[IndexedDB] Make database deletion non-cache-filling

Bug: 810564
Change-Id: I69583e3e9bb54a4eff953e5893e0a23818e7ef64
Reviewed-on: https://chromium-review.googlesource.com/950132
Commit-Queue: Daniel Murphy <dmurph@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Reviewed-by: Joshua Bell <jsbell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541668}

content/browser/indexed_db/indexed_db_backing_store.cc

@@ -686,7 +686,8 @@ WARN_UNUSED_RESULT Status IndexedDBBackingStore::SetUpMetadata() {
           DatabaseNameKey::EncodeMinKeyForOrigin(origin_identifier_);
       const std::string stop_key =
           DatabaseNameKey::EncodeStopKeyForOrigin(origin_identifier_);
-      std::unique_ptr<LevelDBIterator> it = db_->CreateIterator();
+      std::unique_ptr<LevelDBIterator> it =
+          db_->CreateIterator(db_->DefaultReadOptions());
       for (s = it->Seek(start_key);
            s.ok() && it->IsValid() && CompareKeys(it->Key(), stop_key) < 0;
            s = it->Next()) {
@@ -1093,7 +1094,9 @@ Status IndexedDBBackingStore::DeleteDatabase(const base::string16& name) {
       DatabaseMetaDataKey::Encode(id + 1, DatabaseMetaDataKey::ORIGIN_NAME);
   {
     IDB_TRACE("IndexedDBBackingStore::DeleteDatabase.DeleteEntries");
-    std::unique_ptr<LevelDBIterator> it = db_->CreateIterator();
+    leveldb::ReadOptions options = db_->DefaultReadOptions();
+    options.fill_cache = false;
+    std::unique_ptr<LevelDBIterator> it = db_->CreateIterator(options);
     for (s = it->Seek(start_key);
          s.ok() && it->IsValid() && CompareKeys(it->Key(), stop_key) < 0;
          s = it->Next())

content/browser/indexed_db/indexed_db_metadata_coding.cc

@@ -48,7 +48,8 @@ Status ReadIndexes(LevelDBDatabase* db,
 
   DCHECK(indexes->empty());
 
-  std::unique_ptr<LevelDBIterator> it = db->CreateIterator();
+  std::unique_ptr<LevelDBIterator> it =
+      db->CreateIterator(db->DefaultReadOptions());
   Status s = it->Seek(start_key);
   while (s.ok() && it->IsValid() && CompareKeys(it->Key(), stop_key) < 0) {
     IndexMetaDataKey meta_data_key;
@@ -149,7 +150,8 @@ Status ReadObjectStores(
 
   DCHECK(object_stores->empty());
 
-  std::unique_ptr<LevelDBIterator> it = db->CreateIterator();
+  std::unique_ptr<LevelDBIterator> it =
+      db->CreateIterator(db->DefaultReadOptions());
   Status s = it->Seek(start_key);
   while (s.ok() && it->IsValid() && CompareKeys(it->Key(), stop_key) < 0) {
     ObjectStoreMetaDataKey meta_data_key;
@@ -321,7 +323,8 @@ leveldb::Status IndexedDBMetadataCoding::ReadDatabaseNames(
 
   DCHECK(names->empty());
 
-  std::unique_ptr<LevelDBIterator> it = db->CreateIterator();
+  std::unique_ptr<LevelDBIterator> it =
+      db->CreateIterator(db->DefaultReadOptions());
   Status s;
   for (s = it->Seek(start_key);
        s.ok() && it->IsValid() && CompareKeys(it->Key(), stop_key) < 0;

content/browser/indexed_db/leveldb/leveldb_database.cc

@@ -430,20 +430,15 @@ leveldb::Status LevelDBDatabase::Write(const LevelDBWriteBatch& write_batch) {
 }
 
 std::unique_ptr<LevelDBIterator> LevelDBDatabase::CreateIterator(
-    const LevelDBSnapshot* snapshot) {
-  leveldb::ReadOptions read_options;
-  read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
-                                         // performance impact is too great.
-  read_options.snapshot = snapshot ? snapshot->snapshot_ : nullptr;
-
+    const leveldb::ReadOptions& options) {
   num_iterators_++;
   max_iterators_ = std::max(max_iterators_, num_iterators_);
   // Iterator isn't added to lru cache until it is used, as memory isn't loaded
   // for the iterator until it's first Seek call.
-  std::unique_ptr<leveldb::Iterator> i(db_->NewIterator(read_options));
+  std::unique_ptr<leveldb::Iterator> i(db_->NewIterator(options));
   return std::unique_ptr<LevelDBIterator>(
       IndexedDBClassFactory::Get()->CreateIteratorImpl(std::move(i), this,
-                                                       read_options.snapshot));
+                                                       options.snapshot));
 }
 
 const LevelDBComparator* LevelDBDatabase::Comparator() const {
@@ -464,6 +459,19 @@ void LevelDBDatabase::CompactAll() {
   db_->CompactRange(nullptr, nullptr);
 }
 
+leveldb::ReadOptions LevelDBDatabase::DefaultReadOptions() {
+  return DefaultReadOptions(nullptr);
+}
+
+leveldb::ReadOptions LevelDBDatabase::DefaultReadOptions(
+    const LevelDBSnapshot* snapshot) {
+  leveldb::ReadOptions read_options;
+  read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
+                                         // performance impact is too great.
+  read_options.snapshot = snapshot ? snapshot->snapshot_ : nullptr;
+  return read_options;
+}
+
 bool LevelDBDatabase::OnMemoryDump(
     const base::trace_event::MemoryDumpArgs& args,
     base::trace_event::ProcessMemoryDump* pmd) {

content/browser/indexed_db/leveldb/leveldb_database.h

@@ -17,6 +17,7 @@
 #include "base/trace_event/memory_dump_provider.h"
 #include "content/common/content_export.h"
 #include "third_party/leveldatabase/src/include/leveldb/comparator.h"
+#include "third_party/leveldatabase/src/include/leveldb/options.h"
 #include "third_party/leveldatabase/src/include/leveldb/status.h"
 
 namespace leveldb {
@@ -84,11 +85,16 @@ class CONTENT_EXPORT LevelDBDatabase
                               bool* found,
                               const LevelDBSnapshot* = 0);
   leveldb::Status Write(const LevelDBWriteBatch& write_batch);
-  std::unique_ptr<LevelDBIterator> CreateIterator(const LevelDBSnapshot* = 0);
+  // Note: Use DefaultReadOptions() and then adjust any values afterwards.
+  std::unique_ptr<LevelDBIterator> CreateIterator(
+      const leveldb::ReadOptions& options);
   const LevelDBComparator* Comparator() const;
   void Compact(const base::StringPiece& start, const base::StringPiece& stop);
   void CompactAll();
 
+  leveldb::ReadOptions DefaultReadOptions();
+  leveldb::ReadOptions DefaultReadOptions(const LevelDBSnapshot* snapshot);
+
   // base::trace_event::MemoryDumpProvider implementation.
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                     base::trace_event::ProcessMemoryDump* pmd) override;

content/browser/indexed_db/leveldb/leveldb_transaction.cc

@@ -240,8 +240,8 @@ LevelDBTransaction::TransactionIterator::TransactionIterator(
     : transaction_(transaction),
       comparator_(transaction_->comparator_),
       data_iterator_(DataIterator::Create(transaction_.get())),
-      db_iterator_(
-          transaction_->db_->CreateIterator(&transaction_->snapshot_)) {
+      db_iterator_(transaction_->db_->CreateIterator(
+          transaction_->db_->DefaultReadOptions(&transaction_->snapshot_))) {
   transaction_->RegisterIterator(this);
 }