diff options
Diffstat (limited to 'container-search/src/main/java/com/yahoo/fs4/PacketDecoder.java')
| -rw-r--r-- | container-search/src/main/java/com/yahoo/fs4/PacketDecoder.java | 200 |
1 files changed, 0 insertions, 200 deletions
diff --git a/container-search/src/main/java/com/yahoo/fs4/PacketDecoder.java b/container-search/src/main/java/com/yahoo/fs4/PacketDecoder.java deleted file mode 100644 index 3e673717d02..00000000000 --- a/container-search/src/main/java/com/yahoo/fs4/PacketDecoder.java +++ /dev/null @@ -1,200 +0,0 @@ -// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root. -package com.yahoo.fs4; - -import java.nio.ByteBuffer; - -/** - * Returns the correct package for a package byte stream - * - * @author bratseth - * @author <a href="mailto:borud@yahoo-inc.com">Bj\u00f8rn Borud</a> - */ -public class PacketDecoder { - - /** Represents a packet and the data used to construct it */ - public static class DecodedPacket { - public BasicPacket packet; - public ByteBuffer consumedBytes; - - DecodedPacket(BasicPacket packet, ByteBuffer consumedBytes) { - this.packet = packet; - this.consumedBytes = consumedBytes; - } - } - - private PacketDecoder() {} - - /** - * Returns the package starting at the current position in the buffer - * - * @throws IllegalArgumentException if an unknown package code is - * encountered - * @throws java.nio.BufferUnderflowException if the buffer contains too little - * data to decode the pcode. - */ - public static BasicPacket decode(ByteBuffer buffer) { - int packetCode = buffer.getInt(buffer.position()+4); - packetCode &= BasicPacket.CODE_MASK; - - switch (packetCode) { - case 200: - return EolPacket.create().decode(buffer); - - case 203: - return ErrorPacket.create().decode(buffer); - - case 205: - return DocsumPacket.create().decode(buffer); - - case 217: - return QueryResultPacket.create().decode(buffer); - - case 221: - return PongPacket.create().decode(buffer); - - default: - throw new IllegalArgumentException("No support for packet " + packetCode); - } - } - - /** Gives the packet along with the bytes consumed to construct it. */ - public static DecodedPacket decodePacket(ByteBuffer buffer) { - ByteBuffer dataUsed = buffer.slice(); - int start = buffer.position(); - - BasicPacket packet = decode(buffer); - dataUsed.limit(buffer.position() - start); - return new DecodedPacket(packet, dataUsed); - } - - /** Sniff channel ID for query result packets */ - public static int sniffChannel(ByteBuffer buffer) { - int remaining = buffer.remaining(); - if (remaining < 12) { - return 0; - } - int packetCode = buffer.getInt(buffer.position()+4); - packetCode &= BasicPacket.CODE_MASK; - switch (packetCode) { - case 202: - case 208: - case 214: - case 217: - return buffer.getInt(buffer.position()+8); - default: - return 0; - } - } - - /** - * Test whether the buffer contains (the start of) a pong packet. - * - * Returns false if there is not enough data to determine the - * answer. - */ - public static boolean isPongPacket(ByteBuffer buffer) { - - int remaining = buffer.remaining(); - if (remaining < 8) - return false; - int packetCode = buffer.getInt(buffer.position()+4); - packetCode &= BasicPacket.CODE_MASK; - if (packetCode == 221) - return true; - else - return false; - } - - /** - * Note that it assumes that the position of the ByteBuffer is at the - * start of a packet and that we have enough data to actually read - * an integer out of the buffer. - * - * @return Return the length of the fs4 packet. Returns -1 if length - * could not be determined because we had too little - * data in the buffer. - * - */ - public static int packetLength(ByteBuffer buffer) - { - if (buffer.remaining() < 4) { - return -1; - } - return (buffer.getInt(buffer.position()) + 4); - } - - /** - * Takes a buffer possibly containing a packet. - * - * <P> - * If we return a packet when we return: - * <UL> - * <LI> the buffer is positioned at the beginning of the next - * packet when we return. - * <LI> limit is unchanged - * </UL> - * - * <P> - * If we return <code>null</code> there were no more packets - * there to decode and the following is true of the buffer - * <UL> - * <LI> the buffer is compacted, ie. partial packet is - * moved to the start, or if no more data is available - * the buffer is cleared. - * <LI> the position is set to the next byte after the valid - * data so the buffer is ready for reading. - * </UL> - * - * If there are no packets to be returned the buffer is compacted - * (ie. content is moved to the start and read-pointer is positioned - * - * @return Returns the next available packet from the buffer or - * <code>null</code> if there are no more <b>complete</b> - * packets in the buffer at this time. - */ - public static DecodedPacket extractPacket(ByteBuffer buffer) - throws BufferTooSmallException - { - int remaining = buffer.remaining(); - - // if we are empty we can reset the buffer - if (remaining == 0) { - buffer.clear(); - return null; - } - - // if we can't figure out the size because we have less than - // 4 bytes we prepare the buffer for more data reading. - if (remaining < 4) { - buffer.compact(); - return null; - } - - int plen = packetLength(buffer); - - // -1 means that we do not have enough data to read the packet - // size yet - if (plen == -1) { - buffer.compact(); - return null; - } - - // if we haven't read an entire packet yet, we compact and return - // (same as above but separate code for clarity). note that this - // also occurs when there is no physical room for the packet, so - // clients of this API need to be aware of this and check for it - if (remaining < plen) { - - // if the read buffer is too small we must take drastic action - if (buffer.capacity() < plen) { - throw new BufferTooSmallException("Buffer too small to hold packet"); - } - - buffer.compact(); - return null; - } - - return PacketDecoder.decodePacket(buffer); - } - -} |