src/cx/streams.h

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @file streams.h
 *
 * @brief Utility functions for data streams.
 *
 * @author Mike Becker
 * @author Olaf Wintermann
 * @copyright 2-Clause BSD License
 */

#ifndef UCX_STREAMS_H
#define UCX_STREAMS_H

#include "common.h"

/**
 * Reads data from a stream and writes it to another stream.
 *
 * @param src the source stream
 * @param dest the destination stream
 * @param rfnc the read function
 * @param wfnc the write function
 * @param buf a pointer to the copy buffer or @c NULL if a buffer
 * shall be implicitly created on the heap
 * @param bufsize the size of the copy buffer - if @p buf is @c NULL, you can
 * set this to zero to let the implementation decide
 * @param n the maximum number of bytes that shall be copied.
 * If this is larger than @p bufsize, the content is copied over multiple
 * iterations.
 * @return the total number of bytes copied
 */
CX_EXTERN CX_NONNULL_ARG(1, 2, 3, 4)
CX_ACCESS_R(1) CX_ACCESS_W(2) CX_ACCESS_W(5)
size_t cx_stream_bncopy(void *src, void *dest,
        cx_read_func rfnc, cx_write_func wfnc,
        char *buf, size_t bufsize, size_t n);

/**
 * Reads data from a stream and writes it to another stream.
 *
 * @param src (@c void*) the source stream
 * @param dest (@c void*) the destination stream
 * @param rfnc (@c cx_read_func) the read function
 * @param wfnc (@c cx_write_func) the write function
 * @param buf (@c char*) a pointer to the copy buffer or @c NULL if a buffer
 * shall be implicitly created on the heap
 * @param bufsize (@c size_t) the size of the copy buffer - if @p buf is
 * @c NULL, you can set this to zero to let the implementation decide
 * @return total number of bytes copied
 */
#define cx_stream_bcopy(src, dest, rfnc, wfnc, buf, bufsize) \
    cx_stream_bncopy(src, dest, rfnc, wfnc, buf, bufsize, SIZE_MAX)

/**
 * Reads data from a stream and writes it to another stream.
 *
 * The data is temporarily stored in a stack-allocated buffer.
 *
 * @param src the source stream
 * @param dest the destination stream
 * @param rfnc the read function
 * @param wfnc the write function
 * @param n the maximum number of bytes that shall be copied.
 * @return total number of bytes copied
 */
CX_EXTERN CX_NONNULL CX_ACCESS_R(1) CX_ACCESS_W(2)
size_t cx_stream_ncopy(void *src, void *dest,
        cx_read_func rfnc, cx_write_func wfnc, size_t n);

/**
 * Reads data from a stream and writes it to another stream.
 *
 * The data is temporarily stored in a stack-allocated buffer.
 *
 * @param src (@c void*) the source stream
 * @param dest (@c void*) the destination stream
 * @param rfnc (@c cx_read_func) the read function
 * @param wfnc (@c cx_write_func) the write function
 * @return total number of bytes copied
 */
#define cx_stream_copy(src, dest, rfnc, wfnc) \
    cx_stream_ncopy(src, dest, rfnc, wfnc, SIZE_MAX)

#endif // UCX_STREAMS_H