abstractiobuffer.java

mina是以Java实现的一个开源的网络程序框架

        case 1:
            dataLength = getUnsigned(position());
            break;
        case 2:
            dataLength = getUnsignedShort(position());
            break;
        case 4:
            dataLength = getInt(position());
            break;
        default:
            throw new IllegalArgumentException("prefixLength: " + prefixLength);
        }

        if (dataLength < 0 || dataLength > maxDataLength) {
            throw new BufferDataException("dataLength: " + dataLength);
        }

        return remaining() - prefixLength >= dataLength;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int indexOf(byte b) {
        if (hasArray()) {
            int arrayOffset = arrayOffset();
            int beginPos = arrayOffset + position();
            int limit = arrayOffset + limit();
            byte[] array = array();

            for (int i = beginPos; i < limit; i++) {
                if (array[i] == b) {
                    return i - arrayOffset;
                }
            }
        } else {
            int beginPos = position();
            int limit = limit();

            for (int i = beginPos; i < limit; i++) {
                if (get(i) == b) {
                    return i;
                }
            }
        }

        return -1;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer skip(int size) {
        autoExpand(size);
        return position(position() + size);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer fill(byte value, int size) {
        autoExpand(size);
        int q = size >>> 3;
        int r = size & 7;

        if (q > 0) {
            int intValue = value | value << 8 | value << 16 | value << 24;
            long longValue = intValue;
            longValue <<= 32;
            longValue |= intValue;

            for (int i = q; i > 0; i--) {
                putLong(longValue);
            }
        }

        q = r >>> 2;
        r = r & 3;

        if (q > 0) {
            int intValue = value | value << 8 | value << 16 | value << 24;
            putInt(intValue);
        }

        q = r >> 1;
        r = r & 1;

        if (q > 0) {
            short shortValue = (short) (value | value << 8);
            putShort(shortValue);
        }

        if (r > 0) {
            put(value);
        }

        return this;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer fillAndReset(byte value, int size) {
        autoExpand(size);
        int pos = position();
        try {
            fill(value, size);
        } finally {
            position(pos);
        }
        return this;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer fill(int size) {
        autoExpand(size);
        int q = size >>> 3;
        int r = size & 7;

        for (int i = q; i > 0; i--) {
            putLong(0L);
        }

        q = r >>> 2;
        r = r & 3;

        if (q > 0) {
            putInt(0);
        }

        q = r >> 1;
        r = r & 1;

        if (q > 0) {
            putShort((short) 0);
        }

        if (r > 0) {
            put((byte) 0);
        }

        return this;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer fillAndReset(int size) {
        autoExpand(size);
        int pos = position();
        try {
            fill(size);
        } finally {
            position(pos);
        }

        return this;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> E getEnum(Class<E> enumClass) {
        return toEnum(enumClass, getUnsigned());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> E getEnum(int index, Class<E> enumClass) {
        return toEnum(enumClass, getUnsigned(index));
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> E getEnumShort(Class<E> enumClass) {
        return toEnum(enumClass, getUnsignedShort());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> E getEnumShort(int index, Class<E> enumClass) {
        return toEnum(enumClass, getUnsignedShort(index));
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> E getEnumInt(Class<E> enumClass) {
        return toEnum(enumClass, getInt());
    }

    /**
     * {@inheritDoc}
     */
    public <E extends Enum<E>> E getEnumInt(int index, Class<E> enumClass) {
        return toEnum(enumClass, getInt(index));
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer putEnum(Enum<?> e) {
        if (e.ordinal() > BYTE_MASK) {
            throw new IllegalArgumentException(enumConversionErrorMessage(e,
                    "byte"));
        }
        return put((byte) e.ordinal());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer putEnum(int index, Enum<?> e) {
        if (e.ordinal() > BYTE_MASK) {
            throw new IllegalArgumentException(enumConversionErrorMessage(e,
                    "byte"));
        }
        return put(index, (byte) e.ordinal());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer putEnumShort(Enum<?> e) {
        if (e.ordinal() > SHORT_MASK) {
            throw new IllegalArgumentException(enumConversionErrorMessage(e,
                    "short"));
        }
        return putShort((short) e.ordinal());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer putEnumShort(int index, Enum<?> e) {
        if (e.ordinal() > SHORT_MASK) {
            throw new IllegalArgumentException(enumConversionErrorMessage(e,
                    "short"));
        }
        return putShort(index, (short) e.ordinal());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer putEnumInt(Enum<?> e) {
        return putInt(e.ordinal());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IoBuffer putEnumInt(int index, Enum<?> e) {
        return putInt(index, e.ordinal());
    }

    private <E> E toEnum(Class<E> enumClass, int i) {
        E[] enumConstants = enumClass.getEnumConstants();
        if (i > enumConstants.length) {
            throw new IndexOutOfBoundsException(String.format(
                    "%d is too large of an ordinal to convert to the enum %s",
                    i, enumClass.getName()));
        }
        return enumConstants[i];
    }

    private String enumConversionErrorMessage(Enum<?> e, String type) {
        return String.format("%s.%s has an ordinal value too large for a %s", e
                .getClass().getName(), e.name(), type);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> EnumSet<E> getEnumSet(Class<E> enumClass) {
        return toEnumSet(enumClass, get() & BYTE_MASK);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> EnumSet<E> getEnumSet(int index,
            Class<E> enumClass) {
        return toEnumSet(enumClass, get(index) & BYTE_MASK);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> EnumSet<E> getEnumSetShort(Class<E> enumClass) {
        return toEnumSet(enumClass, getShort() & SHORT_MASK);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> EnumSet<E> getEnumSetShort(int index,
            Class<E> enumClass) {
        return toEnumSet(enumClass, getShort(index) & SHORT_MASK);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> EnumSet<E> getEnumSetInt(Class<E> enumClass) {
        return toEnumSet(enumClass, getInt() & INT_MASK);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> EnumSet<E> getEnumSetInt(int index,
            Class<E> enumClass) {
        return toEnumSet(enumClass, getInt(index) & INT_MASK);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> EnumSet<E> getEnumSetLong(Class<E> enumClass) {
        return toEnumSet(enumClass, getLong());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> EnumSet<E> getEnumSetLong(int index,
            Class<E> enumClass) {
        return toEnumSet(enumClass, getLong(index));
    }

    private <E extends Enum<E>> EnumSet<E> toEnumSet(Class<E> clazz, long vector) {
        EnumSet<E> set = EnumSet.noneOf(clazz);
        long mask = 1;
        for (E e : clazz.getEnumConstants()) {
            if ((mask & vector) == mask) {
                set.add(e);
            }
            mask <<= 1;
        }
        return set;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> IoBuffer putEnumSet(Set<E> set) {
        long vector = toLong(set);
        if ((vector & ~BYTE_MASK) != 0) {
            throw new IllegalArgumentException(
                    "The enum set is too large to fit in a byte: " + set);
        }
        return put((byte) vector);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> IoBuffer putEnumSet(int index, Set<E> set) {
        long vector = toLong(set);
        if ((vector & ~BYTE_MASK) != 0) {
            throw new IllegalArgumentException(
                    "The enum set is too large to fit in a byte: " + set);
        }
        return put(index, (byte) vector);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> IoBuffer putEnumSetShort(Set<E> set) {
        long vector = toLong(set);
        if ((vector & ~SHORT_MASK) != 0) {
            throw new IllegalArgumentException(
                    "The enum set is too large to fit in a short: " + set);
        }
        return putShort((short) vector);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> IoBuffer putEnumSetShort(int index, Set<E> set) {
        long vector = toLong(set);
        if ((vector & ~SHORT_MASK) != 0) {
            throw new IllegalArgumentException(
                    "The enum set is too large to fit in a short: " + set);
        }
        return putShort(index, (short) vector);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> IoBuffer putEnumSetInt(Set<E> set) {
        long vector = toLong(set);
        if ((vector & ~INT_MASK) != 0) {
            throw new IllegalArgumentException(
                    "The enum set is too large to fit in an int: " + set);
        }
        return putInt((int) vector);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> IoBuffer putEnumSetInt(int index, Set<E> set) {
        long vector = toLong(set);
        if ((vector & ~INT_MASK) != 0) {
            throw new IllegalArgumentException(
                    "The enum set is too large to fit in an int: " + set);
        }
        return putInt(index, (int) vector);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> IoBuffer putEnumSetLong(Set<E> set) {
        return putLong(toLong(set));
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public <E extends Enum<E>> IoBuffer putEnumSetLong(int index, Set<E> set) {
        return putLong(index, toLong(set));
    }

    private <E extends Enum<E>> long toLong(Set<E> set) {
        long vector = 0;
        for (E e : set) {
            if (e.ordinal() >= Long.SIZE) {
                throw new IllegalArgumentException(
                        "The enum set is too large to fit in a bit vector: "
                                + set);
            }
            vector |= 1L << e.ordinal();
        }
        return vector;
    }

    /**
     * This method forwards the call to {@link #expand(int)} only when
     * <tt>autoExpand</tt> property is <tt>true</tt>.
     */
    private IoBuffer autoExpand(int expectedRemaining) {
        if (isAutoExpand()) {
            expand(expectedRemaining, true);
        }
        return this;
    }

    /**
     * This method forwards the call to {@link #expand(int)} only when
     * <tt>autoExpand</tt> property is <tt>true</tt>.
     */
    private IoBuffer autoExpand(int pos, int expectedRemaining) {
        if (isAutoExpand()) {
            expand(pos, expectedRemaining, true);
        }
        return this;
    }

    private static void checkFieldSize(int fieldSize) {
        if (fieldSize < 0) {
            throw new IllegalArgumentException("fieldSize cannot be negative: "
                    + fieldSize);
        }
    }
}