5b82ffc291
After we've been hit by Large File Support problems several times in the past week (which only occur on 32 bit platforms, which I don't have), this is yet another attempt to fix the issue.
162 lines
3.8 KiB
C
162 lines
3.8 KiB
C
/*
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* Copyright (C) 2003-2009 The Music Player Daemon Project
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* http://www.musicpd.org
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "config.h"
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#include "fifo_buffer.h"
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#include <glib.h>
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#include <assert.h>
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#include <string.h>
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struct fifo_buffer {
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size_t size, start, end;
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unsigned char buffer[sizeof(size_t)];
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};
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struct fifo_buffer *
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fifo_buffer_new(size_t size)
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{
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struct fifo_buffer *buffer;
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assert(size > 0);
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buffer = (struct fifo_buffer *)g_malloc(sizeof(*buffer) -
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sizeof(buffer->buffer) + size);
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buffer->size = size;
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buffer->start = 0;
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buffer->end = 0;
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return buffer;
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}
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void
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fifo_buffer_free(struct fifo_buffer *buffer)
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{
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assert(buffer != NULL);
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g_free(buffer);
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}
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void
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fifo_buffer_clear(struct fifo_buffer *buffer)
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{
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assert(buffer != NULL);
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buffer->start = 0;
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buffer->end = 0;
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}
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const void *
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fifo_buffer_read(const struct fifo_buffer *buffer, size_t *length_r)
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{
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assert(buffer != NULL);
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assert(buffer->end >= buffer->start);
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assert(length_r != NULL);
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if (buffer->start == buffer->end)
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/* the buffer is empty */
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return NULL;
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*length_r = buffer->end - buffer->start;
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return buffer->buffer + buffer->start;
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}
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void
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fifo_buffer_consume(struct fifo_buffer *buffer, size_t length)
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{
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assert(buffer != NULL);
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assert(buffer->end >= buffer->start);
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assert(buffer->start + length <= buffer->end);
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buffer->start += length;
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}
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/**
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* Move data to the beginning of the buffer, to make room at the end.
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*/
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static void
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fifo_buffer_move(struct fifo_buffer *buffer)
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{
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if (buffer->start == 0)
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return;
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if (buffer->end > buffer->start)
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memmove(buffer->buffer,
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buffer->buffer + buffer->start,
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buffer->end - buffer->start);
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buffer->end -= buffer->start;
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buffer->start = 0;
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}
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void *
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fifo_buffer_write(struct fifo_buffer *buffer, size_t *max_length_r)
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{
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assert(buffer != NULL);
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assert(buffer->end <= buffer->size);
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assert(max_length_r != NULL);
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if (buffer->end == buffer->size) {
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fifo_buffer_move(buffer);
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if (buffer->end == buffer->size)
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return NULL;
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} else if (buffer->start > 0 && buffer->start == buffer->end) {
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buffer->start = 0;
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buffer->end = 0;
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}
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*max_length_r = buffer->size - buffer->end;
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return buffer->buffer + buffer->end;
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}
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void
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fifo_buffer_append(struct fifo_buffer *buffer, size_t length)
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{
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assert(buffer != NULL);
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assert(buffer->end >= buffer->start);
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assert(buffer->end + length <= buffer->size);
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buffer->end += length;
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}
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bool
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fifo_buffer_is_empty(struct fifo_buffer *buffer)
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{
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return buffer->start == buffer->end;
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}
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bool
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fifo_buffer_is_full(struct fifo_buffer *buffer)
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{
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return buffer->start == 0 && buffer->end == buffer->size;
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}
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