HADOOP-18029: Update CompressionCodecFactory to handle uppercase file extensions (#3739)

Co-authored-by: Desmond Sisson <sissonde@amazon.com>

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/CompressionCodecFactory.java

@@ -57,7 +57,7 @@ public class CompressionCodecFactory {
   private Map<String, CompressionCodec> codecsByName = null;
 
   /**
-   * A map from class names to the codecs
+   * A map from class names to the codecs.
    */
   private HashMap<String, CompressionCodec> codecsByClassName = null;
 
@@ -110,8 +110,8 @@ public class CompressionCodecFactory {
    */
   public static List<Class<? extends CompressionCodec>> getCodecClasses(
       Configuration conf) {
-    List<Class<? extends CompressionCodec>> result
+    List<Class<? extends CompressionCodec>> result =
-      = new ArrayList<Class<? extends CompressionCodec>>();
+            new ArrayList<Class<? extends CompressionCodec>>();
     // Add codec classes discovered via service loading
     synchronized (CODEC_PROVIDERS) {
       // CODEC_PROVIDERS is a lazy collection. Synchronize so it is
@@ -200,11 +200,13 @@ public class CompressionCodecFactory {
       String filename = file.getName();
       String reversedFilename =
           new StringBuilder(filename).reverse().toString();
+      String lowerReversedFilename =
+              StringUtils.toLowerCase(reversedFilename);
       SortedMap<String, CompressionCodec> subMap =
-        codecs.headMap(reversedFilename);
+              codecs.headMap(lowerReversedFilename);
       if (!subMap.isEmpty()) {
         String potentialSuffix = subMap.lastKey();
-        if (reversedFilename.startsWith(potentialSuffix)) {
+        if (lowerReversedFilename.startsWith(potentialSuffix)) {
           result = codecs.get(potentialSuffix);
         }
       }
@@ -323,8 +325,12 @@ public class CompressionCodecFactory {
                 len = in.read(buffer);
               }
             } finally {
-              if(out != null) { out.close(); }
+              if(out != null) {
-              if(in  != null) { in.close(); }
+                out.close();
+              }
+              if(in  != null) {
+                in.close();
+              }
             }
           } else {
             CompressionInputStream in = null;
@@ -338,7 +344,9 @@ public class CompressionCodecFactory {
                 len = in.read(buffer);
               }
             } finally {
-              if(in != null) { in.close(); }
+              if(in != null) {
+                in.close();
+              }
             }
           }
         }

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/compress/TestCodecFactory.java

@@ -29,6 +29,7 @@ import org.apache.hadoop.conf.Configuration;
 
 import org.junit.Test;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.fail;
 
 public class TestCodecFactory {
@@ -125,7 +126,7 @@ public class TestCodecFactory {
   }
   
   /**
-   * Returns a factory for a given set of codecs
+   * Returns a factory for a given set of codecs.
    * @param classes the codec classes to include
    * @return a new factory
    */
@@ -137,10 +138,16 @@ public class TestCodecFactory {
   
   private static void checkCodec(String msg, 
                                  Class expected, CompressionCodec actual) {
+    if (expected == null) {
+      assertNull(msg, actual);
+    } else if (actual == null) {
+      fail(msg + " result was null");
+    } else {
       assertEquals(msg + " unexpected codec found",
               expected.getName(),
               actual.getClass().getName());
     }
+  }
 
   @Test
   public void testFinding() {
@@ -153,6 +160,8 @@ public class TestCodecFactory {
     
     codec = factory.getCodec(new Path("/tmp/foo.gz"));
     checkCodec("default factory for .gz", GzipCodec.class, codec);
+    codec = factory.getCodec(new Path("/tmp/foo.GZ"));
+    checkCodec("default factory for .GZ", GzipCodec.class, codec);
     codec = factory.getCodecByClassName(GzipCodec.class.getCanonicalName());
     checkCodec("default factory for gzip codec", GzipCodec.class, codec);
     codec = factory.getCodecByName("gzip");
@@ -168,6 +177,8 @@ public class TestCodecFactory {
 
     codec = factory.getCodec(new Path("/tmp/foo.bz2"));
     checkCodec("default factory for .bz2", BZip2Codec.class, codec);
+    codec = factory.getCodec(new Path("/tmp/foo.BZ2"));
+    checkCodec("default factory for .BZ2", BZip2Codec.class, codec);
     codec = factory.getCodecByClassName(BZip2Codec.class.getCanonicalName());
     checkCodec("default factory for bzip2 codec", BZip2Codec.class, codec);
     codec = factory.getCodecByName("bzip2");
@@ -221,16 +232,22 @@ public class TestCodecFactory {
                                      FooBarCodec.class});
     codec = factory.getCodec(new Path("/tmp/.foo.bar.gz"));
     checkCodec("full factory gz codec", GzipCodec.class, codec);
+    codec = factory.getCodec(new Path("/tmp/.foo.bar.GZ"));
+    checkCodec("full factory GZ codec", GzipCodec.class, codec);
     codec = factory.getCodecByClassName(GzipCodec.class.getCanonicalName());
     checkCodec("full codec gz codec", GzipCodec.class, codec);
      
     codec = factory.getCodec(new Path("/tmp/foo.bz2"));
     checkCodec("full factory for .bz2", BZip2Codec.class, codec);
+    codec = factory.getCodec(new Path("/tmp/foo.BZ2"));
+    checkCodec("full factory for .BZ2", BZip2Codec.class, codec);
     codec = factory.getCodecByClassName(BZip2Codec.class.getCanonicalName());
     checkCodec("full codec bzip2 codec", BZip2Codec.class, codec);
 
     codec = factory.getCodec(new Path("/tmp/foo.bar"));
     checkCodec("full factory bar codec", BarCodec.class, codec);
+    codec = factory.getCodec(new Path("/tmp/foo.BAR"));
+    checkCodec("full factory BAR codec", BarCodec.class, codec);
     codec = factory.getCodecByClassName(BarCodec.class.getCanonicalName());
     checkCodec("full factory bar codec", BarCodec.class, codec);
     codec = factory.getCodecByName("bar");
@@ -240,6 +257,8 @@ public class TestCodecFactory {
 
     codec = factory.getCodec(new Path("/tmp/foo/baz.foo.bar"));
     checkCodec("full factory foo bar codec", FooBarCodec.class, codec);
+    codec = factory.getCodec(new Path("/tmp/foo/baz.FOO.bar"));
+    checkCodec("full factory FOO bar codec", FooBarCodec.class, codec);
     codec = factory.getCodecByClassName(FooBarCodec.class.getCanonicalName());
     checkCodec("full factory foo bar codec", FooBarCodec.class, codec);
     codec = factory.getCodecByName("foobar");
@@ -249,6 +268,8 @@ public class TestCodecFactory {
 
     codec = factory.getCodec(new Path("/tmp/foo.foo"));
     checkCodec("full factory foo codec", FooCodec.class, codec);
+    codec = factory.getCodec(new Path("/tmp/FOO.FOO"));
+    checkCodec("full factory FOO codec", FooCodec.class, codec);
     codec = factory.getCodecByClassName(FooCodec.class.getCanonicalName());
     checkCodec("full factory foo codec", FooCodec.class, codec);
     codec = factory.getCodecByName("foo");
@@ -259,6 +280,8 @@ public class TestCodecFactory {
     factory = setClasses(new Class[]{NewGzipCodec.class});
     codec = factory.getCodec(new Path("/tmp/foo.gz"));
     checkCodec("overridden factory for .gz", NewGzipCodec.class, codec);
+    codec = factory.getCodec(new Path("/tmp/foo.GZ"));
+    checkCodec("overridden factory for .GZ", NewGzipCodec.class, codec);
     codec = factory.getCodecByClassName(NewGzipCodec.class.getCanonicalName());
     checkCodec("overridden factory for gzip codec", NewGzipCodec.class, codec);