Update to Jackson 2.4.3

- Update pom to 2.4.3 from 2.4.2
- Enable the CBOR data header (aka tag) from the CBOR Generator to provide binary identification like the Smile format
- Check for the CBOR header and ensure that the data sent in represents a "major type" that is an object
- Cleans up `JsonVsCborTests` unused imports

pom.xml

@@ -31,6 +31,7 @@
     </parent>
 
     <properties>
+        <jackson.version>2.4.3</jackson.version>
         <lucene.version>5.0.0</lucene.version>
         <lucene.maven.version>5.0.0-snapshot-1641343</lucene.maven.version>
         <tests.jvms>auto</tests.jvms>
@@ -226,28 +227,28 @@
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-core</artifactId>
-            <version>2.4.2</version>
+            <version>${jackson.version}</version>
             <scope>compile</scope>
         </dependency>
 
         <dependency>
             <groupId>com.fasterxml.jackson.dataformat</groupId>
             <artifactId>jackson-dataformat-smile</artifactId>
-            <version>2.4.2</version>
+            <version>${jackson.version}</version>
             <scope>compile</scope>
         </dependency>
 
         <dependency>
             <groupId>com.fasterxml.jackson.dataformat</groupId>
             <artifactId>jackson-dataformat-yaml</artifactId>
-            <version>2.4.2</version>
+            <version>${jackson.version}</version>
             <scope>compile</scope>
         </dependency>
 
         <dependency>
             <groupId>com.fasterxml.jackson.dataformat</groupId>
             <artifactId>jackson-dataformat-cbor</artifactId>
-            <version>2.4.2</version>
+            <version>${jackson.version}</version>
             <scope>compile</scope>
         </dependency>
 

src/main/java/org/elasticsearch/common/xcontent/XContentFactory.java

@@ -157,9 +157,9 @@ public class XContentFactory {
             return XContentType.YAML;
         }
 
-        // CBOR is not supported
+        // CBOR is not supported because it is a binary-only format
 
-        for (int i = 0; i < length; i++) {
+        for (int i = 1; i < length; i++) {
             char c = content.charAt(i);
             if (c == '{') {
                 return XContentType.JSON;
@@ -208,41 +208,48 @@ public class XContentFactory {
      * Guesses the content type based on the provided input stream.
      */
     public static XContentType xContentType(InputStream si) throws IOException {
+        // Need minimum of 3 bytes for everything (except really JSON)
         int first = si.read();
-        if (first == -1) {
-            return null;
-        }
         int second = si.read();
-        if (second == -1) {
+        int third = si.read();
+
+        // Cannot short circuit based on third (or later fourth) because "{}" is valid JSON
+        if (first == -1 || second == -1) {
             return null;
         }
-        if (first == SmileConstants.HEADER_BYTE_1 && second == SmileConstants.HEADER_BYTE_2) {
+
-            int third = si.read();
+        if (first == SmileConstants.HEADER_BYTE_1 && second == SmileConstants.HEADER_BYTE_2 &&
-            if (third == SmileConstants.HEADER_BYTE_3) {
+            third == SmileConstants.HEADER_BYTE_3) {
-                return XContentType.SMILE;
+            return XContentType.SMILE;
-            }
         }
-        if (first == '{' || second == '{') {
+        if (first == '-' && second == '-' && third == '-') {
+            return XContentType.YAML;
+        }
+
+        // Need 4 bytes for CBOR
+        int fourth = si.read();
+
+        if (first == '{' || second == '{' || third == '{' || fourth == '{') {
             return XContentType.JSON;
         }
-        if (first == '-' && second == '-') {
+
-            int third = si.read();
+        // ensure that we don't only have two or three bytes (definitely not CBOR and everything else was checked)
-            if (third == '-') {
+        if (third != -1 && fourth != -1) {
-                return XContentType.YAML;
+            if (isCBORObjectHeader((byte)first, (byte)second, (byte)third, (byte)fourth)) {
-            }
+                return XContentType.CBOR;
-        }
+            }
-        if (first == (CBORConstants.BYTE_OBJECT_INDEFINITE & 0xff)){
+
-            return XContentType.CBOR;
+            for (int i = 4; i < GUESS_HEADER_LENGTH; i++) {
-        }
+                int val = si.read();
-        for (int i = 2; i < GUESS_HEADER_LENGTH; i++) {
+                if (val == -1) {
-            int val = si.read();
+                    return null;
-            if (val == -1) {
+                }
-                return null;
+                if (val == '{') {
-            }
+                    return XContentType.JSON;
-            if (val == '{') {
+                }
-                return XContentType.JSON;
             }
         }
+
         return null;
     }
 
@@ -273,20 +280,53 @@ public class XContentFactory {
         if (first == '{') {
             return XContentType.JSON;
         }
-        if (length > 2 && first == SmileConstants.HEADER_BYTE_1 && bytes.get(1) == SmileConstants.HEADER_BYTE_2 && bytes.get(2) == SmileConstants.HEADER_BYTE_3) {
+        if (length > 2) {
-            return XContentType.SMILE;
+            byte second = bytes.get(1);
-        }
+            byte third = bytes.get(2);
-        if (length > 2 && first == '-' && bytes.get(1) == '-' && bytes.get(2) == '-') {
+
-            return XContentType.YAML;
+            if (first == SmileConstants.HEADER_BYTE_1 && second == SmileConstants.HEADER_BYTE_2 && third == SmileConstants.HEADER_BYTE_3) {
-        }
+                return XContentType.SMILE;
-        if (first == CBORConstants.BYTE_OBJECT_INDEFINITE){
+            }
-            return XContentType.CBOR;
+            if (first == '-' && second == '-' && third == '-') {
-        }
+                return XContentType.YAML;
-        for (int i = 0; i < length; i++) {
+            }
-            if (bytes.get(i) == '{') {
+            if (length > 3 && isCBORObjectHeader(first, second, third, bytes.get(3))) {
-                return XContentType.JSON;
+                return XContentType.CBOR;
+            }
+            // note: technically this only needs length >= 2, but if the string is just " {", then it's not JSON, but
+            //  " {}" is JSON (3 characters)
+            for (int i = 1; i < length; i++) {
+                if (bytes.get(i) == '{') {
+                    return XContentType.JSON;
+                }
             }
         }
         return null;
     }
+
+    /**
+     * Determine if the specified bytes represent a CBOR encoded stream.
+     * <p />
+     * This performs two checks to verify that it is indeed valid/usable CBOR data:
+     * <ol>
+     * <li>Checks the first three bytes for the
+     * {@link CBORConstants#TAG_ID_SELF_DESCRIBE self-identifying CBOR tag (header)}</li>
+     * <li>Checks that the fourth byte represents a major type that is an object, as opposed to some other type (e.g.,
+     * text)</li>
+     * </ol>
+     *
+     * @param first The first byte of the header
+     * @param second The second byte of the header
+     * @param third The third byte of the header
+     * @param fourth The fourth byte represents the <em>first</em> byte of the CBOR data, indicating the data's type
+     *
+     * @return {@code true} if a CBOR byte stream is detected. {@code false} otherwise.
+     */
+    private static boolean isCBORObjectHeader(byte first, byte second, byte third, byte fourth) {
+        // Determine if it uses the ID TAG (0xd9f7), then see if it starts with an object (equivalent to
+        //  checking in JSON if it starts with '{')
+        return CBORConstants.hasMajorType(CBORConstants.MAJOR_TYPE_TAG, first) &&
+               (((second << 8) & 0xff00) | (third & 0xff)) == CBORConstants.TAG_ID_SELF_DESCRIBE &&
+               CBORConstants.hasMajorType(CBORConstants.MAJOR_TYPE_OBJECT, fourth);
+    }
 }

src/main/java/org/elasticsearch/common/xcontent/cbor/CborXContent.java

@@ -21,6 +21,8 @@ package org.elasticsearch.common.xcontent.cbor;
 
 import com.fasterxml.jackson.core.JsonEncoding;
 import com.fasterxml.jackson.dataformat.cbor.CBORFactory;
+import com.fasterxml.jackson.dataformat.cbor.CBORGenerator;
+
 import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.FastStringReader;
@@ -43,6 +45,8 @@ public class CborXContent implements XContent {
     static {
         cborFactory = new CBORFactory();
         cborFactory.configure(CBORFactory.Feature.FAIL_ON_SYMBOL_HASH_OVERFLOW, false); // this trips on many mappings now...
+        // Enable prefixing the entire byte stream with a CBOR header ("tag")
+        cborFactory.configure(CBORGenerator.Feature.WRITE_TYPE_HEADER, true);
         cborXContent = new CborXContent();
     }
 

src/test/java/org/elasticsearch/common/xcontent/XContentFactoryTests.java

@@ -29,37 +29,45 @@ import java.io.IOException;
 import static org.hamcrest.Matchers.equalTo;
 
 /**
- *
+ * Tests {@link XContentFactory} type generation.
  */
 public class XContentFactoryTests extends ElasticsearchTestCase {
 
 
     @Test
     public void testGuessJson() throws IOException {
-        testGuessType(XContentType.JSON);
+        assertType(XContentType.JSON);
     }
 
     @Test
     public void testGuessSmile() throws IOException {
-        testGuessType(XContentType.SMILE);
+        assertType(XContentType.SMILE);
     }
 
     @Test
     public void testGuessYaml() throws IOException {
-        testGuessType(XContentType.YAML);
+        assertType(XContentType.YAML);
     }
 
     @Test
     public void testGuessCbor() throws IOException {
-        testGuessType(XContentType.CBOR);
+        assertType(XContentType.CBOR);
     }
 
-    private void testGuessType(XContentType type) throws IOException {
+    private void assertType(XContentType type) throws IOException {
-        XContentBuilder builder = XContentFactory.contentBuilder(type);
+        for (XContentBuilder builder : generateBuilders(type)) {
-        builder.startObject();
+            assertBuilderType(builder, type);
-        builder.field("field1", "value1");
+        }
-        builder.endObject();
+    }
 
+    /**
+     * Assert the {@code builder} maps to the appropriate {@code type}.
+     *
+     * @param builder Builder to check.
+     * @param type Type to match.
+     * @throws IOException if any error occurs while checking the builder
+     */
+    private void assertBuilderType(XContentBuilder builder, XContentType type) throws IOException {
         assertThat(XContentFactory.xContentType(builder.bytes()), equalTo(type));
         BytesArray bytesArray = builder.bytes().toBytesArray();
         assertThat(XContentFactory.xContentType(new BytesStreamInput(bytesArray.array(), bytesArray.arrayOffset(), bytesArray.length(), false)), equalTo(type));
@@ -69,4 +77,30 @@ public class XContentFactoryTests extends ElasticsearchTestCase {
             assertThat(XContentFactory.xContentType(builder.string()), equalTo(type));
         }
     }
+
+    /**
+     * Generate builders to test various use cases to check.
+     *
+     * @param type The type to use.
+     * @return Never {@code null} array of unique {@link XContentBuilder}s testing different edge cases.
+     * @throws IOException if any error occurs while generating builders
+     */
+    private XContentBuilder[] generateBuilders(XContentType type) throws IOException {
+        XContentBuilder[] builders = new XContentBuilder[] {
+            XContentFactory.contentBuilder(type), XContentFactory.contentBuilder(type)
+        };
+
+        // simple object
+        builders[0].startObject();
+        builders[0].field("field1", "value1");
+            builders[0].startObject("object1");
+            builders[0].field("field2", "value2");
+            builders[0].endObject();
+        builders[0].endObject();
+
+        // empty object
+        builders[1].startObject().endObject();
+
+        return builders;
+    }
 }

src/test/java/org/elasticsearch/common/xcontent/cbor/JsonVsCborTests.java

@@ -19,10 +19,6 @@
 
 package org.elasticsearch.common.xcontent.cbor;
 
-import com.fasterxml.jackson.core.JsonFactory;
-import com.fasterxml.jackson.core.JsonGenerator;
-import com.fasterxml.jackson.core.JsonParser;
-import com.fasterxml.jackson.dataformat.cbor.CBORFactory;
 import org.elasticsearch.common.io.stream.BytesStreamOutput;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentGenerator;
@@ -31,7 +27,6 @@ import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.test.ElasticsearchTestCase;
 import org.junit.Test;
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 
 import static org.hamcrest.Matchers.equalTo;