mpd/src/lib/zlib/GunzipReader.cxx
2021-12-03 14:35:41 +01:00

97 lines
2.5 KiB
C++

/*
* Copyright 2014-2019 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 "GunzipReader.hxx"
#include "lib/zlib/Error.hxx"
GunzipReader::GunzipReader(Reader &_next)
:next(_next)
{
z.next_in = nullptr;
z.avail_in = 0;
z.zalloc = Z_NULL;
z.zfree = Z_NULL;
z.opaque = Z_NULL;
int result = inflateInit2(&z, 16 + MAX_WBITS);
if (result != Z_OK)
throw ZlibError(result);
}
inline bool
GunzipReader::FillBuffer()
{
auto w = buffer.Write();
assert(!w.empty());
size_t nbytes = next.Read(w.data, w.size);
if (nbytes == 0)
return false;
buffer.Append(nbytes);
return true;
}
size_t
GunzipReader::Read(void *data, size_t size)
{
if (eof)
return 0;
z.next_out = (Bytef *)data;
z.avail_out = size;
while (true) {
int flush = Z_NO_FLUSH;
auto r = buffer.Read();
if (r.empty()) {
if (FillBuffer())
r = buffer.Read();
else
flush = Z_FINISH;
}
z.next_in = r.data;
z.avail_in = r.size;
int result = inflate(&z, flush);
if (result == Z_STREAM_END) {
eof = true;
return size - z.avail_out;
} else if (result != Z_OK)
throw ZlibError(result);
buffer.Consume(r.size - z.avail_in);
if (z.avail_out < size)
return size - z.avail_out;
}
}