implementing OptionalFloatThriftCodec and float coercion

drift-codec/src/main/java/com/facebook/drift/codec/ThriftCodecManager.java

@@ -32,6 +32,7 @@
 import com.facebook.drift.codec.internal.builtin.LongThriftCodec;
 import com.facebook.drift.codec.internal.builtin.MapThriftCodec;
 import com.facebook.drift.codec.internal.builtin.OptionalDoubleThriftCodec;
+import com.facebook.drift.codec.internal.builtin.OptionalFloatThriftCodec;
 import com.facebook.drift.codec.internal.builtin.OptionalIntThriftCodec;
 import com.facebook.drift.codec.internal.builtin.OptionalLongThriftCodec;
 import com.facebook.drift.codec.internal.builtin.OptionalThriftCodec;
@@ -186,6 +187,7 @@ public ThriftCodec<?> load(ThriftType type)
         addBuiltinCodec(new DoubleArrayThriftCodec());
         addBuiltinCodec(new FloatArrayThriftCodec());
         addBuiltinCodec(new OptionalDoubleThriftCodec());
+        addBuiltinCodec(new OptionalFloatThriftCodec());
         addBuiltinCodec(new OptionalIntThriftCodec());
         addBuiltinCodec(new OptionalLongThriftCodec());
 

drift-codec/src/main/java/com/facebook/drift/codec/internal/builtin/OptionalFloatThriftCodec.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2017 Facebook, Inc.
+ *
+ * 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
+ *
+ * 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 com.facebook.drift.codec.internal.builtin;
+
+import com.facebook.drift.codec.ThriftCodec;
+import com.facebook.drift.codec.metadata.ThriftType;
+import com.facebook.drift.protocol.TProtocolReader;
+import com.facebook.drift.protocol.TProtocolWriter;
+
+import javax.annotation.concurrent.Immutable;
+
+import java.util.Optional;
+
+import static java.util.Objects.requireNonNull;
+
+@Immutable
+public class OptionalFloatThriftCodec
+        implements ThriftCodec<Optional<Float>>
+{
+    @Override
+    public ThriftType getType()
+    {
+        return new ThriftType(ThriftType.FLOAT, new TypeToken<Optional<Float>>() {}.getType(), Optional.empty());
+    }
+
+    @Override
+    public Optional<Float> read(TProtocolReader protocol)
+            throws Exception
+    {
+        requireNonNull(protocol, "protocol is null");
+        return Optional.of(protocol.readFloat());
+    }
+
+    @Override
+    public void write(Optional<Float> value, TProtocolWriter protocol)
+            throws Exception
+    {
+        requireNonNull(value, "value is null");
+        requireNonNull(protocol, "protocol is null");
+
+        // write can not be called with a missing value, and instead the write should be skipped
+        // after check the result from isNull
+        protocol.writeFloat(value.orElseThrow((() -> new IllegalArgumentException("value is not present"))));
+    }
+
+    @Override
+    public boolean isNull(Optional<Float> value)
+    {
+        return value == null || !value.isPresent();
+    }
+}

drift-codec/src/main/java/com/facebook/drift/codec/internal/coercion/DefaultJavaCoercions.java

@@ -86,6 +86,18 @@ public static long boxedLongToLong(Long value)
         return value;
     }
 
+    @FromThrift
+    public static Float floatToBoxedFloat(float value)
+    {
+        return value;
+    }
+
+    @ToThrift
+    public static float boxedFloatToFloat(Float value)
+    {
+        return value;
+    }
+
     @FromThrift
     public static float doubleToPrimitiveFloat(double value)
     {

drift-codec/src/main/java/com/facebook/drift/codec/internal/compiler/ThriftCodecByteCodeGenerator.java

@@ -1102,7 +1102,10 @@ public static ParameterizedType toParameterizedType(ThriftTypeReference typeRef)
         }
 
         if (ReflectionHelper.isOptional(typeRef.getJavaType())) {
-            return type(Optional.class, toParameterizedType(typeRef.get().getValueTypeReference()));
+            ThriftType valueType = typeRef.get().getValueTypeReference().get();
+            if (!valueType.equals(ThriftType.FLOAT)) {
+                return type(Optional.class, toParameterizedType(typeRef.get().getValueTypeReference()));
+            }
         }
 
         switch (typeRef.getProtocolType()) {

drift-codec/src/main/java/com/facebook/drift/codec/metadata/ThriftCatalog.java

@@ -21,6 +21,7 @@
 import com.facebook.drift.annotations.ThriftUnion;
 import com.facebook.drift.codec.ThriftProtocolType;
 import com.facebook.drift.codec.internal.builtin.OptionalDoubleThriftCodec;
+import com.facebook.drift.codec.internal.builtin.OptionalFloatThriftCodec;
 import com.facebook.drift.codec.internal.builtin.OptionalIntThriftCodec;
 import com.facebook.drift.codec.internal.builtin.OptionalLongThriftCodec;
 import com.facebook.drift.codec.internal.coercion.DefaultJavaCoercions;
@@ -116,6 +117,7 @@ public ThriftCatalog(Monitor monitor)
         this.monitor = monitor;
         addDefaultCoercions(DefaultJavaCoercions.class);
         addThriftType(new OptionalDoubleThriftCodec().getType());
+        addThriftType(new OptionalFloatThriftCodec().getType());
         addThriftType(new OptionalIntThriftCodec().getType());
         addThriftType(new OptionalLongThriftCodec().getType());
     }