1 files changed, 121 insertions, 0 deletions
diff --git a/ctdb/common/srvid.h b/ctdb/common/srvid.h
new file mode 100644
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+++ b/ctdb/common/srvid.h
@@ -0,0 +1,121 @@
+/*
+   Message handler database based on srvid
+
+   Copyright (C) Amitay Isaacs  2015
+
+   This program 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 of the License, or
+   (at your option) any later version.
+
+   This program 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 this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __CTDB_SRVID_H__
+#define __CTDB_SRVID_H__
+
+#include <talloc.h>
+#include <tdb.h>
+
+/**
+ * @file srvid.h
+ *
+ * @brief Database of message handlers based on srvid
+ *
+ * CTDB can be used to send messages between clients across nodes using
+ * CTDB_REQ_MESSAGE. Clients register for messages based on srvid. CTDB itself
+ * uses a small set of srvid messages. A large range (2^56) of srvid messages
+ * is reserved for Samba.
+ */
+
+/**
+ * @brief Message handler function
+ *
+ * To receive messages for a specific srvid, register a message handler function
+ * for the srvid.
+ */
+typedef void (*srvid_handler_fn)(uint64_t srvid, TDB_DATA data,
+				 void *private_data);
+
+/**
+ * @brief Abstract struct to store srvid message handler database
+ */
+struct srvid_context;
+
+/**
+ * @brief Initialize srvid message handler database
+ *
+ * This returns a new srvid message handler database context. Freeing
+ * this context will free all the memory associated with the hash table.
+ *
+ * @param[in] mem_ctx Talloc memory context
+ * @param[out] result The new db_hash_context structure
+ * @return 0 on success, errno on failure
+ */
+int srvid_init(TALLOC_CTX *mem_ctx, struct srvid_context **result);
+
+/**
+ * @brief Register a message handler for a srvid
+ *
+ * The message handler is allocated using the specified talloc context. Freeing
+ * this talloc context, removes the message handler.
+ *
+ * @param[in] srv The srvid message handler database context
+ * @param[in] mem_ctx Talloc memory context for message handler
+ * @param[in] srvid The srvid
+ * @param[in] handler The message handler function for srvid
+ * @param[in] private_data Private data for message handler function
+ * @return 0 on success, errno on failure
+ */
+int srvid_register(struct srvid_context *srv, TALLOC_CTX *mem_ctx,
+		   uint64_t srvid, srvid_handler_fn handler,
+		   void *private_data);
+
+/**
+ * @brief Unregister a message handler for a srvid
+ *
+ * @param[in] srv The srvid message handler database context
+ * @param[in] srvid The srvid
+ * @param[in] private_data Private data of message handler function
+ * @return 0 on success, errno on failure
+ */
+int srvid_deregister(struct srvid_context *srv, uint64_t srvid,
+		     void *private_data);
+
+/**
+ * @brief Check if any message handler is registered for srvid
+ *
+ * If private_data is NULL, then check if there is any registration
+ * for * specified srvid.  If private_data is not NULL, then check for
+ * registration that matches the specified private data.
+ *
+ * @param[in] srv The srvid message handler database context
+ * @param[in] srvid The srvid
+ * @param[in] private_data Private data
+ * @return 0 on success, errno on failure
+ */
+int srvid_exists(struct srvid_context *srv, uint64_t srvid,
+		 void *private_data);
+
+/**
+ * @brief Call message handlers for given srvid
+ *
+ * @param[in] srv The srvid message handler database context
+ * @param[in] srvid The srvid
+ * @param[in] srvid_all The srvid that gets all messages
+ * @param[in] data The data passed to each message handler
+ * @return 0 on success, errno on failure
+ *
+ * If srvid_all passed is 0, the message is not sent to message handlers
+ * registered with special srvid to receive all messages.
+ */
+int srvid_dispatch(struct srvid_context *srv, uint64_t srvid,
+		   uint64_t srvid_all, TDB_DATA data);
+
+#endif /* __CTDB_SRVID_H__ */