diff options
Diffstat (limited to 'src/fs/io')
| -rw-r--r-- | src/fs/io/GunzipReader.cxx | 102 | ||||
| -rw-r--r-- | src/fs/io/GunzipReader.hxx | 69 |
2 files changed, 171 insertions, 0 deletions
diff --git a/src/fs/io/GunzipReader.cxx b/src/fs/io/GunzipReader.cxx new file mode 100644 index 000000000..388b26412 --- /dev/null +++ b/src/fs/io/GunzipReader.cxx @@ -0,0 +1,102 @@ +/* + * 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 "GunzipReader.hxx" +#include "util/Error.hxx" +#include "util/Domain.hxx" + +const Domain zlib_domain("zlib"); + +GunzipReader::GunzipReader(Reader &_next, Error &error) + :next(_next), eof(false) +{ + 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) { + z.opaque = this; + error.Set(zlib_domain, result, zError(result)); + } +} + +GunzipReader::~GunzipReader() +{ + if (IsDefined()) + inflateEnd(&z); +} + +inline bool +GunzipReader::FillBuffer(Error &error) +{ + auto w = buffer.Write(); + assert(!w.IsEmpty()); + + size_t nbytes = next.Read(w.data, w.size, error); + if (nbytes == 0) + return false; + + buffer.Append(nbytes); + return true; +} + +size_t +GunzipReader::Read(void *data, size_t size, Error &error) +{ + 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.IsEmpty()) { + if (FillBuffer(error)) + r = buffer.Read(); + else if (error.IsDefined()) + return 0; + 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) { + error.Set(zlib_domain, result, zError(result)); + return 0; + } + + buffer.Consume(r.size - z.avail_in); + + if (z.avail_out < size) + return size - z.avail_out; + } +} diff --git a/src/fs/io/GunzipReader.hxx b/src/fs/io/GunzipReader.hxx new file mode 100644 index 000000000..689125a6a --- /dev/null +++ b/src/fs/io/GunzipReader.hxx @@ -0,0 +1,69 @@ +/* + * 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. + */ + +#ifndef MPD_GUNZIP_READER_HXX +#define MPD_GUNZIP_READER_HXX + +#include "check.h" +#include "Reader.hxx" +#include "util/StaticFifoBuffer.hxx" + +#include <zlib.h> + +class Error; +class Domain; + +extern const Domain zlib_domain; + +/** + * A filter that decompresses data using zlib. + */ +class GunzipReader final : public Reader { + Reader &next; + + bool eof; + + z_stream z; + + StaticFifoBuffer<Bytef, 4096> buffer; + +public: + /** + * Construct the filter. Call IsDefined() to check whether + * the constructor has succeeded. If not, #error will hold + * information about the failure. + */ + GunzipReader(Reader &_next, Error &error); + ~GunzipReader(); + + /** + * Check whether the constructor has succeeded. + */ + bool IsDefined() const { + return z.opaque == nullptr; + } + + /* virtual methods from class Reader */ + virtual size_t Read(void *data, size_t size, Error &error) override; + +private: + bool FillBuffer(Error &error); +}; + +#endif |