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/**
* ByteBuffer
* Copyright 2004 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
* First published 2004 on http://yacy.net
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program in the file lgpl21.txt
* If not, see <http://www.gnu.org/licenses/>.
*/
package net.yacy.cora.util;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import net.yacy.cora.document.encoding.UTF8;
public final class ByteBuffer extends OutputStream {
private byte[] buffer;
private int offset;
private int length;
public ByteBuffer() {
this.buffer = new byte[10];
this.length = 0;
this.offset = 0;
}
public ByteBuffer(final int initLength) {
this.buffer = new byte[initLength];
this.length = 0;
this.offset = 0;
}
public ByteBuffer(final byte[] bb) {
this.buffer = bb;
this.length = bb.length;
this.offset = 0;
}
public ByteBuffer(final String s) {
this.buffer = UTF8.getBytes(s);
this.length = this.buffer.length;
this.offset = 0;
}
public void clear() {
// we keep the byte[] and just set the pointer to write positions to zero
this.length = 0;
this.offset = 0;
}
public int length() {
return this.length;
}
public boolean isEmpty() {
return this.length == 0;
}
private void grow() {
int newsize = this.buffer.length * 2 + 1;
if (newsize < 256) newsize = 256;
final byte[] tmp = new byte[newsize];
System.arraycopy(this.buffer, this.offset, tmp, 0, this.length);
this.buffer = tmp;
this.offset = 0;
}
@Override
public void write(final int b) {
write((byte) (b & 0xff));
}
public void write(final char b) {
write((byte) b);
}
private void write(final byte b) {
if (this.offset + this.length + 1 > this.buffer.length) grow();
this.buffer[this.offset + this.length++] = b;
}
@Override
public void write(final byte[] bb) {
write(bb, 0, bb.length);
}
@Override
public void write(final byte[] bb, final int of, final int le) {
while (this.offset + this.length + le > this.buffer.length) grow();
System.arraycopy(bb, of, this.buffer, this.offset + this.length, le);
this.length += le;
}
public ByteBuffer append(final byte b) {
write(b);
return this;
}
public ByteBuffer append(final char b) {
write(b);
return this;
}
public ByteBuffer append(final int i) {
write((byte) (i & 0xFF));
return this;
}
public ByteBuffer append(final byte[] bb) {
write(bb, 0, bb.length);
return this;
}
public ByteBuffer append(final byte[] bb, final int of, final int le) {
write(bb, of, le);
return this;
}
public ByteBuffer append(final String s) {
return append(UTF8.getBytes(s));
}
public byte byteAt(final int pos) {
if (pos > this.length) return -1;
return this.buffer[this.offset + pos];
}
public int indexOf(final byte[] bs, final int start) {
if (start + bs.length > this.length) return -1;
loop: for (int i = start; i <= this.length - bs.length; i++) {
// first test only first byte
if (this.buffer[this.offset + i] != bs[0]) continue loop;
// then test all remaining bytes
for (int j = 1; j < bs.length; j++) {
if (this.buffer[this.offset + i + j] != bs[j]) continue loop;
}
// found hit
return i;
}
return -1;
}
public boolean startsWith(final byte[] bs, final int start) {
if (this.length - start < bs.length) return false;
for (int i = 0; i < bs.length; i++) {
if (this.buffer[this.offset + i + start] != bs[i]) return false;
}
return true;
}
public byte[] getBytes() {
return getBytes(0);
}
private byte[] getBytes(final int start) {
return getBytes(start, this.length);
}
public byte[] getBytes(final int start, final int len) {
// start is inclusive, end is exclusive
if (len > this.length) throw new IndexOutOfBoundsException("getBytes: len > length");
if (start > this.length) throw new IndexOutOfBoundsException("getBytes: start > length");
if ((start == 0) && (len == this.length) && (len == this.buffer.length)) return this.buffer;
final byte[] tmp = new byte[len];
System.arraycopy(this.buffer, this.offset + start, tmp, 0, len);
return tmp;
}
public void copyTo(byte[] otherArray, int offset) {
System.arraycopy(this.buffer, 0, otherArray, offset, this.length);
}
public ByteBuffer trim(final int start) {
this.offset += start;
this.length -= start;
return this;
}
public ByteBuffer trim(final int start, final int len) {
if (start + len > this.length) throw new IndexOutOfBoundsException("trim: start + len > length; this.offset = " + this.offset + ", this.length = " + this.length + ", start = " + start + ", len = " + len);
this.offset = this.offset + start;
this.length = len;
return this;
}
@Override
public String toString() {
return UTF8.String(this.buffer, this.offset, this.length);
}
public String toString(final int left, final int length) {
return UTF8.String(this.buffer, this.offset + left, length);
}
public StringBuilder toStringBuilder(final int left, final int length, final int sblength) {
assert sblength >= length;
final StringBuilder sb = new StringBuilder(sblength);
int i = 0;
sb.setLength(length);
for (int j = left; j < left + length; j++) sb.setCharAt(i++, (char) this.buffer[this.offset + j]);
return sb;
}
/**
* @param buffer the buffer to test. Must not be null.
* @param pattern a pattern to check for presence at the beginning of the buffer. Must not be null.
* @return true when the buffer starts with the given pattern
*/
public static boolean startsWith(final byte[] buffer, final byte[] pattern) {
if (buffer.length < pattern.length) {
return false;
}
for (int i = 0; i < pattern.length; i++) {
if (buffer[i] != pattern[i]) {
return false;
}
}
return true;
}
public static boolean equals(final byte[] b0, final int off0, final byte[] b1, final int off1, final int length) {
if (b0.length - off0 < length || b1.length - off1 < length) return false;
for (int i = 0; i < length; i++) if (b0[off0 + i] != b1[off1 + i]) return false;
return true;
}
public void writeTo(final OutputStream dest) throws IOException {
dest.write(this.buffer, this.offset, this.length);
dest.flush();
}
public static boolean contains(final Collection<byte[]> collection, final byte[] key) {
for (final byte[] v: collection) {
if (Arrays.equals(v, key)) return true;
}
return false;
}
public static int remove(final Collection<byte[]> collection, final byte[] key) {
Iterator<byte[]> i = collection.iterator();
byte[] v;
int c = 0;
while (i.hasNext()) {
v = i.next();
if (Arrays.equals(v, key)) {
i.remove();
c++;
}
}
return c;
}
public static List<byte[]> split(final byte[] b, final byte s) {
final ArrayList<byte[]> a = new ArrayList<byte[]>();
int c = 0;
loop: while (c < b.length) {
int i = c;
search: while (i < b.length) {
if (b[i] == s) break search;
i++;
}
if (i >= b.length) {
// nothing found; this is the end of the search
final byte[] bb = new byte[b.length - c];
System.arraycopy(b, c, bb, 0, bb.length);
a.add(bb);
break loop;
}
// found a separator
final byte[] bb = new byte[i - c];
System.arraycopy(b, c, bb, 0, bb.length);
a.add(bb);
c = i + 1;
}
return a;
}
}
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