Update field_adapter extension as per revised wrapper design

Summary:
Facebook :
Design doc - https://fb.quip.com/mzaaAOaErmEN

Revised design -
- struct will only have a single getter method to get the wrapped object
- wrapper will have thrift only methods that can be used during serialization.
- No separate adapter class

In this diff change the hhvm serialization extension as per the revised field wrapper design .

Old FieldAdapter implementation -
```
class MyStruct {
   MyWrapper<int> $field;
   public function getWrapped_field():MyWrapper<int> { ... }
   public function setWrapped_field(MyWrapper<int>):void { ... }
   public function get_field():int { ... }
   public function set_field(int):void { ... }
}

class MyAdapter { ... }
class MyWrapper { ... }
```
Revised design
```
class MyStruct {
   MyWrapper<int> $field;
   public function get_field():MyWrapper<int> { ... }

}

class MyWrapper {
   public function getValue_DO_NOT_USE_THRIFT_INTERNAL() { ... }
   public function setValue_DO_NOT_USE_THRIFT_INTERNAL($val) { ... }
   .....
 }
```

#forcetdhashing

Reviewed By: andrii-korotkov

Differential Revision: D34590769

fbshipit-source-id: da6a1c956cc9a2bfbd4ccba492540423ce0e58c5

hphp/runtime/ext/thrift/binary.cpp

@@ -26,7 +26,7 @@
 #include "hphp/runtime/ext/reflection/ext_reflection.h"
 #include "hphp/runtime/ext/std/ext_std_classobj.h"
 #include "hphp/runtime/ext/thrift/adapter.h"
-#include "hphp/runtime/ext/thrift/field_adapter.h"
+#include "hphp/runtime/ext/thrift/field_wrapper.h"
 #include "hphp/runtime/ext/thrift/ext_thrift.h"
 #include "hphp/runtime/ext/thrift/spec-holder.h"
 #include "hphp/runtime/ext/thrift/transport.h"
@@ -410,7 +410,7 @@ void binary_deserialize_slow(const Object& zthis,
     if (const auto* fieldspec = getFieldSlow(spec, fieldno)) {
       if (ttypes_are_compatible(ttype, fieldspec->type)) {
         Variant rv = binary_deserialize(ttype, transport, *fieldspec, options);
-        if (fieldspec->field_adapter) {
+        if (fieldspec->isWrapped) {
           setThriftType(rv, zthis, StrNR(fieldspec->name));
         } else {
           zthis->o_set(StrNR(fieldspec->name), rv, zthis->getClassName());
@@ -480,7 +480,7 @@ Object binary_deserialize_struct(const String& clsName,
     }
     auto index = cls->propSlotToIndex(i);
     auto value = binary_deserialize(fieldType, transport, fields[i], options);
-    if (fields[i].field_adapter) {
+    if (fields[i].isWrapped) {
       setThriftType(value, dest, StrNR(fields[i].name));
     } else {
       tvSet(*value.asTypedValue(), objProps->at(index));
@@ -615,7 +615,7 @@ void binary_serialize_slow(const FieldSpec& field,
   INC_TPC(thrift_write_slow);
   StrNR fieldName(field.name);
   Variant fieldVal;
-  if (field.field_adapter) {
+  if (field.isWrapped) {
     fieldVal = getThriftType(obj, fieldName);
   } else {
      fieldVal = obj->o_get(fieldName, true, obj->getClassName());
@@ -643,7 +643,7 @@ void binary_serialize_struct(const Object& obj, PHPOutputTransport& transport) {
       auto index = cls->propSlotToIndex(slot);
       VarNR fieldWrapper(objProps->at(index).tv());
       Variant fieldVal;
-      if (fields[slot].field_adapter) {
+      if (fields[slot].isWrapped) {
         fieldVal = getThriftType(obj, StrNR(fields[slot].name));
       } else {
         fieldVal = fieldWrapper;

hphp/runtime/ext/thrift/compact.cpp

@@ -28,7 +28,7 @@
 #include "hphp/runtime/ext/collections/ext_collections-vector.h"
 #include "hphp/runtime/ext/reflection/ext_reflection.h"
 #include "hphp/runtime/ext/thrift/adapter.h"
-#include "hphp/runtime/ext/thrift/field_adapter.h"
+#include "hphp/runtime/ext/thrift/field_wrapper.h"
 #include "hphp/runtime/ext/thrift/spec-holder.h"
 #include "hphp/runtime/ext/thrift/transport.h"
 #include "hphp/runtime/ext/thrift/util.h"
@@ -246,7 +246,7 @@ struct CompactWriter {
       INC_TPC(thrift_write_slow);
       StrNR fieldName(field.name);
       Variant fieldVal;
-      if (field.field_adapter) {
+      if (field.isWrapped) {
         fieldVal = getThriftType(obj, fieldName);
       } else {
         fieldVal = obj->o_get(fieldName, true, obj->getClassName());
@@ -292,7 +292,7 @@ struct CompactWriter {
             fieldInfo.prop = &prop[slot];
             fieldInfo.fieldNum = fields[slot].fieldNum;
 
-            if (fields[slot].field_adapter) {
+            if (fields[slot].isWrapped) {
               auto value = getThriftType(obj, StrNR(fields[slot].name));
               writeField(value, fields[slot], fieldType, fieldInfo);
             } else {
@@ -666,7 +666,7 @@ struct CompactReader {
           if (typesAreCompatible(fieldType, fieldSpec->type)) {
             readComplete = true;
             Variant fieldValue = readField(*fieldSpec, fieldType);
-            if (fieldSpec->field_adapter) {
+            if (fieldSpec->isWrapped) {
               setThriftType(fieldValue, dest, StrNR(fieldSpec->name));
             } else {
               dest->o_set(
@@ -732,7 +732,7 @@ struct CompactReader {
         }
         auto index = cls->propSlotToIndex(slot);
         auto value = readField(fields[slot], fieldType);
-        if (fields[slot].field_adapter) {
+        if (fields[slot].isWrapped) {
           setThriftType(value, dest, StrNR(fields[slot].name));
         } else {
           tvSet(*value.asTypedValue(), objProp->at(index));

hphp/runtime/ext/thrift/config.cmake

@@ -1,14 +1,14 @@
 HHVM_DEFINE_EXTENSION("thrift"
   SOURCES
     adapter.cpp
-    field_adapter.cpp
+    field_wrapper.cpp
     binary.cpp
     compact.cpp
     ext_thrift.cpp
     spec-holder.cpp
   HEADERS
     adapter.h
-    field_adapter.h
+    field_wrapper.h
     util.h
     ext_thrift.h
     spec-holder.h

hphp/runtime/ext/thrift/field_adapter.cpp → hphp/runtime/ext/thrift/field_wrapper.cpp

@@ -27,32 +27,38 @@ namespace HPHP {
 namespace thrift {
 ///////////////////////////////////////////////////////////////////////////////
 
-const StaticString s_fieldAdapter("field_adapter");
-
-Class* getFieldAdapter(const Array& spec) {
-  const auto adapterName = spec.lookup(s_fieldAdapter, AccessFlags::Key);
-  if (isNullType(adapterName.type())) {
-    return nullptr;
-  }
-  const auto adapterNameString = tvCastToString(adapterName);
-  const auto adapter = Class::load(adapterNameString.get());
-  if (!adapter) {
+void setThriftType(Variant value, const Object& obj, const String& fieldName) {
+  auto getter_name = "get_" + fieldName;
+  auto field_val =
+      obj->o_invoke_few_args(getter_name, RuntimeCoeffects::pure(), 0);
+  if (field_val.isObject()) {
+    auto wrapped_obj = field_val.toObject();
+    wrapped_obj->o_invoke_few_args(
+        "setValue_DO_NOT_USE_THRIFT_INTERNAL",
+        RuntimeCoeffects::write_this_props(),
+        1,
+        value);
+  } else {
     thrift_error(
-        folly::sformat("adapter class {} doesn't exist", adapterNameString),
+        folly::sformat("Method {} returned a non-object.", getter_name),
         ERR_INVALID_DATA);
   }
-  return adapter;
-}
-
-void
-setThriftType(Variant value, const Object& obj, const String& fieldName) {
-  auto setter_name = "set_" + fieldName;
-  obj->o_invoke_few_args(setter_name, RuntimeCoeffects::defaults(), 1,value);
 }
 
 Variant getThriftType(const Object& obj, const String& fieldName) {
   auto getter_name = "get_" + fieldName;
-  return obj->o_invoke_few_args(getter_name, RuntimeCoeffects::defaults(), 0);
+  auto field_val =
+      obj->o_invoke_few_args(getter_name, RuntimeCoeffects::pure(), 0);
+  if (field_val.isObject()) {
+    auto wrapped_obj = field_val.toObject();
+    return wrapped_obj->o_invoke_few_args(
+        "getValue_DO_NOT_USE_THRIFT_INTERNAL",
+        RuntimeCoeffects::write_this_props(),
+        0);
+  }
+  thrift_error(
+      folly::sformat("Method {} returned a non-object.", getter_name),
+      ERR_INVALID_DATA);
 }
 
 ///////////////////////////////////////////////////////////////////////////////

hphp/runtime/ext/thrift/field_adapter.h → hphp/runtime/ext/thrift/field_wrapper.h

@@ -25,8 +25,6 @@ namespace HPHP {
 namespace thrift {
 ///////////////////////////////////////////////////////////////////////////////
 
-Class* getFieldAdapter(const Array& spec);
-
 void
 setThriftType(Variant value, const Object& obj, const String& fieldName);
 

hphp/runtime/ext/thrift/spec-holder.cpp

@@ -23,7 +23,7 @@
 #include "hphp/runtime/ext/collections/ext_collections-set.h"
 #include "hphp/runtime/ext/collections/ext_collections-vector.h"
 #include "hphp/runtime/ext/thrift/adapter.h"
-#include "hphp/runtime/ext/thrift/field_adapter.h"
+#include "hphp/runtime/ext/thrift/field_wrapper.h"
 #include "hphp/runtime/ext/thrift/util.h"
 #include "hphp/util/hash-map.h"
 
@@ -46,7 +46,8 @@ const StaticString
   s_vtype("vtype"),
   s_etype("etype"),
   s_format("format"),
-  s_SPEC("SPEC");
+  s_SPEC("SPEC"),
+  s_isWrapped("is_wrapped");
 
 Array get_tspec(const Class* cls) {
   auto lookup = cls->clsCnsGet(s_SPEC.get());
@@ -246,7 +247,8 @@ FieldSpec FieldSpec::compile(const Array& fieldSpec, bool topLevel) {
     break;
   }
   field.adapter = getAdapter(fieldSpec);
-  field.field_adapter = getFieldAdapter(fieldSpec);
+  field.isWrapped = tvCastToBoolean(
+      fieldSpec.lookup(s_isWrapped, AccessFlags::Key));
   return field;
 }
 

hphp/runtime/ext/thrift/spec-holder.h

@@ -47,7 +47,7 @@ struct FieldSpec {
     return StrNR(className_);
   }
   Class* adapter{};
-  Class* field_adapter{};
+  bool isWrapped{}; // true if the field has field_wrapper annotation
   bool noTypeCheck{}; // If this field doesn't need type checking
                       // (conservatively).
   static FieldSpec compile(const Array& fieldSpec, bool topLevel);