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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// 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.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// 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 COPYRIGHT
// OWNER 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.
// Author: brianolson@google.com (Brian Olson)
//
// This file contains the implementation of classes GzipInputStream and
// GzipOutputStream.
#include "config.h"
#if HAVE_ZLIB
#include <google/protobuf/io/gzip_stream.h>
#include <google/protobuf/stubs/common.h>
namespace google {
namespace protobuf {
namespace io {
static const int kDefaultBufferSize = 65536;
GzipInputStream::GzipInputStream(
ZeroCopyInputStream* sub_stream, Format format, int buffer_size)
: format_(format), sub_stream_(sub_stream), zerror_(Z_OK), byte_count_(0) {
zcontext_.state = Z_NULL;
zcontext_.zalloc = Z_NULL;
zcontext_.zfree = Z_NULL;
zcontext_.opaque = Z_NULL;
zcontext_.total_out = 0;
zcontext_.next_in = NULL;
zcontext_.avail_in = 0;
zcontext_.total_in = 0;
zcontext_.msg = NULL;
if (buffer_size == -1) {
output_buffer_length_ = kDefaultBufferSize;
} else {
output_buffer_length_ = buffer_size;
}
output_buffer_ = operator new(output_buffer_length_);
GOOGLE_CHECK(output_buffer_ != NULL);
zcontext_.next_out = static_cast<Bytef*>(output_buffer_);
zcontext_.avail_out = output_buffer_length_;
output_position_ = output_buffer_;
}
GzipInputStream::~GzipInputStream() {
operator delete(output_buffer_);
zerror_ = inflateEnd(&zcontext_);
}
static inline int internalInflateInit2(
z_stream* zcontext, GzipInputStream::Format format) {
int windowBitsFormat = 0;
switch (format) {
case GzipInputStream::GZIP: windowBitsFormat = 16; break;
case GzipInputStream::AUTO: windowBitsFormat = 32; break;
case GzipInputStream::ZLIB: windowBitsFormat = 0; break;
}
return inflateInit2(zcontext, /* windowBits */15 | windowBitsFormat);
}
int GzipInputStream::Inflate(int flush) {
if ((zerror_ == Z_OK) && (zcontext_.avail_out == 0)) {
// previous inflate filled output buffer. don't change input params yet.
} else if (zcontext_.avail_in == 0) {
const void* in;
int in_size;
bool first = zcontext_.next_in == NULL;
bool ok = sub_stream_->Next(&in, &in_size);
if (!ok) {
zcontext_.next_out = NULL;
zcontext_.avail_out = 0;
return Z_STREAM_END;
}
zcontext_.next_in = static_cast<Bytef*>(const_cast<void*>(in));
zcontext_.avail_in = in_size;
if (first) {
int error = internalInflateInit2(&zcontext_, format_);
if (error != Z_OK) {
return error;
}
}
}
zcontext_.next_out = static_cast<Bytef*>(output_buffer_);
zcontext_.avail_out = output_buffer_length_;
output_position_ = output_buffer_;
int error = inflate(&zcontext_, flush);
return error;
}
void GzipInputStream::DoNextOutput(const void** data, int* size) {
*data = output_position_;
*size = ((uintptr_t)zcontext_.next_out) - ((uintptr_t)output_position_);
output_position_ = zcontext_.next_out;
}
// implements ZeroCopyInputStream ----------------------------------
bool GzipInputStream::Next(const void** data, int* size) {
bool ok = (zerror_ == Z_OK) || (zerror_ == Z_STREAM_END)
|| (zerror_ == Z_BUF_ERROR);
if ((!ok) || (zcontext_.next_out == NULL)) {
return false;
}
if (zcontext_.next_out != output_position_) {
DoNextOutput(data, size);
return true;
}
if (zerror_ == Z_STREAM_END) {
if (zcontext_.next_out != NULL) {
// sub_stream_ may have concatenated streams to follow
zerror_ = inflateEnd(&zcontext_);
byte_count_ += zcontext_.total_out;
if (zerror_ != Z_OK) {
return false;
}
zerror_ = internalInflateInit2(&zcontext_, format_);
if (zerror_ != Z_OK) {
return false;
}
} else {
*data = NULL;
*size = 0;
return false;
}
}
zerror_ = Inflate(Z_NO_FLUSH);
if ((zerror_ == Z_STREAM_END) && (zcontext_.next_out == NULL)) {
// The underlying stream's Next returned false inside Inflate.
return false;
}
ok = (zerror_ == Z_OK) || (zerror_ == Z_STREAM_END)
|| (zerror_ == Z_BUF_ERROR);
if (!ok) {
return false;
}
DoNextOutput(data, size);
return true;
}
void GzipInputStream::BackUp(int count) {
output_position_ = reinterpret_cast<void*>(
reinterpret_cast<uintptr_t>(output_position_) - count);
}
bool GzipInputStream::Skip(int count) {
const void* data;
int size;
bool ok = Next(&data, &size);
while (ok && (size < count)) {
count -= size;
ok = Next(&data, &size);
}
if (size > count) {
BackUp(size - count);
}
return ok;
}
int64 GzipInputStream::ByteCount() const {
int64 ret = byte_count_ + zcontext_.total_out;
if (zcontext_.next_out != NULL && output_position_ != NULL) {
ret += reinterpret_cast<uintptr_t>(zcontext_.next_out) -
reinterpret_cast<uintptr_t>(output_position_);
}
return ret;
}
// =========================================================================
GzipOutputStream::Options::Options()
: format(GZIP),
buffer_size(kDefaultBufferSize),
compression_level(Z_DEFAULT_COMPRESSION),
compression_strategy(Z_DEFAULT_STRATEGY) {}
GzipOutputStream::GzipOutputStream(ZeroCopyOutputStream* sub_stream) {
Init(sub_stream, Options());
}
GzipOutputStream::GzipOutputStream(ZeroCopyOutputStream* sub_stream,
const Options& options) {
Init(sub_stream, options);
}
void GzipOutputStream::Init(ZeroCopyOutputStream* sub_stream,
const Options& options) {
sub_stream_ = sub_stream;
sub_data_ = NULL;
sub_data_size_ = 0;
input_buffer_length_ = options.buffer_size;
input_buffer_ = operator new(input_buffer_length_);
GOOGLE_CHECK(input_buffer_ != NULL);
zcontext_.zalloc = Z_NULL;
zcontext_.zfree = Z_NULL;
zcontext_.opaque = Z_NULL;
zcontext_.next_out = NULL;
zcontext_.avail_out = 0;
zcontext_.total_out = 0;
zcontext_.next_in = NULL;
zcontext_.avail_in = 0;
zcontext_.total_in = 0;
zcontext_.msg = NULL;
// default to GZIP format
int windowBitsFormat = 16;
if (options.format == ZLIB) {
windowBitsFormat = 0;
}
zerror_ = deflateInit2(
&zcontext_,
options.compression_level,
Z_DEFLATED,
/* windowBits */15 | windowBitsFormat,
/* memLevel (default) */8,
options.compression_strategy);
}
GzipOutputStream::~GzipOutputStream() {
Close();
if (input_buffer_ != NULL) {
operator delete(input_buffer_);
}
}
// private
int GzipOutputStream::Deflate(int flush) {
int error = Z_OK;
do {
if ((sub_data_ == NULL) || (zcontext_.avail_out == 0)) {
bool ok = sub_stream_->Next(&sub_data_, &sub_data_size_);
if (!ok) {
sub_data_ = NULL;
sub_data_size_ = 0;
return Z_BUF_ERROR;
}
GOOGLE_CHECK_GT(sub_data_size_, 0);
zcontext_.next_out = static_cast<Bytef*>(sub_data_);
zcontext_.avail_out = sub_data_size_;
}
error = deflate(&zcontext_, flush);
} while (error == Z_OK && zcontext_.avail_out == 0);
if ((flush == Z_FULL_FLUSH) || (flush == Z_FINISH)) {
// Notify lower layer of data.
sub_stream_->BackUp(zcontext_.avail_out);
// We don't own the buffer anymore.
sub_data_ = NULL;
sub_data_size_ = 0;
}
return error;
}
// implements ZeroCopyOutputStream ---------------------------------
bool GzipOutputStream::Next(void** data, int* size) {
if ((zerror_ != Z_OK) && (zerror_ != Z_BUF_ERROR)) {
return false;
}
if (zcontext_.avail_in != 0) {
zerror_ = Deflate(Z_NO_FLUSH);
if (zerror_ != Z_OK) {
return false;
}
}
if (zcontext_.avail_in == 0) {
// all input was consumed. reset the buffer.
zcontext_.next_in = static_cast<Bytef*>(input_buffer_);
zcontext_.avail_in = input_buffer_length_;
*data = input_buffer_;
*size = input_buffer_length_;
} else {
// The loop in Deflate should consume all avail_in
GOOGLE_LOG(DFATAL) << "Deflate left bytes unconsumed";
}
return true;
}
void GzipOutputStream::BackUp(int count) {
GOOGLE_CHECK_GE(zcontext_.avail_in, count);
zcontext_.avail_in -= count;
}
int64 GzipOutputStream::ByteCount() const {
return zcontext_.total_in + zcontext_.avail_in;
}
bool GzipOutputStream::Flush() {
zerror_ = Deflate(Z_FULL_FLUSH);
// Return true if the flush succeeded or if it was a no-op.
return (zerror_ == Z_OK) ||
(zerror_ == Z_BUF_ERROR && zcontext_.avail_in == 0 &&
zcontext_.avail_out != 0);
}
bool GzipOutputStream::Close() {
if ((zerror_ != Z_OK) && (zerror_ != Z_BUF_ERROR)) {
return false;
}
do {
zerror_ = Deflate(Z_FINISH);
} while (zerror_ == Z_OK);
zerror_ = deflateEnd(&zcontext_);
bool ok = zerror_ == Z_OK;
zerror_ = Z_STREAM_END;
return ok;
}
} // namespace io
} // namespace protobuf
} // namespace google
#endif // HAVE_ZLIB