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/*
* Copyright (C) 2014-2018 Max Kellermann <max.kellermann@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - 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
* FOUNDATION 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.
*/
#include "GzipOutputStream.hxx"
#include "lib/zlib/Error.hxx"
GzipOutputStream::GzipOutputStream(OutputStream &_next)
: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)
throw ZlibError(result);
}
GzipOutputStream::~GzipOutputStream()
{
deflateEnd(&z);
}
void
GzipOutputStream::Flush()
{
/* 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);
if (result == Z_STREAM_END)
break;
else if (result != Z_OK)
throw ZlibError(result);
}
}
void
GzipOutputStream::Write(const void *_data, size_t size)
{
/* 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)
throw ZlibError(result);
if (z.next_out > output)
next.Write(output, z.next_out - output);
}
}