Commit Brian Olson's gzip stream implementations.

1 files changed, 296 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..d8d0e70d
--- /dev/null
+++ b/src/google/protobuf/io/gzip_stream.cc
@@ -0,0 +1,296 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2009 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// 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)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+//
+// 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) {
+  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_);
+}
+
+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 windowBitsFormat = 0;
+      switch (format_) {
+        case GZIP: windowBitsFormat = 16; break;
+        case AUTO: windowBitsFormat = 32; break;
+        case ZLIB: windowBitsFormat = 0; break;
+      }
+      int error = inflateInit2(&zcontext_,
+        /* windowBits */15 | windowBitsFormat);
+      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) {
+    *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 {
+  return zcontext_.total_out +
+    (((uintptr_t)zcontext_.next_out) - ((uintptr_t)output_position_));
+}
+
+// =========================================================================
+
+GzipOutputStream::GzipOutputStream(
+    ZeroCopyOutputStream* sub_stream, Format format, int buffer_size)
+  : sub_stream_(sub_stream), sub_data_(NULL), sub_data_size_(0) {
+  if (buffer_size == -1) {
+    input_buffer_length_ = kDefaultBufferSize;
+  } else {
+    input_buffer_length_ = 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 (format == ZLIB) {
+    windowBitsFormat = 0;
+  }
+  zerror_ = deflateInit2(
+      &zcontext_,
+      Z_BEST_COMPRESSION,
+      Z_DEFLATED,
+      /* windowBits */15 | windowBitsFormat,
+      /* memLevel (default) */8,
+      Z_DEFAULT_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))
+      && (zcontext_.avail_out != sub_data_size_)) {
+    // 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() {
+  do {
+    zerror_ = Deflate(Z_FULL_FLUSH);
+  } while (zerror_ == Z_OK);
+  return zerror_ == Z_OK;
+}
+
+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