[IndexedDB] Pool and evict leveldb iterators, to save memory

content/browser/indexed_db/leveldb/leveldb_database.h

Index: content/browser/indexed_db/leveldb/leveldb_database.h
diff --git a/content/browser/indexed_db/leveldb/leveldb_database.h b/content/browser/indexed_db/leveldb/leveldb_database.h
index cdcabb54647c83c9d2f56690e2a84ba2fecd87c9..e0d855ce499be42d70d3eb574867de13c22a3fb6 100644
--- a/content/browser/indexed_db/leveldb/leveldb_database.h
+++ b/content/browser/indexed_db/leveldb/leveldb_database.h
@@ -8,6 +8,7 @@
 #include <memory>
 #include <string>
 
+#include "base/containers/mru_cache.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
@@ -102,6 +103,9 @@ class CONTENT_EXPORT LevelDBDatabase
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                     base::trace_event::ProcessMemoryDump* pmd) override;
 
+  void NotifyIteratorUsed(LevelDBIterator*);
+  void NotifyIteratorDestroyed(LevelDBIterator*);
+
  protected:
   LevelDBDatabase();
 
@@ -115,6 +119,8 @@ class CONTENT_EXPORT LevelDBDatabase
   std::unique_ptr<leveldb::DB> db_;
   std::unique_ptr<const leveldb::FilterPolicy> filter_policy_;
   const LevelDBComparator* comparator_;
+  base::MRUCache<LevelDBIterator*, LevelDBIterator*> iterator_lru_;

[jsbell, 2017/03/21 00:15:48]

MRU vs lru ?

[dmurph, 2017/03/21 20:13:26]

Incorrect type name. Very annoying for me haha.

+
   std::string file_name_for_tracing;
 };