Issue 40: Serializers Implementation for Schema Registry

build.gradle

@@ -212,6 +212,39 @@ def getProjectVersion() {
     return ver
 }
 
+project('serializers') {
+    dependencies {
+        compile project(':common')
+        compile project(':client')
+        compile group: 'org.apache.avro', name: 'avro', version: avroVersion
+        compile group: 'com.google.protobuf', name: 'protobuf-java', version: protobufProtocVersion
+        compile group: 'com.google.protobuf', name: 'protobuf-java-util', version: protobufUtilVersion
+        compile group: 'io.pravega', name: 'pravega-client', version: pravegaVersion
+        compile group: 'org.xerial.snappy', name: 'snappy-java', version: snappyVersion
+        compile group: 'com.fasterxml.jackson.module', name: 'jackson-module-jsonSchema', version: jacksonVersion
+        testCompile group: 'org.slf4j', name: 'log4j-over-slf4j', version: slf4jApiVersion
+        testCompile group: 'ch.qos.logback', name: 'logback-classic', version: qosLogbackVersion
+        testCompile group: 'io.pravega', name: 'pravega-test-testcommon', version: pravegaVersion
+    }
+
+    javadoc {
+        title = "Serializers"
+        dependsOn delombok
+        source = delombok.outputDir
+        failOnError = true
+        exclude "**/impl/**";
+        options.addBooleanOption("Xdoclint:all,-reference", true)
+    }
+
+    jar {
+        manifest {}
+
+        from {
+            configurations.compile.collect { it.isDirectory() ? it : zipTree(it) }
+        }
+    }
+}
+
 project('server') {
     sourceSets {
         main.resources.srcDirs += "$projectDir/src/conf"
@@ -307,6 +340,15 @@ distributions {
             from 'NOTICE'
         }
     }
+    serializers {
+        baseName = "schema-registry-serializers"
+        contents {
+            from { project(":serializers").configurations.runtime }
+            from { project(":serializers").configurations.runtime.allArtifacts.files }
+            from 'LICENSE'
+            from 'NOTICE'
+        }
+    }
 }
 
 task sourceCopy(type: Copy) {
@@ -346,6 +388,7 @@ task publishAllJars() {
     dependsOn ':common:publish'
     dependsOn ':contract:publish'
     dependsOn ':server:publish'
+    dependsOn ':serializers:publish'
 }
 
 task prepareRegistryImage(type: Copy) {

checkstyle/spotbugs-exclude.xml

@@ -5,6 +5,9 @@
     <Match> <!-- generated code -->
         <Package name="io.pravega.schemaregistry.test.integrationtest.generated" />
     </Match>
+    <Match> <!-- generated code -->
+        <Package name="io.pravega.schemaregistry.testobjs.generated" />
+    </Match>
     <Match> <!-- does not work well with futures -->
         <Bug pattern="NP_NONNULL_PARAM_VIOLATION" />
     </Match>

gradle.properties

@@ -26,7 +26,7 @@ gradleLombokPluginVersion=3.2.0
 gradleSshPluginVersion=2.9.0
 guavaVersion=28.1-jre
 javaxServletApiVersion=4.0.0
-jacksonVersion=2.10.3
+jacksonVersion=2.11.1
 javaxwsrsApiVersion=2.1
 jaxbVersion=2.3.0
 javaxAnnotationVersion=1.3.2
@@ -49,7 +49,7 @@ pravegaVersion=0.7.0
 pravegaKeyCloakVersion=0.7.0
 
 # Version and base tags can be overridden at build time
-schemaregistryVersion=0.0.1-SNAPSHOT
+schemaregistryVersion=0.1.0-SNAPSHOT
 schemaregistryBaseTag=pravega/schemaregistry
 
 # Pravega Signing Key

serializers/src/main/java/io/pravega/schemaregistry/codec/Codec.java

@@ -0,0 +1,30 @@
+/**
+ * Copyright (c) Dell Inc., or its subsidiaries. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ */
+package io.pravega.schemaregistry.codec;
+
+import io.pravega.schemaregistry.contract.data.CodecType;
+import io.pravega.schemaregistry.contract.data.EncodingInfo;
+
+/**
+ * Codec interface extends {@link Encoder} and {@link Decoder} interfaces that defines methods to encode and decode
+ * data. Encoder interface takes a codec type and encoding function. Decoder interface defines a decoding function. 
+ */
+public interface Codec extends Encoder, Decoder {
+    /**
+     * Name identifying the Codec Type. 
+     * This name should be same as the {@link CodecType#getName()} that is registered for the group in schema registry 
+     * service. 
+     * The deserializers will find the decoder for the encoded data from {@link EncodingInfo#getCodecType()} by matching 
+     * the name.
+     * 
+     * @return Name of the codec. 
+     */
+    String getName();
+}

serializers/src/main/java/io/pravega/schemaregistry/codec/Codecs.java

@@ -0,0 +1,147 @@
+/**
+ * Copyright (c) Dell Inc., or its subsidiaries. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ */
+package io.pravega.schemaregistry.codec;
+
+import com.fasterxml.jackson.databind.util.ByteBufferBackedInputStream;
+import io.pravega.schemaregistry.contract.data.CodecType;
+import lombok.Getter;
+import org.apache.commons.io.IOUtils;
+import org.xerial.snappy.Snappy;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.util.Map;
+import java.util.zip.GZIPInputStream;
+import java.util.zip.GZIPOutputStream;
+
+/**
+ * Utility class for creating codecs for none, snappy or gzip. 
+ */
+public enum Codecs {
+    None(Constants.NOOP),
+    GzipCompressor(Constants.GZIP_CODEC), 
+    SnappyCompressor(Constants.SNAPPY_CODEC);
+
+    @Getter
+    private final Codec codec;
+
+    Codecs(Codec codec) {
+        this.codec = codec;  
+    }
+
+    private static class Noop implements Codec {
+        private static final CodecType CODEC_TYPE_NONE = new CodecType(Constants.NONE);
+
+        @Override
+        public String getName() {
+            return CODEC_TYPE_NONE.getName();
+        }
+
+        @Override
+        public CodecType getCodecType() {
+            return CODEC_TYPE_NONE;
+        }
+
+        @Override
+        public void encode(ByteBuffer data, ByteArrayOutputStream bos) {
+            if (data.hasArray()) {
+                bos.write(data.array(), data.arrayOffset() + data.position(), data.remaining());
+            } else {
+                byte[] b = new byte[data.remaining()];
+                data.get(b);
+                bos.write(b, 0, b.length);
+            }
+        }
+
+        @Override
+        public ByteBuffer decode(ByteBuffer data, Map<String, String> codecProperties) {
+            return data;
+        }
+    }
+
+    private static class GZipCodec implements Codec {
+        private static final CodecType CODEC_TYPE_GZIP = new CodecType(Constants.APPLICATION_X_GZIP);
+        @Override
+        public String getName() {
+            return CODEC_TYPE_GZIP.getName();
+        }
+
+        @Override
+        public CodecType getCodecType() {
+            return CODEC_TYPE_GZIP;
+        }
+
+        @Override
+        public void encode(ByteBuffer data, ByteArrayOutputStream bos) throws IOException {
+            byte[] b = data.hasArray() ? data.array() : getBytes(data);
+            int offset = data.hasArray() ? data.arrayOffset() + data.position() : 0;
+            try (GZIPOutputStream gzipOS = new GZIPOutputStream(bos)) {
+                gzipOS.write(b, offset, data.remaining());
+            }
+        }
+
+        @Override
+        public ByteBuffer decode(ByteBuffer data, Map<String, String> codecProperties) throws IOException {
+            InputStream bis = new ByteBufferBackedInputStream(data);
+            return ByteBuffer.wrap(IOUtils.toByteArray(new GZIPInputStream(bis)));
+        }
+    }
+
+    private static byte[] getBytes(ByteBuffer data) {
+        byte[] b = new byte[data.remaining()];
+        data.get(b);
+        return b;
+    }
+
+    private static class SnappyCodec implements Codec {
+        private static final CodecType CODEC_TYPE_SNAPPY = new CodecType(Constants.APPLICATION_X_SNAPPY_FRAMED);
+        @Override
+        public String getName() {
+            return CODEC_TYPE_SNAPPY.getName();
+        }
+
+        @Override
+        public CodecType getCodecType() {
+            return CODEC_TYPE_SNAPPY;
+        }
+
+        @Override
+        public void encode(ByteBuffer data, ByteArrayOutputStream bos) throws IOException {
+            int capacity = Snappy.maxCompressedLength(data.remaining());
+            byte[] encoded = new byte[capacity];
+
+            byte[] b = data.hasArray() ? data.array() : getBytes(data);
+            int offset = data.hasArray() ? data.arrayOffset() + data.position() : 0;
+            int size = Snappy.compress(b, offset, data.remaining(), encoded, 0);
+            bos.write(encoded, 0, size);
+        }
+
+        @Override
+        public ByteBuffer decode(ByteBuffer data, Map<String, String> codecProperties) throws IOException {
+            byte[] b = data.hasArray() ? data.array() : getBytes(data);
+            int offset = data.hasArray() ? data.arrayOffset() + data.position() : 0;
+
+            ByteBuffer decoded = ByteBuffer.allocate(Snappy.uncompressedLength(b, offset, data.remaining()));
+            Snappy.uncompress(b, offset, data.remaining(), decoded.array(), 0);
+            return decoded;
+        }
+    }
+
+    static class Constants {
+        static final Noop NOOP = new Noop();
+        static final GZipCodec GZIP_CODEC = new GZipCodec();
+        static final SnappyCodec SNAPPY_CODEC = new SnappyCodec();
+        static final String NONE = "";
+        static final String APPLICATION_X_GZIP = "application/x-gzip";
+        static final String APPLICATION_X_SNAPPY_FRAMED = "application/x-snappy-framed";
+    }
+}

serializers/src/main/java/io/pravega/schemaregistry/codec/Decoder.java

@@ -0,0 +1,31 @@
+/**
+ * Copyright (c) Dell Inc., or its subsidiaries. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ */
+package io.pravega.schemaregistry.codec;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.Map;
+
+/**
+ * Decoder interface that defines method to decode data.
+ */
+@FunctionalInterface
+public interface Decoder {
+    /**
+     * Implementation should decode the remaining bytes in the buffer and return a new ByteBuffer that includes
+     * the decoded data at its current position. 
+     *
+     * @param data encoded ByteBuffer to decode. 
+     * @param codecProperties codec properties. 
+     * @return decoded ByteBuffer with position set to the start of decoded data. 
+     * @throws IOException can be thrown while reading from or writing to byte buffers.
+     */
+    ByteBuffer decode(ByteBuffer data, Map<String, String> codecProperties) throws IOException;
+}

serializers/src/main/java/io/pravega/schemaregistry/codec/Encoder.java

@@ -0,0 +1,40 @@
+/**
+ * Copyright (c) Dell Inc., or its subsidiaries. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ */
+package io.pravega.schemaregistry.codec;
+
+import io.pravega.schemaregistry.contract.data.CodecType;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+/**
+ * Defines method to encode data.
+ */
+public interface Encoder {
+    /**
+     * Codec type for the encoder. 
+     * 
+     * @return Codec Type for the encoder. 
+     */
+    CodecType getCodecType();
+
+    /**
+     * Implementation should encode the remaining bytes in the buffer and return a new ByteBuffer that includes
+     * the encoded data at its current position. 
+     * 
+     * The implementation can optionally call flush or close on outputstream with no consequence. 
+     * 
+     * @param data ByteBuffer to encode.
+     * @param outputStream ByteArrayOutputStream where the encoded data should be written.
+     * @throws IOException IOException can be thrown while reading from or writing to byte buffers.
+     */
+    void encode(ByteBuffer data, ByteArrayOutputStream outputStream) throws IOException;
+}