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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 LengthDelimitedEncoder extends AbstractContentEncoder implements FileContentEncoder { private final long contentLength; private final int fragHint; private long remaining; /** * @since 4.3 * * @param channel underlying channel. * @param buffer session buffer. * @param metrics transport metrics. * @param contentLength content length. * @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 LengthDelimitedEncoder( final WritableByteChannel channel, final SessionOutputBuffer buffer, final BasicHttpTransportMetrics metrics, final long contentLength, final int chunkSizeHint) { super(channel, buffer, metrics); Args.notNegative(contentLength, "Content length"); this.contentLength = contentLength; this.fragHint = chunkSizeHint > 0 ? chunkSizeHint : 0; this.remaining = contentLength; } public LengthDelimitedEncoder( final WritableByteChannel channel, final SessionOutputBuffer buffer, final BasicHttpTransportMetrics metrics, final long contentLength) { this(channel, buffer, metrics, contentLength, 0); } private int nextChunk(final ByteBuffer src) { return (int) Math.min(Math.min(this.remaining, Integer.MAX_VALUE), src.remaining()); } @Override public int write(final ByteBuffer src) throws IOException { if (src == null) { return 0; } assertNotCompleted(); int total = 0; while (src.hasRemaining() && this.remaining > 0) { if (this.buffer.hasData() || this.fragHint > 0) { final int chunk = nextChunk(src); if (chunk <= this.fragHint) { final int capacity = this.fragHint - this.buffer.length(); if (capacity > 0) { final int limit = Math.min(capacity, chunk); final int bytesWritten = writeToBuffer(src, limit); this.remaining -= bytesWritten; total += bytesWritten; } } } if (this.buffer.hasData()) { final int chunk = nextChunk(src); if (this.buffer.length() >= this.fragHint || chunk > 0) { final int bytesWritten = flushToChannel(); if (bytesWritten == 0) { break; } } } if (!this.buffer.hasData()) { final int chunk = nextChunk(src); if (chunk > this.fragHint) { final int bytesWritten = writeToChannel(src, chunk); this.remaining -= bytesWritten; total += bytesWritten; if (bytesWritten == 0) { break; } } } } if (this.remaining <= 0) { super.complete(null); } 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 chunk = Math.min(this.remaining, count); final long bytesWritten = src.transferTo(position, chunk, this.channel); if (bytesWritten > 0) { this.metrics.incrementBytesTransferred(bytesWritten); } this.remaining -= bytesWritten; if (this.remaining <= 0) { super.complete(null); } return bytesWritten; } @Override public String toString() { final StringBuilder sb = new StringBuilder(); sb.append("[content length: "); sb.append(this.contentLength); sb.append("; pos: "); sb.append(this.contentLength - this.remaining); sb.append("; completed: "); sb.append(isCompleted()); sb.append("]"); return sb.toString(); } }