Disk cache: Add a method to cancel pending sparse operations.

The sparse IO methods require exclusive use of the cache entry
and they complain when that requirement is violated. When the
user cancels a request and reissues another one to the same entry,
we may be waiting for the previous operation to finish when we
receive a new IO request, so we fail.

This CL add a way for the HTTP cache to cancel IO operations and
get a notification when the disk cache is able to operate on that
entry again.

BUG=23862
TEST=unittests

Review URL: http://codereview.chromium.org/256090

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@28475 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 14 insertions, 0 deletions

diff --git a/net/disk_cache/entry_impl.cc b/net/disk_cache/entry_impl.cc
index 4854a49..7d877c5 100644
--- a/net/disk_cache/entry_impl.cc
+++ b/net/disk_cache/entry_impl.cc
@@ -384,6 +384,20 @@ int EntryImpl::GetAvailableRange(int64 offset, int len, int64* start) {
   return sparse_->GetAvailableRange(offset, len, start);
 }
 
+void EntryImpl::CancelSparseIO() {
+  if (!sparse_.get())
+    return;
+
+  sparse_->CancelIO();
+}
+
+int EntryImpl::ReadyForSparseIO(net::CompletionCallback* completion_callback) {
+  if (!sparse_.get())
+    return net::OK;
+
+  return sparse_->ReadyToUse(completion_callback);
+}
+
 // ------------------------------------------------------------------------
 
 uint32 EntryImpl::GetHash() {