package org.infinispan.server.memcached;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.math.BigInteger;
import java.nio.charset.Charset;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.infinispan.util.KeyValuePair;
import io.netty.buffer.ByteBuf;
/**
* Memcached text protocol utilities.
*
* @author Galder Zamarreño
* @since 4.1
*/
public class TextProtocolUtil {
private TextProtocolUtil() { }
// todo: refactor name once old code has been removed?
public static final String CRLF = "\r\n";
public static final byte[] CRLFBytes = "\r\n".getBytes();
public static final byte[] END = "END\r\n".getBytes();
public static final int END_SIZE = END.length;
public static final byte[] DELETED = "DELETED\r\n".getBytes();
public static final byte[] NOT_FOUND = "NOT_FOUND\r\n".getBytes();
public static final byte[] EXISTS = "EXISTS\r\n".getBytes();
public static final byte[] STORED = "STORED\r\n".getBytes();
public static final byte[] NOT_STORED = "NOT_STORED\r\n".getBytes();
public static final byte[] OK = "OK\r\n".getBytes();
public static final byte[] ERROR = "ERROR\r\n".getBytes();
public static final String CLIENT_ERROR_BAD_FORMAT = "CLIENT_ERROR bad command line format: ";
public static final String SERVER_ERROR = "SERVER_ERROR ";
public static final byte[] VALUE = "VALUE ".getBytes();
public static final int VALUE_SIZE = VALUE.length;
public static final byte[] ZERO = "0".getBytes();
public static final int SP = 32;
public static final int CR = 13;
public static final int LF = 10;
public static final BigInteger MAX_UNSIGNED_LONG = new BigInteger("18446744073709551615");
public static final BigInteger MIN_UNSIGNED = new BigInteger("0");
public static final Charset CHARSET = Charset.forName("UTF-8");
/**
* In the particular case of Memcached, the end of operation/command
* is signaled by "\r\n" characters. So, if end of operation is
* found, this method would return true. On the contrary, if space was
* found instead of end of operation character, then it'd return the element and false.
*/
static boolean readElement(ByteBuf buffer, OutputStream byteBuffer) throws IOException {
byte next = buffer.readByte();
if (next == SP) { // Space
return false;
}
else if (next == CR) { // CR
next = buffer.readByte();
if (next == LF) { // LF
return true;
} else {
byteBuffer.write(next);
return readElement(buffer, byteBuffer);
}
}
else {
byteBuffer.write(next);
return readElement(buffer, byteBuffer);
}
}
static String extractString(ByteArrayOutputStream byteBuffer) {
String string = new String(byteBuffer.toByteArray(), CHARSET);
byteBuffer.reset();
return string;
}
static KeyValuePair<String, Boolean> readElement(ByteBuf buffer, StringBuilder sb) {
byte next = buffer.readByte();
if (next == SP) { // Space
return new KeyValuePair<>(sb.toString().trim(), false);
}
else if (next == CR) { // CR
next = buffer.readByte();
if (next == LF) { // LF
return new KeyValuePair<>(sb.toString().trim(), true);
} else {
sb.append(next);
return readElement(buffer, sb);
}
}
else {
sb.append(next);
return readElement(buffer, sb);
}
}
static String readDiscardedLine(ByteBuf buffer) {
if (readableBytes(buffer) > 0)
return readDiscardedLine(buffer, new StringBuilder());
else
return "";
}
private static int readableBytes(ByteBuf buffer) {
return buffer.writerIndex() - buffer.readerIndex();
}
private static String readDiscardedLine(ByteBuf buffer, StringBuilder sb) {
byte next = buffer.readByte();
if (next == CR) { // CR
next = buffer.readByte();
if (next == LF) { // LF
return sb.toString().trim();
} else {
sb.append((char) next);
return readDiscardedLine(buffer, sb);
}
} else if (next == LF) { //LF
return sb.toString().trim();
} else {
sb.append((char) next);
return readDiscardedLine(buffer, sb);
}
}
static void skipLine(ByteBuf buffer) {
if (readableBytes(buffer) > 0) {
byte next = buffer.readByte();
if (next == CR) { // CR
next = buffer.readByte();
if (next == LF) { // LF
return;
} else {
skipLine(buffer);
}
} else if (next == LF) { //LF
return;
} else {
skipLine(buffer);
}
}
}
static byte[] concat(byte[] a, byte[] b) {
byte[] data = new byte[a.length + b.length];
System.arraycopy(a, 0, data, 0, a.length);
System.arraycopy(b, 0, data, a.length, b.length);
return data;
}
static List<String> readSplitLine(ByteBuf buffer) {
if (readableBytes(buffer) > 0)
return readSplitLine(buffer, Stream.builder(), buffer.readerIndex(), 0).collect(Collectors.toList());
else
return Collections.emptyList();
}
private static Stream<String> readSplitLine(ByteBuf buffer, Stream.Builder<String> builder, int start, int length) {
byte next = buffer.readByte();
if (next == CR) { // CR
next = buffer.readByte();
if (next == LF) { // LF
byte[] bytes = new byte[length];
buffer.getBytes(start, bytes);
builder.add(new String(bytes, CHARSET));
return builder.build();
} else {
return readSplitLine(buffer, builder, start, length + 1);
}
} else if (next == LF) { // LF
byte[] bytes = new byte[length];
buffer.getBytes(start, bytes);
builder.add(new String(bytes, CHARSET));
return builder.build();
} else if (next == SP) {
byte[] bytes = new byte[length];
buffer.getBytes(start, bytes);
builder.add(new String(bytes, CHARSET));
return readSplitLine(buffer, builder, start + length + 1, 0);
} else {
return readSplitLine(buffer, builder, start, length + 1);
}
}
}