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The following commit(s) were added to refs/heads/master by this push:
new 8a3d7a4 NIFI-5867 - add thread() EL function to get thread name
8a3d7a4 is described below
commit 8a3d7a453a7792d89f6f099e53cd9fc301efcf4c
Author: Pierre Villard <pierre.villard...@gmail.com>
AuthorDate: Tue Dec 4 22:28:33 2018 +0100
NIFI-5867 - add thread() EL function to get thread name
moved thread name evaluation in evaluate method
Signed-off-by: Matthew Burgess <mattyb...@apache.org>
This closes #3198
---
.../language/antlr/AttributeExpressionLexer.g | 1 +
.../language/antlr/AttributeExpressionParser.g | 2 +-
.../language/compile/ExpressionCompiler.java | 4 +++
.../evaluation/functions/ThreadEvaluator.java | 39 ++++++++++++++++++++++
.../attribute/expression/language/TestQuery.java | 5 +++
.../main/asciidoc/expression-language-guide.adoc | 18 ++++++++++
6 files changed, 68 insertions(+), 1 deletion(-)
diff --git
a/nifi-commons/nifi-expression-language/src/main/antlr3/org/apache/nifi/attribute/expression/language/antlr/AttributeExpressionLexer.g
b/nifi-commons/nifi-expression-language/src/main/antlr3/org/apache/nifi/attribute/expression/language/antlr/AttributeExpressionLexer.g
index fb3958c..d1b22e9 100644
---
a/nifi-commons/nifi-expression-language/src/main/antlr3/org/apache/nifi/attribute/expression/language/antlr/AttributeExpressionLexer.g
+++
b/nifi-commons/nifi-expression-language/src/main/antlr3/org/apache/nifi/attribute/expression/language/antlr/AttributeExpressionLexer.g
@@ -107,6 +107,7 @@ IP : 'ip';
UUID : 'UUID';
HOSTNAME : 'hostname'; // requires boolean arg: prefer FQDN
NOW : 'now';
+THREAD : 'thread';
// 0 arg functions
diff --git
a/nifi-commons/nifi-expression-language/src/main/antlr3/org/apache/nifi/attribute/expression/language/antlr/AttributeExpressionParser.g
b/nifi-commons/nifi-expression-language/src/main/antlr3/org/apache/nifi/attribute/expression/language/antlr/AttributeExpressionParser.g
index 4d48ee0..0c63c55 100644
---
a/nifi-commons/nifi-expression-language/src/main/antlr3/org/apache/nifi/attribute/expression/language/antlr/AttributeExpressionParser.g
+++
b/nifi-commons/nifi-expression-language/src/main/antlr3/org/apache/nifi/attribute/expression/language/antlr/AttributeExpressionParser.g
@@ -128,7 +128,7 @@ functionCall : functionRef ->
^(FUNCTION_CALL functionRef);
booleanLiteral : TRUE | FALSE;
-zeroArgStandaloneFunction : (IP | UUID | NOW | NEXT_INT | HOSTNAME | RANDOM)
LPAREN! RPAREN!;
+zeroArgStandaloneFunction : (IP | UUID | NOW | NEXT_INT | HOSTNAME | THREAD |
RANDOM) LPAREN! RPAREN!;
oneArgStandaloneFunction : ((TO_LITERAL | MATH | GET_STATE_VALUE)^ LPAREN!
anyArg RPAREN!) |
(HOSTNAME^ LPAREN! booleanLiteral RPAREN!);
standaloneFunction : zeroArgStandaloneFunction | oneArgStandaloneFunction;
diff --git
a/nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/compile/ExpressionCompiler.java
b/nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/compile/ExpressionCompiler.java
index 4a4a204..de4333c 100644
---
a/nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/compile/ExpressionCompiler.java
+++
b/nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/compile/ExpressionCompiler.java
@@ -91,6 +91,7 @@ import
org.apache.nifi.attribute.expression.language.evaluation.functions.Substr
import
org.apache.nifi.attribute.expression.language.evaluation.functions.SubstringBeforeEvaluator;
import
org.apache.nifi.attribute.expression.language.evaluation.functions.SubstringBeforeLastEvaluator;
import
org.apache.nifi.attribute.expression.language.evaluation.functions.SubstringEvaluator;
+import
org.apache.nifi.attribute.expression.language.evaluation.functions.ThreadEvaluator;
import
org.apache.nifi.attribute.expression.language.evaluation.functions.ToLowerEvaluator;
import
org.apache.nifi.attribute.expression.language.evaluation.functions.ToRadixEvaluator;
import
org.apache.nifi.attribute.expression.language.evaluation.functions.ToStringEvaluator;
@@ -199,6 +200,7 @@ import static
org.apache.nifi.attribute.expression.language.antlr.AttributeExpre
import static
org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.SUBSTRING_AFTER_LAST;
import static
org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.SUBSTRING_BEFORE;
import static
org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.SUBSTRING_BEFORE_LAST;
+import static
org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.THREAD;
import static
org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.TO_DATE;
import static
org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.TO_DECIMAL;
import static
org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.TO_LITERAL;
@@ -1009,6 +1011,8 @@ public class ExpressionCompiler {
throw new AttributeExpressionLanguageException(e);
}
}
+ case THREAD:
+ return addToken(new ThreadEvaluator(), "thread");
case HOSTNAME: {
if (tree.getChildCount() == 0) {
try {
diff --git
a/nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/evaluation/functions/ThreadEvaluator.java
b/nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/evaluation/functions/ThreadEvaluator.java
new file mode 100644
index 0000000..4ebfbe5
--- /dev/null
+++
b/nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/evaluation/functions/ThreadEvaluator.java
@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.attribute.expression.language.evaluation.functions;
+
+import java.util.Map;
+
+import org.apache.nifi.attribute.expression.language.evaluation.Evaluator;
+import org.apache.nifi.attribute.expression.language.evaluation.QueryResult;
+import
org.apache.nifi.attribute.expression.language.evaluation.StringEvaluator;
+import
org.apache.nifi.attribute.expression.language.evaluation.StringQueryResult;
+
+public class ThreadEvaluator extends StringEvaluator {
+
+ @Override
+ public QueryResult<String> evaluate(final Map<String, String> attributes) {
+ // See org.apache.nifi.engine.FlowEngine
+ return new StringQueryResult(Thread.currentThread().getName());
+ }
+
+ @Override
+ public Evaluator<?> getSubjectEvaluator() {
+ return null;
+ }
+
+}
diff --git
a/nifi-commons/nifi-expression-language/src/test/java/org/apache/nifi/attribute/expression/language/TestQuery.java
b/nifi-commons/nifi-expression-language/src/test/java/org/apache/nifi/attribute/expression/language/TestQuery.java
index 5b36813..67e5b51 100644
---
a/nifi-commons/nifi-expression-language/src/test/java/org/apache/nifi/attribute/expression/language/TestQuery.java
+++
b/nifi-commons/nifi-expression-language/src/test/java/org/apache/nifi/attribute/expression/language/TestQuery.java
@@ -1810,6 +1810,11 @@ public class TestQuery {
verifyEquals("${literal(true):ifElse(false, 'b')}", attributes,
"false");
}
+ @Test
+ public void testThread() {
+ final Map<String, String> attributes = new HashMap<>();
+ verifyEquals("${thread()}", attributes, "main");
+ }
private void verifyEquals(final String expression, final Map<String,
String> attributes, final Object expectedResult) {
verifyEquals(expression,attributes, null, expectedResult);
diff --git a/nifi-docs/src/main/asciidoc/expression-language-guide.adoc
b/nifi-docs/src/main/asciidoc/expression-language-guide.adoc
index 3ade4bb..70b2802 100644
--- a/nifi-docs/src/main/asciidoc/expression-language-guide.adoc
+++ b/nifi-docs/src/main/asciidoc/expression-language-guide.adoc
@@ -2062,6 +2062,24 @@ names begin with the letter `a`.
*Examples*: UpdateAttribute processor has stored the key "count" with value
"20" in state. '${getStateValue("count")}` returns `20`.
+
+
+[.function]
+=== thread
+
+*Description*: [.description]#Returns the name of the thread used by the
processor when evaluating the Expression. This can be useful
+ when using a processor with multiple concurrent tasks and where some data
uniqueness is required.#
+
+*Subject Type*: [.subjectless]#No Subject#
+
+*Arguments*: No arguments
+
+*Return Type*: [.returnType]#String#
+
+*Examples*: `${thread()}` could return something like `Timer-Driven Process
Thread-4`.
+
+
+
[[multi]]
== Evaluating Multiple Attributes
