Disk cache: Reference CL for the implementation of file format version 3.

net/disk_cache/addr.cc

 // Copyright (c) 2012 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/addr.h"
 
 #include "base/logging.h"
 
 namespace disk_cache {
 
 int Addr::start_block() const {
   DCHECK(is_block_file());
   return value_ & kStartBlockMask;
 }
 
 int Addr::num_blocks() const {
   DCHECK(is_block_file() || !value_);
   return ((value_ & kNumBlocksMask) >> kNumBlocksOffset) + 1;
 }
 
 bool Addr::SetFileNumber(int file_number) {
   DCHECK(is_separate_file());
   if (file_number & ~kFileNameMask)
     return false;
   value_ = kInitializedMask | file_number;
   return true;
 }
 
-bool Addr::SanityCheck() const {
+Addr Addr::AsExternal() const {
+  DCHECK(file_type() == BLOCK_FILES);
+  Addr new_addr(value_);
+  new_addr.SetFileType(EXTERNAL);
+  return new_addr;
+}
+
+Addr Addr::AsBlockFile() const {
+  DCHECK(is_separate_file());
+  Addr new_addr(value_);
+  new_addr.SetFileType(BLOCK_FILES);
+  return new_addr;
+}
+
+bool Addr::SanityCheckV2() const {
   if (!is_initialized())
     return !value_;
 
-  if (((value_ & kFileTypeMask) >> kFileTypeOffset) > 4)
+  if (file_type() > BLOCK_4K)
     return false;
 
   if (is_separate_file())
     return true;
 
-  const uint32 kReservedBitsMask = 0x0c000000;
-  return !(value_ & kReservedBitsMask);
+  return !reserved_bits();
 }
 
-bool Addr::SanityCheckForEntry() const {
-  if (!SanityCheck() || !is_initialized())
+bool Addr::SanityCheckV3() const {
+  if (!is_initialized())
+    return !value_;
+
+  // For actual entries, SanityCheckForEntryV3 should be used.
+  if (file_type() > BLOCK_FILES)
+    return false;
+
+  if (is_separate_file())
+    return true;
+
+  return !reserved_bits();
+}
+
+bool Addr::SanityCheckForEntryV2() const {
+  if (!SanityCheckV2() || !is_initialized())
     return false;
 
   if (is_separate_file() || file_type() != BLOCK_256)
     return false;
 
   return true;
 }
 
+bool Addr::SanityCheckForEntryV3() const {
+  if (!is_initialized())
+    return false;
+
+  if (reserved_bits())
+    return false;
+
+  if (file_type() != BLOCK_ENTRIES && file_type() != BLOCK_EVICTED)
+    return false;
+
+  if (num_blocks() != 1)
+    return false;
+
+  return true;
+}
+
 bool Addr::SanityCheckForRankings() const {
-  if (!SanityCheck() || !is_initialized())
+  if (!SanityCheckV2() || !is_initialized())
     return false;
 
   if (is_separate_file() || file_type() != RANKINGS || num_blocks() != 1)
     return false;
 
   return true;
 }
 
+void Addr::SetFileType(FileType type) {
+  value_ &= ~kFileTypeMask;
+  value_ += type << kFileTypeOffset;
+}
+
 }  // namespace disk_cache