mpd/src/fs/io/GzipOutputStream.cxx

106 lines
2.5 KiB
C++
Raw Normal View History

/*
* Copyright (C) 2003-2014 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 "config.h"
#include "GzipOutputStream.hxx"
#include "lib/zlib/Domain.hxx"
#include "util/Error.hxx"
#include "util/Domain.hxx"
GzipOutputStream::GzipOutputStream(OutputStream &_next, Error &error)
:next(_next)
{
z.next_in = nullptr;
z.avail_in = 0;
z.zalloc = Z_NULL;
z.zfree = Z_NULL;
z.opaque = Z_NULL;
constexpr int windowBits = 15;
constexpr int gzip_encoding = 16;
int result = deflateInit2(&z, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
windowBits | gzip_encoding,
8, Z_DEFAULT_STRATEGY);
if (result != Z_OK) {
z.opaque = this;
error.Set(zlib_domain, result, zError(result));
}
}
GzipOutputStream::~GzipOutputStream()
{
if (IsDefined())
deflateEnd(&z);
}
bool
GzipOutputStream::Flush(Error &error)
{
/* no more input */
z.next_in = nullptr;
z.avail_in = 0;
while (true) {
Bytef output[4096];
z.next_out = output;
z.avail_out = sizeof(output);
int result = deflate(&z, Z_FINISH);
if (z.next_out > output &&
!next.Write(output, z.next_out - output, error))
return false;
if (result == Z_STREAM_END)
return true;
else if (result != Z_OK) {
error.Set(zlib_domain, result, zError(result));
return false;
}
}
}
bool
GzipOutputStream::Write(const void *_data, size_t size, Error &error)
{
/* zlib's API requires non-const input pointer */
void *data = const_cast<void *>(_data);
z.next_in = reinterpret_cast<Bytef *>(data);
z.avail_in = size;
while (z.avail_in > 0) {
Bytef output[4096];
z.next_out = output;
z.avail_out = sizeof(output);
int result = deflate(&z, Z_NO_FLUSH);
if (result != Z_OK) {
error.Set(zlib_domain, result, zError(result));
return false;
}
if (z.next_out > output &&
!next.Write(output, z.next_out - output, error))
return false;
}
return true;
}