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* http://www.apache.org/licenses/LICENSE-2.0
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*
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*
* This decoder is optimized to transfer data directly from * a {@link FileChannel} to the underlying I/O session's channel whenever * possible avoiding intermediate buffering in the session buffer. * * @since 4.0 */ public class IdentityEncoder extends AbstractContentEncoder implements FileContentEncoder { private final int fragHint; /** * @since 4.3 * * @param channel underlying channel. * @param buffer session buffer. * @param metrics transport metrics. * @param chunkSizeHint fragment size hint defining an minimal size of a fragment * that should be written out directly to the channel bypassing the session buffer. * Value {@code 0} disables fragment buffering. */ public IdentityEncoder( final WritableByteChannel channel, final SessionOutputBuffer buffer, final BasicHttpTransportMetrics metrics, final int chunkSizeHint) { super(channel, buffer, metrics); this.fragHint = chunkSizeHint > 0 ? chunkSizeHint : 0; } public IdentityEncoder( final WritableByteChannel channel, final SessionOutputBuffer buffer, final BasicHttpTransportMetrics metrics) { this(channel, buffer, metrics, 0); } @Override public int write(final ByteBuffer src) throws IOException { if (src == null) { return 0; } assertNotCompleted(); int total = 0; while (src.hasRemaining()) { if (this.buffer.hasData() || this.fragHint > 0) { if (src.remaining() <= this.fragHint) { final int capacity = this.fragHint - this.buffer.length(); if (capacity > 0) { final int limit = Math.min(capacity, src.remaining()); final int bytesWritten = writeToBuffer(src, limit); total += bytesWritten; } } } if (this.buffer.hasData()) { if (this.buffer.length() >= this.fragHint || src.hasRemaining()) { final int bytesWritten = flushToChannel(); if (bytesWritten == 0) { break; } } } if (!this.buffer.hasData() && src.remaining() > this.fragHint) { final int bytesWritten = writeToChannel(src); total += bytesWritten; if (bytesWritten == 0) { break; } } } return total; } @Override public long transfer( final FileChannel src, final long position, final long count) throws IOException { if (src == null) { return 0; } assertNotCompleted(); flushToChannel(); if (this.buffer.hasData()) { return 0; } final long bytesWritten = src.transferTo(position, count, this.channel); if (bytesWritten > 0) { this.metrics.incrementBytesTransferred(bytesWritten); } return bytesWritten; } @Override public String toString() { final StringBuilder sb = new StringBuilder(); sb.append("[identity; completed: "); sb.append(isCompleted()); sb.append("]"); return sb.toString(); } }