119 lines
3.2 KiB
Java
119 lines
3.2 KiB
Java
import java.io.ByteArrayOutputStream;
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import java.nio.charset.StandardCharsets;
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import java.util.Arrays;
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public class MutableByteString {
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private byte[] bytes;
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private int length;
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public MutableByteString(byte... bytes) {
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setInternal(bytes);
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}
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public int length() {
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return length;
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}
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public boolean isEmpty() {
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return length == 0;
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}
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public byte get(int index) {
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return bytes[check(index)];
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}
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public void set(byte[] bytes) {
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setInternal(bytes);
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}
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public void set(int index, byte b) {
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bytes[check(index)] = b;
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}
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public void append(byte b) {
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if (length >= bytes.length) {
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int len = 2 * bytes.length;
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if (len < 0)
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len = Integer.MAX_VALUE;
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bytes = Arrays.copyOf(bytes, len);
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}
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bytes[length] = b;
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length++;
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}
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public MutableByteString substring(int from, int to) {
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return new MutableByteString(Arrays.copyOfRange(bytes, from, to));
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}
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public void replace(byte[] from, byte[] to) {
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ByteArrayOutputStream copy = new ByteArrayOutputStream();
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if (from.length == 0) {
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for (byte b : bytes) {
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copy.write(to, 0, to.length);
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copy.write(b);
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}
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copy.write(to, 0, to.length);
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} else {
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for (int i = 0; i < length; i++) {
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if (regionEquals(i, from)) {
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copy.write(to, 0, to.length);
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i += from.length - 1;
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} else {
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copy.write(bytes[i]);
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}
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}
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}
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set(copy.toByteArray());
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}
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public boolean regionEquals(int offset, MutableByteString other, int otherOffset, int len) {
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if (Math.max(offset, otherOffset) + len < 0)
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return false;
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if (offset + len > length || otherOffset + len > other.length())
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return false;
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for (int i = 0; i < len; i++) {
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if (bytes[offset + i] != other.get(otherOffset + i))
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return false;
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}
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return true;
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}
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public String toHexString() {
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char[] hex = new char[2 * length];
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for (int i = 0; i < length; i++) {
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hex[2 * i] = "0123456789abcdef".charAt(bytes[i] >> 4 & 0x0F);
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hex[2 * i + 1] = "0123456789abcdef".charAt(bytes[i] & 0x0F);
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}
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return new String(hex);
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}
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public String toStringUtf8() {
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return new String(bytes, 0, length, StandardCharsets.UTF_8);
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}
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private void setInternal(byte[] bytes) {
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this.bytes = bytes.clone();
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this.length = bytes.length;
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}
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private boolean regionEquals(int offset, byte[] other) {
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int len = other.length;
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if (offset < 0 || offset + len < 0)
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return false;
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if (offset + len > length)
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return false;
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for (int i = 0; i < len; i++) {
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if (bytes[offset + i] != other[i])
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return false;
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}
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return true;
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}
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private int check(int index) {
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if (index < 0 || index >= length)
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throw new IndexOutOfBoundsException(String.valueOf(index));
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return index;
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}
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}
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