| 1 | /* |
| 2 | * SPDX-License-Identifier: LGPL-2.1-only |
| 3 | * |
| 4 | * Copyright (C) 2015 EfficiOS Inc. |
| 5 | * Copyright (C) 2015 Alexandre Montplaisir <alexmonthy@efficios.com> |
| 6 | * Copyright (C) 2013 David Goulet <dgoulet@efficios.com> |
| 7 | */ |
| 8 | |
| 9 | package org.lttng.ust.agent.client; |
| 10 | |
| 11 | import java.nio.ByteBuffer; |
| 12 | import java.nio.ByteOrder; |
| 13 | import java.util.Collection; |
| 14 | |
| 15 | /** |
| 16 | * Session daemon command asking the Java agent to list its registered loggers, |
| 17 | * which corresponds to event names in the tracing session. |
| 18 | * |
| 19 | * @author Alexandre Montplaisir |
| 20 | * @author David Goulet |
| 21 | */ |
| 22 | class SessiondListLoggersCommand extends SessiondCommand { |
| 23 | |
| 24 | @Override |
| 25 | public LttngAgentResponse execute(ILttngTcpClientListener agent) { |
| 26 | final Collection<String> loggerList = agent.listAvailableEvents(); |
| 27 | return new SessiondListLoggersResponse(loggerList); |
| 28 | } |
| 29 | |
| 30 | private static class SessiondListLoggersResponse extends LttngAgentResponse { |
| 31 | |
| 32 | private final static int SIZE = 12; |
| 33 | |
| 34 | private final Collection<String> loggers; |
| 35 | |
| 36 | public SessiondListLoggersResponse(Collection<String> loggers) { |
| 37 | this.loggers = loggers; |
| 38 | } |
| 39 | |
| 40 | @Override |
| 41 | public ReturnCode getReturnCode() { |
| 42 | /* This command can't really fail */ |
| 43 | return ReturnCode.CODE_SUCCESS_CMD; |
| 44 | } |
| 45 | |
| 46 | @Override |
| 47 | public byte[] getBytes() { |
| 48 | /* |
| 49 | * Compute the data size, which is the number of bytes of each |
| 50 | * encoded string, +1 per string for the \0 |
| 51 | */ |
| 52 | int dataSize = 0; |
| 53 | for (String logger : loggers) { |
| 54 | dataSize += logger.getBytes(SESSIOND_PROTOCOL_CHARSET).length + 1; |
| 55 | } |
| 56 | |
| 57 | /* Prepare the buffer */ |
| 58 | byte data[] = new byte[SIZE + dataSize]; |
| 59 | ByteBuffer buf = ByteBuffer.wrap(data); |
| 60 | buf.order(ByteOrder.BIG_ENDIAN); |
| 61 | |
| 62 | /* Write the header section of the response */ |
| 63 | buf.putInt(getReturnCode().getCode()); |
| 64 | buf.putInt(dataSize); |
| 65 | buf.putInt(loggers.size()); |
| 66 | |
| 67 | /* Write the payload */ |
| 68 | for (String logger : loggers) { |
| 69 | buf.put(logger.getBytes(SESSIOND_PROTOCOL_CHARSET)); |
| 70 | /* NULL terminated byte after the logger name. */ |
| 71 | buf.put((byte) 0x0); |
| 72 | } |
| 73 | return data; |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | } |