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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ART_SRC_INTERN_TABLE_H_
#define ART_SRC_INTERN_TABLE_H_
#include <iosfwd>
#include "heap.h"
#include "mutex.h"
#include "object.h"
#include "safe_map.h"
namespace art {
/**
* Used to intern strings.
*
* There are actually two tables: one that holds strong references to its strings, and one that
* holds weak references. The former is used for string literals, for which there is an effective
* reference from the constant pool. The latter is used for strings interned at runtime via
* String.intern. Some code (XML parsers being a prime example) relies on being able to intern
* arbitrarily many strings for the duration of a parse without permanently increasing the memory
* footprint.
*/
class InternTable {
public:
InternTable();
// Interns a potentially new string in the 'strong' table. (See above.)
String* InternStrong(int32_t utf16_length, const char* utf8_data);
// Interns a potentially new string in the 'strong' table. (See above.)
String* InternStrong(const char* utf8_data);
// Interns a potentially new string in the 'strong' table. (See above.)
String* InternStrong(String* s);
// Interns a potentially new string in the 'weak' table. (See above.)
String* InternWeak(String* s);
// Register a String trusting that it is safe to intern.
// Used when reinitializing InternTable from an image.
void RegisterStrong(String* s);
void SweepInternTableWeaks(Heap::IsMarkedTester is_marked, void* arg);
bool ContainsWeak(String* s);
size_t Size() const;
void VisitRoots(Heap::RootVisitor* visitor, void* arg) const;
void DumpForSigQuit(std::ostream& os) const;
private:
typedef std::multimap<int32_t, String*> Table;
String* Insert(String* s, bool is_strong);
String* Lookup(Table& table, String* s, uint32_t hash_code);
String* Insert(Table& table, String* s, uint32_t hash_code);
void Remove(Table& table, const String* s, uint32_t hash_code);
mutable Mutex intern_table_lock_;
Table image_strong_interns_ GUARDED_BY(intern_table_lock_);
Table strong_interns_ GUARDED_BY(intern_table_lock_);
Table weak_interns_ GUARDED_BY(intern_table_lock_);
};
} // namespace art
#endif // ART_SRC_CLASS_LINKER_H_