Fix: Correctly compute Java agent list loggers response size

[lttng-ust.git] / liblttng-ust-java-agent / java / lttng-ust-agent-common / org / lttng / ust / agent / client / SessiondListLoggersCommand.java

diff --git a/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondListLoggersCommand.java b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondListLoggersCommand.java
index f5ad9c50443f6ec805ced0191e2456600693e148..4dee6ae406c954466899357c0020257e41ddc49f 100644 (file)
--- a/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondListLoggersCommand.java
+++ b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondListLoggersCommand.java
@@ -20,10 +20,7 @@ package org.lttng.ust.agent.client;
 
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
-import java.util.ArrayList;
-import java.util.List;
-
-import org.lttng.ust.agent.AbstractLttngAgent;
+import java.util.Collection;
 
 /**
  * Session daemon command asking the Java agent to list its registered loggers,
@@ -32,31 +29,22 @@ import org.lttng.ust.agent.AbstractLttngAgent;
  * @author Alexandre Montplaisir
  * @author David Goulet
  */
-class SessiondListLoggersCommand implements ISessiondCommand {
+class SessiondListLoggersCommand extends SessiondCommand {
 
        @Override
-       public LttngAgentResponse execute(AbstractLttngAgent<?> agent) {
-               final List<String> loggerList = new ArrayList<String>();
-               int dataSize = 0;
-
-               for (String event : agent.listEnabledEvents()) {
-                       loggerList.add(event);
-                       dataSize += event.length() + 1;
-               }
-
-               return new SessiondListLoggersResponse(loggerList, dataSize);
+       public LttngAgentResponse execute(ILttngTcpClientListener agent) {
+               final Collection<String> loggerList = agent.listAvailableEvents();
+               return new SessiondListLoggersResponse(loggerList);
        }
 
        private static class SessiondListLoggersResponse extends LttngAgentResponse {
 
                private final static int SIZE = 12;
 
-               private final List<String> loggers;
-               private final int dataSize;
+               private final Collection<String> loggers;
 
-               public SessiondListLoggersResponse(List<String> loggers, int dataSize) {
+               public SessiondListLoggersResponse(Collection<String> loggers) {
                        this.loggers = loggers;
-                       this.dataSize = dataSize;
                }
 
                @Override
@@ -67,17 +55,28 @@ class SessiondListLoggersCommand implements ISessiondCommand {
 
                @Override
                public byte[] getBytes() {
+                       /*
+                        * Compute the data size, which is the number of bytes of each
+                        * encoded string, +1 per string for the \0
+                        */
+                       int dataSize = 0;
+                       for (String logger : loggers) {
+                               dataSize += logger.getBytes(SESSIOND_PROTOCOL_CHARSET).length + 1;
+                       }
+
+                       /* Prepare the buffer */
                        byte data[] = new byte[SIZE + dataSize];
                        ByteBuffer buf = ByteBuffer.wrap(data);
                        buf.order(ByteOrder.BIG_ENDIAN);
 
-                       /* Returned code */
+                       /* Write the header section of the response */
                        buf.putInt(getReturnCode().getCode());
                        buf.putInt(dataSize);
                        buf.putInt(loggers.size());
 
+                       /* Write the payload */
                        for (String logger : loggers) {
-                               buf.put(logger.getBytes());
+                               buf.put(logger.getBytes(SESSIOND_PROTOCOL_CHARSET));
                                /* NULL terminated byte after the logger name. */
                                buf.put((byte) 0x0);
                        }