diff src/org/tmatesoft/hg/internal/ByteArrayDataAccess.java @ 157:d5268ca7715b

Merged branch wrap-data-access into default for resource-friendly data access. Updated API to promote that friendliness to clients (channels, not byte[]). More exceptions
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Wed, 09 Mar 2011 05:22:17 +0100
parents src/com/tmate/hgkit/fs/ByteArrayDataAccess.java@9429c7bd1920
children b413b16d10a5
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/internal/ByteArrayDataAccess.java	Wed Mar 09 05:22:17 2011 +0100
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2011 TMate Software Ltd
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program 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 for more details.
+ *
+ * For information on how to redistribute this software under
+ * the terms of a license other than GNU General Public License
+ * contact TMate Software at support@hg4j.com
+ */
+package org.tmatesoft.hg.internal;
+
+import java.io.IOException;
+
+
+/**
+ *   
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public class ByteArrayDataAccess extends DataAccess {
+
+	private final byte[] data;
+	private final int offset;
+	private final int length;
+	private int pos;
+
+	public ByteArrayDataAccess(byte[] data) {
+		this(data, 0, data.length);
+	}
+
+	public ByteArrayDataAccess(byte[] data, int offset, int length) {
+		this.data = data;
+		this.offset = offset;
+		this.length = length;
+		pos = 0;
+	}
+	
+	@Override
+	public byte readByte() throws IOException {
+		if (pos >= length) {
+			throw new IOException();
+		}
+		return data[offset + pos++];
+	}
+	@Override
+	public void readBytes(byte[] buf, int off, int len) throws IOException {
+		if (len > (this.length - pos)) {
+			throw new IOException();
+		}
+		System.arraycopy(data, pos, buf, off, len);
+		pos += len;
+	}
+
+	@Override
+	public ByteArrayDataAccess reset() {
+		pos = 0;
+		return this;
+	}
+	@Override
+	public long length() {
+		return length;
+	}
+	@Override
+	public void seek(long offset) {
+		pos = (int) offset;
+	}
+	@Override
+	public void skip(int bytes) throws IOException {
+		seek(pos + bytes);
+	}
+	@Override
+	public boolean isEmpty() {
+		return pos >= length;
+	}
+	
+	//
+	
+	// when byte[] needed from DA, we may save few cycles and some memory giving this (otherwise unsafe) access to underlying data
+	@Override
+	public byte[] byteArray() {
+		return data;
+	}
+}