package net.minecraft.src;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

public class RegionFileCache {
	/** A map containing Files as keys and RegionFiles as values */
	private static final Map regionsByFilename = new HashMap();

	public static synchronized RegionFile createOrLoadRegionFile(File par0File, int par1, int par2) {
		File var3 = new File(par0File, "region");
		File var4 = new File(var3, "r." + (par1 >> 5) + "." + (par2 >> 5) + ".mca");
		RegionFile var5 = (RegionFile) regionsByFilename.get(var4);

		if (var5 != null) {
			return var5;
		} else {
			if (!var3.exists()) {
				var3.mkdirs();
			}

			if (regionsByFilename.size() >= 256) {
				clearRegionFileReferences();
			}

			RegionFile var6 = new RegionFile(var4);
			regionsByFilename.put(var4, var6);
			return var6;
		}
	}

	/**
	 * clears region file references
	 */
	public static synchronized void clearRegionFileReferences() {
		Iterator var0 = regionsByFilename.values().iterator();

		while (var0.hasNext()) {
			RegionFile var1 = (RegionFile) var0.next();

			try {
				if (var1 != null) {
					var1.close();
				}
			} catch (IOException var3) {
				var3.printStackTrace();
			}
		}

		regionsByFilename.clear();
	}

	/**
	 * Returns an input stream for the specified chunk. Args: worldDir, chunkX,
	 * chunkZ
	 */
	public static DataInputStream getChunkInputStream(File par0File, int par1, int par2) {
		RegionFile var3 = createOrLoadRegionFile(par0File, par1, par2);
		return var3.getChunkDataInputStream(par1 & 31, par2 & 31);
	}

	/**
	 * Returns an output stream for the specified chunk. Args: worldDir, chunkX,
	 * chunkZ
	 */
	public static DataOutputStream getChunkOutputStream(File par0File, int par1, int par2) {
		RegionFile var3 = createOrLoadRegionFile(par0File, par1, par2);
		return var3.getChunkDataOutputStream(par1 & 31, par2 & 31);
	}
}