Implement data manipulation methods for dataview

This change implements additional methods for manipulating data in the
dataview object. This change includes the following things:
  - Get/Set${type} methods to manipulate data
  - Tests for the methods

PR-URL: #218
Reviewed-By: Michael Dawson <[email protected]>

Author: romandev

napi-inl.h

@@ -1211,6 +1211,14 @@ inline DataView::DataView() : Object() {
 }
 
 inline DataView::DataView(napi_env env, napi_value value) : Object(env, value) {
+  napi_status status = napi_get_dataview_info(
+    _env,
+    _value   /* dataView */,
+    &_length /* byteLength */,
+    &_data   /* data */,
+    nullptr  /* arrayBuffer */,
+    nullptr  /* byteOffset */);
+  NAPI_THROW_IF_FAILED(_env, status);
 }
 
 inline Napi::ArrayBuffer DataView::ArrayBuffer() const {
@@ -1240,16 +1248,99 @@ inline size_t DataView::ByteOffset() const {
 }
 
 inline size_t DataView::ByteLength() const {
-  size_t byteLength;
-  napi_status status = napi_get_dataview_info(
-    _env,
-    _value      /* dataView */,
-    &byteLength /* byteLength */,
-    nullptr     /* data */,
-    nullptr     /* arrayBuffer */,
-    nullptr     /* byteOffset */);
-  NAPI_THROW_IF_FAILED(_env, status, 0);
-  return byteLength;
+  return _length;
+}
+
+inline void* DataView::Data() const {
+  return _data;
+}
+
+inline float DataView::GetFloat32(size_t byteOffset) const {
+  return ReadData<float>(byteOffset);
+}
+
+inline double DataView::GetFloat64(size_t byteOffset) const {
+  return ReadData<double>(byteOffset);
+}
+
+inline int8_t DataView::GetInt8(size_t byteOffset) const {
+  return ReadData<int8_t>(byteOffset);
+}
+
+inline int16_t DataView::GetInt16(size_t byteOffset) const {
+  return ReadData<int16_t>(byteOffset);
+}
+
+inline int32_t DataView::GetInt32(size_t byteOffset) const {
+  return ReadData<int32_t>(byteOffset);
+}
+
+inline uint8_t DataView::GetUint8(size_t byteOffset) const {
+  return ReadData<uint8_t>(byteOffset);
+}
+
+inline uint16_t DataView::GetUint16(size_t byteOffset) const {
+  return ReadData<uint16_t>(byteOffset);
+}
+
+inline uint32_t DataView::GetUint32(size_t byteOffset) const {
+  return ReadData<uint32_t>(byteOffset);
+}
+
+inline void DataView::SetFloat32(size_t byteOffset, float value) const {
+  WriteData<float>(byteOffset, value);
+}
+
+inline void DataView::SetFloat64(size_t byteOffset, double value) const {
+  WriteData<double>(byteOffset, value);
+}
+
+inline void DataView::SetInt8(size_t byteOffset, int8_t value) const {
+  WriteData<int8_t>(byteOffset, value);
+}
+
+inline void DataView::SetInt16(size_t byteOffset, int16_t value) const {
+  WriteData<int16_t>(byteOffset, value);
+}
+
+inline void DataView::SetInt32(size_t byteOffset, int32_t value) const {
+  WriteData<int32_t>(byteOffset, value);
+}
+
+inline void DataView::SetUint8(size_t byteOffset, uint8_t value) const {
+  WriteData<uint8_t>(byteOffset, value);
+}
+
+inline void DataView::SetUint16(size_t byteOffset, uint16_t value) const {
+  WriteData<uint16_t>(byteOffset, value);
+}
+
+inline void DataView::SetUint32(size_t byteOffset, uint32_t value) const {
+  WriteData<uint32_t>(byteOffset, value);
+}
+
+template <typename T>
+inline T DataView::ReadData(size_t byteOffset) const {
+  if (byteOffset + sizeof(T) > _length ||
+      byteOffset + sizeof(T) < byteOffset) {  // overflow
+    NAPI_THROW(RangeError::New(_env,
+        "Offset is outside the bounds of the DataView"));
+    return 0;
+  }
+
+  return *reinterpret_cast<T*>(static_cast<uint8_t*>(_data) + byteOffset);
+}
+
+template <typename T>
+inline void DataView::WriteData(size_t byteOffset, T value) const {
+  if (byteOffset + sizeof(T) > _length ||
+      byteOffset + sizeof(T) < byteOffset) {  // overflow
+    NAPI_THROW(RangeError::New(_env,
+        "Offset is outside the bounds of the DataView"));
+    return;
+  }
+
+  *reinterpret_cast<T*>(static_cast<uint8_t*>(_data) + byteOffset) = value;
 }
 #endif
 

napi.h

@@ -800,11 +800,35 @@ namespace Napi {
     size_t ByteOffset() const;    ///< Gets the offset into the buffer where the array starts.
     size_t ByteLength() const;    ///< Gets the length of the array in bytes.
 
-    // TODO: This class isn't a complete implementation yet, and will
-    // incrementally add additional methods to read/write data into buffer.
-    // Currently, this class is wrapped by the NAPI_DATA_VIEW_FEATURE macro flag
-    // and this should be enabled only in the tests until the implementation is
-    // completed.
+    void* Data() const;
+
+    float GetFloat32(size_t byteOffset) const;
+    double GetFloat64(size_t byteOffset) const;
+    int8_t GetInt8(size_t byteOffset) const;
+    int16_t GetInt16(size_t byteOffset) const;
+    int32_t GetInt32(size_t byteOffset) const;
+    uint8_t GetUint8(size_t byteOffset) const;
+    uint16_t GetUint16(size_t byteOffset) const;
+    uint32_t GetUint32(size_t byteOffset) const;
+
+    void SetFloat32(size_t byteOffset, float value) const;
+    void SetFloat64(size_t byteOffset, double value) const;
+    void SetInt8(size_t byteOffset, int8_t value) const;
+    void SetInt16(size_t byteOffset, int16_t value) const;
+    void SetInt32(size_t byteOffset, int32_t value) const;
+    void SetUint8(size_t byteOffset, uint8_t value) const;
+    void SetUint16(size_t byteOffset, uint16_t value) const;
+    void SetUint32(size_t byteOffset, uint32_t value) const;
+
+  private:
+    template <typename T>
+    T ReadData(size_t byteOffset) const;
+
+    template <typename T>
+    void WriteData(size_t byteOffset, T value) const;
+
+    void* _data;
+    size_t _length;
   };
 #endif
 

test/binding.cc

@@ -8,6 +8,7 @@ Object InitBasicTypesNumber(Env env);
 Object InitBasicTypesValue(Env env);
 Object InitBuffer(Env env);
 Object InitDataView(Env env);
+Object InitDataViewReadWrite(Env env);
 Object InitError(Env env);
 Object InitExternal(Env env);
 Object InitFunction(Env env);
@@ -24,6 +25,8 @@ Object Init(Env env, Object exports) {
   exports.Set("basic_types_value", InitBasicTypesValue(env));
   exports.Set("buffer", InitBuffer(env));
   exports.Set("dataview", InitDataView(env));
+  exports.Set("dataview_read_write", InitDataView(env));
+  exports.Set("dataview_read_write", InitDataViewReadWrite(env));
   exports.Set("error", InitError(env));
   exports.Set("external", InitExternal(env));
   exports.Set("function", InitFunction(env));

test/binding.gyp

@@ -8,6 +8,7 @@
         'binding.cc',
         'buffer.cc',
         'dataview/dataview.cc',
+        'dataview/dataview_read_write.cc',
         'error.cc',
         'external.cc',
         'function.cc',

test/dataview/dataview_read_write.cc

@@ -0,0 +1,115 @@
+#include "napi.h"
+
+using namespace Napi;
+
+static Value GetFloat32(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  return Number::New(info.Env(), info[0].As<DataView>().GetFloat32(byteOffset));
+}
+
+static Value GetFloat64(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  return Number::New(info.Env(), info[0].As<DataView>().GetFloat64(byteOffset));
+}
+
+static Value GetInt8(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  return Number::New(info.Env(), info[0].As<DataView>().GetInt8(byteOffset));
+}
+
+static Value GetInt16(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  return Number::New(info.Env(), info[0].As<DataView>().GetInt16(byteOffset));
+}
+
+static Value GetInt32(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  return Number::New(info.Env(), info[0].As<DataView>().GetInt32(byteOffset));
+}
+
+static Value GetUint8(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  return Number::New(info.Env(), info[0].As<DataView>().GetUint8(byteOffset));
+}
+
+static Value GetUint16(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  return Number::New(info.Env(), info[0].As<DataView>().GetUint16(byteOffset));
+}
+
+static Value GetUint32(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  return Number::New(info.Env(), info[0].As<DataView>().GetUint32(byteOffset));
+}
+
+static void SetFloat32(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  auto value = info[2].As<Number>().FloatValue();
+  info[0].As<DataView>().SetFloat32(byteOffset, value);
+}
+
+static void SetFloat64(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  auto value = info[2].As<Number>().DoubleValue();
+  info[0].As<DataView>().SetFloat64(byteOffset, value);
+}
+
+static void SetInt8(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  auto value = info[2].As<Number>().Int32Value();
+  info[0].As<DataView>().SetInt8(byteOffset, value);
+}
+
+static void SetInt16(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  auto value = info[2].As<Number>().Int32Value();
+  info[0].As<DataView>().SetInt16(byteOffset, value);
+}
+
+static void SetInt32(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  auto value = info[2].As<Number>().Int32Value();
+  info[0].As<DataView>().SetInt32(byteOffset, value);
+}
+
+static void SetUint8(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  auto value = info[2].As<Number>().Uint32Value();
+  info[0].As<DataView>().SetUint8(byteOffset, value);
+}
+
+static void SetUint16(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  auto value = info[2].As<Number>().Uint32Value();
+  info[0].As<DataView>().SetUint16(byteOffset, value);
+}
+
+static void SetUint32(const CallbackInfo& info) {
+  size_t byteOffset = info[1].As<Number>().Uint32Value();
+  auto value = info[2].As<Number>().Uint32Value();
+  info[0].As<DataView>().SetUint32(byteOffset, value);
+}
+
+Object InitDataViewReadWrite(Env env) {
+  Object exports = Object::New(env);
+
+  exports["getFloat32"] = Function::New(env, GetFloat32);
+  exports["getFloat64"] = Function::New(env, GetFloat64);
+  exports["getInt8"] = Function::New(env, GetInt8);
+  exports["getInt16"] = Function::New(env, GetInt16);
+  exports["getInt32"] = Function::New(env, GetInt32);
+  exports["getUint8"] = Function::New(env, GetUint8);
+  exports["getUint16"] = Function::New(env, GetUint16);
+  exports["getUint32"] = Function::New(env, GetUint32);
+
+  exports["setFloat32"] = Function::New(env, SetFloat32);
+  exports["setFloat64"] = Function::New(env, SetFloat64);
+  exports["setInt8"] = Function::New(env, SetInt8);
+  exports["setInt16"] = Function::New(env, SetInt16);
+  exports["setInt32"] = Function::New(env, SetInt32);
+  exports["setUint8"] = Function::New(env, SetUint8);
+  exports["setUint16"] = Function::New(env, SetUint16);
+  exports["setUint32"] = Function::New(env, SetUint32);
+
+  return exports;
+}

test/dataview/dataview_read_write.js

@@ -0,0 +1,86 @@
+'use strict';
+
+const buildType = process.config.target_defaults.default_configuration;
+const assert = require('assert');
+
+test(require(`../build/${buildType}/binding.node`));
+test(require(`../build/${buildType}/binding_noexcept.node`));
+
+function test(binding) {
+  function expected(type, value) {
+    return eval(`(new ${type}Array([${value}]))[0]`);
+  }
+
+  function nativeReadDataView(dataview, type, offset, value) {
+    return eval(`binding.dataview_read_write.get${type}(dataview, offset)`);
+  }
+
+  function nativeWriteDataView(dataview, type, offset, value) {
+    eval(`binding.dataview_read_write.set${type}(dataview, offset, value)`);
+  }
+
+  function jsReadDataView(dataview, type, offset, value) {
+    return eval(`dataview.get${type}(offset, true)`);
+  }
+
+  function jsWriteDataView(dataview, type, offset, value) {
+    eval(`dataview.set${type}(offset, value, true)`);
+  }
+
+  function testReadData(dataview, type, offset, value) {
+    jsWriteDataView(dataview, type, offset, 0);
+    assert.strictEqual(jsReadDataView(dataview, type, offset), 0);
+
+    jsWriteDataView(dataview, type, offset, value);
+    assert.strictEqual(
+        nativeReadDataView(dataview, type, offset), expected(type, value));
+  }
+
+  function testWriteData(dataview, type, offset, value) {
+    jsWriteDataView(dataview, type, offset, 0);
+    assert.strictEqual(jsReadDataView(dataview, type, offset), 0);
+
+    nativeWriteDataView(dataview, type, offset, value);
+    assert.strictEqual(
+        jsReadDataView(dataview, type, offset), expected(type, value));
+  }
+
+  function testInvalidOffset(dataview, type, offset, value) {
+    assert.throws(() => {
+      nativeReadDataView(dataview, type, offset);
+    }, RangeError);
+
+    assert.throws(() => {
+      nativeWriteDataView(dataview, type, offset, value);
+    }, RangeError);
+  }
+
+  const dataview = new DataView(new ArrayBuffer(22));
+
+  testReadData(dataview, 'Float32', 0, 10.2);
+  testReadData(dataview, 'Float64', 4, 20.3);
+  testReadData(dataview, 'Int8', 5, 120);
+  testReadData(dataview, 'Int16', 7, 15000);
+  testReadData(dataview, 'Int32', 11, 200000);
+  testReadData(dataview, 'Uint8', 12, 128);
+  testReadData(dataview, 'Uint16', 14, 32768);
+  testReadData(dataview, 'Uint32', 18, 1000000);
+
+  testWriteData(dataview, 'Float32', 0, 10.2);
+  testWriteData(dataview, 'Float64', 4, 20.3);
+  testWriteData(dataview, 'Int8', 5, 120);
+  testWriteData(dataview, 'Int16', 7, 15000);
+  testWriteData(dataview, 'Int32', 11, 200000);
+  testWriteData(dataview, 'Uint8', 12, 128);
+  testWriteData(dataview, 'Uint16', 14, 32768);
+  testWriteData(dataview, 'Uint32', 18, 1000000);
+
+  testInvalidOffset(dataview, 'Float32', 22, 10.2);
+  testInvalidOffset(dataview, 'Float64', 22, 20.3);
+  testInvalidOffset(dataview, 'Int8', 22, 120);
+  testInvalidOffset(dataview, 'Int16', 22, 15000);
+  testInvalidOffset(dataview, 'Int32', 22, 200000);
+  testInvalidOffset(dataview, 'Uint8', 22, 128);
+  testInvalidOffset(dataview, 'Uint16', 22, 32768);
+  testInvalidOffset(dataview, 'Uint32', 22, 1000000);
+}