Skip to content

src: remove unnecessary calculation in base64.h #33839

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

src: remove unnecessary calculation in base64.h #33839

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
66 changes: 26 additions & 40 deletions src/base64.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -11,37 +11,26 @@
namespace node {
//// Base 64 ////
static inline constexpr size_t base64_encoded_size(size_t size) {
return ((size + 2 - ((size + 2) % 3)) / 3 * 4);
return ((size + 2) / 3 * 4);
}

// Doesn't check for padding at the end. Can be 1-2 bytes over.
static inline size_t base64_decoded_size_fast(size_t size) {
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;
static inline constexpr size_t base64_decoded_size_fast(size_t size) {
// 1-byte input cannot be decoded
return size > 1 ? (size / 4) * 3 + (size % 4 + 1) / 2 : 0;
}

template <typename TypeName>
size_t base64_decoded_size(const TypeName* src, size_t size) {
if (size == 0)
// 1-byte input cannot be decoded
if (size < 2)
return 0;

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

if (src[size - 1] == '=')
size--;
}
return base64_decoded_size_fast(size);
}

Expand Down Expand Up @@ -166,25 +155,22 @@ static size_t base64_encode(const char* src,
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;
}
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;
Expand Down