jlibredis/src/main/java/redis/clients/util/RedisOutputStream.java

package redis.clients.util;

import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
 * The class implements a buffered output stream without synchronization There
 * are also special operations like in-place string encoding. This stream fully
 * ignore mark/reset and should not be used outside Jedis
 */
public final class RedisOutputStream extends FilterOutputStream {
    protected final byte buf[];

    protected int count;

    public RedisOutputStream(final OutputStream out) {
	this(out, 8192);
    }

    public RedisOutputStream(final OutputStream out, final int size) {
	super(out);
	if (size <= 0) {
	    throw new IllegalArgumentException("Buffer size <= 0");
	}
	buf = new byte[size];
    }

    private void flushBuffer() throws IOException {
	if (count > 0) {
	    out.write(buf, 0, count);
	    count = 0;
	}
    }

    public void write(final byte b) throws IOException {
	if (count == buf.length) {
	    flushBuffer();
	}
	buf[count++] = b;
    }

    public void write(final byte[] b) throws IOException {
	write(b, 0, b.length);
    }

    public void write(final byte b[], final int off, final int len)
	    throws IOException {
	if (len >= buf.length) {
	    flushBuffer();
	    out.write(b, off, len);
	} else {
	    if (len >= buf.length - count) {
		flushBuffer();
	    }

	    System.arraycopy(b, off, buf, count, len);
	    count += len;
	}
    }

    public void writeAsciiCrLf(final String in) throws IOException {
	final int size = in.length();

	for (int i = 0; i != size; ++i) {
	    if (count == buf.length) {
		flushBuffer();
	    }
	    buf[count++] = (byte) in.charAt(i);
	}

	writeCrLf();
    }

    public static boolean isSurrogate(final char ch) {
	return ch >= Character.MIN_SURROGATE && ch <= Character.MAX_SURROGATE;
    }

    public static int utf8Length(final String str) {
	int strLen = str.length(), utfLen = 0;
	for (int i = 0; i != strLen; ++i) {
	    char c = str.charAt(i);
	    if (c < 0x80) {
		utfLen++;
	    } else if (c < 0x800) {
		utfLen += 2;
	    } else if (isSurrogate(c)) {
		i++;
		utfLen += 4;
	    } else {
		utfLen += 3;
	    }
	}
	return utfLen;
    }

    public void writeCrLf() throws IOException {
	if (2 >= buf.length - count) {
	    flushBuffer();
	}

	buf[count++] = '\r';
	buf[count++] = '\n';
    }

    public void writeUtf8CrLf(final String str) throws IOException {
	int strLen = str.length();

	int i;
	for (i = 0; i < strLen; i++) {
	    char c = str.charAt(i);
	    if (!(c < 0x80))
		break;
	    if (count == buf.length) {
		flushBuffer();
	    }
	    buf[count++] = (byte) c;
	}

	for (; i < strLen; i++) {
	    char c = str.charAt(i);
	    if (c < 0x80) {
		if (count == buf.length) {
		    flushBuffer();
		}
		buf[count++] = (byte) c;
	    } else if (c < 0x800) {
		if (2 >= buf.length - count) {
		    flushBuffer();
		}
		buf[count++] = (byte) (0xc0 | (c >> 6));
		buf[count++] = (byte) (0x80 | (c & 0x3f));
	    } else if (isSurrogate(c)) {
		if (4 >= buf.length - count) {
		    flushBuffer();
		}
		int uc = Character.toCodePoint(c, str.charAt(i++));
		buf[count++] = ((byte) (0xf0 | ((uc >> 18))));
		buf[count++] = ((byte) (0x80 | ((uc >> 12) & 0x3f)));
		buf[count++] = ((byte) (0x80 | ((uc >> 6) & 0x3f)));
		buf[count++] = ((byte) (0x80 | (uc & 0x3f)));
	    } else {
		if (3 >= buf.length - count) {
		    flushBuffer();
		}
		buf[count++] = ((byte) (0xe0 | ((c >> 12))));
		buf[count++] = ((byte) (0x80 | ((c >> 6) & 0x3f)));
		buf[count++] = ((byte) (0x80 | (c & 0x3f)));
	    }
	}

	writeCrLf();
    }

    private final static int[] sizeTable = { 9, 99, 999, 9999, 99999, 999999,
	    9999999, 99999999, 999999999, Integer.MAX_VALUE };

    private final static byte[] DigitTens = { '0', '0', '0', '0', '0', '0',
	    '0', '0', '0', '0', '1', '1', '1', '1', '1', '1', '1', '1', '1',
	    '1', '2', '2', '2', '2', '2', '2', '2', '2', '2', '2', '3', '3',
	    '3', '3', '3', '3', '3', '3', '3', '3', '4', '4', '4', '4', '4',
	    '4', '4', '4', '4', '4', '5', '5', '5', '5', '5', '5', '5', '5',
	    '5', '5', '6', '6', '6', '6', '6', '6', '6', '6', '6', '6', '7',
	    '7', '7', '7', '7', '7', '7', '7', '7', '7', '8', '8', '8', '8',
	    '8', '8', '8', '8', '8', '8', '9', '9', '9', '9', '9', '9', '9',
	    '9', '9', '9', };

    private final static byte[] DigitOnes = { '0', '1', '2', '3', '4', '5',
	    '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8',
	    '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1',
	    '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4',
	    '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7',
	    '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',
	    '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3',
	    '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6',
	    '7', '8', '9', };

    private final static byte[] digits = { '0', '1', '2', '3', '4', '5', '6',
	    '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
	    'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
	    'x', 'y', 'z' };

    public void writeIntCrLf(int value) throws IOException {
	if (value < 0) {
	    write((byte) '-');
	    value = -value;
	}

	int size = 0;
	while (value > sizeTable[size])
	    size++;

	size++;
	if (size >= buf.length - count) {
	    flushBuffer();
	}

	int q, r;
	int charPos = count + size;

	while (value >= 65536) {
	    q = value / 100;
	    r = value - ((q << 6) + (q << 5) + (q << 2));
	    value = q;
	    buf[--charPos] = DigitOnes[r];
	    buf[--charPos] = DigitTens[r];
	}

	for (;;) {
	    q = (value * 52429) >>> (16 + 3);
	    r = value - ((q << 3) + (q << 1));
	    buf[--charPos] = digits[r];
	    value = q;
	    if (value == 0)
		break;
	}
	count += size;

	writeCrLf();
    }

    public void flush() throws IOException {
	flushBuffer();
	out.flush();
    }
}