LevelDB storage for data reduction proxy to store data usage stats.

components/data_reduction_proxy/core/browser/data_reduction_proxy_store_impl.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_store_impl.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_store_impl.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_store_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..96b4b8b94b992d315aff580dcd0c15a1bcbb1f1f
--- /dev/null
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_store_impl.cc
@@ -0,0 +1,131 @@
+// Copyright 2015 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 "components/data_reduction_proxy/core/browser/data_reduction_proxy_store_impl.h"
+
+#include "base/files/file_util.h"
+#include "base/logging.h"
+#include "base/memory/ref_counted.h"
+#include "base/metrics/histogram_macros.h"
+#include "components/data_reduction_proxy/proto/store.pb.h"
+#include "third_party/leveldatabase/env_chromium.h"
+#include "third_party/leveldatabase/src/include/leveldb/db.h"
+#include "third_party/leveldatabase/src/include/leveldb/env.h"
+#include "third_party/leveldatabase/src/include/leveldb/options.h"
+#include "third_party/leveldatabase/src/include/leveldb/status.h"
+#include "third_party/leveldatabase/src/include/leveldb/write_batch.h"
+
+namespace {
+
+const base::FilePath::CharType kDBName[] =
+    FILE_PATH_LITERAL("data_reduction_proxy_leveldb");
+
+data_reduction_proxy::DataReductionProxyStore::Status LevelDbToDRPStoreStatus(
+    leveldb::Status leveldb_status) {
+  if (leveldb_status.ok())
+    return data_reduction_proxy::DataReductionProxyStore::Status::OK;
+  else if (leveldb_status.IsNotFound())
+    return data_reduction_proxy::DataReductionProxyStore::Status::NOT_FOUND;
+  else if (leveldb_status.IsCorruption())
+    return data_reduction_proxy::DataReductionProxyStore::Status::CORRUPTED;
+  else if (leveldb_status.IsIOError())
+    return data_reduction_proxy::DataReductionProxyStore::Status::IO_ERROR;
+  else

[bengr, 2015/06/25 23:22:55]

You can delete this line.

[Not at Google. Contact bengr, 2015/06/29 20:53:27]

Having the 'else' will prevent you from adding to the Status enum without
updating this method. Otherwise any new entry in the enum will cause this method
to always return MISC_ERROR.

[Not at Google. Contact bengr, 2015/07/01 17:13:48]

Ignore above comment. Done.

+    return data_reduction_proxy::DataReductionProxyStore::Status::MISC_ERROR;
+}
+
+}  // namespace
+
+namespace data_reduction_proxy {
+
+DataReductionProxyStoreImpl::DataReductionProxyStoreImpl(
+    const base::FilePath& profile_path)
+    : profile_path_(profile_path) {
+  thread_checker_.DetachFromThread();
+}
+
+void DataReductionProxyStoreImpl::InitializeOnDBThread() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(!db_);
+
+  DataReductionProxyStore::Status status = OpenDB();
+  if (status == CORRUPTED)
+    RecreateDB();
+}
+
+DataReductionProxyStore::Status DataReductionProxyStoreImpl::Get(
+    const std::string& key,
+    std::string* value) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (db_.get() == nullptr) {
+    return MISC_ERROR;
+  }
+
+  leveldb::ReadOptions read_options;
+  read_options.verify_checksums = true;
+  leveldb::Slice slice(key);
+  leveldb::Status status = db_->Get(read_options, slice, value);
+  if (status.IsCorruption())
+    RecreateDB();
+
+  return LevelDbToDRPStoreStatus(status);
+}
+
+DataReductionProxyStore::Status DataReductionProxyStoreImpl::Put(
+    const std::map<std::string, std::string>& map) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (db_.get() == nullptr) {
+    return MISC_ERROR;
+  }
+
+  leveldb::WriteBatch batch;
+  for (const auto& iter : map) {
+    leveldb::Slice key_slice(iter.first);
+    leveldb::Slice value_slice(iter.second);
+    batch.Put(key_slice, value_slice);
+  }
+
+  leveldb::WriteOptions write_options;
+  leveldb::Status status = db_->Write(write_options, &batch);
+  if (status.IsCorruption())
+    RecreateDB();
+
+  return LevelDbToDRPStoreStatus(status);
+}
+
+DataReductionProxyStoreImpl::~DataReductionProxyStoreImpl() {

[michaeln, 2015/06/26 20:15:01]

What ensures this refcounted object isn't deleted on the UI or IO thread? It
will close the db_ in here which involves file io which we don't want to do on
the UI or IO threads.

[Not at Google. Contact bengr, 2015/06/29 20:53:27]

Added check for valid thread. Users of this class will ensure that destruction
is on the correct thread. Currently, DRP_compression_stats releases
DataUsageStorageHelper on DB thread, which triggers the destruction of this
class.

+}
+
+DataReductionProxyStore::Status DataReductionProxyStoreImpl::OpenDB() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  leveldb::Options options;
+  options.create_if_missing = true;
+  options.paranoid_checks = true;
+  options.reuse_logs = leveldb_env::kDefaultLogReuseOptionValue;
+  std::string db_name = profile_path_.Append(kDBName).AsUTF8Unsafe();

[michaeln, 2015/06/26 20:15:01]

What about incognito? Is this used for incognito profiles where we don't want to
write anything to disk?

[Not at Google. Contact bengr, 2015/06/29 20:53:27]

No, data_reduction_proxy component does not run for incognito.

+  leveldb::DB* dbptr = nullptr;
+  Status status =
+      LevelDbToDRPStoreStatus(leveldb::DB::Open(options, db_name, &dbptr));
+  UMA_HISTOGRAM_ENUMERATION("DataReductionProxy.LevelDBOpenStatus", status,
+                            STATUS_MAX);
+
+  if (status != OK)
+    LOG(ERROR) << "Failed to open Data Reduction Proxy DB: " << status;
+
+  db_.reset(dbptr);
+  return status;
+}
+
+void DataReductionProxyStoreImpl::RecreateDB() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  LOG(WARNING) << "Deleting corrupt Data Reduction Proxy LevelDB";
+  db_.reset(nullptr);
+  base::DeleteFile(profile_path_.Append(kDBName), true);
+
+  OpenDB();
+}
+
+}  // namespace data_reduction_proxy