Add callback to LevelDBWrapperImpl to allow extra operations on commit.

content/browser/leveldb_wrapper_impl.cc

 // Copyright 2016 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 "content/browser/leveldb_wrapper_impl.h"
 
 #include "base/bind.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/leveldb/public/cpp/util.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 23 matching lines @@
 LevelDBWrapperImpl::CommitBatch::CommitBatch() : clear_all_first(false) {}
 LevelDBWrapperImpl::CommitBatch::~CommitBatch() {}
 
 LevelDBWrapperImpl::LevelDBWrapperImpl(
     leveldb::mojom::LevelDBDatabase* database,
     const std::string& prefix,
     size_t max_size,
     base::TimeDelta default_commit_delay,
     int max_bytes_per_hour,
     int max_commits_per_hour,
-    const base::Closure& no_bindings_callback)
+    const base::Closure& no_bindings_callback,
+    const PrepareToCommitCallback& prepare_to_commit_callback)
     : prefix_(leveldb::StdStringToUint8Vector(prefix)),
       no_bindings_callback_(no_bindings_callback),
+      prepare_to_commit_callback_(prepare_to_commit_callback),
       database_(database),
       bytes_used_(0),
       max_size_(max_size),
       start_time_(base::TimeTicks::Now()),
       default_commit_delay_(default_commit_delay),
       data_rate_limiter_(max_bytes_per_hour, base::TimeDelta::FromHours(1)),
       commit_rate_limiter_(max_commits_per_hour, base::TimeDelta::FromHours(1)),
       weak_ptr_factory_(this) {
   bindings_.set_connection_error_handler(base::Bind(
       &LevelDBWrapperImpl::OnConnectionError, base::Unretained(this)));
@@ skipping 270 matching lines @@
 
 void LevelDBWrapperImpl::CommitChanges() {
   DCHECK(database_);
   DCHECK(map_);
   if (!commit_batch_)
     return;
 
   commit_rate_limiter_.add_samples(1);
 
   // Commit all our changes in a single batch.
-  std::vector<leveldb::mojom::BatchedOperationPtr> operations;
+  std::vector<leveldb::mojom::BatchedOperationPtr> operations =
+      prepare_to_commit_callback_.Run();
   if (commit_batch_->clear_all_first) {
     leveldb::mojom::BatchedOperationPtr item =
         leveldb::mojom::BatchedOperation::New();
     item->type = leveldb::mojom::BatchOperationType::DELETE_PREFIXED_KEY;
     item->key = prefix_;
     operations.push_back(std::move(item));
   }
   size_t data_size = 0;
   for (const auto& key: commit_batch_->changed_keys) {
     data_size += key.size();
@@ skipping 25 matching lines @@
                               weak_ptr_factory_.GetWeakPtr()));
 }
 
 void LevelDBWrapperImpl::OnCommitComplete(leveldb::mojom::DatabaseError error) {
   // TODO(michaeln): What if it fails, uma here or in the DB class?
   --commit_batches_in_flight_;
   StartCommitTimer();
 }
 
 }  // namespace content