CompressorFactory.compressor (#131655)

* Refactor: split out non-detecting compressor method

* Unit test

* Fix createParser not to detect XContentType

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.compressorForUnknownXContentType(request.bytes());
         StreamInput in = request.bytes().streamInput();
         try {
             if (compressor != null) {

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

@@ -135,7 +135,7 @@ public CompressedXContent(ToXContent xcontent, ToXContent.Params params) throws
      * that may already be compressed.
      */
     public CompressedXContent(BytesReference data) throws IOException {
-        Compressor compressor = CompressorFactory.compressor(data);
+        Compressor compressor = CompressorFactory.compressorForUnknownXContentType(data);
         if (compressor != null) {
             // already compressed...
             this.bytes = BytesReference.toBytes(data);
@@ -148,7 +148,7 @@ public CompressedXContent(BytesReference data) throws IOException {
     }
 
     private void assertConsistent() {
-        assert CompressorFactory.compressor(new BytesArray(bytes)) != null;
+        assert CompressorFactory.compressorForUnknownXContentType(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

@@ -22,7 +22,7 @@ public class CompressorFactory {
     public static final Compressor COMPRESSOR = new DeflateCompressor();
 
     public static boolean isCompressed(BytesReference bytes) {
-        return compressor(bytes) != null;
+        return compressorForUnknownXContentType(bytes) != null;
     }
 
     @Nullable
@@ -34,6 +34,15 @@ public static Compressor compressor(BytesReference bytes) {
             assert XContentHelper.xContentType(bytes) == null;
             return COMPRESSOR;
         }
+        return null;
+    }
+
+    @Nullable
+    public static Compressor compressorForUnknownXContentType(BytesReference bytes) {
+        Compressor compressor = compressor(bytes);
+        if (compressor != null) {
+            return compressor;
+        }
 
         XContentType contentType = XContentHelper.xContentType(bytes);
         if (contentType == null) {
@@ -56,13 +65,13 @@ 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 = compressorForUnknownXContentType(Objects.requireNonNull(bytes, "the BytesReference must not be null"));
         return compressor == null ? bytes : compressor.uncompress(bytes);
     }
 
     /** Decompress the provided {@link BytesReference}. */
     public static BytesReference uncompress(BytesReference bytes) throws IOException {
-        Compressor compressor = compressor(bytes);
+        Compressor compressor = compressorForUnknownXContentType(bytes);
         if (compressor == null) {
             throw new NotCompressedException();
         }

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

@@ -67,7 +67,7 @@ public static XContentParser createParser(NamedXContentRegistry registry, Deprec
      */
     @Deprecated
     public static XContentParser createParser(XContentParserConfiguration config, BytesReference bytes) throws IOException {
-        Compressor compressor = CompressorFactory.compressor(bytes);
+        Compressor compressor = CompressorFactory.compressorForUnknownXContentType(bytes);
         if (compressor != null) {
             InputStream compressedInput = compressor.threadLocalInputStream(bytes.streamInput());
             if (compressedInput.markSupported() == false) {
@@ -568,7 +568,7 @@ public interface CustomMerge {
     @Deprecated
     public static void writeRawField(String field, BytesReference source, XContentBuilder builder, ToXContent.Params params)
         throws IOException {
-        Compressor compressor = CompressorFactory.compressor(source);
+        Compressor compressor = CompressorFactory.compressorForUnknownXContentType(source);
         if (compressor != null) {
             try (InputStream compressedStreamInput = compressor.threadLocalInputStream(source.streamInput())) {
                 builder.rawField(field, compressedStreamInput);
@@ -592,7 +592,7 @@ public static void writeRawField(
         ToXContent.Params params
     ) throws IOException {
         Objects.requireNonNull(xContentType);
-        Compressor compressor = CompressorFactory.compressor(source);
+        Compressor compressor = CompressorFactory.compressorForUnknownXContentType(source);
         if (compressor != null) {
             try (InputStream compressedStreamInput = compressor.threadLocalInputStream(source.streamInput())) {
                 builder.rawField(field, compressedStreamInput, xContentType);
@@ -677,7 +677,7 @@ public static BytesReference toXContent(ChunkedToXContent toXContent, XContentTy
      */
     @Deprecated
     public static XContentType xContentTypeMayCompressed(BytesReference bytes) {
-        Compressor compressor = CompressorFactory.compressor(bytes);
+        Compressor compressor = CompressorFactory.compressorForUnknownXContentType(bytes);
         if (compressor != null) {
             try {
                 InputStream compressedStreamInput = compressor.threadLocalInputStream(bytes.streamInput());

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.compressorForUnknownXContentType(request.bytes());
                 if (compressor != null) {
                     in = compressor.threadLocalStreamInput(in);
                 }

server/src/test/java/org/elasticsearch/common/xcontent/support/XContentHelperTests.java

@@ -12,12 +12,14 @@
 import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.compress.CompressedXContent;
+import org.elasticsearch.common.compress.NotXContentException;
 import org.elasticsearch.common.util.Maps;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.xcontent.ToXContent;
 import org.elasticsearch.xcontent.ToXContentObject;
 import org.elasticsearch.xcontent.XContentBuilder;
+import org.elasticsearch.xcontent.XContentParseException;
 import org.elasticsearch.xcontent.XContentParser;
 import org.elasticsearch.xcontent.XContentParserConfiguration;
 import org.elasticsearch.xcontent.XContentType;
@@ -421,4 +423,19 @@ public void testParseToType() throws IOException {
 
         assertThat(names, equalTo(Set.of("a", "c")));
     }
+
+    public void testGetParserWithInvalidInput() throws IOException {
+        assertThrows(
+            "Should detect bad JSON",
+            NotXContentException.class,
+            () -> XContentHelper.createParser(XContentParserConfiguration.EMPTY, new BytesArray("not actually XContent"))
+        );
+        XContentParser parser = XContentHelper.createParser(
+            XContentParserConfiguration.EMPTY,
+            new BytesArray("not actually XContent"),
+            XContentType.JSON
+        );
+        assertNotNull("Should not detect bad JSON", parser); // This is more like assertNotThrows
+        assertThrows("Should detect bad JSON at parse time", XContentParseException.class, parser::numberValue);
+    }
 }