towards pluggable block library

1 files changed, 181 insertions, 0 deletions

diff --git a/src/block/block.c b/src/block/block.c
index 72dedd7be..cb6837499 100644
--- a/src/block/block.c
+++ b/src/block/block.c
@@ -27,6 +27,7 @@
 #include "gnunet_util_lib.h"
 #include "gnunet_signatures.h"
 #include "gnunet_block_lib.h"
+#include "plugin_block.h"
 
 /**
  * Check if the given KBlock is well-formed.
@@ -226,5 +227,185 @@ GNUNET_BLOCK_check_block (enum GNUNET_BLOCK_Type type,
   return GNUNET_OK;
 }
 
+/* ***************** NEW API ******************* */
+
+/**
+ * Handle for a plugin.
+ */
+struct Plugin
+{
+  /**
+   * Name of the shared library.
+   */ 
+  char *library_name;
+  
+  /**
+   * Plugin API.
+   */
+  struct GNUNET_BLOCK_PluginFunctions *api;
+};
+
+/**
+ * Handle to an initialized block library.
+ */
+struct GNUNET_BLOCK_Context
+{
+  /**
+   * NULL-terminated array of our plugins.
+   */
+  struct Plugin **plugins;
+
+  /**
+   * Our configuration.
+   */ 
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+};
+
+
+/**
+ * Create a block context.  Loads the block plugins.
+ *
+ * @param cfg configuration to use
+ * @return NULL on error
+ */
+struct GNUNET_BLOCK_Context *
+GNUNET_BLOCK_context_create (const struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct GNUNET_BLOCK_Context *ctx;
+  unsigned int num_plugins;
+
+  ctx = GNUNET_malloc (sizeof (struct GNUNET_BLOCK_Context));
+  ctx->cfg = cfg;
+  num_plugins = 0;
+  /* FIXME: actually load plugins... */
+  GNUNET_array_append (ctx->plugins,
+                       num_plugins,
+                       NULL);
+  return ctx;
+}
+
+
+/**
+ * Destroy the block context.
+ *
+ * @param ctx context to destroy
+ */
+void
+GNUNET_BLOCK_context_destroy (struct GNUNET_BLOCK_Context *ctx)
+{
+  unsigned int i;
+  struct Plugin *plugin;
+
+  i = 0;
+  while (NULL != (plugin = ctx->plugins[i]))
+    {
+      GNUNET_break (NULL == 
+                    GNUNET_PLUGIN_unload (plugin->library_name,
+                                          plugin->api));
+      GNUNET_free (plugin->library_name);
+      GNUNET_free (plugin);
+      i++;
+    }
+  GNUNET_free (ctx->plugins);
+  GNUNET_free (ctx);
+}
+
+
+/**
+ * Find a plugin for the given type.
+ *
+ * @param ctx context to search
+ * @param type type to look for
+ * @return NULL if no matching plugin exists
+ */
+static struct GNUNET_BLOCK_PluginFunctions *
+find_plugin (struct GNUNET_BLOCK_Context *ctx,
+             enum GNUNET_BLOCK_Type type)
+{
+  struct Plugin *plugin;
+  unsigned int i;
+  unsigned int j;
+
+  i = 0;
+  while (NULL != (plugin = ctx->plugins[i]))
+    {
+      j = 0;
+      while (0 != (plugin->api->types[j]))
+        {
+          if (type == plugin->api->types[j])
+            return plugin->api;
+          j++;
+        }
+      i++;
+    }
+  return NULL;
+}
+
+
+/**
+ * Function called to validate a reply or a request.  For
+ * request evaluation, simply pass "NULL" for the reply_block.
+ * Note that it is assumed that the reply has already been 
+ * matched to the key (and signatures checked) as it would
+ * be done with the "get_key" function.
+ *
+ * @param ctx block contxt
+ * @param type block type
+ * @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
+ * @param reply_block_size number of bytes in reply block
+ * @return characterization of result
+ */
+enum GNUNET_BLOCK_EvaluationResult
+GNUNET_BLOCK_evaluate (struct GNUNET_BLOCK_Context *ctx,
+                       enum GNUNET_BLOCK_Type type,
+                       const 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);
+
+  if (plugin == NULL)
+    return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
+  return plugin->evaluate (plugin->cls,
+                           type, query, bf, bf_mutator,
+                           xquery, xquery_size, reply_block, reply_block_size);
+}
+
+
+/**
+ * Function called to obtain the key for a block.
+ *
+ * @param ctx block context
+ * @param type block type
+ * @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
+ *         (or if extracting a key from a block of this type does not work)
+ */
+int
+GNUNET_BLOCK_get_key (struct GNUNET_BLOCK_Context *ctx,
+                      enum GNUNET_BLOCK_Type type,
+                      const void *block,
+                      size_t block_size,
+                      GNUNET_HashCode *key)
+{
+  struct GNUNET_BLOCK_PluginFunctions *plugin = find_plugin (ctx, type);
+
+  if (plugin == NULL)
+    return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
+  return plugin->get_key (plugin->cls,
+                          type, block, block_size, key);
+}
+
 
 /* end of block.c */