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

net/disk_cache/sparse_control.h

 // 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.
 
 #ifndef NET_DISK_CACHE_SPARSE_CONTROL_H_
 #define NET_DISK_CACHE_SPARSE_CONTROL_H_
 
 #include <string>
+#include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "net/base/completion_callback.h"
 #include "net/disk_cache/bitmap.h"
 #include "net/disk_cache/disk_format.h"
 
 namespace net {
 class IOBuffer;
 class ReusedIOBuffer;
@@ skipping 37 matching lines @@
   // |buf_len| specify the actual data to use and |callback| is the callback
   // to use for asynchronous operations. See the description of the Read /
   // WriteSparseData for details about the arguments. The return value is the
   // number of bytes read or written, or a net error code.
   int StartIO(SparseOperation op, int64 offset, net::IOBuffer* buf,
               int buf_len, net::CompletionCallback* callback);
 
   // Implements Entry::GetAvailableRange().
   int GetAvailableRange(int64 offset, int len, int64* start);
 
+  // Cancels the current sparse operation (if any).
+  void CancelIO();
+
+  // Returns OK if the entry can be used for new IO or ERR_IO_PENDING if we are
+  // busy. If the entry is busy, we'll invoke the callback when we are ready
+  // again. See disk_cache::Entry::ReadyToUse() for more info.
+  int ReadyToUse(net::CompletionCallback* completion_callback);
+
   // Deletes the children entries of |entry|.
   static void DeleteChildren(EntryImpl* entry);
 
  private:
   // Creates a new sparse entry or opens an aready created entry from disk.
   // These methods just read / write the required info from disk for the current
   // entry, and verify that everything is correct. The return value is a net
   // error code.
   int CreateSparseEntry();
   int OpenSparseEntry(int data_len);
@@ skipping 51 matching lines @@
   int DoGetAvailableRange();
 
   // Performs the required work after a single IO operations finishes.
   void DoChildIOCompleted(int result);
 
   // Invoked by the callback of asynchronous operations.
   void OnChildIOCompleted(int result);
 
   // Reports to the user that we are done.
   void DoUserCallback();
+  void DoAbortCallbacks();
 
   EntryImpl* entry_;  // The sparse entry.
   Entry* child_;  // The current child entry.
   SparseOperation operation_;
   bool pending_;  // True if any child IO operation returned pending.
   bool finished_;
   bool init_;
   bool range_found_;  // True if GetAvailableRange found something.
+  bool abort_;  // True if we should abort the current operation ASAP.
 
   SparseHeader sparse_header_;  // Data about the children of entry_.
   Bitmap children_map_;  // The actual bitmap of children.
   SparseData child_data_;  // Parent and allocation map of child_.
   Bitmap child_map_;  // The allocation map as a bitmap.
 
   net::CompletionCallbackImpl<SparseControl> child_callback_;
   net::CompletionCallback* user_callback_;
+  std::vector<net::CompletionCallback*> abort_callbacks_;
   int64 offset_;  // Current sparse offset.
   scoped_refptr<net::ReusedIOBuffer> user_buf_;
   int buf_len_;  // Bytes to read or write.
   int child_offset_;  // Offset to use for the current child.
   int child_len_;  // Bytes to read or write for this child.
   int result_;
 
   DISALLOW_COPY_AND_ASSIGN(SparseControl);
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_SPARSE_CONTROL_H_