Disk cache: Add support for an extra data stream for each cache entry.

This is the first step to allow the http cache to store additional metadata
for certain entries.

The cache file format changes to version 2.0 so an effect of this cl is
that the borwser will discard the old cache files.

Review URL: http://codereview.chromium.org/12880

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@6392 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 15 insertions, 9 deletions

diff --git a/net/disk_cache/entry_impl.cc b/net/disk_cache/entry_impl.cc
index 2e7b8c46..cc2b07d 100644
--- a/net/disk_cache/entry_impl.cc
+++ b/net/disk_cache/entry_impl.cc
@@ -16,6 +16,9 @@ using base::TimeDelta;
 
 namespace {
 
+// Index for the file used to store the key, if any (files_[kKeyFileIndex]).
+const int kKeyFileIndex = 3;
+
 // This class implements FileIOCallback to buffer the callback from a file IO
 // operation from the actual net class.
 class SyncCallback: public disk_cache::FileIOCallback {
@@ -72,7 +75,8 @@ EntryImpl::EntryImpl(BackendImpl* backend, Addr address)
   entry_.LazyInit(backend->File(address), address);
   doomed_ = false;
   backend_ = backend;
-  unreported_size_[0] = unreported_size_[1] = 0;
+  for (int i = 0; i < NUM_STREAMS; i++)
+    unreported_size_[i] = 0;
 }
 
 // When an entry is deleted from the cache, we clean up all the data associated
@@ -85,7 +89,7 @@ EntryImpl::~EntryImpl() {
   if (doomed_) {
     UMA_HISTOGRAM_COUNTS(L"DiskCache.DeleteHeader", GetDataSize(0));
     UMA_HISTOGRAM_COUNTS(L"DiskCache.DeleteData", GetDataSize(1));
-    for (int index = 0; index < kKeyFileIndex; index++) {
+    for (int index = 0; index < NUM_STREAMS; index++) {
       Addr address(entry_.Data()->data_addr[index]);
       if (address.is_initialized()) {
         DeleteData(address, index);
@@ -106,7 +110,7 @@ EntryImpl::~EntryImpl() {
     backend_->DeleteBlock(entry_.address(), false);
   } else {
     bool ret = true;
-    for (int index = 0; index < kKeyFileIndex; index++) {
+    for (int index = 0; index < NUM_STREAMS; index++) {
       if (user_buffers_[index].get()) {
         if (!(ret = Flush(index, entry_.Data()->data_size[index], false)))
           LOG(ERROR) << "Failed to save user data";
@@ -154,6 +158,7 @@ std::string EntryImpl::GetKey() const {
   if (entry->Data()->key_len > kMaxInternalKeyLength) {
     Addr address(entry->Data()->long_key);
     DCHECK(address.is_initialized());
+    COMPILE_ASSERT(NUM_STREAMS == kKeyFileIndex, invalid_key_index);
     File* file = const_cast<EntryImpl*>(this)->GetBackingFile(address,
                                                               kKeyFileIndex);
 
@@ -182,7 +187,7 @@ Time EntryImpl::GetLastModified() const {
 }
 
 int32 EntryImpl::GetDataSize(int index) const {
-  if (index < 0 || index > 1)
+  if (index < 0 || index >= NUM_STREAMS)
     return 0;
 
   CacheEntryBlock* entry = const_cast<CacheEntryBlock*>(&entry_);
@@ -192,7 +197,7 @@ int32 EntryImpl::GetDataSize(int index) const {
 int EntryImpl::ReadData(int index, int offset, char* buf, int buf_len,
                         net::CompletionCallback* completion_callback) {
   DCHECK(node_.Data()->dirty);
-  if (index < 0 || index > 1)
+  if (index < 0 || index >= NUM_STREAMS)
     return net::ERR_INVALID_ARGUMENT;
 
   int entry_size = entry_.Data()->data_size[index];
@@ -258,7 +263,7 @@ int EntryImpl::WriteData(int index, int offset, const char* buf, int buf_len,
                          net::CompletionCallback* completion_callback,
                          bool truncate) {
   DCHECK(node_.Data()->dirty);
-  if (index < 0 || index > 1)
+  if (index < 0 || index >= NUM_STREAMS)
     return net::ERR_INVALID_ARGUMENT;
 
   if (offset < 0 || buf_len < 0)
@@ -372,6 +377,7 @@ bool EntryImpl::CreateEntry(Addr node_address, const std::string& key,
   node->pointer = this;
 
   entry_store->hash = hash;
+  entry_store->creation_time = Time::Now().ToInternalValue();
   entry_store->key_len = static_cast<int32>(key.size());
   if (entry_store->key_len > kMaxInternalKeyLength) {
     Addr address(0);
@@ -507,7 +513,7 @@ void EntryImpl::SetTimes(base::Time last_used, base::Time last_modified) {
 
 bool EntryImpl::CreateDataBlock(int index, int size) {
   Addr address(entry_.Data()->data_addr[index]);
-  DCHECK(0 == index || 1 == index);
+  DCHECK(index >= 0 && index < NUM_STREAMS);
 
   if (!CreateBlock(size, &address))
     return false;
@@ -577,10 +583,10 @@ File* EntryImpl::GetBackingFile(Addr address, int index) {
 }
 
 File* EntryImpl::GetExternalFile(Addr address, int index) {
-  DCHECK(index >= 0 && index <= 2);
+  DCHECK(index >= 0 && index <= kKeyFileIndex);
   if (!files_[index].get()) {
     // For a key file, use mixed mode IO.
-    scoped_refptr<File> file(new File(2 == index));
+    scoped_refptr<File> file(new File(kKeyFileIndex == index));
     if (file->Init(backend_->GetFileName(address)))
       files_[index].swap(file);
   }