From d8b975f4e73ae940c0c0f9c8c6c7aac1199fee09 Mon Sep 17 00:00:00 2001 From: Martin Sustrik Date: Sat, 28 Aug 2010 13:14:45 +0200 Subject: msg_store_t renamed to swap_t --- src/swap.hpp | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 src/swap.hpp (limited to 'src/swap.hpp') diff --git a/src/swap.hpp b/src/swap.hpp new file mode 100644 index 0000000..c9dfd99 --- /dev/null +++ b/src/swap.hpp @@ -0,0 +1,114 @@ +/* + Copyright (c) 2007-2010 iMatix Corporation + + This file is part of 0MQ. + + 0MQ is free software; you can redistribute it and/or modify it under + the terms of the Lesser GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + 0MQ 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 + Lesser GNU General Public License for more details. + + You should have received a copy of the Lesser GNU General Public License + along with this program. If not, see . +*/ + +#ifndef __ZMQ_SWAP_HPP_INCLUDED__ +#define __ZMQ_SWAP_HPP_INCLUDED__ + +#include "../include/zmq.h" + +#include +#include "stdint.hpp" + +namespace zmq +{ + + // This class implements a message swap. Messages are retrieved from + // the swap in the same order as they entered it. + + class swap_t + { + public: + + enum { default_block_size = 8192 }; + + // Creates the swap. + swap_t (int64_t filesize_, size_t block_size_ = default_block_size); + + ~swap_t (); + + int init (); + + // Stores the message into the swap. The function + // returns false if the swap is full; true otherwise. + bool store (zmq_msg_t *msg_); + + // Fetches the oldest message from the swap. It is an error + // to call this function when the swap is empty. + void fetch (zmq_msg_t *msg_); + + void commit (); + + void rollback (); + + // Returns true if the swap is empty; false otherwise. + bool empty (); + + // Returns true if and only if the swap is full. + bool full (); + + private: + + // Copies data from a memory buffer to the backing file. + // Wraps around when reaching maximum file size. + void copy_from_file (void *buffer_, size_t count_); + + // Copies data from the backing file to the memory buffer. + // Wraps around when reaching end-of-file. + void copy_to_file (const void *buffer_, size_t count_); + + // Returns the buffer space available. + int64_t buffer_space (); + + void fill_buf (char *buf, int64_t pos); + + void save_write_buf (); + + // File descriptor to the backing file. + int fd; + + // Name of the backing file. + std::string filename; + + // Maximum size of the backing file. + int64_t filesize; + + // File offset associated with the fd file descriptor. + int64_t file_pos; + + // File offset the next message will be stored at. + int64_t write_pos; + + // File offset the next message will be read from. + int64_t read_pos; + + int64_t commit_pos; + + size_t block_size; + + char *buf1; + char *buf2; + char *read_buf; + char *write_buf; + + int64_t write_buf_start_addr; + }; + +} + +#endif -- cgit v1.2.3