/**
* Compares the two specified buffers as described in {@link
* ChannelBuffer#compareTo(ChannelBuffer)}. This method is useful when implementing a new buffer
* type.
*/
public static int compare(ChannelBuffer bufferA, ChannelBuffer bufferB) {
final int aLen = bufferA.readableBytes();
final int bLen = bufferB.readableBytes();
final int minLength = Math.min(aLen, bLen);
final int uintCount = minLength >>> 2;
final int byteCount = minLength & 3;
int aIndex = bufferA.readerIndex();
int bIndex = bufferB.readerIndex();
if (bufferA.order() == bufferB.order()) {
for (int i = uintCount; i > 0; i--) {
long va = bufferA.getUnsignedInt(aIndex);
long vb = bufferB.getUnsignedInt(bIndex);
if (va > vb) {
return 1;
} else if (va < vb) {
return -1;
}
aIndex += 4;
bIndex += 4;
}
} else {
for (int i = uintCount; i > 0; i--) {
long va = bufferA.getUnsignedInt(aIndex);
long vb = swapInt(bufferB.getInt(bIndex)) & 0xFFFFFFFFL;
if (va > vb) {
return 1;
} else if (va < vb) {
return -1;
}
aIndex += 4;
bIndex += 4;
}
}
for (int i = byteCount; i > 0; i--) {
short va = bufferA.getUnsignedByte(aIndex);
short vb = bufferB.getUnsignedByte(bIndex);
if (va > vb) {
return 1;
} else if (va < vb) {
return -1;
}
aIndex++;
bIndex++;
}
return aLen - bLen;
}
/**
* Calculates the hash code of the specified buffer. This method is useful when implementing a new
* buffer type.
*/
public static int hashCode(ChannelBuffer buffer) {
final int aLen = buffer.readableBytes();
final int intCount = aLen >>> 2;
final int byteCount = aLen & 3;
int hashCode = 1;
int arrayIndex = buffer.readerIndex();
if (buffer.order() == BIG_ENDIAN) {
for (int i = intCount; i > 0; i--) {
hashCode = 31 * hashCode + buffer.getInt(arrayIndex);
arrayIndex += 4;
}
} else {
for (int i = intCount; i > 0; i--) {
hashCode = 31 * hashCode + swapInt(buffer.getInt(arrayIndex));
arrayIndex += 4;
}
}
for (int i = byteCount; i > 0; i--) {
hashCode = 31 * hashCode + buffer.getByte(arrayIndex++);
}
if (hashCode == 0) {
hashCode = 1;
}
return hashCode;
}
/**
* Returns {@code true} if and only if the two specified buffers are identical to each other as
* described in {@code ChannelBuffer#equals(Object)}. This method is useful when implementing a
* new buffer type.
*/
public static boolean equals(ChannelBuffer bufferA, ChannelBuffer bufferB) {
final int aLen = bufferA.readableBytes();
if (aLen != bufferB.readableBytes()) {
return false;
}
final int longCount = aLen >>> 3;
final int byteCount = aLen & 7;
int aIndex = bufferA.readerIndex();
int bIndex = bufferB.readerIndex();
if (bufferA.order() == bufferB.order()) {
for (int i = longCount; i > 0; i--) {
if (bufferA.getLong(aIndex) != bufferB.getLong(bIndex)) {
return false;
}
aIndex += 8;
bIndex += 8;
}
} else {
for (int i = longCount; i > 0; i--) {
if (bufferA.getLong(aIndex) != swapLong(bufferB.getLong(bIndex))) {
return false;
}
aIndex += 8;
bIndex += 8;
}
}
for (int i = byteCount; i > 0; i--) {
if (bufferA.getByte(aIndex) != bufferB.getByte(bIndex)) {
return false;
}
aIndex++;
bIndex++;
}
return true;
}
/**
* Creates a new composite buffer which wraps the readable bytes of the specified buffers without
* copying them. A modification on the content of the specified buffers will be visible to the
* returned buffer.
*
* @throws IllegalArgumentException if the specified buffers' endianness are different from each
* other
*/
public static ChannelBuffer wrappedBuffer(ChannelBuffer... buffers) {
switch (buffers.length) {
case 0:
break;
case 1:
if (buffers[0].readable()) {
return wrappedBuffer(buffers[0]);
}
break;
default:
ByteOrder order = null;
final List<ChannelBuffer> components = new ArrayList<ChannelBuffer>(buffers.length);
for (ChannelBuffer c : buffers) {
if (c == null) {
break;
}
if (c.readable()) {
if (order != null) {
if (!order.equals(c.order())) {
throw new IllegalArgumentException("inconsistent byte order");
}
} else {
order = c.order();
}
if (c instanceof CompositeChannelBuffer) {
// Expand nested composition.
components.addAll(
((CompositeChannelBuffer) c).decompose(c.readerIndex(), c.readableBytes()));
} else {
// An ordinary buffer (non-composite)
components.add(c.slice());
}
}
}
return compositeBuffer(order, components);
}
return EMPTY_BUFFER;
}
public ByteOrder order() {
return buffer.order();
}
