Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 98 insertions, 0 deletions

diff --git a/ctdb/common/pkt_read.h b/ctdb/common/pkt_read.h
new file mode 100644
index 0000000..25d4a51
--- /dev/null
+++ b/ctdb/common/pkt_read.h
@@ -0,0 +1,98 @@
+/*
+   API for reading packets using fixed and dynamic buffer
+
+   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_READ_H__
+#define __CTDB_PKT_READ_H__
+
+#include <talloc.h>
+#include <tevent.h>
+
+/**
+ * @file pkt_read.h
+ *
+ * @brief Read a packet using fixed size buffer or allocated memory.
+ *
+ * CTDB communication uses lots of small packets.  This abstraction avoids the
+ * need to allocate memory for small packets.  Only if the received packet is
+ * larger than the fixed memory buffer, use talloc to allocate memory.
+ */
+
+/**
+ * @brief Start async computation to read a packet
+ *
+ * This returns a tevent request to read a packet from 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 read from
+ * @param[in] initial Initial amount of data to read
+ * @param[in] buf The static buffer to read data in
+ * @param[in] buflen The size of the static buffer
+ * @param[in] more The function to check if the bytes read forms a packet
+ * @param[in] private_data Private data to pass to more function
+ * @return new tevent request or NULL on failure
+ */
+struct tevent_req *pkt_read_send(TALLOC_CTX *mem_ctx,
+				 struct tevent_context *ev,
+				 int fd, size_t initial,
+				 uint8_t *buf, size_t buflen,
+				 ssize_t (*more)(uint8_t *buf,
+						 size_t buflen,
+						 void *private_data),
+				 void *private_data);
+
+/**
+ * @brief Function to actually read data from the socket
+ *
+ * This function should be called, when tevent fd event is triggered.  This
+ * function has the syntax of tevent_fd_handler_t.  The private_data for this
+ * function is the tevent request created by pkt_read_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_read_handler(struct tevent_context *ev, struct tevent_fd *fde,
+		      uint16_t flags, struct tevent_req *req);
+
+/**
+ * @brief Retrieve a packet
+ *
+ * This function returns the pkt read from fd.
+ *
+ * @param[in] req Tevent request
+ * @param[in] mem_ctx Talloc memory context
+ * @param[out] pbuf The pointer to the buffer
+ * @param[out] free_buf Boolean to indicate that caller should free buffer
+ * @param[out] perrno errno in case of failure
+ * @return the size of the pkt, or -1 on failure
+ *
+ * If the pkt data is dynamically allocated, then it is moved under the
+ * specified talloc memory context and free_buf is set to true.  It is the
+ * responsibility of the caller to the free the memory returned.
+ *
+ * If the pkt data is stored in the fixed buffer, then free_buf is set to false.
+ */
+ssize_t pkt_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
+		      uint8_t **pbuf, bool *free_buf, int *perrno);
+
+#endif /* __CTDB_PKT_READ_H__ */