Spectral/include/cmark/houdini_html_u.c

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C
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#include <assert.h>
#include <stdio.h>
#include <string.h>
#include "buffer.h"
#include "houdini.h"
#include "utf8.h"
#include "entities.inc"
/* Binary tree lookup code for entities added by JGM */
static const unsigned char *S_lookup(int i, int low, int hi,
const unsigned char *s, int len) {
int j;
int cmp =
strncmp((const char *)s, (const char *)cmark_entities[i].entity, len);
if (cmp == 0 && cmark_entities[i].entity[len] == 0) {
return (const unsigned char *)cmark_entities[i].bytes;
} else if (cmp <= 0 && i > low) {
j = i - ((i - low) / 2);
if (j == i)
j -= 1;
return S_lookup(j, low, i - 1, s, len);
} else if (cmp > 0 && i < hi) {
j = i + ((hi - i) / 2);
if (j == i)
j += 1;
return S_lookup(j, i + 1, hi, s, len);
} else {
return NULL;
}
}
static const unsigned char *S_lookup_entity(const unsigned char *s, int len) {
return S_lookup(CMARK_NUM_ENTITIES / 2, 0, CMARK_NUM_ENTITIES - 1, s, len);
}
bufsize_t houdini_unescape_ent(cmark_strbuf *ob, const uint8_t *src,
bufsize_t size) {
bufsize_t i = 0;
if (size >= 3 && src[0] == '#') {
int codepoint = 0;
int num_digits = 0;
if (_isdigit(src[1])) {
for (i = 1; i < size && _isdigit(src[i]); ++i) {
codepoint = (codepoint * 10) + (src[i] - '0');
if (codepoint >= 0x110000) {
// Keep counting digits but
// avoid integer overflow.
codepoint = 0x110000;
}
}
num_digits = i - 1;
}
else if (src[1] == 'x' || src[1] == 'X') {
for (i = 2; i < size && _isxdigit(src[i]); ++i) {
codepoint = (codepoint * 16) + ((src[i] | 32) % 39 - 9);
if (codepoint >= 0x110000) {
// Keep counting digits but
// avoid integer overflow.
codepoint = 0x110000;
}
}
num_digits = i - 2;
}
if (num_digits >= 1 && num_digits <= 8 && i < size && src[i] == ';') {
if (codepoint == 0 || (codepoint >= 0xD800 && codepoint < 0xE000) ||
codepoint >= 0x110000) {
codepoint = 0xFFFD;
}
cmark_utf8proc_encode_char(codepoint, ob);
return i + 1;
}
}
else {
if (size > CMARK_ENTITY_MAX_LENGTH)
size = CMARK_ENTITY_MAX_LENGTH;
for (i = CMARK_ENTITY_MIN_LENGTH; i < size; ++i) {
if (src[i] == ' ')
break;
if (src[i] == ';') {
const unsigned char *entity = S_lookup_entity(src, i);
if (entity != NULL) {
cmark_strbuf_puts(ob, (const char *)entity);
return i + 1;
}
break;
}
}
}
return 0;
}
int houdini_unescape_html(cmark_strbuf *ob, const uint8_t *src,
bufsize_t size) {
bufsize_t i = 0, org, ent;
while (i < size) {
org = i;
while (i < size && src[i] != '&')
i++;
if (likely(i > org)) {
if (unlikely(org == 0)) {
if (i >= size)
return 0;
cmark_strbuf_grow(ob, HOUDINI_UNESCAPED_SIZE(size));
}
cmark_strbuf_put(ob, src + org, i - org);
}
/* escaping */
if (i >= size)
break;
i++;
ent = houdini_unescape_ent(ob, src + i, size - i);
i += ent;
/* not really an entity */
if (ent == 0)
cmark_strbuf_putc(ob, '&');
}
return 1;
}
void houdini_unescape_html_f(cmark_strbuf *ob, const uint8_t *src,
bufsize_t size) {
if (!houdini_unescape_html(ob, src, size))
cmark_strbuf_put(ob, src, size);
}