SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package net.multiphasicapps.classfile;

import cc.squirreljme.runtime.cldc.debug.Debugging;
import java.io.DataInputStream;
import java.io.IOException;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.Map;

/**
 * This represents the attribute table that exists within a class.
 *
 * @since 2018/05/14
 */
public final class AttributeTable
{
    /** The attribute table. */
    private final Map<String, Attribute> _attributes;
    
    /**
     * Initializes the attribute table.
     *
     * @param __a The input attributes.
     * @throws NullPointerException On null arguments.
     * @since 2018/05/15
     */
    public AttributeTable(Attribute... __a)
        throws NullPointerException
    {
        this(Arrays.<Attribute>asList((__a != null ? __a :
            new Attribute[0])));
    }
    
    /**
     * Initializes the attribute table.
     *
     * @param __a The input attributes.
     * @throws NullPointerException On null arguments.
     * @since 2018/05/15
     */
    public AttributeTable(Iterable<Attribute> __a)
        throws NullPointerException
    {
        if (__a == null)
            throw new NullPointerException("NARG");
        
        Map<String, Attribute> attributes = new LinkedHashMap<>();
        for (Attribute a : __a)
        {
            if (a == null)
                throw new NullPointerException("NARG");
            
            String n = a.name();
            if (!attributes.containsKey(n))
                attributes.put(n, a);
        }
        this._attributes = attributes;
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/05/15
     */
    @Override
    public final boolean equals(Object __o)
    {
        throw Debugging.todo();
    }
    
    /**
     * Returns the attribute that uses the specified name.
     *
     * @param __n The name of the attribute to get.
     * @return The specified attribute or {@code null} if it does not exist.
     * @throws NullPointerException On null arguments.
     * @since 2018/05/15
     */
    public final Attribute get(String __n)
        throws NullPointerException
    {
        if (__n == null)
            throw new NullPointerException("NARG");
        
        return this._attributes.get(__n);
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/05/15
     */
    @Override
    public final int hashCode()
    {
        throw Debugging.todo();
    }
    
    /**
     * Opens the attribute by the specified key.
     *
     * @param __n The name of the attribute to open.
     * @return The stream to the given attribute or {@code null} if it is not
     * valid.
     * @throws NullPointerException On null arguments.
     * @since 2018/05/15
     */
    public final DataInputStream open(String __n)
        throws NullPointerException
    {
        if (__n == null)
            throw new NullPointerException("NARG");
        
        Attribute a = this.get(__n);
        if (a == null)
            return null;
        return a.open();
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/05/15
     */
    @Override
    public final String toString()
    {
        throw Debugging.todo();
    }
    
    /**
     * Returns the length of the attribute table.
     *
     * @return The attribute table length.
     * @since 2018/05/14
     */
    public final int size()
    {
        return this._attributes.size();
    }
    
    /**
     * Parses the attribute table.
     *
     * @param __in The input stream.
     * @param __pool The constant pool.
     * @return The attribute table.
     * @throws InvalidClassFormatException If the table is not correct.
     * @throws IOException On read errors.
     * @throws NullPointerException On null arguments.
     * @since 2018/05/14
     */
    public static AttributeTable parse(Pool __pool, DataInputStream __in)
        throws InvalidClassFormatException, IOException, NullPointerException
    {
        if (__in == null || __pool == null)
            throw new NullPointerException("NARG");
        
        int n = __in.readUnsignedShort();
        Attribute[] rv = new Attribute[n];
        
        // Read each entry
        for (int i = 0; i < n; i++)
        {
            String name = __pool.<UTFConstantEntry>require(
                UTFConstantEntry.class, __in.readUnsignedShort()).toString();
            
            /* {@squirreljme.error JC1x Attributes with a size larger than two
            gigabytes are not supported.} */
            int len = __in.readInt();
            if (len < 0)
                throw new InvalidClassFormatException("JC1x");
            
            byte[] data = new byte[len];
            __in.readFully(data);
            
            rv[i] = new Attribute(name, data, 0, len);
        }
        
        return new AttributeTable(rv);
    }
}