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author | Mattias Andrée <maandree@kth.se> | 2016-07-11 20:28:28 +0200 |
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committer | Mattias Andrée <maandree@kth.se> | 2016-07-11 20:28:28 +0200 |
commit | 564cbb378e1480ff736a14c832d39fe6db9f7891 (patch) | |
tree | 4f5e3377f21c173b6a7f72a11071fa8aa0637fd9 /src/message.h | |
parent | Add signal handlers (diff) | |
download | coopgammad-564cbb378e1480ff736a14c832d39fe6db9f7891.tar.gz coopgammad-564cbb378e1480ff736a14c832d39fe6db9f7891.tar.bz2 coopgammad-564cbb378e1480ff736a14c832d39fe6db9f7891.tar.xz |
whitespace + Add message.[ch]
Signed-off-by: Mattias Andrée <maandree@kth.se>
Diffstat (limited to 'src/message.h')
-rw-r--r-- | src/message.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/src/message.h b/src/message.h new file mode 100644 index 0000000..163d806 --- /dev/null +++ b/src/message.h @@ -0,0 +1,132 @@ +/** + * gammad -- Cooperative gamma server + * Copyright (C) 2016 Mattias Andrée (maandree@kth.se) + * + * This library 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 library 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 library. If not, see <http://www.gnu.org/licenses/>. + */ +#include <stddef.h> + + + +/** + * Message passed between a server and a client + */ +struct message +{ + /** + * The headers in the message, each element in this list + * as an unparsed header, it consists of both the header + * name and its associated value, joined by ": ". A header + * cannot be `NULL` (unless its memory allocation failed,) + * but `headers` itself is `NULL` if there are no headers. + * The "Length" header should be included in this list. + */ + char** headers; + + /** + * The number of headers in the message + */ + size_t header_count; + + /** + * The payload of the message, `NULL` if none (of zero-length) + */ + char* payload; + + /** + * The size of the payload + */ + size_t payload_size; + + /** + * How much of the payload that has been stored (internal data) + */ + size_t payload_ptr; + + /** + * Internal buffer for the reading function (internal data) + */ + char* buffer; + + /** + * The size allocated to `buffer` (internal data) + */ + size_t buffer_size; + + /** + * The number of bytes used in `buffer` (internal data) + */ + size_t buffer_ptr; + + /** + * 0 while reading headers, 1 while reading payload, and 2 when done (internal data) + */ + int stage; + +}; + + + +/** + * Initialise a message slot so that it can + * be used by to read messages + * + * @param this Memory slot in which to store the new message + * @return Non-zero on error, `errno` will be set accordingly + */ +int message_initialise(struct message* this); + +/** + * Release all resources in a message, should + * be done even if initialisation fails + * + * @param this The message + */ +void message_destroy(struct message* this); + +/** + * Marshal a message for state serialisation + * + * @param this The message + * @param buf Output buffer for the marshalled data, + * `NULL` just measure how large the buffers + * needs to be + * @return The number of marshalled byte + */ +size_t message_marshal(const struct message* this, void* buf); + +/** + * Unmarshal a message for state deserialisation + * + * @param this Memory slot in which to store the new message + * @param buf In buffer with the marshalled data + * @return The number of unmarshalled bytes, 0 on error + */ +size_t message_unmarshal(struct message* this, const void* buf); + +/** + * Read the next message from a file descriptor + * + * @param this Memory slot in which to store the new message + * @param fd The file descriptor + * @return Non-zero on error or interruption, `errno` will be + * set accordingly. Destroy the message on error, + * be aware that the reading could have been + * interrupted by a signal rather than canonical error. + * If -2 is returned `errno` will not have been set, + * -2 indicates that the message is malformated, + * which is a state that cannot be recovered from. + */ +int message_read(struct message* this, int fd); + |