morfologik.stemming.BufferUtils Maven / Gradle / Ivy
package morfologik.stemming;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
public final class BufferUtils {
/**
* No instances.
*/
private BufferUtils() {
// empty
}
/**
* Ensure the byte buffer's capacity. If a new buffer is allocated, its
* content is empty (the old buffer's contents is not copied).
*
* @param capacity The required capacity of the buffer.
*
* @param buffer
* The buffer to check or null if a new buffer should be
* allocated.
*
* @return Returns the same buffer or a new buffer with the given capacity.
*/
public static ByteBuffer ensureCapacity(ByteBuffer buffer, int capacity) {
// TODO: GH-63
if (buffer == null || buffer.capacity() < capacity) {
buffer = ByteBuffer.allocate(capacity);
}
return buffer;
}
/**
* Ensure the char buffer's capacity. If a new buffer is allocated, its
* content is empty (the old buffer's contents is not copied).
*
* @param capacity The required capacity of the buffer.
*
* @param buffer
* The buffer to check or null if a new buffer should be
* allocated.
*
* @return Returns the same buffer or a new buffer with the given capacity.
*/
public static CharBuffer ensureCapacity(CharBuffer buffer, int capacity) {
// TODO: GH-63
if (buffer == null || buffer.capacity() < capacity) {
buffer = CharBuffer.allocate(capacity);
}
return buffer;
}
/**
* @param buffer The buffer to convert to a string.
* @param charset The charset to use when converting bytes to characters.
* @return A string representation of buffer's content.
*/
public static String toString(ByteBuffer buffer, Charset charset) {
buffer = buffer.slice();
byte [] buf = new byte [buffer.remaining()];
buffer.get(buf);
return new String(buf, charset);
}
/**
* @param buffer The buffer to read from.
* @return Returns the remaining bytes from the buffer copied to an array.
*/
public static byte[] toArray(ByteBuffer buffer) {
byte [] dst = new byte [buffer.remaining()];
buffer.mark();
buffer.get(dst);
buffer.reset();
return dst;
}
/**
* Compute the length of the shared prefix between two byte sequences.
*/
static int sharedPrefixLength(ByteBuffer a, int aStart, ByteBuffer b, int bStart) {
int i = 0;
final int max = Math.min(a.remaining() - aStart, b.remaining() - bStart);
aStart += a.position();
bStart += b.position();
while (i < max && a.get(aStart++) == b.get(bStart++)) {
i++;
}
return i;
}
/**
* Compute the length of the shared prefix between two byte sequences.
*/
static int sharedPrefixLength(ByteBuffer a, ByteBuffer b) {
return sharedPrefixLength(a, 0, b, 0);
}
}