fix exists check with compression

indexing-hadoop/src/main/java/io/druid/indexer/DetermineHashedPartitionsJob.java

@@ -128,7 +128,7 @@ public class DetermineHashedPartitionsJob implements Jobby
       if (!config.getSegmentGranularIntervals().isPresent()) {
         final Path intervalInfoPath = config.makeIntervalInfoPath();
         fileSystem = intervalInfoPath.getFileSystem(groupByJob.getConfiguration());
-        if (!fileSystem.exists(intervalInfoPath)) {
+        if (!Utils.exists(groupByJob, fileSystem, intervalInfoPath)) {
           throw new ISE("Path[%s] didn't exist!?", intervalInfoPath);
         }
         List<Interval> intervals = config.jsonMapper.readValue(
@@ -148,7 +148,7 @@ public class DetermineHashedPartitionsJob implements Jobby
         if (fileSystem == null) {
           fileSystem = partitionInfoPath.getFileSystem(groupByJob.getConfiguration());
         }
-        if (fileSystem.exists(partitionInfoPath)) {
+        if (Utils.exists(groupByJob, fileSystem, partitionInfoPath)) {
           Long cardinality = config.jsonMapper.readValue(
             Utils.openInputStream(groupByJob, partitionInfoPath), new TypeReference<Long>()
         {

indexing-hadoop/src/main/java/io/druid/indexer/DeterminePartitionsJob.java

@@ -215,7 +215,7 @@ public class DeterminePartitionsJob implements Jobby
         if (fileSystem == null) {
           fileSystem = partitionInfoPath.getFileSystem(dimSelectionJob.getConfiguration());
         }
-        if (fileSystem.exists(partitionInfoPath)) {
+        if (Utils.exists(dimSelectionJob, fileSystem, partitionInfoPath)) {
           List<ShardSpec> specs = config.jsonMapper.readValue(
               Utils.openInputStream(dimSelectionJob, partitionInfoPath), new TypeReference<List<ShardSpec>>()
           {

indexing-hadoop/src/main/java/io/druid/indexer/Utils.java

@@ -65,7 +65,8 @@ public class Utils
     return retVal;
   }
 
-  public static OutputStream makePathAndOutputStream(JobContext job, Path outputPath, boolean deleteExisting) throws IOException
+  public static OutputStream makePathAndOutputStream(JobContext job, Path outputPath, boolean deleteExisting)
+      throws IOException
   {
     OutputStream retVal;
     FileSystem fs = outputPath.getFileSystem(job.getConfiguration());
@@ -73,8 +74,7 @@ public class Utils
     if (fs.exists(outputPath)) {
       if (deleteExisting) {
         fs.delete(outputPath, false);
-      }
-      else {
+      } else {
         throw new ISE("outputPath[%s] must not exist.", outputPath);
       }
     }
@@ -97,6 +97,17 @@ public class Utils
     return openInputStream(inputPath, inputPath.getFileSystem(job.getConfiguration()));
   }
 
+  public static boolean exists(JobContext job, FileSystem fs, Path inputPath) throws IOException
+  {
+    if (!FileOutputFormat.getCompressOutput(job)) {
+      return fs.exists(inputPath);
+    } else {
+      Class<? extends CompressionCodec> codecClass = FileOutputFormat.getOutputCompressorClass(job, GzipCodec.class);
+      CompressionCodec codec = ReflectionUtils.newInstance(codecClass, job.getConfiguration());
+      return fs.exists(new Path(inputPath.toString() + codec.getDefaultExtension()));
+    }
+  }
+
   public static InputStream openInputStream(Path inputPath, final FileSystem fileSystem) throws IOException
   {
     return fileSystem.open(inputPath);
@@ -109,7 +120,9 @@ public class Utils
 
     return jsonMapper.readValue(
         fs.open(statsPath),
-        new TypeReference<Map<String, Object>>(){}
+        new TypeReference<Map<String, Object>>()
+        {
+        }
     );
   }