Remove //net (except for Android test stuff) and sdch

net/disk_cache/simple/simple_version_upgrade.cc

Index: net/disk_cache/simple/simple_version_upgrade.cc
diff --git a/net/disk_cache/simple/simple_version_upgrade.cc b/net/disk_cache/simple/simple_version_upgrade.cc
deleted file mode 100644
index c20a1ba71bf68bc5aed895101914b1717ddc9760..0000000000000000000000000000000000000000
--- a/net/disk_cache/simple/simple_version_upgrade.cc
+++ /dev/null
@@ -1,199 +0,0 @@
-// Copyright 2013 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 "net/disk_cache/simple/simple_version_upgrade.h"
-
-#include <cstring>
-
-#include "base/files/file.h"
-#include "base/files/file_path.h"
-#include "base/files/file_util.h"
-#include "base/files/memory_mapped_file.h"
-#include "base/logging.h"
-#include "base/pickle.h"
-#include "net/disk_cache/simple/simple_backend_version.h"
-#include "net/disk_cache/simple/simple_entry_format_history.h"
-#include "third_party/zlib/zlib.h"
-
-namespace {
-
-// It is not possible to upgrade cache structures on disk that are of version
-// below this, the entire cache should be dropped for them.
-const uint32 kMinVersionAbleToUpgrade = 5;
-
-const char kFakeIndexFileName[] = "index";
-const char kIndexFileName[] = "the-real-index";
-
-void LogMessageFailedUpgradeFromVersion(int version) {
-  LOG(ERROR) << "Failed to upgrade Simple Cache from version: " << version;
-}
-
-bool WriteFakeIndexFile(const base::FilePath& file_name) {
-  base::File file(file_name,  base::File::FLAG_CREATE | base::File::FLAG_WRITE);
-  if (!file.IsValid())
-    return false;
-
-  disk_cache::FakeIndexData file_contents;
-  file_contents.initial_magic_number =
-      disk_cache::simplecache_v5::kSimpleInitialMagicNumber;
-  file_contents.version = disk_cache::kSimpleVersion;
-  int bytes_written = file.Write(0, reinterpret_cast<char*>(&file_contents),
-                                 sizeof(file_contents));
-  if (bytes_written != sizeof(file_contents)) {
-    LOG(ERROR) << "Failed to write fake index file: "
-               << file_name.LossyDisplayName();
-    return false;
-  }
-  return true;
-}
-
-}  // namespace
-
-namespace disk_cache {
-
-FakeIndexData::FakeIndexData() {
-  // Make hashing repeatable: leave no padding bytes untouched.
-  std::memset(this, 0, sizeof(*this));
-}
-
-// Migrates the cache directory from version 4 to version 5.
-// Returns true iff it succeeds.
-//
-// The V5 and V6 caches differ in the name of the index file (it moved to a
-// subdirectory) and in the file format (directory last-modified time observed
-// by the index writer has gotten appended to the pickled format).
-//
-// To keep complexity small this specific upgrade code *deletes* the old index
-// file. The directory for the new index file has to be created lazily anyway,
-// so it is not done in the upgrader.
-//
-// Below is the detailed description of index file format differences. It is for
-// reference purposes. This documentation would be useful to move closer to the
-// next index upgrader when the latter gets introduced.
-//
-// Path:
-//   V5: $cachedir/the-real-index
-//   V6: $cachedir/index-dir/the-real-index
-//
-// Pickled file format:
-//   Both formats extend Pickle::Header by 32bit value of the CRC-32 of the
-//   pickled data.
-//   <v5-index> ::= <v5-index-metadata> <entry-info>*
-//   <v5-index-metadata> ::= UInt64(kSimpleIndexMagicNumber)
-//                           UInt32(4)
-//                           UInt64(<number-of-entries>)
-//                           UInt64(<cache-size-in-bytes>)
-//   <entry-info> ::= UInt64(<hash-of-the-key>)
-//                    Int64(<entry-last-used-time>)
-//                    UInt64(<entry-size-in-bytes>)
-//   <v6-index> ::= <v6-index-metadata>
-//                  <entry-info>*
-//                  Int64(<cache-dir-mtime>)
-//   <v6-index-metadata> ::= UInt64(kSimpleIndexMagicNumber)
-//                           UInt32(5)
-//                           UInt64(<number-of-entries>)
-//                           UInt64(<cache-size-in-bytes>)
-//   Where:
-//     <entry-size-in-bytes> is equal the sum of all file sizes of the entry.
-//     <cache-dir-mtime> is the last modification time with nanosecond precision
-//       of the directory, where all files for entries are stored.
-//     <hash-of-the-key> represent the first 64 bits of a SHA-1 of the key.
-bool UpgradeIndexV5V6(const base::FilePath& cache_directory) {
-  const base::FilePath old_index_file =
-      cache_directory.AppendASCII(kIndexFileName);
-  if (!base::DeleteFile(old_index_file, /* recursive = */ false))
-    return false;
-  return true;
-}
-
-// Some points about the Upgrade process are still not clear:
-// 1. if the upgrade path requires dropping cache it would be faster to just
-//    return an initialization error here and proceed with asynchronous cache
-//    cleanup in CacheCreator. Should this hack be considered valid? Some smart
-//    tests may fail.
-// 2. Because Android process management allows for killing a process at any
-//    time, the upgrade process may need to deal with a partially completed
-//    previous upgrade. For example, while upgrading A -> A + 2 we are the
-//    process gets killed and some parts are remaining at version A + 1. There
-//    are currently no generic mechanisms to resolve this situation, co the
-//    upgrade codes need to ensure they can continue after being stopped in the
-//    middle. It also means that the "fake index" must be flushed in between the
-//    upgrade steps. Atomicity of this is an interesting research topic. The
-//    intermediate fake index flushing must be added as soon as we add more
-//    upgrade steps.
-bool UpgradeSimpleCacheOnDisk(const base::FilePath& path) {
-  // There is a convention among disk cache backends: looking at the magic in
-  // the file "index" it should be sufficient to determine if the cache belongs
-  // to the currently running backend. The Simple Backend stores its index in
-  // the file "the-real-index" (see simple_index_file.cc) and the file "index"
-  // only signifies presence of the implementation's magic and version. There
-  // are two reasons for that:
-  // 1. Absence of the index is itself not a fatal error in the Simple Backend
-  // 2. The Simple Backend has pickled file format for the index making it hacky
-  //    to have the magic in the right place.
-  const base::FilePath fake_index = path.AppendASCII(kFakeIndexFileName);
-  base::File fake_index_file(fake_index,
-                             base::File::FLAG_OPEN | base::File::FLAG_READ);
-
-  if (!fake_index_file.IsValid()) {
-    if (fake_index_file.error_details() == base::File::FILE_ERROR_NOT_FOUND) {
-      return WriteFakeIndexFile(fake_index);
-    }
-    return false;
-  }
-
-  FakeIndexData file_header;
-  int bytes_read = fake_index_file.Read(0,
-                                        reinterpret_cast<char*>(&file_header),
-                                        sizeof(file_header));
-  if (bytes_read != sizeof(file_header) ||
-      file_header.initial_magic_number !=
-          disk_cache::simplecache_v5::kSimpleInitialMagicNumber) {
-    LOG(ERROR) << "File structure does not match the disk cache backend.";
-    return false;
-  }
-  fake_index_file.Close();
-
-  uint32 version_from = file_header.version;
-  if (version_from < kMinVersionAbleToUpgrade ||
-      version_from > kSimpleVersion) {
-    LOG(ERROR) << "Inconsistent cache version.";
-    return false;
-  }
-  bool upgrade_needed = (version_from != kSimpleVersion);
-  if (version_from == kMinVersionAbleToUpgrade) {
-    // Upgrade only the index for V4 -> V5 move.
-    if (!UpgradeIndexV5V6(path)) {
-      LogMessageFailedUpgradeFromVersion(file_header.version);
-      return false;
-    }
-    version_from++;
-  }
-  if (version_from == kSimpleVersion) {
-    if (!upgrade_needed) {
-      return true;
-    } else {
-      const base::FilePath temp_fake_index = path.AppendASCII("upgrade-index");
-      if (!WriteFakeIndexFile(temp_fake_index)) {
-        base::DeleteFile(temp_fake_index, /* recursive = */ false);
-        LOG(ERROR) << "Failed to write a new fake index.";
-        LogMessageFailedUpgradeFromVersion(file_header.version);
-        return false;
-      }
-      if (!base::ReplaceFile(temp_fake_index, fake_index, NULL)) {
-        LOG(ERROR) << "Failed to replace the fake index.";
-        LogMessageFailedUpgradeFromVersion(file_header.version);
-        return false;
-      }
-      return true;
-    }
-  }
-  // Verify during the test stage that the upgraders are implemented for all
-  // versions. The release build would cause backend initialization failure
-  // which would then later lead to removing all files known to the backend.
-  DCHECK_EQ(kSimpleVersion, version_from);
-  return false;
-}
-
-}  // namespace disk_cache