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Name change, some updates using "from end" indexing.

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This commit is contained in:
Christoffer Lerno
2023-06-24 15:20:40 +02:00
parent a187c55dfe
commit fedffc2f35
2 changed files with 77 additions and 78 deletions
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147
lib/std/encoding/base64.c3
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@@ -10,7 +10,7 @@ const URL_ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz012345
const MASK @private = 0b111111;
struct Encoder
struct Base64Encoder
{
int padding;
String alphabet;
@@ -32,7 +32,7 @@ fault Base64Error
* @require padding < 256
* @return! Base64Error.DUPLICATE_IN_ALPHABET, Base64Error.PADDING_IN_ALPHABET
**/
fn void! Encoder.init(Encoder* b, String alphabet, int padding = '=')
fn void! Base64Encoder.init(Base64Encoder* b, String alphabet, int padding = '=')
{
check_alphabet(alphabet, padding)!;
*b = { .padding = padding, .alphabet = alphabet };
@@ -43,7 +43,7 @@ fn void! Encoder.init(Encoder* b, String alphabet, int padding = '=')
* @param n "Size of the input to be encoded."
* @return "The size of the input once encoded."
**/
fn usz Encoder.encode_len(Encoder *b, usz n)
fn usz Base64Encoder.encode_len(Base64Encoder *b, usz n)
{
if (b.padding >= 0) return (n + 2) / 3 * 4;
usz trailing = n % 3;
@@ -57,54 +57,54 @@ fn usz Encoder.encode_len(Encoder *b, usz n)
* @return "The encoded size."
* @return! Base64Error.DESTINATION_TOO_SMALL
**/
fn usz! Encoder.encode(Encoder *b, char[] src, char[] dst)
fn usz! Base64Encoder.encode(Base64Encoder *b, char[] src, char[] dst)
{
if (src.len == 0) return 0;
usz dn = b.encode_len(src.len);
if (dst.len < dn) return Base64Error.DESTINATION_TOO_SMALL?;
usz trailing = src.len % 3;
char[] src3 = src[:src.len - trailing];
char[] src3 = src[:^trailing];
while (src3.len > 0)
{
uint group = (uint)src3[0]<<16 | (uint)src3[1]<<8 | (uint)src3[2];
dst[0] = b.alphabet[group>>18 & MASK];
dst[1] = b.alphabet[group>>12 & MASK];
dst[2] = b.alphabet[group>>6 & MASK];
uint group = (uint)src3[0] << 16 | (uint)src3[1] << 8 | (uint)src3[2];
dst[0] = b.alphabet[group >> 18 & MASK];
dst[1] = b.alphabet[group >> 12 & MASK];
dst[2] = b.alphabet[group >> 6 & MASK];
dst[3] = b.alphabet[group & MASK];
dst = dst[4:];
src3 = src3[3:];
dst = dst[4..];
src3 = src3[3..];
}
// Encode the remaining bytes according to:
// https://www.rfc-editor.org/rfc/rfc4648#section-3.5
switch (trailing)
{
case 1:
uint group = (uint)src[src.len-1]<<16;
dst[0] = b.alphabet[group>>18 & MASK];
dst[1] = b.alphabet[group>>12 & MASK];
if (b.padding >= 0)
{
char pad = (char)b.padding;
dst[2] = pad;
dst[3] = pad;
}
case 2:
uint group = (uint)src[src.len-2]<<16 | (uint)src[src.len-1]<<8;
dst[0] = b.alphabet[group>>18 & MASK];
dst[1] = b.alphabet[group>>12 & MASK];
dst[2] = b.alphabet[group>>6 & MASK];
if (b.padding >= 0)
{
char pad = (char)b.padding;
dst[3] = pad;
}
case 1:
uint group = (uint)src[^1] << 16;
dst[0] = b.alphabet[group >> 18 & MASK];
dst[1] = b.alphabet[group >> 12 & MASK];
if (b.padding >= 0)
{
char pad = (char)b.padding;
dst[2] = pad;
dst[3] = pad;
}
case 2:
uint group = (uint)src[^2] << 16 | (uint)src[^1] << 8;
dst[0] = b.alphabet[group >> 18 & MASK];
dst[1] = b.alphabet[group >> 12 & MASK];
dst[2] = b.alphabet[group >> 6 & MASK];
if (b.padding >= 0)
{
char pad = (char)b.padding;
dst[3] = pad;
}
}
return dn;
}
struct Decoder
struct Base64Decoder
{
int padding;
String alphabet;
@@ -119,7 +119,7 @@ struct Decoder
* @require padding < 256
* @return! Base64Error.DUPLICATE_IN_ALPHABET, Base64Error.PADDING_IN_ALPHABET
**/
fn void! Decoder.init(Decoder* b, String alphabet, int padding = '=')
fn void! Base64Decoder.init(Base64Decoder* b, String alphabet, int padding = '=')
{
check_alphabet(alphabet, padding)!;
*b = { .padding = padding, .alphabet = alphabet };
@@ -153,7 +153,7 @@ fn void! Decoder.init(Decoder* b, String alphabet, int padding = '=')
* @return "The size of the input once decoded."
* @return! Base64Error.INVALID_PADDING
**/
fn usz! Decoder.decode_len(Decoder *b, usz n)
fn usz! Base64Decoder.decode_len(Base64Decoder *b, usz n)
{
usz dn = n / 4 * 3;
usz trailing = n % 4;
@@ -177,7 +177,7 @@ fn usz! Decoder.decode_len(Decoder *b, usz n)
* @return "The decoded size."
* @return! Base64Error.DESTINATION_TOO_SMALL, Base64Error.INVALID_PADDING, Base64Error.INVALID_CHARACTER
**/
fn usz! Decoder.decode(Decoder *b, char[] src, char[] dst)
fn usz! Base64Decoder.decode(Base64Decoder *b, char[] src, char[] dst)
{
if (src.len == 0) return 0;
usz dn = b.decode_len(src.len)!;
@@ -187,14 +187,14 @@ fn usz! Decoder.decode(Decoder *b, char[] src, char[] dst)
char[] src4 = src;
switch
{
case b.padding < 0:
src4 = src[:src.len - trailing];
default:
// If there is padding, keep the last 4 bytes for later.
// NB. src.len >= 4 as decode_len passed
trailing = 4;
char pad = (char)b.padding;
if (src[src.len - 1] == pad) src4 = src[:src.len - 4];
case b.padding < 0:
src4 = src[:^trailing];
default:
// If there is padding, keep the last 4 bytes for later.
// NB. src.len >= 4 as decode_len passed
trailing = 4;
char pad = (char)b.padding;
if (src[^1] == pad) src4 = src[:^4];
}
while (src4.len > 0)
{
@@ -204,23 +204,23 @@ fn usz! Decoder.decode(Decoder *b, char[] src, char[] dst)
char c3 = b.reverse[src4[3]];
switch (b.invalid)
{
case c0:
case c1:
case c2:
case c3:
return Base64Error.INVALID_CHARACTER?;
case c0:
case c1:
case c2:
case c3:
return Base64Error.INVALID_CHARACTER?;
}
uint group = (uint)c0<<18 | (uint)c1<<12 | (uint)c2<<6 | (uint)c3;
uint group = (uint)c0 << 18 | (uint)c1 << 12 | (uint)c2 << 6 | (uint)c3;
dst[0] = (char)(group >> 16);
dst[1] = (char)(group >> 8);
dst[2] = (char)group;
dst = dst[3:];
src4 = src4[4:];
dst = dst[3..];
src4 = src4[4..];
}
if (trailing == 0) return dn;
src = src[src.len - trailing:];
src = src[^trailing:];
char c0 = b.reverse[src[0]];
char c1 = b.reverse[src[1]];
if (c0 == b.invalid || c1 == b.invalid) return Base64Error.INVALID_PADDING?;
@@ -228,15 +228,15 @@ fn usz! Decoder.decode(Decoder *b, char[] src, char[] dst)
{
switch (src.len)
{
case 2:
uint group = (uint)c0<<18 | (uint)c1<<12;
dst[0] = (char)(group >> 16);
case 3:
char c2 = b.reverse[src[2]];
if (c2 == b.invalid) return Base64Error.INVALID_CHARACTER?;
uint group = (uint)c0<<18 | (uint)c1<<12 | (uint)c2<<6;
dst[0] = (char)(group >> 16);
dst[1] = (char)(group >> 8);
case 2:
uint group = (uint)c0 << 18 | (uint)c1 << 12;
dst[0] = (char)(group >> 16);
case 3:
char c2 = b.reverse[src[2]];
if (c2 == b.invalid) return Base64Error.INVALID_CHARACTER?;
uint group = (uint)c0 << 18 | (uint)c1 << 12 | (uint)c2 << 6;
dst[0] = (char)(group >> 16);
dst[1] = (char)(group >> 8);
}
}
else
@@ -247,21 +247,20 @@ fn usz! Decoder.decode(Decoder *b, char[] src, char[] dst)
char pad = (char)b.padding;
switch (pad)
{
case src[2]:
if (src[3] != pad) return Base64Error.INVALID_PADDING?;
uint group = (uint)c0<<18 | (uint)c1<<12;
dst[0] = (char)(group >> 16);
dn -= 2;
case src[3]:
char c2 = b.reverse[src[2]];
if (c2 == b.invalid) return Base64Error.INVALID_CHARACTER?;
uint group = (uint)c0<<18 | (uint)c1<<12 | (uint)c2<<6;
dst[0] = (char)(group >> 16);
dst[1] = (char)(group >> 8);
dn -= 1;
case src[2]:
if (src[3] != pad) return Base64Error.INVALID_PADDING?;
uint group = (uint)c0 << 18 | (uint)c1 << 12;
dst[0] = (char)(group >> 16);
dn -= 2;
case src[3]:
char c2 = b.reverse[src[2]];
if (c2 == b.invalid) return Base64Error.INVALID_CHARACTER?;
uint group = (uint)c0 << 18 | (uint)c1 << 12 | (uint)c2 << 6;
dst[0] = (char)(group >> 16);
dst[1] = (char)(group >> 8);
dn -= 1;
}
}
return dn;
}