lts/src/string_bytes.cc
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.
#include "string_bytes.h"
#include "base64.h"
#include "env-inl.h"
#include "node_buffer.h"
#include "node_errors.h"
#include "util.h"
#include <climits>
#include <cstring> // memcpy
#include <algorithm>
// When creating strings >= this length v8's gc spins up and consumes
// most of the execution time. For these cases it's more performant to
// use external string resources.
#define EXTERN_APEX 0xFBEE9
namespace node {
using v8::HandleScope;
using v8::Isolate;
using v8::Just;
using v8::Local;
using v8::Maybe;
using v8::MaybeLocal;
using v8::Nothing;
using v8::String;
using v8::Value;
namespace {
template <typename ResourceType, typename TypeName>
class ExternString: public ResourceType {
public:
~ExternString() override {
free(const_cast<TypeName*>(data_));
isolate()->AdjustAmountOfExternalAllocatedMemory(-byte_length());
}
const TypeName* data() const override {
return data_;
}
size_t length() const override {
return length_;
}
int64_t byte_length() const {
return length() * sizeof(*data());
}
static MaybeLocal<Value> NewFromCopy(Isolate* isolate,
const TypeName* data,
size_t length,
Local<Value>* error) {
if (length == 0)
return String::Empty(isolate);
if (length < EXTERN_APEX)
return NewSimpleFromCopy(isolate, data, length, error);
TypeName* new_data = node::UncheckedMalloc<TypeName>(length);
if (new_data == nullptr) {
*error = node::ERR_MEMORY_ALLOCATION_FAILED(isolate);
return MaybeLocal<Value>();
}
memcpy(new_data, data, length * sizeof(*new_data));
return ExternString<ResourceType, TypeName>::New(isolate,
new_data,
length,
error);
}
// uses "data" for external resource, and will be free'd on gc
static MaybeLocal<Value> New(Isolate* isolate,
TypeName* data,
size_t length,
Local<Value>* error) {
if (length == 0)
return String::Empty(isolate);
if (length < EXTERN_APEX) {
MaybeLocal<Value> str = NewSimpleFromCopy(isolate, data, length, error);
free(data);
return str;
}
ExternString* h_str = new ExternString<ResourceType, TypeName>(isolate,
data,
length);
MaybeLocal<Value> str = NewExternal(isolate, h_str);
isolate->AdjustAmountOfExternalAllocatedMemory(h_str->byte_length());
if (str.IsEmpty()) {
delete h_str;
*error = node::ERR_STRING_TOO_LONG(isolate);
return MaybeLocal<Value>();
}
return str.ToLocalChecked();
}
inline Isolate* isolate() const { return isolate_; }
private:
ExternString(Isolate* isolate, const TypeName* data, size_t length)
: isolate_(isolate), data_(data), length_(length) { }
static MaybeLocal<Value> NewExternal(Isolate* isolate,
ExternString* h_str);
// This method does not actually create ExternString instances.
static MaybeLocal<Value> NewSimpleFromCopy(Isolate* isolate,
const TypeName* data,
size_t length,
Local<Value>* error);
Isolate* isolate_;
const TypeName* data_;
size_t length_;
};
typedef ExternString<String::ExternalOneByteStringResource,
char> ExternOneByteString;
typedef ExternString<String::ExternalStringResource,
uint16_t> ExternTwoByteString;
template <>
MaybeLocal<Value> ExternOneByteString::NewExternal(
Isolate* isolate, ExternOneByteString* h_str) {
return String::NewExternalOneByte(isolate, h_str).FromMaybe(Local<Value>());
}
template <>
MaybeLocal<Value> ExternTwoByteString::NewExternal(
Isolate* isolate, ExternTwoByteString* h_str) {
return String::NewExternalTwoByte(isolate, h_str).FromMaybe(Local<Value>());
}
template <>
MaybeLocal<Value> ExternOneByteString::NewSimpleFromCopy(Isolate* isolate,
const char* data,
size_t length,
Local<Value>* error) {
MaybeLocal<String> str =
String::NewFromOneByte(isolate,
reinterpret_cast<const uint8_t*>(data),
v8::NewStringType::kNormal,
length);
if (str.IsEmpty()) {
*error = node::ERR_STRING_TOO_LONG(isolate);
return MaybeLocal<Value>();
}
return str.ToLocalChecked();
}
template <>
MaybeLocal<Value> ExternTwoByteString::NewSimpleFromCopy(Isolate* isolate,
const uint16_t* data,
size_t length,
Local<Value>* error) {
MaybeLocal<String> str =
String::NewFromTwoByte(isolate,
data,
v8::NewStringType::kNormal,
length);
if (str.IsEmpty()) {
*error = node::ERR_STRING_TOO_LONG(isolate);
return MaybeLocal<Value>();
}
return str.ToLocalChecked();
}
} // anonymous namespace
// supports regular and URL-safe base64
const int8_t unbase64_table[256] =
{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -1, -1, -2, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};
static const int8_t unhex_table[256] =
{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};
static inline unsigned unhex(uint8_t x) {
return unhex_table[x];
}
template <typename TypeName>
static size_t hex_decode(char* buf,
size_t len,
const TypeName* src,
const size_t srcLen) {
size_t i;
for (i = 0; i < len && i * 2 + 1 < srcLen; ++i) {
unsigned a = unhex(src[i * 2 + 0]);
unsigned b = unhex(src[i * 2 + 1]);
if (!~a || !~b)
return i;
buf[i] = (a << 4) | b;
}
return i;
}
size_t StringBytes::WriteUCS2(Isolate* isolate,
char* buf,
size_t buflen,
Local<String> str,
int flags,
size_t* chars_written) {
uint16_t* const dst = reinterpret_cast<uint16_t*>(buf);
size_t max_chars = buflen / sizeof(*dst);
if (max_chars == 0) {
return 0;
}
size_t nchars;
size_t alignment = reinterpret_cast<uintptr_t>(dst) % sizeof(*dst);
if (alignment == 0) {
nchars = str->Write(isolate, dst, 0, max_chars, flags);
*chars_written = nchars;
return nchars * sizeof(*dst);
}
uint16_t* aligned_dst =
reinterpret_cast<uint16_t*>(buf + sizeof(*dst) - alignment);
CHECK_EQ(reinterpret_cast<uintptr_t>(aligned_dst) % sizeof(*dst), 0);
// Write all but the last char
max_chars = std::min(max_chars, static_cast<size_t>(str->Length()));
if (max_chars == 0) return 0;
nchars = str->Write(isolate, aligned_dst, 0, max_chars - 1, flags);
CHECK_EQ(nchars, max_chars - 1);
// Shift everything to unaligned-left
memmove(dst, aligned_dst, nchars * sizeof(*dst));
// One more char to be written
uint16_t last;
CHECK_EQ(str->Write(isolate, &last, nchars, 1, flags), 1);
memcpy(buf + nchars * sizeof(*dst), &last, sizeof(last));
nchars++;
*chars_written = nchars;
return nchars * sizeof(*dst);
}
size_t StringBytes::Write(Isolate* isolate,
char* buf,
size_t buflen,
Local<Value> val,
enum encoding encoding,
int* chars_written) {
HandleScope scope(isolate);
size_t nbytes;
int nchars;
if (chars_written == nullptr)
chars_written = &nchars;
CHECK(val->IsString() == true);
Local<String> str = val.As<String>();
int flags = String::HINT_MANY_WRITES_EXPECTED |
String::NO_NULL_TERMINATION |
String::REPLACE_INVALID_UTF8;
switch (encoding) {
case ASCII:
case LATIN1:
if (str->IsExternalOneByte()) {
auto ext = str->GetExternalOneByteStringResource();
nbytes = std::min(buflen, ext->length());
memcpy(buf, ext->data(), nbytes);
} else {
uint8_t* const dst = reinterpret_cast<uint8_t*>(buf);
nbytes = str->WriteOneByte(isolate, dst, 0, buflen, flags);
}
*chars_written = nbytes;
break;
case BUFFER:
case UTF8:
nbytes = str->WriteUtf8(isolate, buf, buflen, chars_written, flags);
break;
case UCS2: {
size_t nchars;
nbytes = WriteUCS2(isolate, buf, buflen, str, flags, &nchars);
*chars_written = static_cast<int>(nchars);
// Node's "ucs2" encoding wants LE character data stored in
// the Buffer, so we need to reorder on BE platforms. See
// https://nodejs.org/api/buffer.html regarding Node's "ucs2"
// encoding specification
if (IsBigEndian())
SwapBytes16(buf, nbytes);
break;
}
case BASE64:
if (str->IsExternalOneByte()) {
auto ext = str->GetExternalOneByteStringResource();
nbytes = base64_decode(buf, buflen, ext->data(), ext->length());
} else {
String::Value value(isolate, str);
nbytes = base64_decode(buf, buflen, *value, value.length());
}
*chars_written = nbytes;
break;
case HEX:
if (str->IsExternalOneByte()) {
auto ext = str->GetExternalOneByteStringResource();
nbytes = hex_decode(buf, buflen, ext->data(), ext->length());
} else {
String::Value value(isolate, str);
nbytes = hex_decode(buf, buflen, *value, value.length());
}
*chars_written = nbytes;
break;
default:
CHECK(0 && "unknown encoding");
break;
}
return nbytes;
}
bool StringBytes::IsValidString(Local<String> string,
enum encoding enc) {
if (enc == HEX && string->Length() % 2 != 0)
return false;
// TODO(bnoordhuis) Add BASE64 check?
return true;
}
// Quick and dirty size calculation
// Will always be at least big enough, but may have some extra
// UTF8 can be as much as 3x the size, Base64 can have 1-2 extra bytes
Maybe<size_t> StringBytes::StorageSize(Isolate* isolate,
Local<Value> val,
enum encoding encoding) {
HandleScope scope(isolate);
size_t data_size = 0;
bool is_buffer = Buffer::HasInstance(val);
if (is_buffer && (encoding == BUFFER || encoding == LATIN1)) {
return Just(Buffer::Length(val));
}
Local<String> str;
if (!val->ToString(isolate->GetCurrentContext()).ToLocal(&str))
return Nothing<size_t>();
switch (encoding) {
case ASCII:
case LATIN1:
data_size = str->Length();
break;
case BUFFER:
case UTF8:
// A single UCS2 codepoint never takes up more than 3 utf8 bytes.
// It is an exercise for the caller to decide when a string is
// long enough to justify calling Size() instead of StorageSize()
data_size = 3 * str->Length();
break;
case UCS2:
data_size = str->Length() * sizeof(uint16_t);
break;
case BASE64:
data_size = base64_decoded_size_fast(str->Length());
break;
case HEX:
CHECK(str->Length() % 2 == 0 && "invalid hex string length");
data_size = str->Length() / 2;
break;
default:
CHECK(0 && "unknown encoding");
break;
}
return Just(data_size);
}
Maybe<size_t> StringBytes::Size(Isolate* isolate,
Local<Value> val,
enum encoding encoding) {
HandleScope scope(isolate);
if (Buffer::HasInstance(val) && (encoding == BUFFER || encoding == LATIN1))
return Just(Buffer::Length(val));
Local<String> str;
if (!val->ToString(isolate->GetCurrentContext()).ToLocal(&str))
return Nothing<size_t>();
switch (encoding) {
case ASCII:
case LATIN1:
return Just<size_t>(str->Length());
case BUFFER:
case UTF8:
return Just<size_t>(str->Utf8Length(isolate));
case UCS2:
return Just(str->Length() * sizeof(uint16_t));
case BASE64: {
String::Value value(isolate, str);
return Just(base64_decoded_size(*value, value.length()));
}
case HEX:
return Just<size_t>(str->Length() / 2);
}
UNREACHABLE();
}
static bool contains_non_ascii_slow(const char* buf, size_t len) {
for (size_t i = 0; i < len; ++i) {
if (buf[i] & 0x80)
return true;
}
return false;
}
static bool contains_non_ascii(const char* src, size_t len) {
if (len < 16) {
return contains_non_ascii_slow(src, len);
}
const unsigned bytes_per_word = sizeof(uintptr_t);
const unsigned align_mask = bytes_per_word - 1;
const unsigned unaligned = reinterpret_cast<uintptr_t>(src) & align_mask;
if (unaligned > 0) {
const unsigned n = bytes_per_word - unaligned;
if (contains_non_ascii_slow(src, n))
return true;
src += n;
len -= n;
}
#if defined(_WIN64) || defined(_LP64)
const uintptr_t mask = 0x8080808080808080ll;
#else
const uintptr_t mask = 0x80808080l;
#endif
const uintptr_t* srcw = reinterpret_cast<const uintptr_t*>(src);
for (size_t i = 0, n = len / bytes_per_word; i < n; ++i) {
if (srcw[i] & mask)
return true;
}
const unsigned remainder = len & align_mask;
if (remainder > 0) {
const size_t offset = len - remainder;
if (contains_non_ascii_slow(src + offset, remainder))
return true;
}
return false;
}
static void force_ascii_slow(const char* src, char* dst, size_t len) {
for (size_t i = 0; i < len; ++i) {
dst[i] = src[i] & 0x7f;
}
}
static void force_ascii(const char* src, char* dst, size_t len) {
if (len < 16) {
force_ascii_slow(src, dst, len);
return;
}
const unsigned bytes_per_word = sizeof(uintptr_t);
const unsigned align_mask = bytes_per_word - 1;
const unsigned src_unalign = reinterpret_cast<uintptr_t>(src) & align_mask;
const unsigned dst_unalign = reinterpret_cast<uintptr_t>(dst) & align_mask;
if (src_unalign > 0) {
if (src_unalign == dst_unalign) {
const unsigned unalign = bytes_per_word - src_unalign;
force_ascii_slow(src, dst, unalign);
src += unalign;
dst += unalign;
len -= src_unalign;
} else {
force_ascii_slow(src, dst, len);
return;
}
}
#if defined(_WIN64) || defined(_LP64)
const uintptr_t mask = ~0x8080808080808080ll;
#else
const uintptr_t mask = ~0x80808080l;
#endif
const uintptr_t* srcw = reinterpret_cast<const uintptr_t*>(src);
uintptr_t* dstw = reinterpret_cast<uintptr_t*>(dst);
for (size_t i = 0, n = len / bytes_per_word; i < n; ++i) {
dstw[i] = srcw[i] & mask;
}
const unsigned remainder = len & align_mask;
if (remainder > 0) {
const size_t offset = len - remainder;
force_ascii_slow(src + offset, dst + offset, remainder);
}
}
size_t StringBytes::hex_encode(
const char* src,
size_t slen,
char* dst,
size_t dlen) {
// We know how much we'll write, just make sure that there's space.
CHECK(dlen >= slen * 2 &&
"not enough space provided for hex encode");
dlen = slen * 2;
for (uint32_t i = 0, k = 0; k < dlen; i += 1, k += 2) {
static const char hex[] = "0123456789abcdef";
uint8_t val = static_cast<uint8_t>(src[i]);
dst[k + 0] = hex[val >> 4];
dst[k + 1] = hex[val & 15];
}
return dlen;
}
std::string StringBytes::hex_encode(const char* src, size_t slen) {
size_t dlen = slen * 2;
std::string dst(dlen, '\0');
hex_encode(src, slen, &dst[0], dlen);
return dst;
}
#define CHECK_BUFLEN_IN_RANGE(len) \
do { \
if ((len) > Buffer::kMaxLength) { \
*error = node::ERR_BUFFER_TOO_LARGE(isolate); \
return MaybeLocal<Value>(); \
} \
} while (0)
MaybeLocal<Value> StringBytes::Encode(Isolate* isolate,
const char* buf,
size_t buflen,
enum encoding encoding,
Local<Value>* error) {
CHECK_BUFLEN_IN_RANGE(buflen);
if (!buflen && encoding != BUFFER) {
return String::Empty(isolate);
}
MaybeLocal<String> val;
switch (encoding) {
case BUFFER:
{
if (buflen > node::Buffer::kMaxLength) {
*error = node::ERR_BUFFER_TOO_LARGE(isolate);
return MaybeLocal<Value>();
}
auto maybe_buf = Buffer::Copy(isolate, buf, buflen);
Local<v8::Object> buf;
if (!maybe_buf.ToLocal(&buf)) {
*error = node::ERR_MEMORY_ALLOCATION_FAILED(isolate);
}
return buf;
}
case ASCII:
if (contains_non_ascii(buf, buflen)) {
char* out = node::UncheckedMalloc(buflen);
if (out == nullptr) {
*error = node::ERR_MEMORY_ALLOCATION_FAILED(isolate);
return MaybeLocal<Value>();
}
force_ascii(buf, out, buflen);
return ExternOneByteString::New(isolate, out, buflen, error);
} else {
return ExternOneByteString::NewFromCopy(isolate, buf, buflen, error);
}
case UTF8:
{
val = String::NewFromUtf8(isolate,
buf,
v8::NewStringType::kNormal,
buflen);
Local<String> str;
if (!val.ToLocal(&str)) {
*error = node::ERR_STRING_TOO_LONG(isolate);
}
return str;
}
case LATIN1:
return ExternOneByteString::NewFromCopy(isolate, buf, buflen, error);
case BASE64: {
size_t dlen = base64_encoded_size(buflen);
char* dst = node::UncheckedMalloc(dlen);
if (dst == nullptr) {
*error = node::ERR_MEMORY_ALLOCATION_FAILED(isolate);
return MaybeLocal<Value>();
}
size_t written = base64_encode(buf, buflen, dst, dlen);
CHECK_EQ(written, dlen);
return ExternOneByteString::New(isolate, dst, dlen, error);
}
case HEX: {
size_t dlen = buflen * 2;
char* dst = node::UncheckedMalloc(dlen);
if (dst == nullptr) {
*error = node::ERR_MEMORY_ALLOCATION_FAILED(isolate);
return MaybeLocal<Value>();
}
size_t written = hex_encode(buf, buflen, dst, dlen);
CHECK_EQ(written, dlen);
return ExternOneByteString::New(isolate, dst, dlen, error);
}
case UCS2: {
if (IsBigEndian()) {
uint16_t* dst = node::UncheckedMalloc<uint16_t>(buflen / 2);
if (dst == nullptr) {
*error = node::ERR_MEMORY_ALLOCATION_FAILED(isolate);
return MaybeLocal<Value>();
}
for (size_t i = 0, k = 0; k < buflen / 2; i += 2, k += 1) {
// The input is in *little endian*, because that's what Node.js
// expects, so the high byte comes after the low byte.
const uint8_t hi = static_cast<uint8_t>(buf[i + 1]);
const uint8_t lo = static_cast<uint8_t>(buf[i + 0]);
dst[k] = static_cast<uint16_t>(hi) << 8 | lo;
}
return ExternTwoByteString::New(isolate, dst, buflen / 2, error);
}
if (reinterpret_cast<uintptr_t>(buf) % 2 != 0) {
// Unaligned data still means we can't directly pass it to V8.
char* dst = node::UncheckedMalloc(buflen);
if (dst == nullptr) {
*error = node::ERR_MEMORY_ALLOCATION_FAILED(isolate);
return MaybeLocal<Value>();
}
memcpy(dst, buf, buflen);
return ExternTwoByteString::New(
isolate, reinterpret_cast<uint16_t*>(dst), buflen / 2, error);
}
return ExternTwoByteString::NewFromCopy(
isolate, reinterpret_cast<const uint16_t*>(buf), buflen / 2, error);
}
default:
CHECK(0 && "unknown encoding");
break;
}
UNREACHABLE();
}
MaybeLocal<Value> StringBytes::Encode(Isolate* isolate,
const uint16_t* buf,
size_t buflen,
Local<Value>* error) {
CHECK_BUFLEN_IN_RANGE(buflen);
// Node's "ucs2" encoding expects LE character data inside a
// Buffer, so we need to reorder on BE platforms. See
// https://nodejs.org/api/buffer.html regarding Node's "ucs2"
// encoding specification
if (IsBigEndian()) {
uint16_t* dst = node::UncheckedMalloc<uint16_t>(buflen);
if (dst == nullptr) {
*error = node::ERR_MEMORY_ALLOCATION_FAILED(isolate);
return MaybeLocal<Value>();
}
size_t nbytes = buflen * sizeof(uint16_t);
memcpy(dst, buf, nbytes);
SwapBytes16(reinterpret_cast<char*>(dst), nbytes);
return ExternTwoByteString::New(isolate, dst, buflen, error);
} else {
return ExternTwoByteString::NewFromCopy(isolate, buf, buflen, error);
}
}
MaybeLocal<Value> StringBytes::Encode(Isolate* isolate,
const char* buf,
enum encoding encoding,
Local<Value>* error) {
const size_t len = strlen(buf);
return Encode(isolate, buf, len, encoding, error);
}
} // namespace node