diff options
Diffstat (limited to 'src/google/protobuf/io/gzip_stream.cc')
-rw-r--r-- | src/google/protobuf/io/gzip_stream.cc | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/src/google/protobuf/io/gzip_stream.cc b/src/google/protobuf/io/gzip_stream.cc new file mode 100644 index 00000000..c9f4ca7f --- /dev/null +++ b/src/google/protobuf/io/gzip_stream.cc @@ -0,0 +1,332 @@ +// 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 |