size_t 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);

}

}

return size;

if (size == 0)

return 0;

if (src[size - 1] == '=')

size--;

if (size > 0 && src[size - 1] == '=')

size--;

return base64_decoded_size_fast(size);

size_t len,

const char *src,

const size_t srcLen) {

char a, b, c, d;

char* dst = buf;

char* dstEnd = buf + len;

const char* srcEnd = src + srcLen;

while (src < srcEnd && dst < dstEnd) {

int remaining = srcEnd - src;

while (unbase64(*src) < 0 && src < srcEnd) src++, remaining--;

if (remaining == 0 || *src == '=') break;

a = unbase64(*src++);

while (unbase64(*src) < 0 && src < srcEnd) src++, remaining--;

if (remaining <= 1 || *src == '=') break;

b = unbase64(*src++);

*dst++ = (a << 2) | ((b & 0x30) >> 4);

if (dst == dstEnd) break;

while (unbase64(*src) < 0 && src < srcEnd) src++, remaining--;

if (remaining <= 2 || *src == '=') break;

c = unbase64(*src++);

*dst++ = ((b & 0x0F) << 4) | ((c & 0x3C) >> 2);

if (dst == dstEnd) break;

while (unbase64(*src) < 0 && src < srcEnd) src++, remaining--;

if (remaining <= 3 || *src == '=') break;

d = unbase64(*src++);

*dst++ = ((c & 0x03) << 6) | (d & 0x3F);

}

return dst - buf;

if (c >= '0' && c <= '9') return c - '0';

if (c >= 'A' && c <= 'F') return 10 + (c - 'A');

if (c >= 'a' && c <= 'f') return 10 + (c - 'a');

return static_cast<unsigned>(-1);

size_t len,

const char *src,

const size_t srcLen) {

size_t i;

for (i = 0; i < len && i * 2 + 1 < srcLen; ++i) {

unsigned a = hex2bin(src[i * 2 + 0]);

unsigned b = hex2bin(src[i * 2 + 1]);

if (!~a || !~b) return i;

buf[i] = a * 16 + b;

}

return i;

size_t buflen,

Handle<Value> val,

enum encoding encoding,

int* chars_written) {

HandleScope scope;

size_t len = 0;

bool is_buffer = Buffer::HasInstance(val);

// sometimes we use 'binary' when we mean 'buffer'

if (is_buffer && (encoding == BINARY || encoding == BUFFER)) {

// fast path, copy buffer data

Local<Object> valObj = Local<Object>::New(val.As<Object>());

const char* data = Buffer::Data(valObj);

size_t size = Buffer::Length(valObj);

size_t len = size < buflen ? size : buflen;

memcpy(buf, data, len);

return len;

}

Local<String> str = val->ToString();

int flags = String::NO_NULL_TERMINATION |

String::HINT_MANY_WRITES_EXPECTED;

switch (encoding) {

case ASCII:

len = str->WriteOneByte(reinterpret_cast<uint8_t*>(buf),

0,

buflen,

flags);

if (chars_written != NULL) {

*chars_written = len;

}

break;

case UTF8:

len = str->WriteUtf8(buf, buflen, chars_written, flags);

break;

case UCS2:

len = str->Write(reinterpret_cast<uint16_t*>(buf), 0, buflen, flags);

if (chars_written != NULL) {

*chars_written = len;

}

len = len * sizeof(uint16_t);

break;

case BASE64: {

String::AsciiValue value(str);

len = base64_decode(buf, buflen, *value, value.length());

if (chars_written != NULL) {

*chars_written = len;

}

break;

}

case BINARY:

case BUFFER: {

// TODO(isaacs): THIS IS AWFUL!!!

uint16_t* twobytebuf = new uint16_t[buflen];

len = str->Write(twobytebuf, 0, buflen, flags);

for (size_t i = 0; i < buflen && i < len; i++) {

unsigned char *b = reinterpret_cast<unsigned char*>(&twobytebuf[i]);

buf[i] = b[0];

}

if (chars_written != NULL) {

*chars_written = len;

}

delete[] twobytebuf;

break;

}

case HEX: {

String::AsciiValue value(str);

len = hex_decode(buf, buflen, *value, value.length());

if (chars_written != NULL) {

*chars_written = len * 2;

}

break;

}

default:

assert(0 && "unknown encoding");

break;

}

return len;

HandleScope scope;

size_t data_size = 0;

bool is_buffer = Buffer::HasInstance(val);

if (is_buffer && (encoding == BUFFER || encoding == BINARY)) {

return Buffer::Length(val);

}

Local<String> str = val->ToString();

switch (encoding) {

case BINARY:

case BUFFER:

case ASCII:

data_size = str->Length();

break;

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:

assert(str->Length() % 2 == 0 && "invalid hex string length");

data_size = str->Length() / 2;

break;

default:

assert(0 && "unknown encoding");

break;

}

return data_size;

HandleScope scope;

size_t data_size = 0;

bool is_buffer = Buffer::HasInstance(val);

if (is_buffer && (encoding == BUFFER || encoding == BINARY)) {

return Buffer::Length(val);

}

Local<String> str = val->ToString();

switch (encoding) {

case BINARY:

case BUFFER:

case ASCII:

data_size = str->Length();

break;

case UTF8:

data_size = str->Utf8Length();

break;

case UCS2:

data_size = str->Length() * sizeof(uint16_t);

break;

case BASE64: {

String::AsciiValue value(str);

data_size = base64_decoded_size(*value, value.length());

break;

}

case HEX:

data_size = str->Length() / 2;

break;

default:

assert(0 && "unknown encoding");

break;

}

return data_size;

for (size_t i = 0; i < len; ++i) {

if (buf[i] & 0x80) return true;

}

return false;

if (len < 16) {

return contains_non_ascii_slow(src, len);

}

const unsigned bytes_per_word = sizeof(void*);

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 BITS_PER_LONG == 64

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;

for (size_t i = 0; i < len; ++i) {

dst[i] = src[i] & 0x7f;

}

if (len < 16) {

force_ascii_slow(src, dst, len);

return;

}

const unsigned bytes_per_word = sizeof(void*);

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 BITS_PER_LONG == 64

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 slen,

char* dst,

size_t dlen) {

// We know how much we'll write, just make sure that there's space.

assert(dlen >= base64_encoded_size(slen) &&

"not enough space provided for base64 encode");

dlen = base64_encoded_size(slen);

unsigned a;

unsigned b;

unsigned c;

unsigned i;

unsigned k;

unsigned n;

static const char table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

"abcdefghijklmnopqrstuvwxyz"

"0123456789+/";

i = 0;

k = 0;

n = slen / 3 * 3;

while (i < n) {

a = src[i + 0] & 0xff;

b = src[i + 1] & 0xff;

c = src[i + 2] & 0xff;

dst[k + 0] = table[a >> 2];

dst[k + 1] = table[((a & 3) << 4) | (b >> 4)];

dst[k + 2] = table[((b & 0x0f) << 2) | (c >> 6)];

dst[k + 3] = table[c & 0x3f];

i += 3;

k += 4;

}

if (n != slen) {

switch (slen - n) {

case 1:

a = src[i + 0] & 0xff;

dst[k + 0] = table[a >> 2];

dst[k + 1] = table[(a & 3) << 4];

dst[k + 2] = '=';

dst[k + 3] = '=';

break;

case 2:

a = src[i + 0] & 0xff;

b = src[i + 1] & 0xff;

dst[k + 0] = table[a >> 2];

dst[k + 1] = table[((a & 3) << 4) | (b >> 4)];

dst[k + 2] = table[(b & 0x0f) << 2];

dst[k + 3] = '=';

break;

}

}

return dlen;

// We know how much we'll write, just make sure that there's space.

assert(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;

size_t buflen,

enum encoding encoding) {

HandleScope scope;

assert(buflen <= Buffer::kMaxLength);

if (!buflen && encoding != BUFFER)

return scope.Close(String::Empty());

Local<String> val;

switch (encoding) {

case BUFFER:

return scope.Close(Buffer::New(buf, buflen)->handle_);

case ASCII:

if (contains_non_ascii(buf, buflen)) {

char* out = new char[buflen];

force_ascii(buf, out, buflen);

val = String::New(out, buflen);

delete[] out;

} else {

val = String::New(buf, buflen);

}

break;

case UTF8:

val = String::New(buf, buflen);

break;

case BINARY: {

// TODO(isaacs) use ExternalTwoByteString?

const unsigned char *cbuf = reinterpret_cast<const unsigned char*>(buf);

uint16_t * twobytebuf = new uint16_t[buflen];

for (size_t i = 0; i < buflen; i++) {

// XXX is the following line platform independent?

twobytebuf[i] = cbuf[i];

}

val = String::New(twobytebuf, buflen);

delete[] twobytebuf;

break;

}

case BASE64: {

size_t dlen = base64_encoded_size(buflen);

char* dst = new char[dlen];

size_t written = base64_encode(buf, buflen, dst, dlen);

assert(written == dlen);

val = String::New(dst, dlen);

delete[] dst;

break;

}

case UCS2: {

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

val = String::New(data, buflen / 2);

break;

}

case HEX: {

size_t dlen = buflen * 2;

char* dst = new char[dlen];

size_t written = hex_encode(buf, buflen, dst, dlen);

assert(written == dlen);

val = String::New(dst, dlen);

delete[] dst;

break;

}

default:

assert(0 && "unknown encoding");

break;

}

return scope.Close(val);