Commit 69f9629
src: remove unnecessary calculation in base64.h
PR-URL: #33839
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>1 parent a9dbb22 commit 69f9629
1 file changed
Lines changed: 26 additions & 40 deletions
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -11,37 +11,26 @@ | |||
| 11 | 11 | namespace node { | |
| 12 | 12 | //// Base 64 //// | |
| 13 | 13 | static inline constexpr size_t base64_encoded_size(size_t size) { | |
| 14 | - return ((size + 2 - ((size + 2) % 3)) / 3 * 4); | ||
| 14 | + return ((size + 2) / 3 * 4); | ||
| 15 | 15 | } | |
| 16 | 16 | ||
| 17 | 17 | // Doesn't check for padding at the end. Can be 1-2 bytes over. | |
| 18 | - static inline size_t base64_decoded_size_fast(size_t size) { | ||
| 19 | - size_t remainder = size % 4; | ||
| 20 | - | ||
| 21 | - size = (size / 4) * 3; | ||
| 22 | - if (remainder) { | ||
| 23 | - if (size == 0 && remainder == 1) { | ||
| 24 | - // special case: 1-byte input cannot be decoded | ||
| 25 | - size = 0; | ||
| 26 | - } else { | ||
| 27 | - // non-padded input, add 1 or 2 extra bytes | ||
| 28 | - size += 1 + (remainder == 3); | ||
| 29 | - } | ||
| 30 | - } | ||
| 31 | - | ||
| 32 | - return size; | ||
| 18 | + static inline constexpr size_t base64_decoded_size_fast(size_t size) { | ||
| 19 | + // 1-byte input cannot be decoded | ||
| 20 | + return size > 1 ? (size / 4) * 3 + (size % 4 + 1) / 2 : 0; | ||
| 33 | 21 | } | |
| 34 | 22 | ||
| 35 | 23 | template <typename TypeName> | |
| 36 | 24 | size_t base64_decoded_size(const TypeName* src, size_t size) { | |
| 37 | - if (size == 0) | ||
| 25 | + // 1-byte input cannot be decoded | ||
| 26 | + if (size < 2) | ||
| 38 | 27 | return 0; | |
| 39 | 28 | ||
| 40 | - if (src[size - 1] == '=') | ||
| 29 | + if (src[size - 1] == '=') { | ||
| 41 | 30 | size--; | |
| 42 | - if (size > 0 && src[size - 1] == '=') | ||
| 43 | - size--; | ||
| 44 | - | ||
| 31 | + if (src[size - 1] == '=') | ||
| 32 | + size--; | ||
| 33 | + } | ||
| 45 | 34 | return base64_decoded_size_fast(size); | |
| 46 | 35 | } | |
| 47 | 36 | ||
@@ -166,25 +155,22 @@ static size_t base64_encode(const char* src, | |||
| 166 | 155 | k += 4; | |
| 167 | 156 | } | |
| 168 | 157 | ||
| 169 | - if (n != slen) { | ||
| 170 | - switch (slen - n) { | ||
| 171 | - case 1: | ||
| 172 | - a = src[i + 0] & 0xff; | ||
| 173 | - dst[k + 0] = table[a >> 2]; | ||
| 174 | - dst[k + 1] = table[(a & 3) << 4]; | ||
| 175 | - dst[k + 2] = '='; | ||
| 176 | - dst[k + 3] = '='; | ||
| 177 | - break; | ||
| 178 | - | ||
| 179 | - case 2: | ||
| 180 | - a = src[i + 0] & 0xff; | ||
| 181 | - b = src[i + 1] & 0xff; | ||
| 182 | - dst[k + 0] = table[a >> 2]; | ||
| 183 | - dst[k + 1] = table[((a & 3) << 4) | (b >> 4)]; | ||
| 184 | - dst[k + 2] = table[(b & 0x0f) << 2]; | ||
| 185 | - dst[k + 3] = '='; | ||
| 186 | - break; | ||
| 187 | - } | ||
| 158 | + switch (slen - n) { | ||
| 159 | + case 1: | ||
| 160 | + a = src[i + 0] & 0xff; | ||
| 161 | + dst[k + 0] = table[a >> 2]; | ||
| 162 | + dst[k + 1] = table[(a & 3) << 4]; | ||
| 163 | + dst[k + 2] = '='; | ||
| 164 | + dst[k + 3] = '='; | ||
| 165 | + break; | ||
| 166 | + case 2: | ||
| 167 | + a = src[i + 0] & 0xff; | ||
| 168 | + b = src[i + 1] & 0xff; | ||
| 169 | + dst[k + 0] = table[a >> 2]; | ||
| 170 | + dst[k + 1] = table[((a & 3) << 4) | (b >> 4)]; | ||
| 171 | + dst[k + 2] = table[(b & 0x0f) << 2]; | ||
| 172 | + dst[k + 3] = '='; | ||
| 173 | + break; | ||
| 188 | 174 | } | |
| 189 | 175 | ||
| 190 | 176 | return dlen; | |
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