towards pluggable block library

1 files changed, 117 insertions, 0 deletions

diff --git a/src/block/plugin_block.h b/src/block/plugin_block.h
new file mode 100644
index 000000000..671f83aad
--- /dev/null
+++ b/src/block/plugin_block.h
@@ -0,0 +1,117 @@
+/*
+     This file is part of GNUnet
+     (C) 2010 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
+     by the Free Software Foundation; either version 3, or (at your
+     option) any later version.
+
+     GNUnet is distributed in the hope that it will be useful, but
+     WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file block/plugin_block.h
+ * @brief API for block plugins.  Each block plugin must conform to 
+ *        the API specified by this header.
+ * @author Christian Grothoff
+ */
+#ifndef PLUGIN_BLOCK_H
+#define PLUGIN_BLOCK_H
+
+#include "gnunet_util_lib.h"
+#include "gnunet_container_lib.h"
+#include "gnunet_block_lib.h"
+
+
+
+/**
+ * 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 cls closure
+ * @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
+ */
+typedef enum GNUNET_BLOCK_EvaluationResult
+  (*GNUNET_BLOCK_EvaluationFunction) (void *cls,
+                                      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);
+
+
+/**
+ * Function called to obtain the key for a block.
+ *
+ * @param cls closure
+ * @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)
+ */
+typedef int
+  (*GNUNET_BLOCK_GetKeyFunction) (void *cls,
+                                  enum GNUNET_BLOCK_Type type,
+                                  const void *block,
+                                  size_t block_size,
+                                  GNUNET_HashCode *key);
+                                  
+
+
+/**
+ * Each plugin is required to return a pointer to a struct of this
+ * type as the return value from its entry point.
+ */
+struct GNUNET_BLOCK_PluginFunctions
+{
+
+  /**
+   * Closure for all of the callbacks.
+   */
+  void *cls;
+
+  /**
+   * 0-terminated array of block types supported by this plugin.
+   */
+  const enum GNUNET_BLOCK_Type *types;
+
+  /**
+   * Main function of a block plugin.  Allows us to check if a 
+   * block matches a query.
+   */
+  GNUNET_BLOCK_EvaluationFunction evaluate;
+
+  /**
+   * Obtain the key for a given block (if possible).
+   */
+  GNUNET_BLOCK_GetKeyFunction get_key;
+
+};
+
+
+#endif