IndexedDB: Reusing leveldb logs when opening database

third_party/leveldatabase/env_chromium.h

 // Copyright (c) 2013 The LevelDB Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file. See the AUTHORS file for names of contributors.
 
 #ifndef THIRD_PARTY_LEVELDATABASE_ENV_CHROMIUM_H_
 #define THIRD_PARTY_LEVELDATABASE_ENV_CHROMIUM_H_
 
 #include <deque>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/metrics/histogram.h"
 #include "leveldb/env.h"
 #include "port/port_chromium.h"
 #include "util/mutexlock.h"
 
 namespace leveldb_env {
 
+// These entries map to values in tools/metrics/histograms/histograms.xml. New
+// values should be appended at the end.
 enum MethodID {
   kSequentialFileRead,
   kSequentialFileSkip,
   kRandomAccessFileRead,
   kWritableFileAppend,
   kWritableFileClose,
   kWritableFileFlush,
   kWritableFileSync,
   kNewSequentialFile,
   kNewRandomAccessFile,
   kNewWritableFile,
   kDeleteFile,
   kCreateDir,
   kDeleteDir,
   kGetFileSize,
   kRenameFile,
   kLockFile,
   kUnlockFile,
   kGetTestDirectory,
   kNewLogger,
   kSyncParent,
   kGetChildren,
+  kNewAppendableFile,
   kNumEntries
 };
 
 const char* MethodIDToString(MethodID method);
 
 leveldb::Status MakeIOError(leveldb::Slice filename,
                             const std::string& message,
                             MethodID method,
                             base::File::Error error);
 leveldb::Status MakeIOError(leveldb::Slice filename,
@@ skipping 68 matching lines @@
   virtual leveldb::Status GetTestDirectory(std::string* path);
   virtual uint64_t NowMicros();
   virtual void SleepForMicroseconds(int micros);
   virtual leveldb::Status NewSequentialFile(const std::string& fname,
                                             leveldb::SequentialFile** result);
   virtual leveldb::Status NewRandomAccessFile(
       const std::string& fname,
       leveldb::RandomAccessFile** result);
   virtual leveldb::Status NewWritableFile(const std::string& fname,
                                           leveldb::WritableFile** result);
+  virtual leveldb::Status NewAppendableFile(const std::string& fname,
+                                            leveldb::WritableFile** result);
   virtual leveldb::Status NewLogger(const std::string& fname,
                                     leveldb::Logger** result);
 
  protected:
   virtual void DidSyncDir(const std::string& fname);
 
   std::string name_;
   bool make_backup_;
 
  private:
@@ skipping 61 matching lines @@
     void (*function)(void*);
   };
   typedef std::deque<BGItem> BGQueue;
   BGQueue queue_;
   LockTable locks_;
 };
 
 }  // namespace leveldb_env
 
 #endif  // THIRD_PARTY_LEVELDATABASE_ENV_CHROMIUM_H_