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 cc.squirreljme.vm;

import cc.squirreljme.jvm.suite.SuiteUtils;
import cc.squirreljme.runtime.cldc.debug.Debugging;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import net.multiphasicapps.zip.streamreader.ZipStreamReader;

/**
 * A class library which is backed by a JAR file on the disk.
 *
 * @since 2020/04/19
 */
public class JarClassLibrary
    implements RawVMClassLibrary
{
    /** The path of the library. */
    protected final Path path;
    
    /** The base class library as loaded into memory. */
    private VMClassLibrary _loaded;
    
    /**
     * Initializes the class library.
     *
     * @param __path The path to the library.
     * @throws NullPointerException On null arguments.
     * @since 2020/04/19
     */
    public JarClassLibrary(Path __path)
        throws NullPointerException
    {
        if (__path == null)
            throw new NullPointerException("NARG");
        
        this.path = __path;
    }
    
    /**
     * {@inheritDoc}
     * @since 2020/04/19
     */
    @Override
    public String[] listResources()
    {
        try
        {
            return this.__load().listResources();
        }
        catch (IOException e)
        {
            /* {@squirreljme.error AK01 Could not read contents. (Jar Path)} */
            throw new RuntimeException("AK01 " + this.path, e);
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2020/04/19
     */
    @Override
    public String name()
    {
        return this.path.getFileName().toString();
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/06/13
     */
    @Override
    public Path path()
    {
        return this.path;
    }
    
    /**
     * {@inheritDoc}
     * @since 2023/12/30
     */
    @Override
    public void rawData(int __jarOffset, byte[] __b, int __o, int __l)
        throws IndexOutOfBoundsException, NullPointerException
    {
        if (__b == null)
            throw new NullPointerException("NARG");
        
        // Check that the size is correct.
        int bufLen = __b.length;
        int libLen = this.rawSize();
        if (__jarOffset < 0 || (__jarOffset + __l) < 0 ||
            (__jarOffset + __l) > libLen || __o < 0 || __l < 0 ||
            (__o + __l) < 0 || (__o + __l) > bufLen)
            throw new IndexOutOfBoundsException("IOOB");
        
        // Seek through and find the data
        try (InputStream in = Files.newInputStream(this.path,
            StandardOpenOption.READ))
        {
            // Seek first, stop if EOF is hit
            for (int at = 0; at < __jarOffset; at++)
                if (in.read() < 0)
                    throw new IllegalStateException("FEOF");
            
            // Do a standard read here
            if (in.read(__b, __o, __l) != __l)
                throw new IllegalStateException("SHRT");
        }
        catch (IOException __e)
        {
            throw new IllegalStateException(__e);
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2023/12/30
     */
    @Override
    public int rawSize()
    {
        try
        {
            return (int)Math.min(Integer.MAX_VALUE, Files.size(this.path));
        }
        catch (IOException __e)
        {
            throw new IllegalStateException(__e);
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2020/04/19
     */
    @Override
    public InputStream resourceAsStream(String __rc)
        throws IOException, NullPointerException
    {
        return this.__load().resourceAsStream(__rc);
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/06/13
     */
    @Override
    public final String toString()
    {
        return this.path.toString();
    }
    
    /**
     * Loads the library into memory.
     *
     * @return The loaded library.
     * @throws IOException If it could not be read.
     * @since 2020/04/19
     */
    private VMClassLibrary __load()
        throws IOException
    {
        // Already pre-cached?
        VMClassLibrary rv = this._loaded;
        if (rv != null)
            return rv;
        
        Path path = this.path;
        try (InputStream in = Files.newInputStream(path,
            StandardOpenOption.READ);
            ZipStreamReader zip = new ZipStreamReader(in))
        {
            this._loaded = (rv = InMemoryClassLibrary.loadZip(
                path.getFileName().toString(), zip));
            return rv;
        }
    }
    
    /**
     * Checks if this is a JAR or not.
     * 
     * @param __s The file name.
     * @return If this is a JAR.
     * @throws NullPointerException On null arguments.
     * @since 2021/06/13
     */
    public static boolean isJar(Path __s)
        throws NullPointerException
    {
        if (__s == null)
            throw new NullPointerException("NARG");
        
        return JarClassLibrary.isJar(__s.toString());
    }
    
    /**
     * Checks if this is a JAR or not.
     * 
     * @param __s The file name.
     * @return If this is a JAR.
     * @throws NullPointerException On null arguments.
     * @since 2021/06/13
     */
    @Deprecated
    public static boolean isJar(String __s)
        throws NullPointerException
    {
        return SuiteUtils.isJar(__s);
    }
    
    /**
     * Returns either a {@link JarClassLibrary} or a
     * {@link DirectoryClassLibrary} depending on if the given path is
     * not a directory or is one.
     *
     * @param __path The path to evaluate and check.
     * @return A class library for the given path.
     * @throws NullPointerException On null arguments.
     * @since 2020/04/19
     */
    public static VMClassLibrary of(Path __path)
        throws NullPointerException
    {
        if (__path == null)
            throw new NullPointerException("NARG");
        
        if (Files.isDirectory(__path))
            return new DirectoryClassLibrary(__path);
        return new JarClassLibrary(__path);
    }
}