/*

 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 * questions.

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 */

#ifndef SHARE_CLASSFILE_STRINGTABLE_HPP

#define SHARE_CLASSFILE_STRINGTABLE_HPP

#include "memory/allocation.hpp"

#include "memory/padded.hpp"

#include "oops/oop.hpp"

#include "oops/weakHandle.hpp"

#include "utilities/tableStatistics.hpp"

class CompactHashtableWriter;

class JavaThread;

class SerializeClosure;

class StringTable;

class StringTableConfig;

class StringTableCreateEntry;

class StringTable : public CHeapObj<mtSymbol>{

  friend class VMStructs;

  friend class Symbol;

  friend class StringTableConfig;

  friend class StringTableCreateEntry;

  static volatile bool _has_work;

  static volatile size_t _uncleaned_items_count;

  // Set if one bucket is out of balance due to hash algorithm deficiency

  static volatile bool _needs_rehashing;

  static void grow(JavaThread* jt);

  static void clean_dead_entries(JavaThread* jt);

  static double get_load_factor();

  static double get_dead_factor();

  static void check_concurrent_work();

  static void trigger_concurrent_work();

  static size_t item_added();

  static void item_removed();

  static size_t add_items_to_clean(size_t ndead);

  static oop intern(Handle string_or_null_h, const jchar* name, int len, TRAPS);

  static oop do_intern(Handle string_or_null, const jchar* name, int len, uintx hash, TRAPS);

  static oop do_lookup(const jchar* name, int len, uintx hash);

  static void print_table_statistics(outputStream* st, const char* table_name);

  static bool do_rehash();

 public:

  static size_t table_size();

  static TableStatistics get_table_statistics();

  static void create_table();

  static void do_concurrent_work(JavaThread* jt);

  static bool has_work() { return _has_work; }

  // GC support

  // Must be called before a parallel walk where strings might die.

  static void reset_dead_counter() { _uncleaned_items_count = 0; }

  // After the parallel walk this method must be called to trigger

  // cleaning. Note it might trigger a resize instead.

  static void finish_dead_counter() { check_concurrent_work(); }

  // If GC uses ParState directly it should add the number of cleared

  // strings to this method.

  static void inc_dead_counter(size_t ndead) { add_items_to_clean(ndead); }

  // Serially invoke "f->do_oop" on the locations of all oops in the table.

  // Used by JFR leak profiler.  TODO: it should find these oops through

  // the WeakProcessor.

  static void oops_do(OopClosure* f);

  // Probing

  static oop lookup(Symbol* symbol);

  static oop lookup(const jchar* chars, int length);

  // Interning

  static oop intern(Symbol* symbol, TRAPS);

  static oop intern(oop string, TRAPS);

  static oop intern(const char *utf8_string, TRAPS);

  // Rehash the string table if it gets out of balance

  static void rehash_table();

  static bool needs_rehashing() { return _needs_rehashing; }

  static inline void update_needs_rehash(bool rehash) {

    if (rehash) {

      _needs_rehashing = true;

    }

  }

  // Sharing

 private:

  static oop lookup_shared(const jchar* name, int len, unsigned int hash) NOT_CDS_JAVA_HEAP_RETURN_(NULL);

  static void copy_shared_string_table(CompactHashtableWriter* ch_table) NOT_CDS_JAVA_HEAP_RETURN;

 public:

  static oop create_archived_string(oop s, Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN_(NULL);

  static void shared_oops_do(OopClosure* f) NOT_CDS_JAVA_HEAP_RETURN;

  static void write_to_archive() NOT_CDS_JAVA_HEAP_RETURN;

  static void serialize_shared_table_header(SerializeClosure* soc) NOT_CDS_JAVA_HEAP_RETURN;

  // Jcmd

  static void dump(outputStream* st, bool verbose=false);

  // Debugging

  static size_t verify_and_compare_entries();

  static void verify();

};

#endif // SHARE_CLASSFILE_STRINGTABLE_HPP