/**
* Split this buffer on the given delimiter. Save memory by reusing the provided {@code List}. The
* delimiter is stripped from the end of the segment if {@code stripDelimiter} is {@code true}.
*
* @param views The already-allocated List to reuse.
* @param delimiter The multi-byte delimiter.
* @param stripDelimiter {@literal true} to ignore the delimiter, {@literal false} to leave it in
* the returned data.
* @return An {@link Iterable} of {@link View Views} that point to the segments of this buffer.
*/
public Iterable<View> split(List<View> views, Buffer delimiter, boolean stripDelimiter) {
snapshot();
byte[] delimBytes = delimiter.asBytes();
if (delimBytes.length == 0) {
return Collections.emptyList();
}
int start = this.position;
for (byte b : this) {
if (b != delimBytes[0]) {
continue;
}
int end = -1;
for (int i = 1; i < delimBytes.length; i++) {
if (read() == delimBytes[i]) {
end = stripDelimiter ? buffer.position() - delimBytes.length : buffer.position();
} else {
end = -1;
break;
}
}
if (end > 0) {
views.add(createView(start, end));
start = end + (stripDelimiter ? delimBytes.length : 0);
}
}
if (start != buffer.position()) {
buffer.position(start);
}
reset();
return views;
}
/**
* Get the first {@code byte} from this {@literal Buffer}.
*
* @return The first {@code byte}.
*/
public byte first() {
snapshot();
if (this.position > 0) {
buffer.position(0); // got to the 1st position
}
byte b = buffer.get(); // get the 1st byte
reset(); // go back to original pos
return b;
}
/**
* Create a new {@code Buffer} by copying the underlying {@link ByteBuffer} into a newly-allocated
* {@code Buffer}.
*
* @return the new {@code Buffer}
*/
public Buffer copy() {
if (buffer == null) return new Buffer();
snapshot();
Buffer b = new Buffer(buffer.remaining(), false);
b.append(buffer);
reset();
return b.flip();
}
/**
* Create a copy of the given range.
*
* @param start start of the range.
* @param len end of the range.
* @return A new {@link Buffer}, constructed from the contents of the given range.
*/
public Buffer slice(int start, int len) {
snapshot();
ByteBuffer bb = ByteBuffer.allocate(len);
buffer.position(start);
bb.put(buffer);
reset();
bb.flip();
return new Buffer(bb);
}
/**
* Slice a portion of this buffer and convert it to a String.
*
* @param start start of the range.
* @param end end of the range.
* @return The contents of the given range as a String.
*/
public String substring(int start, int end) {
snapshot();
buffer.limit((end > start ? end : this.limit));
buffer.position(start);
String s = asString();
reset();
return s;
}
@Override
public int read(ByteBuffer dst) throws IOException {
snapshot();
if (dst.remaining() < this.limit) {
buffer.limit(dst.remaining());
}
int pos = dst.position();
dst.put(buffer);
buffer.limit(this.limit);
return dst.position() - pos;
}
private void expand(int expandSize) {
snapshot();
ByteBuffer newBuff =
(buffer.isDirect()
? ByteBuffer.allocateDirect(buffer.capacity() + expandSize)
: ByteBuffer.allocate(buffer.capacity() + expandSize));
buffer.flip();
newBuff.put(buffer);
buffer = newBuff;
reset();
}
/**
* Return the contents of this buffer copied into a {@code byte[]}.
*
* @return The contents of this buffer as a {@code byte[]}.
*/
public byte[] asBytes() {
if (null != buffer) {
snapshot();
byte[] b = new byte[buffer.remaining()];
buffer.get(b);
reset();
return b;
} else {
return null;
}
}
/**
* Very efficient method for parsing an {@link Integer} from the given {@literal Buffer} range.
* Much faster than {@link Integer#parseInt(String)}.
*
* @param b The {@literal Buffer} to slice.
* @param start start of the range.
* @param end end of the range.
* @return The int value or {@literal null} if the {@literal Buffer} could not be read.
*/
public static Integer parseInt(Buffer b, int start, int end) {
b.snapshot();
b.buffer.limit(end);
b.buffer.position(start);
Integer i = parseInt(b);
b.reset();
return i;
}
/**
* Search the buffer and find the position of the first occurrence of the given {@code byte}
* staring at the start position and searching until (and including) the end position.
*
* @param b the {@code byte} to search for
* @param start the position to start searching
* @param end the position at which to stop searching
* @return the position of the char in the buffer or {@code -1} if not found
*/
public int indexOf(byte b, int start, int end) {
snapshot();
if (buffer.position() != start) {
buffer.position(start);
}
int pos = -1;
while (buffer.hasRemaining() && buffer.position() < end) {
if (buffer.get() == b) {
pos = buffer.position();
break;
}
}
reset();
return pos;
}
/**
* Slice this buffer at the given positions. Useful for extracting multiple segments of data from
* a buffer when the exact indices of that data is already known.
*
* @param positions The start and end positions of the slices.
* @return A list of {@link View Views} pointing to the slices.
*/
public List<View> slice(int... positions) {
Assert.notNull(positions, "Positions cannot be null.");
if (positions.length == 0) {
return Collections.emptyList();
}
snapshot();
List<View> views = new ArrayList<View>();
int len = positions.length;
for (int i = 0; i < len; i++) {
int start = positions[i];
int end = (i + 1 < len ? positions[++i] : this.limit);
views.add(createView(start, end));
reset();
}
return views;
}
private void shift(int right) {
ByteBuffer currentBuffer;
if (null == buffer) {
ensureCapacity(right);
currentBuffer = buffer;
} else {
currentBuffer = buffer.slice();
}
int len = buffer.remaining();
int pos = buffer.position();
ensureCapacity(right + len);
buffer.position(pos + right);
buffer.put(currentBuffer);
buffer.position(pos);
snapshot();
}
/**
* Split this buffer on the given delimiter, save memory by reusing the given {@link List}, and
* optionally leave the delimiter intact rather than stripping it.
*
* @param views The list to store {@link View Views} in.
* @param delimiter The delimiter on which to split this buffer.
* @param stripDelimiter {@literal true} to ignore the delimiter, {@literal false} to leave it in
* the returned data.
* @return A {@link List} of {@link View Views} that point to the segments of this buffer.
*/
public List<View> split(List<View> views, int delimiter, boolean stripDelimiter) {
snapshot();
int start = this.position;
for (byte b : this) {
if (b == delimiter) {
int end = stripDelimiter ? buffer.position() - 1 : buffer.position();
views.add(createView(start, end));
start = end + (stripDelimiter ? 1 : 0);
}
}
if (start != buffer.position()) {
buffer.position(start);
}
reset();
return views;
}
/**
* Very efficient method for parsing an {@link Integer} from the given {@literal Buffer}. Much
* faster than {@link Integer#parseInt(String)}.
*
* @param b The {@literal Buffer} to slice.
* @return The int value or {@literal null} if the {@literal Buffer} could not be read.
*/
public static Integer parseInt(Buffer b) {
if (b.remaining() == 0) {
return null;
}
b.snapshot();
int len = b.remaining();
int num = 0;
int dec = 1;
for (int i = (b.position + len); i > b.position; ) {
char c = (char) b.buffer.get(--i);
num += Character.getNumericValue(c) * dec;
dec *= 10;
}
b.reset();
return num;
}
private String decode() {
if (null == decoder) {
decoder = UTF8.newDecoder();
}
snapshot();
try {
if (null == chars || chars.remaining() < buffer.remaining()) {
chars = CharBuffer.allocate(buffer.remaining());
} else {
chars.rewind();
}
decoder.reset();
CoderResult cr = decoder.decode(buffer.duplicate(), chars, true);
if (cr.isUnderflow()) {
decoder.flush(chars);
}
chars.flip();
return chars.toString();
} finally {
reset();
}
}
/**
* Create a {@link View} of the current range of this {@link Buffer}.
*
* @return The view of the buffer
* @see #position()
* @see #limit()
*/
public View createView() {
snapshot();
return new View(position, limit);
}
/**
* Create a {@link View} of the given range of this {@literal Buffer}.
*
* @param start start of the range.
* @param end end of the range.
* @return A new {@link View} object that represents the given range.
*/
public View createView(int start, int end) {
snapshot();
return new View(start, end);
}