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#include <node_buffer.h>
#include <assert.h>
#include <stdlib.h> // malloc, free
#include <v8.h>
#include <string.h> // memcpy
#include <arpa/inet.h> // htons, htonl
#include <node.h>
#define MIN(a,b) ((a) < (b) ? (a) : (b))
namespace node {
using namespace v8;
#define SLICE_ARGS(start_arg, end_arg) \
if (!start_arg->IsInt32() || !end_arg->IsInt32()) { \
return ThrowException(Exception::TypeError( \
String::New("Bad argument."))); \
} \
int32_t start = start_arg->Int32Value(); \
int32_t end = end_arg->Int32Value(); \
if (start < 0 || end < 0) { \
return ThrowException(Exception::TypeError( \
String::New("Bad argument."))); \
} \
if (!(start <= end)) { \
return ThrowException(Exception::Error( \
String::New("Must have start <= end"))); \
} \
if ((size_t)end > parent->length_) { \
return ThrowException(Exception::Error( \
String::New("end cannot be longer than parent.length"))); \
}
static Persistent<String> length_symbol;
static Persistent<String> chars_written_sym;
static Persistent<String> write_sym;
Persistent<FunctionTemplate> Buffer::constructor_template;
static inline size_t base64_decoded_size(const char *src, size_t size) {
const char *const end = src + size;
const int remainder = size % 4;
size = (size / 4) * 3;
if (remainder) {
if (size == 0 && remainder == 1) {
// special case: 1-byte input cannot be decoded
size = 0;
} else {
// non-padded input, add 1 or 2 extra bytes
size += 1 + (remainder == 3);
}
}
// check for trailing padding (1 or 2 bytes)
if (size > 0) {
if (end[-1] == '=') size--;
if (end[-2] == '=') size--;
}
return size;
}
static size_t ByteLength (Handle<String> string, enum encoding enc) {
HandleScope scope;
if (enc == UTF8) {
return string->Utf8Length();
} else if (enc == BASE64) {
String::Utf8Value v(string);
return base64_decoded_size(*v, v.length());
} else {
return string->Length();
}
}
Buffer* Buffer::New(size_t size) {
HandleScope scope;
Local<Value> arg = Integer::NewFromUnsigned(size);
Local<Object> b = constructor_template->GetFunction()->NewInstance(1, &arg);
return ObjectWrap::Unwrap<Buffer>(b);
}
Buffer* Buffer::New(char* data, size_t len) {
HandleScope scope;
Local<Value> arg = Integer::NewFromUnsigned(len);
Local<Object> obj = constructor_template->GetFunction()->NewInstance(1, &arg);
Buffer *buffer = ObjectWrap::Unwrap<Buffer>(obj);
memcpy(buffer->data_, data, len);
return buffer;
}
char* Buffer::Data(Handle<Object> obj) {
if (obj->HasIndexedPropertiesInPixelData()) {
return (char*)obj->GetIndexedPropertiesPixelData();
}
HandleScope scope;
// Return true for "SlowBuffer"
if (constructor_template->HasInstance(obj)) {
return ObjectWrap::Unwrap<Buffer>(obj)->data_;
}
// Not a buffer.
return NULL;
}
size_t Buffer::Length(Handle<Object> obj) {
if (obj->HasIndexedPropertiesInPixelData()) {
return (size_t)obj->GetIndexedPropertiesPixelDataLength();
}
HandleScope scope;
// Return true for "SlowBuffer"
if (constructor_template->HasInstance(obj)) {
return ObjectWrap::Unwrap<Buffer>(obj)->length_;
}
// Not a buffer.
return 0;
}
Handle<Value> Buffer::New(const Arguments &args) {
if (!args.IsConstructCall()) {
return FromConstructorTemplate(constructor_template, args);
}
HandleScope scope;
Buffer *buffer;
if (args[0]->IsInt32()) {
// var buffer = new Buffer(1024);
size_t length = args[0]->Uint32Value();
buffer = new Buffer(length);
} else {
return ThrowException(Exception::TypeError(String::New("Bad argument")));
}
buffer->Wrap(args.This());
args.This()->SetIndexedPropertiesToExternalArrayData(buffer->data_,
kExternalUnsignedByteArray,
buffer->length_);
args.This()->Set(length_symbol, Integer::New(buffer->length_));
return args.This();
}
Buffer::Buffer(size_t length) : ObjectWrap() {
off_ = 0;
length_ = length;
data_ = new char[length_];
V8::AdjustAmountOfExternalAllocatedMemory(sizeof(Buffer) + length_);
}
Buffer::~Buffer() {
//fprintf(stderr, "free buffer (%d refs left)\n", blob_->refs);
delete data_;
V8::AdjustAmountOfExternalAllocatedMemory(-(sizeof(Buffer) + length_));
}
Handle<Value> Buffer::BinarySlice(const Arguments &args) {
HandleScope scope;
Buffer *parent = ObjectWrap::Unwrap<Buffer>(args.This());
SLICE_ARGS(args[0], args[1])
char *data = parent->data_ + start;
//Local<String> string = String::New(data, end - start);
Local<Value> b = Encode(data, end - start, BINARY);
return scope.Close(b);
}
Handle<Value> Buffer::AsciiSlice(const Arguments &args) {
HandleScope scope;
Buffer *parent = ObjectWrap::Unwrap<Buffer>(args.This());
SLICE_ARGS(args[0], args[1])
char* data = parent->data_ + start;
Local<String> string = String::New(data, end - start);
return scope.Close(string);
}
Handle<Value> Buffer::Utf8Slice(const Arguments &args) {
HandleScope scope;
Buffer *parent = ObjectWrap::Unwrap<Buffer>(args.This());
SLICE_ARGS(args[0], args[1])
char *data = parent->data_ + start;
Local<String> string = String::New(data, end - start);
return scope.Close(string);
}
static const char *base64_table = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
static const int unbase64_table[] =
{-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,62,-1,-1,-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,-1
,-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
};
Handle<Value> Buffer::Base64Slice(const Arguments &args) {
HandleScope scope;
Buffer *parent = ObjectWrap::Unwrap<Buffer>(args.This());
SLICE_ARGS(args[0], args[1])
int n = end - start;
int out_len = (n + 2 - ((n + 2) % 3)) / 3 * 4;
char *out = new char[out_len];
uint8_t bitbuf[3];
int i = start; // data() index
int j = 0; // out index
char c;
bool b1_oob, b2_oob;
while (i < end) {
bitbuf[0] = parent->data_[i++];
if (i < end) {
bitbuf[1] = parent->data_[i];
b1_oob = false;
} else {
bitbuf[1] = 0;
b1_oob = true;
}
i++;
if (i < end) {
bitbuf[2] = parent->data_[i];
b2_oob = false;
} else {
bitbuf[2] = 0;
b2_oob = true;
}
i++;
c = bitbuf[0] >> 2;
assert(c < 64);
out[j++] = base64_table[(int)c];
assert(j < out_len);
c = ((bitbuf[0] & 0x03) << 4) | (bitbuf[1] >> 4);
assert(c < 64);
out[j++] = base64_table[(int)c];
assert(j < out_len);
if (b1_oob) {
out[j++] = '=';
} else {
c = ((bitbuf[1] & 0x0F) << 2) | (bitbuf[2] >> 6);
assert(c < 64);
out[j++] = base64_table[(int)c];
}
assert(j < out_len);
if (b2_oob) {
out[j++] = '=';
} else {
c = bitbuf[2] & 0x3F;
assert(c < 64);
out[j++] = base64_table[(int)c];
}
assert(j <= out_len);
}
Local<String> string = String::New(out, out_len);
delete [] out;
return scope.Close(string);
}
// var bytesCopied = buffer.copy(target, targetStart, sourceStart, sourceEnd);
Handle<Value> Buffer::Copy(const Arguments &args) {
HandleScope scope;
Buffer *source = ObjectWrap::Unwrap<Buffer>(args.This());
if (!Buffer::HasInstance(args[0])) {
return ThrowException(Exception::TypeError(String::New(
"First arg should be a Buffer")));
}
Buffer *target = ObjectWrap::Unwrap<Buffer>(args[0]->ToObject());
ssize_t target_start = args[1]->Int32Value();
ssize_t source_start = args[2]->Int32Value();
ssize_t source_end = args[3]->IsInt32() ? args[3]->Int32Value()
: source->length_;
if (source_end < source_start) {
return ThrowException(Exception::Error(String::New(
"sourceEnd < sourceStart")));
}
// Copy 0 bytes; we're done
if (source_end == source_start) {
return scope.Close(Integer::New(0));
}
if (target_start < 0 || target_start >= target->length_) {
return ThrowException(Exception::Error(String::New(
"targetStart out of bounds")));
}
if (source_start < 0 || source_start >= source->length_) {
return ThrowException(Exception::Error(String::New(
"sourceStart out of bounds")));
}
if (source_end < 0 || source_end > source->length_) {
return ThrowException(Exception::Error(String::New(
"sourceEnd out of bounds")));
}
ssize_t to_copy = MIN(MIN(source_end - source_start,
target->length_ - target_start),
source->length_ - source_start);
// need to use slightly slower memmove is the ranges might overlap
memmove((void*)(target->data_ + target_start),
(const void*)(source->data_ + source_start),
to_copy);
return scope.Close(Integer::New(to_copy));
}
// var charsWritten = buffer.utf8Write(string, offset, [maxLength]);
Handle<Value> Buffer::Utf8Write(const Arguments &args) {
HandleScope scope;
Buffer *buffer = ObjectWrap::Unwrap<Buffer>(args.This());
if (!args[0]->IsString()) {
return ThrowException(Exception::TypeError(String::New(
"Argument must be a string")));
}
Local<String> s = args[0]->ToString();
size_t offset = args[1]->Uint32Value();
if (s->Utf8Length() > 0 && offset >= buffer->length_) {
return ThrowException(Exception::TypeError(String::New(
"Offset is out of bounds")));
}
size_t max_length = args[2]->IsUndefined() ? buffer->length_ - offset
: args[2]->Uint32Value();
max_length = MIN(buffer->length_ - offset, max_length);
char* p = buffer->data_ + offset;
int char_written;
int written = s->WriteUtf8(p,
max_length,
&char_written,
String::HINT_MANY_WRITES_EXPECTED);
constructor_template->GetFunction()->Set(chars_written_sym,
Integer::New(char_written));
if (written > 0 && p[written-1] == '\0') written--;
return scope.Close(Integer::New(written));
}
// var charsWritten = buffer.asciiWrite(string, offset);
Handle<Value> Buffer::AsciiWrite(const Arguments &args) {
HandleScope scope;
Buffer *buffer = ObjectWrap::Unwrap<Buffer>(args.This());
if (!args[0]->IsString()) {
return ThrowException(Exception::TypeError(String::New(
"Argument must be a string")));
}
Local<String> s = args[0]->ToString();
size_t offset = args[1]->Int32Value();
if (s->Length() > 0 && offset >= buffer->length_) {
return ThrowException(Exception::TypeError(String::New(
"Offset is out of bounds")));
}
size_t max_length = args[2]->IsUndefined() ? buffer->length_ - offset
: args[2]->Uint32Value();
max_length = MIN(s->Length(), MIN(buffer->length_ - offset, max_length));
char *p = buffer->data_ + offset;
int written = s->WriteAscii(p,
0,
max_length,
String::HINT_MANY_WRITES_EXPECTED);
return scope.Close(Integer::New(written));
}
// var bytesWritten = buffer.base64Write(string, offset, [maxLength]);
Handle<Value> Buffer::Base64Write(const Arguments &args) {
HandleScope scope;
assert(unbase64_table[(int)'/'] == 63);
assert(unbase64_table[(int)'+'] == 62);
assert(unbase64_table[(int)'T'] == 19);
assert(unbase64_table[(int)'Z'] == 25);
assert(unbase64_table[(int)'t'] == 45);
assert(unbase64_table[(int)'z'] == 51);
Buffer *buffer = ObjectWrap::Unwrap<Buffer>(args.This());
if (!args[0]->IsString()) {
return ThrowException(Exception::TypeError(String::New(
"Argument must be a string")));
}
String::AsciiValue s(args[0]->ToString());
size_t offset = args[1]->Int32Value();
// handle zero-length buffers graciously
if (offset == 0 && buffer->length_ == 0) {
return scope.Close(Integer::New(0));
}
if (offset >= buffer->length_) {
return ThrowException(Exception::TypeError(String::New(
"Offset is out of bounds")));
}
const size_t size = base64_decoded_size(*s, s.length());
if (size > buffer->length_ - offset) {
// throw exception, don't silently truncate
return ThrowException(Exception::TypeError(String::New(
"Buffer too small")));
}
char a, b, c, d;
char* dst = buffer->data_ + offset;
const char *src = *s;
const char *const srcEnd = src + s.length();
while (src < srcEnd) {
const int remaining = srcEnd - src;
if (remaining == 0 || *src == '=') break;
a = unbase64_table[(int)*src++];
if (remaining == 1 || *src == '=') break;
b = unbase64_table[(int)*src++];
*dst++ = (a << 2) | ((b & 0x30) >> 4);
if (remaining == 2 || *src == '=') break;
c = unbase64_table[(int)*src++];
*dst++ = ((b & 0x0F) << 4) | ((c & 0x3C) >> 2);
if (remaining == 3 || *src == '=') break;
d = unbase64_table[(int)*src++];
*dst++ = ((c & 0x03) << 6) | (d & 0x3F);
}
return scope.Close(Integer::New(size));
}
Handle<Value> Buffer::BinaryWrite(const Arguments &args) {
HandleScope scope;
Buffer *buffer = ObjectWrap::Unwrap<Buffer>(args.This());
if (!args[0]->IsString()) {
return ThrowException(Exception::TypeError(String::New(
"Argument must be a string")));
}
Local<String> s = args[0]->ToString();
size_t offset = args[1]->Int32Value();
if (s->Length() > 0 && offset >= buffer->length_) {
return ThrowException(Exception::TypeError(String::New(
"Offset is out of bounds")));
}
char *p = (char*)buffer->data_ + offset;
size_t towrite = MIN((unsigned long) s->Length(), buffer->length_ - offset);
int written = DecodeWrite(p, towrite, s, BINARY);
return scope.Close(Integer::New(written));
}
// var nbytes = Buffer.byteLength("string", "utf8")
Handle<Value> Buffer::ByteLength(const Arguments &args) {
HandleScope scope;
if (!args[0]->IsString()) {
return ThrowException(Exception::TypeError(String::New(
"Argument must be a string")));
}
Local<String> s = args[0]->ToString();
enum encoding e = ParseEncoding(args[1], UTF8);
return scope.Close(Integer::New(node::ByteLength(s, e)));
}
Handle<Value> Buffer::MakeFastBuffer(const Arguments &args) {
HandleScope scope;
Buffer *buffer = ObjectWrap::Unwrap<Buffer>(args[0]->ToObject());
Local<Object> fast_buffer = args[1]->ToObject();;
uint32_t offset = args[2]->Uint32Value();
uint32_t length = args[3]->Uint32Value();
fast_buffer->SetIndexedPropertiesToPixelData((uint8_t*)buffer->data_ + offset,
length);
return Undefined();
}
bool Buffer::HasInstance(v8::Handle<v8::Value> val) {
if (!val->IsObject()) return false;
v8::Local<v8::Object> obj = val->ToObject();
if (obj->HasIndexedPropertiesInPixelData()) return true;
// Return true for "SlowBuffer"
if (constructor_template->HasInstance(obj)) return true;
return false;
}
void Buffer::Initialize(Handle<Object> target) {
HandleScope scope;
length_symbol = Persistent<String>::New(String::NewSymbol("length"));
chars_written_sym = Persistent<String>::New(String::NewSymbol("_charsWritten"));
Local<FunctionTemplate> t = FunctionTemplate::New(Buffer::New);
constructor_template = Persistent<FunctionTemplate>::New(t);
constructor_template->InstanceTemplate()->SetInternalFieldCount(1);
constructor_template->SetClassName(String::NewSymbol("SlowBuffer"));
// copy free
NODE_SET_PROTOTYPE_METHOD(constructor_template, "binarySlice", Buffer::BinarySlice);
NODE_SET_PROTOTYPE_METHOD(constructor_template, "asciiSlice", Buffer::AsciiSlice);
NODE_SET_PROTOTYPE_METHOD(constructor_template, "base64Slice", Buffer::Base64Slice);
// TODO NODE_SET_PROTOTYPE_METHOD(t, "utf16Slice", Utf16Slice);
// copy
NODE_SET_PROTOTYPE_METHOD(constructor_template, "utf8Slice", Buffer::Utf8Slice);
NODE_SET_PROTOTYPE_METHOD(constructor_template, "utf8Write", Buffer::Utf8Write);
NODE_SET_PROTOTYPE_METHOD(constructor_template, "asciiWrite", Buffer::AsciiWrite);
NODE_SET_PROTOTYPE_METHOD(constructor_template, "binaryWrite", Buffer::BinaryWrite);
NODE_SET_PROTOTYPE_METHOD(constructor_template, "base64Write", Buffer::Base64Write);
NODE_SET_PROTOTYPE_METHOD(constructor_template, "copy", Buffer::Copy);
NODE_SET_METHOD(constructor_template->GetFunction(),
"byteLength",
Buffer::ByteLength);
NODE_SET_METHOD(constructor_template->GetFunction(),
"makeFastBuffer",
Buffer::MakeFastBuffer);
target->Set(String::NewSymbol("SlowBuffer"), constructor_template->GetFunction());
}
} // namespace node
NODE_MODULE(node_buffer, node::Buffer::Initialize);