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/*
* Copyright 2003-2020 The Music Player Daemon Project
* http://www.musicpd.org
*
* 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 2 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, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "FlacIOHandle.hxx"
#include "Log.hxx"
#include "util/Compiler.h"
#include "system/Error.hxx"
#include <errno.h>
#include <stdio.h>
static size_t
FlacIORead(void *ptr, size_t size, size_t nmemb, FLAC__IOHandle handle)
{
auto *is = (InputStream *)handle;
uint8_t *const p0 = (uint8_t *)ptr, *p = p0,
*const end = p0 + size * nmemb;
/* libFLAC is very picky about short reads, and expects the IO
callback to fill the whole buffer (undocumented!) */
while (p < end) {
try {
size_t nbytes = is->LockRead(p, end - p);
if (nbytes == 0)
/* end of file */
break;
p += nbytes;
#ifndef _WIN32
} catch (const std::system_error &e) {
errno = e.code().category() == ErrnoCategory()
? e.code().value()
/* just some random non-zero errno
value */
: EINVAL;
return 0;
#endif
} catch (...) {
/* just some random non-zero errno value */
errno = EINVAL;
return 0;
}
}
/* libFLAC expects a clean errno after returning from the IO
callbacks (undocumented!) */
errno = 0;
return (p - p0) / size;
}
static int
FlacIOSeek(FLAC__IOHandle handle, FLAC__int64 _offset, int whence)
{
auto *is = (InputStream *)handle;
offset_type offset = _offset;
switch (whence) {
case SEEK_SET:
break;
case SEEK_CUR:
offset += is->GetOffset();
break;
case SEEK_END:
if (!is->KnownSize())
return -1;
offset += is->GetSize();
break;
default:
return -1;
}
try {
is->LockSeek(offset);
return 0;
} catch (...) {
LogError(std::current_exception());
return -1;
}
}
static FLAC__int64
FlacIOTell(FLAC__IOHandle handle)
{
auto *is = (InputStream *)handle;
return is->GetOffset();
}
static int
FlacIOEof(FLAC__IOHandle handle)
{
auto *is = (InputStream *)handle;
return is->LockIsEOF();
}
static int
FlacIOClose(gcc_unused FLAC__IOHandle handle)
{
/* no-op because the libFLAC caller is responsible for closing
the #InputStream */
return 0;
}
const FLAC__IOCallbacks flac_io_callbacks = {
FlacIORead,
nullptr,
nullptr,
nullptr,
FlacIOEof,
FlacIOClose,
};
const FLAC__IOCallbacks flac_io_callbacks_seekable = {
FlacIORead,
nullptr,
FlacIOSeek,
FlacIOTell,
FlacIOEof,
FlacIOClose,
};
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