Stop detecting XContent type when nobody asked

Author: prdoyle

server/src/main/java/org/elasticsearch/cluster/coordination/PublicationTransportHandler.java

@@ -130,7 +130,7 @@ private void handleIncomingPublishRequest(
         ActionListener<PublishWithJoinResponse> publishResponseListener
     ) throws IOException {
         assert ThreadPool.assertCurrentThreadPool(GENERIC);
-        final Compressor compressor = CompressorFactory.compressor(request.bytes());
+        final Compressor compressor = CompressorFactory.compressorAndCheckXContentType(request.bytes());
         StreamInput in = request.bytes().streamInput();
         try {
             if (compressor != null) {

server/src/main/java/org/elasticsearch/common/compress/CompressedXContent.java

@@ -141,14 +141,15 @@ public CompressedXContent(BytesReference data) throws IOException {
             this.bytes = BytesReference.toBytes(data);
             this.sha256 = sha256FromCompressed(this.bytes);
         } else {
+            CompressorFactory.checkXContentType(data);
             this.bytes = BytesReference.toBytes(CompressorFactory.COMPRESSOR.compress(data));
             this.sha256 = sha256(data);
         }
         assertConsistent();
     }
 
     private void assertConsistent() {
-        assert CompressorFactory.compressor(new BytesArray(bytes)) != null;
+        assert CompressorFactory.compressorAndCheckXContentType(new BytesArray(bytes)) != null;
         assert this.sha256.equals(sha256(uncompressed()));
         assert this.sha256.equals(sha256FromCompressed(bytes));
     }

server/src/main/java/org/elasticsearch/common/compress/CompressorFactory.java

@@ -15,16 +15,35 @@
 import org.elasticsearch.xcontent.XContentType;
 
 import java.io.IOException;
-import java.util.Objects;
+
+import static java.util.Objects.requireNonNull;
 
 public class CompressorFactory {
 
     public static final Compressor COMPRESSOR = new DeflateCompressor();
 
     public static boolean isCompressed(BytesReference bytes) {
-        return compressor(bytes) != null;
+        return COMPRESSOR.isCompressed(bytes);
+    }
+
+    /**
+     * @deprecated Use {@link #compressor} and {@link #checkXContentType} as appropriate.
+     */
+    @Deprecated
+    @Nullable
+    public static Compressor compressorAndCheckXContentType(BytesReference bytes) {
+        Compressor compressor = compressor(bytes);
+        if (compressor != null) {
+            return compressor;
+        }
+
+        checkXContentType(bytes);
+        return null;
     }
 
+    /**
+     * @return the {@link Compressor} if {@code bytes} are compressed; otherwise null
+     */
     @Nullable
     public static Compressor compressor(BytesReference bytes) {
         if (COMPRESSOR.isCompressed(bytes)) {
@@ -34,16 +53,24 @@ public static Compressor compressor(BytesReference bytes) {
             assert XContentHelper.xContentType(bytes) == null;
             return COMPRESSOR;
         }
+        return null;
+    }
 
+    /**
+     * Throw if {@code bytes} do not represent valid XContent.
+     *
+     * @deprecated XContent type detection is deprecated; see {@link XContentHelper#xContentType}.
+     */
+    @Deprecated
+    public static XContentType checkXContentType(BytesReference bytes) {
         XContentType contentType = XContentHelper.xContentType(bytes);
         if (contentType == null) {
             if (isAncient(bytes)) {
                 throw new IllegalStateException("unsupported compression: index was created before v2.0.0.beta1 and wasn't upgraded?");
             }
             throw new NotXContentException("Compressor detection can only be called on some xcontent bytes or compressed xcontent bytes");
         }
-
-        return null;
+        return requireNonNull(contentType);
     }
 
     /** true if the bytes were compressed with LZF: only used before elasticsearch 2.0 */
@@ -56,7 +83,7 @@ private static boolean isAncient(BytesReference bytes) {
      * @throws NullPointerException a NullPointerException will be thrown when bytes is null
      */
     public static BytesReference uncompressIfNeeded(BytesReference bytes) throws IOException {
-        Compressor compressor = compressor(Objects.requireNonNull(bytes, "the BytesReference must not be null"));
+        Compressor compressor = compressorAndCheckXContentType(requireNonNull(bytes, "the BytesReference must not be null"));
         return compressor == null ? bytes : compressor.uncompress(bytes);
     }
 

server/src/main/java/org/elasticsearch/common/xcontent/XContentHelper.java

@@ -76,7 +76,7 @@ public static XContentParser createParser(XContentParserConfiguration config, By
             final XContentType contentType = XContentFactory.xContentType(compressedInput);
             return XContentFactory.xContent(contentType).createParser(config, compressedInput);
         } else {
-            return createParserNotCompressed(config, bytes, xContentType(bytes));
+            return createParserNotCompressed(config, bytes, CompressorFactory.checkXContentType(bytes));
         }
     }
 
@@ -574,6 +574,7 @@ public static void writeRawField(String field, BytesReference source, XContentBu
                 builder.rawField(field, compressedStreamInput);
             }
         } else {
+            CompressorFactory.checkXContentType(source);
             try (InputStream stream = source.streamInput()) {
                 builder.rawField(field, stream);
             }
@@ -690,7 +691,7 @@ public static XContentType xContentTypeMayCompressed(BytesReference bytes) {
                 throw new UncheckedIOException(e);
             }
         } else {
-            return XContentHelper.xContentType(bytes);
+            return CompressorFactory.checkXContentType(bytes);
         }
     }
 

server/src/test/java/org/elasticsearch/cluster/coordination/PublicationTransportHandlerTests.java

@@ -145,7 +145,7 @@ private static boolean isDiff(BytesTransportRequest request, TransportVersion ve
             StreamInput in = null;
             try {
                 in = request.bytes().streamInput();
-                final Compressor compressor = CompressorFactory.compressor(request.bytes());
+                final Compressor compressor = CompressorFactory.compressorAndCheckXContentType(request.bytes());
                 if (compressor != null) {
                     in = compressor.threadLocalStreamInput(in);
                 }