/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2007 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package alterrs.asm.optimizer;

import java.util.HashMap;

import alterrs.asm.Type;

/**
 * A constant pool.
 * 
 * @author Eric Bruneton
 */
public class ConstantPool extends HashMap {

	private final Constant key1 = new Constant();

	private final Constant key2 = new Constant();

	private final Constant key3 = new Constant();

	public Constant newInteger(final int value) {
		key1.set(value);
		Constant result = get(key1);
		if (result == null) {
			result = new Constant(key1);
			put(result);
		}
		return result;
	}

	public Constant newFloat(final float value) {
		key1.set(value);
		Constant result = get(key1);
		if (result == null) {
			result = new Constant(key1);
			put(result);
		}
		return result;
	}

	public Constant newLong(final long value) {
		key1.set(value);
		Constant result = get(key1);
		if (result == null) {
			result = new Constant(key1);
			put(result);
		}
		return result;
	}

	public Constant newDouble(final double value) {
		key1.set(value);
		Constant result = get(key1);
		if (result == null) {
			result = new Constant(key1);
			put(result);
		}
		return result;
	}

	public Constant newUTF8(final String value) {
		key1.set('s', value, null, null);
		Constant result = get(key1);
		if (result == null) {
			result = new Constant(key1);
			put(result);
		}
		return result;
	}

	private Constant newString(final String value) {
		key2.set('S', value, null, null);
		Constant result = get(key2);
		if (result == null) {
			newUTF8(value);
			result = new Constant(key2);
			put(result);
		}
		return result;
	}

	public Constant newClass(final String value) {
		key2.set('C', value, null, null);
		Constant result = get(key2);
		if (result == null) {
			newUTF8(value);
			result = new Constant(key2);
			put(result);
		}
		return result;
	}

	public Constant newConst(final Object cst) {
		if (cst instanceof Integer) {
			int val = ((Integer) cst).intValue();
			return newInteger(val);
		} else if (cst instanceof Float) {
			float val = ((Float) cst).floatValue();
			return newFloat(val);
		} else if (cst instanceof Long) {
			long val = ((Long) cst).longValue();
			return newLong(val);
		} else if (cst instanceof Double) {
			double val = ((Double) cst).doubleValue();
			return newDouble(val);
		} else if (cst instanceof String) {
			return newString((String) cst);
		} else if (cst instanceof Type) {
			Type t = (Type) cst;
			return newClass(t.getSort() == Type.OBJECT ? t.getInternalName()
					: t.getDescriptor());
		} else {
			throw new IllegalArgumentException("value " + cst);
		}
	}

	public Constant newField(final String owner, final String name,
			final String desc) {
		key3.set('G', owner, name, desc);
		Constant result = get(key3);
		if (result == null) {
			newClass(owner);
			newNameType(name, desc);
			result = new Constant(key3);
			put(result);
		}
		return result;
	}

	public Constant newMethod(final String owner, final String name,
			final String desc, final boolean itf) {
		key3.set(itf ? 'N' : 'M', owner, name, desc);
		Constant result = get(key3);
		if (result == null) {
			newClass(owner);
			newNameType(name, desc);
			result = new Constant(key3);
			put(result);
		}
		return result;
	}

	public Constant newNameType(final String name, final String desc) {
		key2.set('T', name, desc, null);
		Constant result = get(key2);
		if (result == null) {
			newUTF8(name);
			newUTF8(desc);
			result = new Constant(key2);
			put(result);
		}
		return result;
	}

	private Constant get(final Constant key) {
		return (Constant) get((Object) key);
	}

	private void put(final Constant cst) {
		put(cst, cst);
	}
}