[avro] 07/14: Adding alternative to GenericDatumeReader which uses Advancers.

[th...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

thiru pushed a commit to branch fast-decoder-thiru
in repository https://gitbox.apache.org/repos/asf/avro.git

commit e23abae419376f4c69f6f13c2d25bd6afedb7474
Author: rstata <rs...@yahoo.com>
AuthorDate: Tue Apr 30 01:36:29 2019 -0700

    Adding alternative to GenericDatumeReader which uses Advancers.
---
 .../apache/avro/generic/GenericDatumReader2.java   | 79 ++++++++++++++++++++++
 1 file changed, 79 insertions(+)

diff --git a/lang/java/avro/src/main/java/org/apache/avro/generic/GenericDatumReader2.java b/lang/java/avro/src/main/java/org/apache/avro/generic/GenericDatumReader2.java
new file mode 100644
index 0000000..d86b038
--- /dev/null
+++ b/lang/java/avro/src/main/java/org/apache/avro/generic/GenericDatumReader2.java
@@ -0,0 +1,79 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.avro.generic;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+import org.apache.avro.Resolver;
+import org.apache.avro.Schema;
+import org.apache.avro.io.DatumReader;
+import org.apache.avro.io.Decoder;
+
+public class GenericDatumReader2<D> implements DatumReader<D> {
+  private final Advancer.Record advancer;
+  private final GenericData data;
+
+  private GenericDatumReader2(Advancer.Record a, GenericData d) {
+    advancer = a;
+    data = d;
+  }
+
+  public static GenericDatumReader2 getReaderFor(Schema writer, Schema reader, GenericData data) {
+    // TODO: add caching
+    Resolver.Action a = Resolver.resolve(writer, reader, data);
+    Advancer.Record r = (Advancer.Record)Advancer.from(a);
+    return new GenericDatumReader2(r, data);
+  }
+
+  public D read(D reuse, Decoder in) throws IOException {
+    for (int i = 0; i < advancer.advancers.length; i++) {
+      int p = advancer.readerOrder[i].pos();
+      reuse.set(p, read(in, null, advancer.advancers[i]));
+    }
+    advancer.done(in);
+  }
+
+  public Object read(Object reuse, Schema expected, Advancer a, Decoder in)
+    throws IOException
+  {
+    switch (expected.getType()) {
+    case NULL: return a.nextNull(in);
+    case BOOLEAN: return (Boolean) a.nextBoolean(in);
+    case INT: return (Integer) a.nextInt(in);
+    case LONG: return (Long) a.nextLong(in);
+    case FLOAT: return (Float) a.nextFloat(in);
+    case DOUBLE: return (Double) a.nextDouble(in);
+    case STRING: return (String) a.nextString(in);
+    case BYTES: return a.nextBytes(in, (ByteBuffer)reuse);
+    case FIXED:
+    case ARRAY:
+    case MAP:
+    case RECORD:
+    case UNION:
+    default:
+      throw new IllegalArgumentException("Can't handle this yet.");
+    }
+  }
+
+  /** Throws {@link UnsupportedOperationException}.  (In retrospect, making
+    * DatumReaders mutable wasn't a good idea...) */
+  public void setSchema(Schema s) {
+    throw new UnsupportedOperationException();
+  }
+}
\ No newline at end of file