tdlib-session-container/src/main/java/it/tdlight/utils/VertxBufferInputStream.java
Andrea Cavalli 355b419736 Version 5
2021-01-23 18:49:21 +01:00

133 lines
3.3 KiB
Java

package it.tdlight.utils;
import io.vertx.core.buffer.Buffer;
import org.warp.commonutils.stream.SafeMeasurableInputStream;
import org.warp.commonutils.stream.SafeRepositionableStream;
public class VertxBufferInputStream extends SafeMeasurableInputStream implements SafeRepositionableStream {
private final Buffer buffer;
/** The first valid entry. */
public int offset;
/** The number of valid bytes in {@link #buffer} starting from {@link #offset}. */
public int length;
/** The current position as a distance from {@link #offset}. */
private int position;
/** The current mark as a position, or -1 if no mark exists. */
private int mark;
/** Creates a new buffer input stream using a given buffer fragment.
*
* @param buffer the backing buffer.
* @param offset the first valid entry of the buffer.
* @param length the number of valid bytes.
*/
public VertxBufferInputStream(final Buffer buffer, final int offset, final int length) {
this.buffer = buffer;
this.offset = offset;
this.length = length;
}
/** Creates a new buffer input stream using a given buffer fragment.
*
* @param buffer the backing buffer.
* @param offset the first valid entry of the buffer.
*/
public VertxBufferInputStream(final Buffer buffer, final int offset) {
this.buffer = buffer;
this.offset = offset;
this.length = buffer.length();
}
/** Creates a new buffer input stream using a given buffer.
*
* @param buffer the backing buffer.
*/
public VertxBufferInputStream(final Buffer buffer) {
this(buffer, 0, buffer.length());
}
/** Creates a new buffer input stream using a given buffer.
*
* @param in the backing buffer.
*/
public VertxBufferInputStream(final VertxBufferInputStream in) {
this(in.buffer, in.offset + in.position, in.buffer.length());
}
@Override
public boolean markSupported() {
return true;
}
@Override
public void reset() {
position = mark;
}
/** Closing a fast byte buffer input stream has no effect. */
@Override
public void close() {}
@Override
public void mark(final int dummy) {
mark = position;
}
@Override
public int available() {
return length - position;
}
@Override
public long skip(long n) {
if (n <= length - position) {
position += (int)n;
return n;
}
n = length - position;
position = length;
return n;
}
@Override
public int read() {
if (length == position) return -1;
return buffer.getByte(offset + position++) & 0xFF;
}
/** Reads bytes from this byte-buffer input stream as
* specified in {@link java.io.InputStream#read(byte[], int, int)}.
* Note that the implementation given in {@link java.io.ByteArrayInputStream#read(byte[], int, int)}
* will return -1 on a zero-length read at EOF, contrarily to the specification. We won't.
*/
@Override
public int read(final byte b[], final int offset, final int length) {
if (this.length == this.position) return length == 0 ? 0 : -1;
final int n = Math.min(length, this.length - this.position);
buffer.getBytes(this.offset + this.position, this.offset + this.position + n, b, offset);
this.position += n;
return n;
}
@Override
public long position() {
return position;
}
@Override
public void position(final long newPosition) {
position = (int)Math.min(newPosition, length);
}
@Override
public long length() {
return length;
}
}