Receive the event filter string in the Java agent

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

diff --git a/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondEnableEventCommand.java b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondEnableEventCommand.java
index 82204eb19b895af2d22eca200169769f40d59114..c9183d19d9736d2f2cf3f0fab85239c3b6d3d2dd 100644 (file)
--- a/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondEnableEventCommand.java
+++ b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondEnableEventCommand.java
@@ -21,6 +21,9 @@ package org.lttng.ust.agent.client;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 
+import org.lttng.ust.agent.session.EventRule;
+import org.lttng.ust.agent.session.LogLevelSelector;
+
 /**
  * Session daemon command indicating to the Java agent that some events were
  * enabled in the tracing session.
@@ -30,27 +33,70 @@ import java.nio.ByteOrder;
  */
 class SessiondEnableEventCommand implements ISessiondCommand {
 
-       private static final int INT_SIZE = 4;
+       /** Fixed event name length. Value defined by the lttng agent protocol. */
+       private static final int EVENT_NAME_LENGTH = 256;
+
+       private final boolean commandIsValid;
 
-       /** Event name to enable in the tracing session */
+       /* Parameters of the event rule being enabled */
        private final String eventName;
+       private final LogLevelSelector logLevelFilter;
+       private final String filterString;
 
        public SessiondEnableEventCommand(byte[] data) {
                if (data == null) {
                        throw new IllegalArgumentException();
                }
-               int dataOffset = INT_SIZE * 2;
-
                ByteBuffer buf = ByteBuffer.wrap(data);
                buf.order(ByteOrder.LITTLE_ENDIAN);
-               buf.getInt(); // logLevel, currently unused
-               buf.getInt(); // logLevelType, currently unused
-               eventName = new String(data, dataOffset, data.length - dataOffset).trim();
+               int logLevel = buf.getInt();
+               int logLevelType = buf.getInt();
+               logLevelFilter = new LogLevelSelector(logLevel, logLevelType);
+
+               /* Read the event name */
+               byte[] eventNameBytes = new byte[EVENT_NAME_LENGTH];
+               buf.get(eventNameBytes);
+               eventName = new String(eventNameBytes).trim();
+
+               /*
+                * Read the filter string. The buffer contains the length (number of
+                * bytes), then the bytes themselves.
+                *
+                * The length is represented as an unsigned int, but it should never
+                * be greater than Integer.MAX_VALUE.
+                */
+               int filterStringLength = buf.getInt();
+               if (filterStringLength < 0) {
+                       /*
+                        * The (unsigned) length is above what the sessiond should send. The
+                        * command cannot be processed.
+                        */
+                       filterString = null;
+                       commandIsValid = false;
+                       return;
+               }
+               if (filterStringLength == 0) {
+                       /* There is explicitly no filter string */
+                       filterString = "";
+                       commandIsValid = true;
+                       return;
+               }
+
+               byte[] filterStringBytes = new byte[filterStringLength];
+               buf.get(filterStringBytes);
+               filterString = new String(filterStringBytes).trim();
+
+               commandIsValid = true;
        }
 
        @Override
        public LttngAgentResponse execute(ILttngTcpClientListener agent) {
-               boolean success = agent.eventEnabled(this.eventName);
+               if (!commandIsValid) {
+                       return LttngAgentResponse.FAILURE_RESPONSE;
+               }
+
+               EventRule rule = new EventRule(eventName, logLevelFilter, filterString);
+               boolean success = agent.eventEnabled(rule);
                return (success ? LttngAgentResponse.SUCESS_RESPONSE : LttngAgentResponse.FAILURE_RESPONSE);
        }
 }