Move //courgette/third_party to subfolder.

courgette/third_party/bsdiff_apply.cc

-/*-
- * Copyright 2003,2004 Colin Percival
- * All rights reserved
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted providing that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. 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 AUTHOR ``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 AUTHOR 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.
- *
- * Changelog:
- * 2009-03-31 - Change to use Streams.  Move CRC code to crc.{h,cc}
- *                --Stephen Adams <sra@chromium.org>
- * 2013-04-10 - Add wrapper method to apply a patch to files directly.
- *                --Joshua Pawlicki <waffles@chromium.org>
- */
-
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "courgette/third_party/bsdiff.h"
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include "base/files/memory_mapped_file.h"
-#include "courgette/crc.h"
-#include "courgette/streams.h"
-
-namespace courgette {
-
-BSDiffStatus MBS_ReadHeader(SourceStream* stream, MBSPatchHeader* header) {
-  if (!stream->Read(header->tag, sizeof(header->tag))) return READ_ERROR;
-  if (!stream->ReadVarint32(&header->slen)) return READ_ERROR;
-  if (!stream->ReadVarint32(&header->scrc32)) return READ_ERROR;
-  if (!stream->ReadVarint32(&header->dlen)) return READ_ERROR;
-
-  // The string will have a NUL terminator that we don't use, hence '-1'.
-  static_assert(sizeof(MBS_PATCH_HEADER_TAG) - 1 == sizeof(header->tag),
-                "MBS_PATCH_HEADER_TAG must match header field size");
-  if (memcmp(header->tag, MBS_PATCH_HEADER_TAG, 8) != 0)
-    return UNEXPECTED_ERROR;
-
-  return OK;
-}
-
-BSDiffStatus MBS_ApplyPatch(const MBSPatchHeader* header,
-                            SourceStream* patch_stream,
-                            const uint8_t* old_start,
-                            size_t old_size,
-                            SinkStream* new_stream) {
-  const uint8_t* old_end = old_start + old_size;
-
-  SourceStreamSet patch_streams;
-  if (!patch_streams.Init(patch_stream))
-    return READ_ERROR;
-
-  SourceStream* control_stream_copy_counts = patch_streams.stream(0);
-  SourceStream* control_stream_extra_counts = patch_streams.stream(1);
-  SourceStream* control_stream_seeks = patch_streams.stream(2);
-  SourceStream* diff_skips = patch_streams.stream(3);
-  SourceStream* diff_bytes = patch_streams.stream(4);
-  SourceStream* extra_bytes = patch_streams.stream(5);
-
-  const uint8_t* extra_start = extra_bytes->Buffer();
-  const uint8_t* extra_end = extra_start + extra_bytes->Remaining();
-  const uint8_t* extra_position = extra_start;
-
-  const uint8_t* old_position = old_start;
-
-  if (header->dlen && !new_stream->Reserve(header->dlen))
-    return MEM_ERROR;
-
-  uint32_t pending_diff_zeros = 0;
-  if (!diff_skips->ReadVarint32(&pending_diff_zeros))
-    return UNEXPECTED_ERROR;
-
-  while (!control_stream_copy_counts->Empty()) {
-    uint32_t copy_count, extra_count;
-    int32_t seek_adjustment;
-    if (!control_stream_copy_counts->ReadVarint32(&copy_count))
-      return UNEXPECTED_ERROR;
-    if (!control_stream_extra_counts->ReadVarint32(&extra_count))
-      return UNEXPECTED_ERROR;
-    if (!control_stream_seeks->ReadVarint32Signed(&seek_adjustment))
-      return UNEXPECTED_ERROR;
-
-#ifdef DEBUG_bsmedberg
-    printf("Applying block:  copy: %-8u extra: %-8u seek: %+i\n",
-           copy_count, extra_count, seek_adjustment);
-#endif
-    // Byte-wise arithmetically add bytes from old file to bytes from the diff
-    // block.
-    if (copy_count > static_cast<size_t>(old_end - old_position))
-      return UNEXPECTED_ERROR;
-
-    // Add together bytes from the 'old' file and the 'diff' stream.
-    for (size_t i = 0;  i < copy_count;  ++i) {
-      uint8_t diff_byte = 0;
-      if (pending_diff_zeros) {
-        --pending_diff_zeros;
-      } else {
-        if (!diff_skips->ReadVarint32(&pending_diff_zeros))
-          return UNEXPECTED_ERROR;
-        if (!diff_bytes->Read(&diff_byte, 1))
-          return UNEXPECTED_ERROR;
-      }
-      uint8_t byte = old_position[i] + diff_byte;
-      if (!new_stream->Write(&byte, 1))
-        return MEM_ERROR;
-    }
-    old_position += copy_count;
-
-    // Copy bytes from the extra block.
-    if (extra_count > static_cast<size_t>(extra_end - extra_position))
-      return UNEXPECTED_ERROR;
-
-    if (!new_stream->Write(extra_position, extra_count))
-      return MEM_ERROR;
-
-    extra_position += extra_count;
-
-    // "seek" forwards (or backwards) in oldfile.
-    if (old_position + seek_adjustment < old_start ||
-        old_position + seek_adjustment > old_end)
-      return UNEXPECTED_ERROR;
-
-    old_position += seek_adjustment;
-  }
-
-  if (!control_stream_copy_counts->Empty() ||
-      !control_stream_extra_counts->Empty() ||
-      !control_stream_seeks->Empty() ||
-      !diff_skips->Empty() ||
-      !diff_bytes->Empty() ||
-      !extra_bytes->Empty())
-    return UNEXPECTED_ERROR;
-
-  return OK;
-}
-
-BSDiffStatus ApplyBinaryPatch(SourceStream* old_stream,
-                              SourceStream* patch_stream,
-                              SinkStream* new_stream) {
-  MBSPatchHeader header;
-  BSDiffStatus ret = MBS_ReadHeader(patch_stream, &header);
-  if (ret != OK) return ret;
-
-  const uint8_t* old_start = old_stream->Buffer();
-  size_t old_size = old_stream->Remaining();
-
-  if (old_size != header.slen) return UNEXPECTED_ERROR;
-
-  if (CalculateCrc(old_start, old_size) != header.scrc32)
-    return CRC_ERROR;
-
-  MBS_ApplyPatch(&header, patch_stream, old_start, old_size, new_stream);
-
-  return OK;
-}
-
-BSDiffStatus ApplyBinaryPatch(const base::FilePath& old_file_path,
-                              const base::FilePath& patch_file_path,
-                              const base::FilePath& new_file_path) {
-  // Set up the old stream.
-  base::MemoryMappedFile old_file;
-  if (!old_file.Initialize(old_file_path)) {
-    return READ_ERROR;
-  }
-  SourceStream old_file_stream;
-  old_file_stream.Init(old_file.data(), old_file.length());
-
-  // Set up the patch stream.
-  base::MemoryMappedFile patch_file;
-  if (!patch_file.Initialize(patch_file_path)) {
-    return READ_ERROR;
-  }
-  SourceStream patch_file_stream;
-  patch_file_stream.Init(patch_file.data(), patch_file.length());
-
-  // Set up the new stream and apply the patch.
-  SinkStream new_sink_stream;
-  BSDiffStatus status = ApplyBinaryPatch(&old_file_stream,
-                                         &patch_file_stream,
-                                         &new_sink_stream);
-  if (status != OK) {
-    return status;
-  }
-
-  // Write the stream to disk.
-  int written = base::WriteFile(
-      new_file_path,
-      reinterpret_cast<const char*>(new_sink_stream.Buffer()),
-      static_cast<int>(new_sink_stream.Length()));
-  if (written != static_cast<int>(new_sink_stream.Length()))
-    return WRITE_ERROR;
-  return OK;
-}
-
-}  // namespace