Java example source code file (ciConstantPoolCache.cpp)

This example Java source code file (ciConstantPoolCache.cpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

assert_in_vm, growablearray, null, unimplemented

The ciConstantPoolCache.cpp Java example source code

/*
 * Copyright (c) 1999, 2010, 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "precompiled.hpp"
#include "ci/ciConstantPoolCache.hpp"
#include "ci/ciUtilities.hpp"
#include "memory/allocation.hpp"
#include "memory/allocation.inline.hpp"

// ciConstantPoolCache
//
// This class caches indexed constant pool lookups.

// ------------------------------------------------------------------
// ciConstantPoolCache::ciConstantPoolCache
ciConstantPoolCache::ciConstantPoolCache(Arena* arena,
                                 int expected_size) {
  _elements =
    new (arena) GrowableArray<void*>(arena, expected_size, 0, 0);
  _keys = new (arena) GrowableArray<intptr_t>(arena, expected_size, 0, 0);
}

// ------------------------------------------------------------------
// ciConstantPoolCache::get
//
// Get the entry at some index
void* ciConstantPoolCache::get(int index) {
  ASSERT_IN_VM;
  int pos = find(index);
  if (pos >= _keys->length() ||
      _keys->at(pos) != index) {
    // This element is not present in the cache.
    return NULL;
  }
  return _elements->at(pos);
}

// ------------------------------------------------------------------
// ciConstantPoolCache::find
//
// Use binary search to find the position of this index in the cache.
// If there is no entry in the cache corresponding to this oop, return
// the position at which the index would be inserted.
int ciConstantPoolCache::find(int key) {
  int min = 0;
  int max = _keys->length()-1;

  while (max >= min) {
    int mid = (max + min) / 2;
    int value = _keys->at(mid);
    if (value < key) {
      min = mid + 1;
    } else if (value > key) {
      max = mid - 1;
    } else {
      return mid;
    }
  }
  return min;
}

// ------------------------------------------------------------------
// ciConstantPoolCache::insert
//
// Insert a ciObject into the table at some index.
void ciConstantPoolCache::insert(int index, void* elem) {
  int i;
  int pos = find(index);
  for (i = _keys->length()-1; i >= pos; i--) {
    _keys->at_put_grow(i+1, _keys->at(i));
    _elements->at_put_grow(i+1, _elements->at(i));
  }
  _keys->at_put_grow(pos, index);
  _elements->at_put_grow(pos, elem);
}

// ------------------------------------------------------------------
// ciConstantPoolCache::print
//
// Print debugging information about the cache.
void ciConstantPoolCache::print() {
  Unimplemented();
}