ctdb-common: Add communication endpoint abstraction

Signed-off-by: Amitay Isaacs <amitay@gmail.com>
Reviewed-by: Martin Schwenke <martin@meltin.net>

1 files changed, 101 insertions, 0 deletions

diff --git a/ctdb/common/comm.h b/ctdb/common/comm.h
new file mode 100644
index 00000000000..27021e945af
--- /dev/null
+++ b/ctdb/common/comm.h
@@ -0,0 +1,101 @@
+/*
+   Communication endpoint API
+
+   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_COMM_H__
+#define __CTDB_COMM_H__
+
+#include <talloc.h>
+#include <tevent.h>
+
+/**
+ * @file comm.h
+ *
+ * @brief Communication over a socket or file descriptor
+ *
+ * This abstraction is a wrapper around a socket or file descriptor to
+ * send/receive complete packets.
+ */
+
+/**
+ * @brief Packet handler function
+ *
+ * This function is registered while setting up communication endpoint.  Any
+ * time packets are read, this function is called.
+ */
+typedef void (*comm_read_handler_fn)(uint8_t *buf, size_t buflen,
+				     void *private_data);
+
+/**
+ * @brief Communication endpoint dead handler function
+ *
+ * This function is called when the communication endpoint is closed.
+ */
+typedef void (*comm_dead_handler_fn)(void *private_data);
+
+/**
+ * @brief Abstract struct to store communication endpoint details
+ */
+struct comm_context;
+
+/**
+ * @brief Initialize the communication endpoint
+ *
+ * This return a new communication context. Freeing this context will free all
+ * memory assoicated with it.
+ *
+ * @param[in] mem_ctx Talloc memory context
+ * @param[in] ev Tevent context
+ * @param[in] fd The socket or file descriptor
+ * @param[in] read_handler The packet handler function
+ * @param[in] read_private_data Private data for read handler function
+ * @param[in] dead_handler The communication dead handler function
+ * @param[in] dead_private_data Private data for dead handler function
+ * @param[out] result The new comm_context structure
+ * @return 0 on success, errno on failure
+ */
+int comm_setup(TALLOC_CTX *mem_ctx, struct tevent_context *ev, int fd,
+	       comm_read_handler_fn read_handler, void *read_private_data,
+	       comm_dead_handler_fn dead_handler, void *dead_private_data,
+	       struct comm_context **result);
+
+/**
+ * @brief Async computation start to send a packet
+ *
+ * @param[in] mem_ctx Talloc memory context
+ * @param[in] ev Tevent context
+ * @param[in] comm Communication context
+ * @param[in] buf The packet data
+ * @param[in] buflen The size of the packet
+ * @return new tevent request, or NULL on failure
+ */
+struct tevent_req *comm_write_send(TALLOC_CTX *mem_ctx,
+				   struct tevent_context *ev,
+				   struct comm_context *comm,
+				   uint8_t *buf, size_t buflen);
+
+/**
+ * @brief Async computation end to send a packet
+ *
+ * @param[in] req Tevent request
+ * @param[out] perr errno in case of failure
+ * @return true on success, false on failure
+ */
+bool comm_write_recv(struct tevent_req *req, int *perr);
+
+#endif /* __CTDB_COMM_H__ */