svn commit: r1388400 - in /pig/trunk: CHANGES.txt src/org/apache/pig/builtin/STARTSWITH.java test/org/apache/pig/test/TestStringUDFs.java

[gd...@apache.org]

Author: gdfm
Date: Fri Sep 21 10:02:15 2012
New Revision: 1388400

URL: http://svn.apache.org/viewvc?rev=1388400&view=rev
Log:
PIG-2879: Pig current releases lack a UDF startsWith.This UDF tests if a given string starts with the specified prefix. (initialcontext via azaroth)

Added:
    pig/trunk/src/org/apache/pig/builtin/STARTSWITH.java
Modified:
    pig/trunk/CHANGES.txt
    pig/trunk/test/org/apache/pig/test/TestStringUDFs.java

Modified: pig/trunk/CHANGES.txt
URL: http://svn.apache.org/viewvc/pig/trunk/CHANGES.txt?rev=1388400&r1=1388399&r2=1388400&view=diff
==============================================================================
--- pig/trunk/CHANGES.txt (original)
+++ pig/trunk/CHANGES.txt Fri Sep 21 10:02:15 2012
@@ -25,6 +25,8 @@ PIG-1891 Enable StoreFunc to make intell
 
 IMPROVEMENTS
 
+PIG-2879: Pig current releases lack a UDF startsWith.This UDF tests if a given string starts with the specified prefix. (initialcontext via azaroth)
+
 PIG-2712: Pig does not call OutputCommitter.abortJob() on the underlying OutputFormat (rohini via gates)
 
 PIG-2918: Avoid Spillable bag overhead where possible (dvryaboy)

Added: pig/trunk/src/org/apache/pig/builtin/STARTSWITH.java
URL: http://svn.apache.org/viewvc/pig/trunk/src/org/apache/pig/builtin/STARTSWITH.java?rev=1388400&view=auto
==============================================================================
--- pig/trunk/src/org/apache/pig/builtin/STARTSWITH.java (added)
+++ pig/trunk/src/org/apache/pig/builtin/STARTSWITH.java Fri Sep 21 10:02:15 2012
@@ -0,0 +1,45 @@
+package org.apache.pig.builtin;
+
+import java.util.ArrayList;
+import java.util.List;
+import org.apache.pig.EvalFunc;
+import org.apache.pig.FuncSpec;
+import org.apache.pig.data.DataType;
+import org.apache.pig.data.Tuple;
+import org.apache.pig.backend.executionengine.ExecException;
+import org.apache.pig.impl.logicalLayer.FrontendException;
+import org.apache.pig.impl.logicalLayer.schema.Schema;
+
+/**
+ * Pig UDF to test input <code>tuple.get(0)</code> against <code>tuple.get(1)</code>
+ * to determine if the first argument starts with the string in the second.
+ */
+public class STARTSWITH extends EvalFunc<Boolean> {
+    @Override
+    public Boolean exec(Tuple tuple) {
+        if (tuple == null || tuple.size() != 2) {
+            return null;
+        }
+        String argument = null;
+        String testAgainst = null;
+        try {
+            argument = (String) tuple.get(0);
+            testAgainst = (String) tuple.get(1);
+            return argument.startsWith(testAgainst);
+        } catch (ExecException exe) {
+          System.err.println("UDF STARTSWITH threw ExecException while processing '" +
+            argument + "' while attempting to locate prefix '" + testAgainst + "'");
+          return null;
+        }
+    }
+
+    @Override
+    public List<FuncSpec> getArgToFuncMapping() throws FrontendException {
+        List<FuncSpec> funcList = new ArrayList<FuncSpec>();
+        Schema s = new Schema();
+        s.add(new Schema.FieldSchema(null, DataType.CHARARRAY));
+        s.add(new Schema.FieldSchema(null, DataType.CHARARRAY));
+        funcList.add(new FuncSpec(this.getClass().getName(), s));
+        return funcList;
+    }
+}

Modified: pig/trunk/test/org/apache/pig/test/TestStringUDFs.java
URL: http://svn.apache.org/viewvc/pig/trunk/test/org/apache/pig/test/TestStringUDFs.java?rev=1388400&r1=1388399&r2=1388400&view=diff
==============================================================================
--- pig/trunk/test/org/apache/pig/test/TestStringUDFs.java (original)
+++ pig/trunk/test/org/apache/pig/test/TestStringUDFs.java Fri Sep 21 10:02:15 2012
@@ -19,6 +19,8 @@
 package org.apache.pig.test;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
 
 import java.io.IOException;
@@ -27,6 +29,7 @@ import org.apache.pig.EvalFunc;
 import org.apache.pig.builtin.INDEXOF;
 import org.apache.pig.builtin.LAST_INDEX_OF;
 import org.apache.pig.builtin.REPLACE;
+import org.apache.pig.builtin.STARTSWITH;
 import org.apache.pig.builtin.STRSPLIT;
 import org.apache.pig.builtin.SUBSTRING;
 import org.apache.pig.builtin.TRIM;
@@ -174,4 +177,13 @@ public class TestStringUDFs {
         assertEquals("foo", splits.get(0));
         assertEquals("bar:baz", splits.get(1));
     }
+
+    @Test
+    public void testStartsWith() throws IOException {
+        STARTSWITH startsWith = new STARTSWITH();
+        Tuple testTuple1 = Util.buildTuple("foo", "bar");
+        assertFalse("String prefix should not match", startsWith.exec(testTuple1));
+        Tuple testTuple2 = Util.buildTuple("foobaz", "foo");
+        assertTrue("String prefix should match", startsWith.exec(testTuple2));
+    }
 }