Ruby  3.4.0dev (2024-11-05 revision ed06f018bdffe9bb7f8bdbf15fa5a727e402bfe9)
pm_memchr.c
1 #include "prism/util/pm_memchr.h"
2 
3 #define PRISM_MEMCHR_TRAILING_BYTE_MINIMUM 0x40
4 
10 void *
11 pm_memchr(const void *memory, int character, size_t number, bool encoding_changed, const pm_encoding_t *encoding) {
12  if (encoding_changed && encoding->multibyte && character >= PRISM_MEMCHR_TRAILING_BYTE_MINIMUM) {
13  const uint8_t *source = (const uint8_t *) memory;
14  size_t index = 0;
15 
16  while (index < number) {
17  if (source[index] == character) {
18  return (void *) (source + index);
19  }
20 
21  size_t width = encoding->char_width(source + index, (ptrdiff_t) (number - index));
22  if (width == 0) {
23  return NULL;
24  }
25 
26  index += width;
27  }
28 
29  return NULL;
30  } else {
31  return memchr(memory, character, number);
32  }
33 }
34 
35 #undef PRISM_MEMCHR_TRAILING_BYTE_MINIMUM
A custom memchr implementation.
void * pm_memchr(const void *source, int character, size_t number, bool encoding_changed, const pm_encoding_t *encoding)
We need to roll our own memchr to handle cases where the encoding changes and we need to search for a...
Definition: pm_memchr.c:11
This struct defines the functions necessary to implement the encoding interface so we can determine h...
Definition: encoding.h:23
size_t(* char_width)(const uint8_t *b, ptrdiff_t n)
Return the number of bytes that the next character takes if it is valid in the encoding.
Definition: encoding.h:29
bool multibyte
Return true if the encoding is a multibyte encoding.
Definition: encoding.h:61