#include "node.h"

#include "node_buffer.h"

#include "env.h"

#include "env-inl.h"

#include "smalloc.h"

#include "string_bytes.h"

#include "util.h"

#include "util-inl.h"

#include "v8-profiler.h"

#include "v8.h"

#include <string.h>

#include <limits.h>

#define BUFFER_ID 0xB0E4

#define MIN(a, b) ((a) < (b) ? (a) : (b))

#define CHECK_NOT_OOB(r) \

do { \

if (!(r)) return env->ThrowRangeError("out of range index"); \

} while (0)

#define THROW_AND_RETURN_UNLESS_BUFFER(env, obj) \

do { \

if (!HasInstance(obj)) \

return env->ThrowTypeError("argument should be a Buffer"); \

} while (0)

#define ARGS_THIS_DEC(name) \

size_t name##_length; \

char* name##_data;

#define SPREAD_ARG(val, name) \

CHECK((val)->IsUint8Array()); \

Local<Uint8Array> name = (val).As<Uint8Array>(); \

ArrayBuffer::Contents name##_c = name->Buffer()->GetContents(); \

size_t name##_offset = name->ByteOffset(); \

name##_length = name->ByteLength(); \

name##_data = static_cast<char*>(name##_c.Data()) + name##_offset; \

if (name##_length > 0) \

CHECK_NE(name##_data, nullptr);

#define ARGS_THIS(argT, name) \

Local<Object> name = argT; \

name##_length = name->GetIndexedPropertiesExternalArrayDataLength(); \

name##_data = static_cast<char*>( \

name->GetIndexedPropertiesExternalArrayData()); \

if (name##_length > 0) \

CHECK_NE(name##_data, nullptr);

#define SLICE_START_END(start_arg, end_arg, end_max) \

size_t start; \

size_t end; \

CHECK_NOT_OOB(ParseArrayIndex(start_arg, 0, &start)); \

CHECK_NOT_OOB(ParseArrayIndex(end_arg, end_max, &end)); \

if (end < start) end = start; \

CHECK_NOT_OOB(end <= end_max); \

size_t length = end - start;

namespace node {

namespace Buffer {

using v8::ArrayBuffer;

using v8::ArrayBufferCreationMode;

using v8::Context;

using v8::EscapableHandleScope;

using v8::Function;

using v8::FunctionCallbackInfo;

using v8::FunctionTemplate;

using v8::Handle;

using v8::HandleScope;

using v8::Integer;

using v8::Isolate;

using v8::Local;

using v8::Maybe;

using v8::MaybeLocal;

using v8::Number;

using v8::Object;

using v8::Persistent;

using v8::String;

using v8::Uint32;

using v8::Uint8Array;

using v8::Value;

using v8::WeakCallbackData;

class CallbackInfo {

public:

static inline void Free(char* data, void* hint);

static inline CallbackInfo* New(Isolate* isolate,

Handle<Object> object,

FreeCallback callback,

void* hint = 0);

inline void Dispose(Isolate* isolate);

inline Persistent<Object>* persistent();

private:

static void WeakCallback(const WeakCallbackData<Object, CallbackInfo>&);

inline void WeakCallback(Isolate* isolate, Local<Object> object);

inline CallbackInfo(Isolate* isolate,

Handle<Object> object,

FreeCallback callback,

void* hint);

~CallbackInfo();

Persistent<Object> persistent_;

FreeCallback const callback_;

void* const hint_;

DISALLOW_COPY_AND_ASSIGN(CallbackInfo);

};

void CallbackInfo::Free(char* data, void*) {

::free(data);

}

CallbackInfo* CallbackInfo::New(Isolate* isolate,

Handle<Object> object,

FreeCallback callback,

void* hint) {

return new CallbackInfo(isolate, object, callback, hint);

}

void CallbackInfo::Dispose(Isolate* isolate) {

WeakCallback(isolate, PersistentToLocal(isolate, persistent_));

}

Persistent<Object>* CallbackInfo::persistent() {

return &persistent_;

}

CallbackInfo::CallbackInfo(Isolate* isolate,

Handle<Object> object,

FreeCallback callback,

void* hint)

: persistent_(isolate, object),

callback_(callback),

hint_(hint) {

persistent_.SetWeak(this, WeakCallback);

persistent_.SetWrapperClassId(BUFFER_ID);

persistent_.MarkIndependent();

isolate->AdjustAmountOfExternalAllocatedMemory(sizeof(*this));

}

CallbackInfo::~CallbackInfo() {

persistent_.Reset();

}

void CallbackInfo::WeakCallback(

const WeakCallbackData<Object, CallbackInfo>& data) {

data.GetParameter()->WeakCallback(data.GetIsolate(), data.GetValue());

}

void CallbackInfo::WeakCallback(Isolate* isolate, Local<Object> object) {

ARGS_THIS_DEC(obj);

SPREAD_ARG(object, obj);

CHECK_EQ(obj_offset, 0);

CHECK_EQ(obj_c.ByteLength(), obj_length);

obj->Buffer()->Neuter();

callback_(obj_data, hint_);

int64_t change_in_bytes = -static_cast<int64_t>(sizeof(*this));

isolate->AdjustAmountOfExternalAllocatedMemory(change_in_bytes);

delete this;

}

// Buffer methods

bool HasInstance(Handle<Value> val) {

return val->IsObject() && HasInstance(val.As<Object>());

}

bool HasInstance(Handle<Object> obj) {

if (using_old_buffer) {

if (!obj->HasIndexedPropertiesInExternalArrayData())

return false;

v8::ExternalArrayType type =

obj->GetIndexedPropertiesExternalArrayDataType();

return type == v8::kExternalUint8Array;

}

if (!obj->IsUint8Array())

return false;

Local<Uint8Array> array = obj.As<Uint8Array>();

Environment* env = Environment::GetCurrent(array->GetIsolate());

return array->GetPrototype()->StrictEquals(env->buffer_prototype_object());

}

char* Data(Handle<Value> val) {

CHECK(val->IsObject());

// Use a fully qualified name here to work around a bug in gcc 4.2.

// It mistakes an unadorned call to Data() for the v8::String::Data type.

return node::Buffer::Data(val.As<Object>());

}

char* Data(Handle<Object> obj) {

if (using_old_buffer) {

CHECK(obj->HasIndexedPropertiesInExternalArrayData());

return static_cast<char*>(obj->GetIndexedPropertiesExternalArrayData());

}

CHECK(obj->IsUint8Array());

Local<Uint8Array> ui = obj.As<Uint8Array>();

ArrayBuffer::Contents ab_c = ui->Buffer()->GetContents();

return static_cast<char*>(ab_c.Data()) + ui->ByteOffset();

}

size_t Length(Handle<Value> val) {

CHECK(val->IsObject());

return Length(val.As<Object>());

}

size_t Length(Handle<Object> obj) {

if (using_old_buffer) {

CHECK(obj->HasIndexedPropertiesInExternalArrayData());

return obj->GetIndexedPropertiesExternalArrayDataLength();

}

CHECK(obj->IsUint8Array());

Local<Uint8Array> ui = obj.As<Uint8Array>();

return ui->ByteLength();

}

MaybeLocal<Object> New(Isolate* isolate,

Local<String> string,

enum encoding enc) {

EscapableHandleScope scope(isolate);

size_t length = StringBytes::Size(isolate, string, enc);

char* data = static_cast<char*>(malloc(length));

if (data == nullptr)

return Local<Object>();

size_t actual = StringBytes::Write(isolate, data, length, string, enc);

CHECK(actual <= length);

if (actual < length) {

data = static_cast<char*>(realloc(data, actual));

CHECK_NE(data, nullptr);

}

Local<Object> buf;

if (New(isolate, data, actual).ToLocal(&buf))

return scope.Escape(buf);

// Object failed to be created. Clean up resources.

free(data);

return Local<Object>();

}

MaybeLocal<Object> New(Isolate* isolate, size_t length) {

EscapableHandleScope handle_scope(isolate);

Local<Object> obj;

if (Buffer::New(Environment::GetCurrent(isolate), length).ToLocal(&obj))

return handle_scope.Escape(obj);

return Local<Object>();

}

MaybeLocal<Object> New(Environment* env, size_t length) {

EscapableHandleScope scope(env->isolate());

if (using_old_buffer) {

CHECK_LE(length, kMaxLength);

Local<Value> arg = Uint32::NewFromUnsigned(env->isolate(), length);

Local<Object> obj =

env->buffer_constructor_function()->NewInstance(1, &arg);

smalloc::Alloc(env, obj, length);

return scope.Escape(obj);

}

// V8 currently only allows a maximum Typed Array index of max Smi.

if (!IsValidSmi(length)) {

return Local<Object>();

}

void* data;

if (length > 0) {

data = malloc(length);

if (data == nullptr)

return Local<Object>();

} else {

data = nullptr;

}

Local<ArrayBuffer> ab =

ArrayBuffer::New(env->isolate(),

data,

length,

ArrayBufferCreationMode::kInternalized);

Local<Uint8Array> ui = Uint8Array::New(ab, 0, length);

Maybe<bool> mb =

ui->SetPrototype(env->context(), env->buffer_prototype_object());

if (mb.FromMaybe(false))

return scope.Escape(ui);

// Object failed to be created. Clean up resources.

free(data);

return Local<Object>();

}

MaybeLocal<Object> Copy(Isolate* isolate, const char* data, size_t length) {

Environment* env = Environment::GetCurrent(isolate);

EscapableHandleScope handle_scope(env->isolate());

Local<Object> obj;

if (Buffer::New(env, data, length).ToLocal(&obj))

return handle_scope.Escape(obj);

return Local<Object>();

}

// Make a copy of "data". Why this isn't called "Copy", we'll never know.

MaybeLocal<Object> New(Environment* env, const char* data, size_t length) {

EscapableHandleScope scope(env->isolate());

if (using_old_buffer) {

CHECK_LE(length, kMaxLength);

Local<Value> arg = Uint32::NewFromUnsigned(env->isolate(), length);

Local<Object> obj =

env->buffer_constructor_function()->NewInstance(1, &arg);

char* new_data;

if (length > 0) {

new_data = static_cast<char*>(malloc(length));

if (new_data == nullptr)

FatalError("node::Buffer::New(const char*, size_t)", "Out Of Memory");

memcpy(new_data, data, length);

} else {

new_data = nullptr;

}

smalloc::Alloc(env, obj, new_data, length);

return scope.Escape(obj);

}

// V8 currently only allows a maximum Typed Array index of max Smi.

if (!IsValidSmi(length)) {

return Local<Object>();

}

void* new_data;

if (length > 0) {

CHECK_NE(data, nullptr);

new_data = malloc(length);

if (new_data == nullptr)

return Local<Object>();

memcpy(new_data, data, length);

} else {

new_data = nullptr;

}

Local<ArrayBuffer> ab =

ArrayBuffer::New(env->isolate(),

new_data,

length,

ArrayBufferCreationMode::kInternalized);

Local<Uint8Array> ui = Uint8Array::New(ab, 0, length);

Maybe<bool> mb =

ui->SetPrototype(env->context(), env->buffer_prototype_object());

if (mb.FromMaybe(false))

return scope.Escape(ui);

// Object failed to be created. Clean up resources.

free(new_data);

return Local<Object>();

}

MaybeLocal<Object> New(Isolate* isolate,

char* data,

size_t length,

FreeCallback callback,

void* hint) {

Environment* env = Environment::GetCurrent(isolate);

EscapableHandleScope handle_scope(env->isolate());

Local<Object> obj;

if (Buffer::New(env, data, length, callback, hint).ToLocal(&obj))

return handle_scope.Escape(obj);

return Local<Object>();

}

MaybeLocal<Object> New(Environment* env,

char* data,

size_t length,

FreeCallback callback,

void* hint) {

EscapableHandleScope scope(env->isolate());

if (using_old_buffer) {

CHECK_LE(length, kMaxLength);

Local<Value> arg = Uint32::NewFromUnsigned(env->isolate(), length);

Local<Object> obj =

env->buffer_constructor_function()->NewInstance(1, &arg);

smalloc::Alloc(env, obj, data, length, callback, hint);

return scope.Escape(obj);

}

if (!IsValidSmi(length)) {

return Local<Object>();

}

Local<ArrayBuffer> ab = ArrayBuffer::New(env->isolate(), data, length);

Local<Uint8Array> ui = Uint8Array::New(ab, 0, length);

Maybe<bool> mb =

ui->SetPrototype(env->context(), env->buffer_prototype_object());

if (!mb.FromMaybe(false))

return Local<Object>();

CallbackInfo::New(env->isolate(), ui, callback, hint);

return scope.Escape(ui);

}

MaybeLocal<Object> New(Isolate* isolate, char* data, size_t length) {

Environment* env = Environment::GetCurrent(isolate);

EscapableHandleScope handle_scope(env->isolate());

Local<Object> obj;

if (Buffer::New(env, data, length).ToLocal(&obj))

return handle_scope.Escape(obj);

return Local<Object>();

}

MaybeLocal<Object> Use(Environment* env, char* data, size_t length) {

EscapableHandleScope scope(env->isolate());

if (using_old_buffer) {

CHECK_LE(length, kMaxLength);

Local<Value> arg = Uint32::NewFromUnsigned(env->isolate(), length);

Local<Object> obj =

env->buffer_constructor_function()->NewInstance(1, &arg);

smalloc::Alloc(env, obj, data, length);

return scope.Escape(obj);

}

if (length > 0) {

CHECK_NE(data, nullptr);

CHECK(IsValidSmi(length));

}

Local<ArrayBuffer> ab =

ArrayBuffer::New(env->isolate(),

data,

length,

ArrayBufferCreationMode::kInternalized);

Local<Uint8Array> ui = Uint8Array::New(ab, 0, length);

Maybe<bool> mb =

ui->SetPrototype(env->context(), env->buffer_prototype_object());

if (mb.FromMaybe(false))

return scope.Escape(ui);

return Local<Object>();

}

void Create(const FunctionCallbackInfo<Value>& args) {

Isolate* isolate = args.GetIsolate();

Environment* env = Environment::GetCurrent(args);

CHECK(args[0]->IsNumber());

int64_t length = args[0]->IntegerValue();

if (!IsValidSmi(length)) {

return env->ThrowRangeError("invalid Buffer length");

}

void* data;

if (length > 0) {

data = malloc(length);

if (data == nullptr)

return env->ThrowRangeError("invalid Buffer length");

} else {

data = nullptr;

}

Local<ArrayBuffer> ab =

ArrayBuffer::New(isolate,

data,

length,

ArrayBufferCreationMode::kInternalized);

Local<Uint8Array> ui = Uint8Array::New(ab, 0, length);

Maybe<bool> mb =

ui->SetPrototype(env->context(), env->buffer_prototype_object());

if (!mb.FromMaybe(false))

return env->ThrowError("Unable to set Object prototype");

args.GetReturnValue().Set(ui);

}

void CreateFromString(const FunctionCallbackInfo<Value>& args) {

CHECK(args[0]->IsString());

CHECK(args[1]->IsString());

enum encoding enc = ParseEncoding(args.GetIsolate(),

args[1].As<String>(),

UTF8);

Local<Object> buf;

if (New(args.GetIsolate(), args[0].As<String>(), enc).ToLocal(&buf))

args.GetReturnValue().Set(buf);

}

void CreateFromArrayBuffer(const FunctionCallbackInfo<Value>& args) {

Environment* env = Environment::GetCurrent(args);

if (!args[0]->IsArrayBuffer())

return env->ThrowTypeError("argument is not an ArrayBuffer");

Local<ArrayBuffer> ab = args[0].As<ArrayBuffer>();

Local<Uint8Array> ui = Uint8Array::New(ab, 0, ab->ByteLength());

Maybe<bool> mb =

ui->SetPrototype(env->context(), env->buffer_prototype_object());

if (!mb.FromMaybe(false))

return env->ThrowError("Unable to set Object prototype");

args.GetReturnValue().Set(ui);

}

void Slice(const FunctionCallbackInfo<Value>& args) {

CHECK(args[0]->IsUint8Array());

CHECK(args[1]->IsNumber());

CHECK(args[2]->IsNumber());

Environment* env = Environment::GetCurrent(args);

Local<Uint8Array> ab_ui = args[0].As<Uint8Array>();

Local<ArrayBuffer> ab = ab_ui->Buffer();

ArrayBuffer::Contents ab_c = ab->GetContents();

size_t offset = ab_ui->ByteOffset();

size_t start = args[1]->NumberValue() + offset;

size_t end = args[2]->NumberValue() + offset;

CHECK_GE(end, start);

size_t size = end - start;

CHECK_GE(ab_c.ByteLength(), start + size);

Local<Uint8Array> ui = Uint8Array::New(ab, start, size);

Maybe<bool> mb =

ui->SetPrototype(env->context(), env->buffer_prototype_object());

if (!mb.FromMaybe(false))

env->ThrowError("Unable to set Object prototype");

args.GetReturnValue().Set(ui);

}

template <encoding encoding>

void StringSlice(const FunctionCallbackInfo<Value>& args) {

Environment* env = Environment::GetCurrent(args);

Isolate* isolate = env->isolate();

THROW_AND_RETURN_UNLESS_BUFFER(env, args.This());

ARGS_THIS_DEC(ts_obj);

if (using_old_buffer) {

ARGS_THIS(args.This(), ts_obj);

} else {

SPREAD_ARG(args.This(), ts_obj);

}

if (ts_obj_length == 0)

return args.GetReturnValue().SetEmptyString();

SLICE_START_END(args[0], args[1], ts_obj_length)

args.GetReturnValue().Set(

StringBytes::Encode(isolate, ts_obj_data + start, length, encoding));

}

template <>

void StringSlice<UCS2>(const FunctionCallbackInfo<Value>& args) {

Environment* env = Environment::GetCurrent(args);

THROW_AND_RETURN_UNLESS_BUFFER(env, args.This());

ARGS_THIS_DEC(ts_obj);

if (using_old_buffer) {

ARGS_THIS(args.This(), ts_obj);

} else {

SPREAD_ARG(args.This(), ts_obj);

}

if (ts_obj_length == 0)

return args.GetReturnValue().SetEmptyString();

SLICE_START_END(args[0], args[1], ts_obj_length)

length /= 2;

const char* data = ts_obj_data + start;

const uint16_t* buf;

bool release = false;

// Node's "ucs2" encoding expects LE character data inside a Buffer, so we

// need to reorder on BE platforms. See http://nodejs.org/api/buffer.html

// regarding Node's "ucs2" encoding specification.

const bool aligned = (reinterpret_cast<uintptr_t>(data) % sizeof(*buf) == 0);

if (IsLittleEndian() && aligned) {

buf = reinterpret_cast<const uint16_t*>(data);

} else {

// Make a copy to avoid unaligned accesses in v8::String::NewFromTwoByte().

uint16_t* copy = new uint16_t[length];

for (size_t i = 0, k = 0; i < length; i += 1, k += 2) {

// Assumes that the input is little endian.

const uint8_t lo = static_cast<uint8_t>(data[k + 0]);

const uint8_t hi = static_cast<uint8_t>(data[k + 1]);

copy[i] = lo | hi << 8;

}

buf = copy;

release = true;

}

args.GetReturnValue().Set(StringBytes::Encode(env->isolate(), buf, length));

if (release)

delete[] buf;

}

void BinarySlice(const FunctionCallbackInfo<Value>& args) {

StringSlice<BINARY>(args);

}

void AsciiSlice(const FunctionCallbackInfo<Value>& args) {

StringSlice<ASCII>(args);

}

void Utf8Slice(const FunctionCallbackInfo<Value>& args) {

StringSlice<UTF8>(args);

}

void Ucs2Slice(const FunctionCallbackInfo<Value>& args) {

StringSlice<UCS2>(args);

}

void HexSlice(const FunctionCallbackInfo<Value>& args) {

StringSlice<HEX>(args);

}

void Base64Slice(const FunctionCallbackInfo<Value>& args) {

StringSlice<BASE64>(args);

}

// bytesCopied = buffer.copy(target[, targetStart][, sourceStart][, sourceEnd]);

void Copy(const FunctionCallbackInfo<Value> &args) {

Environment* env = Environment::GetCurrent(args);

THROW_AND_RETURN_UNLESS_BUFFER(env, args.This());

THROW_AND_RETURN_UNLESS_BUFFER(env, args[0]);

Local<Object> target_obj = args[0]->ToObject(env->isolate());

ARGS_THIS_DEC(ts_obj);

ARGS_THIS_DEC(target);

if (using_old_buffer) {

ARGS_THIS(args.This(), ts_obj);

target_length = target_obj->GetIndexedPropertiesExternalArrayDataLength();

target_data = static_cast<char*>(

target_obj->GetIndexedPropertiesExternalArrayData());

} else {

SPREAD_ARG(args.This(), ts_obj);

SPREAD_ARG(target_obj, target);

}

size_t target_start;

size_t source_start;

size_t source_end;

CHECK_NOT_OOB(ParseArrayIndex(args[1], 0, &target_start));

CHECK_NOT_OOB(ParseArrayIndex(args[2], 0, &source_start));

CHECK_NOT_OOB(ParseArrayIndex(args[3], ts_obj_length, &source_end));

// Copy 0 bytes; we're done

if (target_start >= target_length || source_start >= source_end)

return args.GetReturnValue().Set(0);

if (source_start > ts_obj_length)

return env->ThrowRangeError("out of range index");

if (source_end - source_start > target_length - target_start)

source_end = source_start + target_length - target_start;

uint32_t to_copy = MIN(MIN(source_end - source_start,

target_length - target_start),

ts_obj_length - source_start);

memmove(target_data + target_start, ts_obj_data + source_start, to_copy);

args.GetReturnValue().Set(to_copy);

}

void Fill(const FunctionCallbackInfo<Value>& args) {

THROW_AND_RETURN_UNLESS_BUFFER(Environment::GetCurrent(args), args[0]);

ARGS_THIS_DEC(ts_obj);

if (using_old_buffer) {

ARGS_THIS(args[0].As<Object>(), ts_obj);

} else {

SPREAD_ARG(args[0], ts_obj);

}

size_t start = args[2]->Uint32Value();

size_t end = args[3]->Uint32Value();

size_t length = end - start;

CHECK(length + start <= ts_obj_length);

if (args[1]->IsNumber()) {

int value = args[1]->Uint32Value() & 255;

memset(ts_obj_data + start, value, length);

return;

}

node::Utf8Value str(args.GetIsolate(), args[1]);

size_t str_length = str.length();

size_t in_there = str_length;

char* ptr = ts_obj_data + start + str_length;

if (str_length == 0)

return;

memcpy(ts_obj_data + start, *str, MIN(str_length, length));

if (str_length >= length)

return;

while (in_there < length - in_there) {

memcpy(ptr, ts_obj_data + start, in_there);

ptr += in_there;

in_there *= 2;

}

if (in_there < length) {

memcpy(ptr, ts_obj_data + start, length - in_there);

in_there = length;

}

}

template <encoding encoding>

void StringWrite(const FunctionCallbackInfo<Value>& args) {

Environment* env = Environment::GetCurrent(args);

ARGS_THIS_DEC(ts_obj);

THROW_AND_RETURN_UNLESS_BUFFER(env, args.This());

if (using_old_buffer) {

ARGS_THIS(args.This(), ts_obj);

} else {

SPREAD_ARG(args.This(), ts_obj);

}

if (!args[0]->IsString())

return env->ThrowTypeError("Argument must be a string");

Local<String> str = args[0]->ToString(env->isolate());

if (encoding == HEX && str->Length() % 2 != 0)

return env->ThrowTypeError("Invalid hex string");

size_t offset;

size_t max_length;

CHECK_NOT_OOB(ParseArrayIndex(args[1], 0, &offset));

CHECK_NOT_OOB(ParseArrayIndex(args[2], ts_obj_length - offset, &max_length));

max_length = MIN(ts_obj_length - offset, max_length);

if (max_length == 0)

return args.GetReturnValue().Set(0);

if (offset >= ts_obj_length)

return env->ThrowRangeError("Offset is out of bounds");

uint32_t written = StringBytes::Write(env->isolate(),

ts_obj_data + offset,

max_length,

str,

encoding,

nullptr);

args.GetReturnValue().Set(written);

}

void Base64Write(const FunctionCallbackInfo<Value>& args) {

StringWrite<BASE64>(args);

}

void BinaryWrite(const FunctionCallbackInfo<Value>& args) {

StringWrite<BINARY>(args);

}

void Utf8Write(const FunctionCallbackInfo<Value>& args) {

StringWrite<UTF8>(args);

}

void Ucs2Write(const FunctionCallbackInfo<Value>& args) {

StringWrite<UCS2>(args);

}

void HexWrite(const FunctionCallbackInfo<Value>& args) {

StringWrite<HEX>(args);

}

void AsciiWrite(const FunctionCallbackInfo<Value>& args) {

StringWrite<ASCII>(args);

}

static inline void Swizzle(char* start, unsigned int len) {

char* end = start + len - 1;

while (start < end) {

char tmp = *start;

*start++ = *end;

*end-- = tmp;

}

}

template <typename T, enum Endianness endianness>

void ReadFloatGeneric(const FunctionCallbackInfo<Value>& args) {

THROW_AND_RETURN_UNLESS_BUFFER(Environment::GetCurrent(args), args[0]);

ARGS_THIS_DEC(ts_obj);

if (using_old_buffer) {

ARGS_THIS(args[0].As<Object>(), ts_obj);

} else {

SPREAD_ARG(args[0], ts_obj);

}

uint32_t offset = args[1]->Uint32Value();

CHECK_LE(offset + sizeof(T), ts_obj_length);

union NoAlias {

T val;

char bytes[sizeof(T)];

};

union NoAlias na;

const char* ptr = static_cast<const char*>(ts_obj_data) + offset;

memcpy(na.bytes, ptr, sizeof(na.bytes));

if (endianness != GetEndianness())

Swizzle(na.bytes, sizeof(na.bytes));

args.GetReturnValue().Set(na.val);

}

void ReadFloatLE(const FunctionCallbackInfo<Value>& args) {

ReadFloatGeneric<float, kLittleEndian>(args);

}

void ReadFloatBE(const FunctionCallbackInfo<Value>& args) {

ReadFloatGeneric<float, kBigEndian>(args);

}

void ReadDoubleLE(const FunctionCallbackInfo<Value>& args) {

ReadFloatGeneric<double, kLittleEndian>(args);

}

void ReadDoubleBE(const FunctionCallbackInfo<Value>& args) {

ReadFloatGeneric<double, kBigEndian>(args);

}

template <typename T, enum Endianness endianness>

uint32_t WriteFloatGeneric(const FunctionCallbackInfo<Value>& args) {

ARGS_THIS_DEC(ts_obj);

if (using_old_buffer) {

ARGS_THIS(args[0].As<Object>(), ts_obj);

} else {

SPREAD_ARG(args[0], ts_obj);

}

T val = args[1]->NumberValue();

uint32_t offset = args[2]->Uint32Value();

CHECK_LE(offset + sizeof(T), ts_obj_length);

union NoAlias {

T val;

char bytes[sizeof(T)];

};

union NoAlias na = { val };

char* ptr = static_cast<char*>(ts_obj_data) + offset;

if (endianness != GetEndianness())

Swizzle(na.bytes, sizeof(na.bytes));

memcpy(ptr, na.bytes, sizeof(na.bytes));

return offset + sizeof(na.bytes);

}

void WriteFloatLE(const FunctionCallbackInfo<Value>& args) {

THROW_AND_RETURN_UNLESS_BUFFER(Environment::GetCurrent(args), args[0]);

args.GetReturnValue().Set(WriteFloatGeneric<float, kLittleEndian>(args));

}

void WriteFloatBE(const FunctionCallbackInfo<Value>& args) {

THROW_AND_RETURN_UNLESS_BUFFER(Environment::GetCurrent(args), args[0]);

args.GetReturnValue().Set(WriteFloatGeneric<float, kBigEndian>(args));

}

void WriteDoubleLE(const FunctionCallbackInfo<Value>& args) {

THROW_AND_RETURN_UNLESS_BUFFER(Environment::GetCurrent(args), args[0]);

args.GetReturnValue().Set(WriteFloatGeneric<double, kLittleEndian>(args));

}

void WriteDoubleBE(const FunctionCallbackInfo<Value>& args) {

THROW_AND_RETURN_UNLESS_BUFFER(Environment::GetCurrent(args), args[0]);

args.GetReturnValue().Set(WriteFloatGeneric<double, kBigEndian>(args));

}

void ByteLengthUtf8(const FunctionCallbackInfo<Value> &args) {

CHECK(args[0]->IsString());

// Fast case: avoid StringBytes on UTF8 string. Jump to v8.

args.GetReturnValue().Set(args[0].As<String>()->Utf8Length());

}

void Compare(const FunctionCallbackInfo<Value> &args) {

Environment* env = Environment::GetCurrent(args);

THROW_AND_RETURN_UNLESS_BUFFER(env, args[0]);

THROW_AND_RETURN_UNLESS_BUFFER(env, args[1]);

ARGS_THIS_DEC(obj_a);

ARGS_THIS_DEC(obj_b);

if (using_old_buffer) {

ARGS_THIS(args[0].As<Object>(), obj_a);

ARGS_THIS(args[1].As<Object>(), obj_b);

} else {

SPREAD_ARG(args[0], obj_a);

SPREAD_ARG(args[1], obj_b);

}

size_t cmp_length = MIN(obj_a_length, obj_b_length);

int32_t val = memcmp(obj_a_data, obj_b_data, cmp_length);

// Normalize val to be an integer in the range of [1, -1] since

// implementations of memcmp() can vary by platform.

if (val == 0) {

if (obj_a_length > obj_b_length)

val = 1;

else if (obj_a_length < obj_b_length)

val = -1;

} else {

if (val > 0)

val = 1;

else

val = -1;

}

args.GetReturnValue().Set(val);

}