ctdb-common: Add packet write abstraction

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

1 files changed, 79 insertions, 0 deletions

diff --git a/ctdb/common/pkt_write.h b/ctdb/common/pkt_write.h
new file mode 100644
index 00000000000..19d8045343e
--- /dev/null
+++ b/ctdb/common/pkt_write.h
@@ -0,0 +1,79 @@
+/*
+   API for writing a packet
+
+   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_PKT_WRITE_H__
+#define __CTDB_PKT_WRITE_H__
+
+#include <talloc.h>
+#include <tevent.h>
+
+/**
+ * @file pkt_write.h
+ *
+ * @brief Write a packet.
+ *
+ * Write a complete packet with possibly multiple system calls.
+ */
+
+/**
+ * @brief Start async computation to write a packet
+ *
+ * This returns a tevent request to write a packet to given fd.  The fd
+ * should be nonblocking. Freeing this request will free all the memory
+ * associated with the request.
+ *
+ * @param[in] mem_ctx Talloc memory context
+ * @param[in] ev Tevent context
+ * @param[in] fd The non-blocking file/socket descriptor to write to
+ * @param[in] buf The data
+ * @param[in] buflen The size of the data
+ * @return new tevent request or NULL on failure
+ */
+struct tevent_req *pkt_write_send(TALLOC_CTX *mem_ctx,
+				  struct tevent_context *ev,
+				  int fd, uint8_t *buf, size_t buflen);
+
+/**
+ * @brief Function to actually write data to the socket
+ *
+ * This function should be called, when tevent fd event is triggered
+ * for TEVENT_FD_WRITE event.  This function has the syntax of
+ * tevent_fd_handler_t.  The private_data for this function is the tevent
+ * request created by pkt_write_send function.
+ *
+ * @param[in] ev Tevent context
+ * @param[in] fde Tevent fd context
+ * @param[in] flags Tevent fd flags
+ * @param[in] req The active tevent request
+ */
+void pkt_write_handler(struct tevent_context *ev, struct tevent_fd *fde,
+		       uint16_t flags, struct tevent_req *req);
+
+/**
+ * @brief Packet is sent
+ *
+ * This function returns the number of bytes written.
+ *
+ * @param[in] req Tevent request
+ * @param[out] perrno errno in case of failure
+ * @return the number of bytes written, or -1 on failure
+ */
+ssize_t pkt_write_recv(struct tevent_req *req, int *perrno);
+
+#endif /* __CTDB_PKT_WRITE_H__ */