
   api->evaluate = &block_plugin_template_evaluate;
   api->get_key = &block_plugin_template_get_key;
+  api->create_group = &block_plugin_template_create_group;
   api->types = types;
   return api;
 }
diff --git a/src/block/plugin_block_test.c b/src/block/plugin_block_test.c
index b692d6230..615f1571b 100644
--- a/src/block/plugin_block_test.c
+++ b/src/block/plugin_block_test.c
@@ -27,7 +27,7 @@
 
 #include "platform.h"
 #include "gnunet_block_plugin.h"
-
+#include "gnunet_block_group_lib.h"
 
 /**
  * Number of bits we set per entry in the bloomfilter.
@@ -36,15 +36,50 @@
 #define BLOOMFILTER_K 16
 
 /**
+ * How big is the BF we use for DHT blocks?
+ */
+#define TEST_BF_SIZE 8
+
+
+/**
+ * Create a new block group.
+ *
+ * @param ctx block context in which the block group is created
+ * @param type type of the block for which we are creating the group
+ * @param nonce random value used to seed the group creation
+ * @param raw_data optional serialized prior state of the group, NULL if unavailable/fresh
+ * @param raw_data_size number of bytes in @a raw_data, 0 if unavailable/fresh
+ * @param va variable arguments specific to @a type
+ * @return block group handle, NULL if block groups are not supported
+ *         by this @a type of block (this is not an error)
+ */
+static struct GNUNET_BLOCK_Group *
+block_plugin_test_create_group (void *cls,
+                                enum GNUNET_BLOCK_Type type,
+                                uint32_t nonce,
+                                const void *raw_data,
+                                size_t raw_data_size,
+                                va_list va)
+{
+  return GNUNET_BLOCK_GROUP_bf_create (cls,
+                                       TEST_BF_SIZE,
+                                       BLOOMFILTER_K,
+                                       type,
+                                       nonce,
+                                       raw_data,
+                                       raw_data_size);
+}
+
+
+/**
  * Function called to validate a reply or a request.  For
  * request evaluation, simply pass "NULL" for the reply_block.
  *
  * @param cls closure
  * @param type block type
+ * @param group group to check against
  * @param eo control flags
  * @param query original query (hash)
- * @param bf pointer to bloom filter associated with query; possibly updated (!)
- * @param bf_mutator mutation value for @a bf
  * @param xquery extrended query data (can be NULL, depending on type)
  * @param xquery_size number of bytes in @a xquery
  * @param reply_block response to validate
@@ -54,20 +89,21 @@
 static enum GNUNET_BLOCK_EvaluationResult
 block_plugin_test_evaluate (void *cls,
                             enum GNUNET_BLOCK_Type type,
+                            struct GNUNET_BLOCK_Group *group,
                             enum GNUNET_BLOCK_EvaluationOptions eo,
                             const struct GNUNET_HashCode *query,
-                            struct GNUNET_CONTAINER_BloomFilter **bf,
-                            int32_t bf_mutator,
                             const void *xquery,
                             size_t xquery_size,
                             const void *reply_block,
                             size_t reply_block_size)
 {
   struct GNUNET_HashCode chash;
-  struct GNUNET_HashCode mhash;
 
   if ( GNUNET_BLOCK_TYPE_TEST != type)
+  {
+    GNUNET_break (0);
     return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
+  }
   if (0 != xquery_size)
   {
     GNUNET_break_op (0);
@@ -75,22 +111,13 @@ block_plugin_test_evaluate (void *cls,
   }
   if (NULL == reply_block)
     return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
-
-  if (NULL != bf)
-  {
-    GNUNET_CRYPTO_hash (reply_block, reply_block_size, &chash);
-    GNUNET_BLOCK_mingle_hash (&chash, bf_mutator, &mhash);
-    if (NULL != *bf)
-    {
-      if (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (*bf, &mhash))
-        return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
-    }
-    else
-    {
-      *bf = GNUNET_CONTAINER_bloomfilter_init (NULL, 8, BLOOMFILTER_K);
-    }
-    GNUNET_CONTAINER_bloomfilter_add (*bf, &mhash);
-  }
+  GNUNET_CRYPTO_hash (reply_block,
+                      reply_block_size,
+                      &chash);
+  if (GNUNET_YES ==
+      GNUNET_BLOCK_GROUP_bf_test_and_set (group,
+                                          &chash))
+    return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
   return GNUNET_BLOCK_EVALUATION_OK_MORE;
 }
 
@@ -107,9 +134,11 @@ block_plugin_test_evaluate (void *cls,
  *         (or if extracting a key from a block of this type does not work)
  */
 static int
-block_plugin_test_get_key (void *cls, enum GNUNET_BLOCK_Type type,
-                           const void *block, size_t block_size,
-                           struct GNUNET_HashCode * key)
+block_plugin_test_get_key (void *cls,
+                           enum GNUNET_BLOCK_Type type,
+                           const void *block,
+                           size_t block_size,
+                           struct GNUNET_HashCode *key)
 {
   /* always fails since there is no fixed relationship between
    * keys and values for test values */
@@ -136,6 +165,7 @@ libgnunet_plugin_block_test_init (void *cls)
   api = GNUNET_new (struct GNUNET_BLOCK_PluginFunctions);
   api->evaluate = &block_plugin_test_evaluate;
   api->get_key = &block_plugin_test_get_key;
+  api->create_group = &block_plugin_test_create_group;
   api->types = types;
   return api;
 }