abstractiobuffer.java

mina是以Java实现的一个开源的网络程序框架

    public boolean equals(Object o) {
        if (!(o instanceof IoBuffer)) {
            return false;
        }

        IoBuffer that = (IoBuffer) o;
        if (this.remaining() != that.remaining()) {
            return false;
        }

        int p = this.position();
        for (int i = this.limit() - 1, j = that.limit() - 1; i >= p; i--, j--) {
            byte v1 = this.get(i);
            byte v2 = that.get(j);
            if (v1 != v2) {
                return false;
            }
        }
        return true;
    }

    /**
     * {@inheritDoc}
     */
    public int compareTo(IoBuffer that) {
        int n = this.position() + Math.min(this.remaining(), that.remaining());
        for (int i = this.position(), j = that.position(); i < n; i++, j++) {
            byte v1 = this.get(i);
            byte v2 = that.get(j);
            if (v1 == v2) {
                continue;
            }
            if (v1 < v2) {
                return -1;
            }

            return +1;
        }
        return this.remaining() - that.remaining();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String toString() {
        StringBuilder buf = new StringBuilder();
        if (isDirect()) {
            buf.append("DirectBuffer");
        } else {
            buf.append("HeapBuffer");
        }
        buf.append("[pos=");
        buf.append(position());
        buf.append(" lim=");
        buf.append(limit());
        buf.append(" cap=");
        buf.append(capacity());
        buf.append(": ");
        buf.append(getHexDump(16));
        buf.append(']');
        return buf.toString();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer get(byte[] dst) {
        return get(dst, 0, dst.length);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer put(IoBuffer src) {
        return put(src.buf());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer put(byte[] src) {
        return put(src, 0, src.length);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int getUnsignedShort() {
        return getShort() & 0xffff;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int getUnsignedShort(int index) {
        return getShort(index) & 0xffff;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public long getUnsignedInt() {
        return getInt() & 0xffffffffL;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int getMediumInt() {
        byte b1 = get();
        byte b2 = get();
        byte b3 = get();
        if (ByteOrder.BIG_ENDIAN.equals(order())) {
            return getMediumInt(b1, b2, b3);
        } else {
            return getMediumInt(b3, b2, b1);
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int getUnsignedMediumInt() {
        int b1 = getUnsigned();
        int b2 = getUnsigned();
        int b3 = getUnsigned();
        if (ByteOrder.BIG_ENDIAN.equals(order())) {
            return b1 << 16 | b2 << 8 | b3;
        } else {
            return b3 << 16 | b2 << 8 | b1;
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int getMediumInt(int index) {
        byte b1 = get(index);
        byte b2 = get(index + 1);
        byte b3 = get(index + 2);
        if (ByteOrder.BIG_ENDIAN.equals(order())) {
            return getMediumInt(b1, b2, b3);
        } else {
            return getMediumInt(b3, b2, b1);
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int getUnsignedMediumInt(int index) {
        int b1 = getUnsigned(index);
        int b2 = getUnsigned(index + 1);
        int b3 = getUnsigned(index + 2);
        if (ByteOrder.BIG_ENDIAN.equals(order())) {
            return b1 << 16 | b2 << 8 | b3;
        } else {
            return b3 << 16 | b2 << 8 | b1;
        }
    }

    /**
     * {@inheritDoc}
     */
    private int getMediumInt(byte b1, byte b2, byte b3) {
        int ret = b1 << 16 & 0xff0000 | b2 << 8 & 0xff00 | b3 & 0xff;
        // Check to see if the medium int is negative (high bit in b1 set)
        if ((b1 & 0x80) == 0x80) {
            // Make the the whole int negative
            ret |= 0xff000000;
        }
        return ret;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer putMediumInt(int value) {
        byte b1 = (byte) (value >> 16);
        byte b2 = (byte) (value >> 8);
        byte b3 = (byte) value;

        if (ByteOrder.BIG_ENDIAN.equals(order())) {
            put(b1).put(b2).put(b3);
        } else {
            put(b3).put(b2).put(b1);
        }

        return this;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer putMediumInt(int index, int value) {
        byte b1 = (byte) (value >> 16);
        byte b2 = (byte) (value >> 8);
        byte b3 = (byte) value;

        if (ByteOrder.BIG_ENDIAN.equals(order())) {
            put(index, b1).put(index + 1, b2).put(index + 2, b3);
        } else {
            put(index, b3).put(index + 1, b2).put(index + 2, b1);
        }

        return this;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public long getUnsignedInt(int index) {
        return getInt(index) & 0xffffffffL;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public InputStream asInputStream() {
        return new InputStream() {
            @Override
            public int available() {
                return AbstractIoBuffer.this.remaining();
            }

            @Override
            public synchronized void mark(int readlimit) {
                AbstractIoBuffer.this.mark();
            }

            @Override
            public boolean markSupported() {
                return true;
            }

            @Override
            public int read() {
                if (AbstractIoBuffer.this.hasRemaining()) {
                    return AbstractIoBuffer.this.get() & 0xff;
                } else {
                    return -1;
                }
            }

            @Override
            public int read(byte[] b, int off, int len) {
                int remaining = AbstractIoBuffer.this.remaining();
                if (remaining > 0) {
                    int readBytes = Math.min(remaining, len);
                    AbstractIoBuffer.this.get(b, off, readBytes);
                    return readBytes;
                } else {
                    return -1;
                }
            }

            @Override
            public synchronized void reset() {
                AbstractIoBuffer.this.reset();
            }

            @Override
            public long skip(long n) {
                int bytes;
                if (n > Integer.MAX_VALUE) {
                    bytes = AbstractIoBuffer.this.remaining();
                } else {
                    bytes = Math
                            .min(AbstractIoBuffer.this.remaining(), (int) n);
                }
                AbstractIoBuffer.this.skip(bytes);
                return bytes;
            }
        };
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public OutputStream asOutputStream() {
        return new OutputStream() {
            @Override
            public void write(byte[] b, int off, int len) {
                AbstractIoBuffer.this.put(b, off, len);
            }

            @Override
            public void write(int b) {
                AbstractIoBuffer.this.put((byte) b);
            }
        };
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getHexDump() {
        return this.getHexDump(Integer.MAX_VALUE);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getHexDump(int lengthLimit) {
        return IoBufferHexDumper.getHexdump(this, lengthLimit);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getString(CharsetDecoder decoder)
            throws CharacterCodingException {
        if (!hasRemaining()) {
            return "";
        }

        boolean utf16 = decoder.charset().name().startsWith("UTF-16");

        int oldPos = position();
        int oldLimit = limit();
        int end = -1;
        int newPos;

        if (!utf16) {
            end = indexOf((byte) 0x00);
            if (end < 0) {
                newPos = end = oldLimit;
            } else {
                newPos = end + 1;
            }
        } else {
            int i = oldPos;
            for (;;) {
                boolean wasZero = get(i) == 0;
                i++;

                if (i >= oldLimit) {
                    break;
                }

                if (get(i) != 0) {
                    i++;
                    if (i >= oldLimit) {
                        break;
                    } else {
                        continue;
                    }
                }

                if (wasZero) {
                    end = i - 1;
                    break;
                }
            }

            if (end < 0) {
                newPos = end = oldPos + (oldLimit - oldPos & 0xFFFFFFFE);
            } else {
                if (end + 2 <= oldLimit) {
                    newPos = end + 2;
                } else {
                    newPos = end;
                }
            }
        }

        if (oldPos == end) {
            position(newPos);
            return "";
        }

        limit(end);
        decoder.reset();

        int expectedLength = (int) (remaining() * decoder.averageCharsPerByte()) + 1;
        CharBuffer out = CharBuffer.allocate(expectedLength);
        for (;;) {
            CoderResult cr;
            if (hasRemaining()) {
                cr = decoder.decode(buf(), out, true);
            } else {
                cr = decoder.flush(out);
            }

            if (cr.isUnderflow()) {
                break;
            }

            if (cr.isOverflow()) {
                CharBuffer o = CharBuffer.allocate(out.capacity()
                        + expectedLength);
                out.flip();
                o.put(out);
                out = o;
                continue;
            }

            if (cr.isError()) {
                // Revert the buffer back to the previous state.
                limit(oldLimit);
                position(oldPos);
                cr.throwException();
            }
        }

        limit(oldLimit);
        position(newPos);
        return out.flip().toString();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getString(int fieldSize, CharsetDecoder decoder)
            throws CharacterCodingException {
        checkFieldSize(fieldSize);

        if (fieldSize == 0) {
            return "";
        }

        if (!hasRemaining()) {
            return "";
        }

        boolean utf16 = decoder.charset().name().startsWith("UTF-16");

        if (utf16 && (fieldSize & 1) != 0) {
            throw new IllegalArgumentException("fieldSize is not even.");
        }

        int oldPos = position();
        int oldLimit = limit();
        int end = oldPos + fieldSize;

        if (oldLimit < end) {
            throw new BufferUnderflowException();
        }

        int i;

        if (!utf16) {
            for (i = oldPos; i < end; i++) {
                if (get(i) == 0) {
                    break;
                }
            }

            if (i == end) {
                limit(end);
            } else {
                limit(i);
            }
        } else {
            for (i = oldPos; i < end; i += 2) {
                if (get(i) == 0 && get(i + 1) == 0) {
                    break;
                }
            }

            if (i == end) {
                limit(end);
            } else {
                limit(i);
            }
        }

        if (!hasRemaining()) {
            limit(oldLimit);
            position(end);
            return "";
        }
        decoder.reset();

        int expectedLength = (int) (remaining() * decoder.averageCharsPerByte()) + 1;
        CharBuffer out = CharBuffer.allocate(expectedLength);
        for (;;) {
            CoderResult cr;
            if (hasRemaining()) {
                cr = decoder.decode(buf(), out, true);
            } else {
                cr = decoder.flush(out);
            }

            if (cr.isUnderflow()) {
                break;
            }

            if (cr.isOverflow()) {
                CharBuffer o = CharBuffer.allocate(out.capacity()
                        + expectedLength);