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-rw-r--r--lib/buffer.c273
1 files changed, 135 insertions, 138 deletions
diff --git a/lib/buffer.c b/lib/buffer.c
index ef448bf..79c18fd 100644
--- a/lib/buffer.c
+++ b/lib/buffer.c
@@ -30,208 +30,205 @@
#include "config.h"
#include "buffer.h"
+#include <limits.h>
#include <stdlib.h>
#include <string.h>
-static const unsigned char json_exceptions[] =
- {
- 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86,
- 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e,
- 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96,
- 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e,
- 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6,
- 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae,
- 0xaf, 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
- 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe,
- 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6,
- 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce,
- 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6,
- 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde,
- 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6,
- 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee,
- 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6,
- 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe,
- 0xff, '\0'
- };
-
-static __thread ul_buffer_t escape_buffer;
-
-static void ul_buffer_finish (void) __attribute__((destructor));
-
-static void
-ul_buffer_finish (void)
+static int
+_ul_buffer_realloc_to_reserve (ul_buffer_t *buffer, size_t size)
{
- free (escape_buffer.msg);
+ size_t new_alloc, ptr_offset;
+ void *new_msg;
+
+ new_alloc = (buffer->alloc_end - buffer->msg + size) * 2;
+ ptr_offset = buffer->ptr - buffer->msg;
+ new_msg = realloc (buffer->msg, new_alloc);
+ if (new_msg == NULL)
+ return -1;
+ buffer->msg = new_msg;
+ buffer->ptr = new_msg + ptr_offset;
+ buffer->alloc_end = new_msg + new_alloc;
+ return 0;
}
-static inline char *
-_ul_str_escape (const char *str, char *dest, size_t *length)
+static inline int
+_ul_buffer_reserve_size (ul_buffer_t *buffer, size_t size)
{
+ if ((size_t)(buffer->alloc_end - buffer->ptr) < size)
+ return _ul_buffer_realloc_to_reserve (buffer, size);
+ return 0;
+}
+
+static inline int
+_ul_str_escape (ul_buffer_t *dest, const char *str)
+{
+ /* Assumes ASCII! Keep in sync with the switch! */
+ static const unsigned char json_exceptions[UCHAR_MAX + 1] =
+ {
+ [0x01] = 1, [0x02] = 1, [0x03] = 1, [0x04] = 1, [0x05] = 1, [0x06] = 1,
+ [0x07] = 1, [0x08] = 1, [0x09] = 1, [0x0a] = 1, [0x0b] = 1, [0x0c] = 1,
+ [0x0d] = 1, [0x0e] = 1, [0x0f] = 1, [0x10] = 1, [0x11] = 1, [0x12] = 1,
+ [0x13] = 1, [0x14] = 1, [0x15] = 1, [0x16] = 1, [0x17] = 1, [0x18] = 1,
+ [0x19] = 1, [0x1a] = 1, [0x1b] = 1, [0x1c] = 1, [0x1d] = 1, [0x1e] = 1,
+ [0x1f] = 1, ['\\'] = 1, ['"'] = 1
+ };
+
const unsigned char *p;
- char *q;
- static unsigned char exmap[256];
- static int exmap_inited;
+ char *q, *end;
if (!str)
- return NULL;
+ return -1;
p = (unsigned char *)str;
- q = dest;
+ q = dest->ptr;
+ end = dest->alloc_end;
+
+#define BUFFER_RESERVE(SIZE) \
+ do \
+ { \
+ if (end - q < (SIZE)) \
+ { \
+ dest->ptr = q; \
+ if (_ul_buffer_reserve_size (dest, (SIZE)) != 0) \
+ return -1; \
+ q = dest->ptr; \
+ end = dest->alloc_end; \
+ } \
+ } \
+ while (0)
- if (!exmap_inited)
+ while (*p)
{
- const unsigned char *e = json_exceptions;
-
- memset (exmap, 0, 256);
- while (*e)
+ if (json_exceptions[*p] == 0)
{
- exmap[*e] = 1;
- e++;
+ /* This is a slightly faster variant of equivalent to
+ BUFFER_RESERVE (1) */
+ if (q == end)
+ {
+ dest->ptr = q;
+ if (_ul_buffer_reserve_size (dest, 1) != 0)
+ return -1;
+ q = dest->ptr;
+ end = dest->alloc_end;
+ }
+ *q++ = *p;
}
- exmap_inited = 1;
- }
-
- while (*p)
- {
- if (exmap[*p])
- *q++ = *p;
else
{
+ /* Keep in sync with json_exceptions! */
switch (*p)
{
case '\b':
- *q++ = '\\';
- *q++ = 'b';
- break;
- case '\f':
- *q++ = '\\';
- *q++ = 'f';
+ BUFFER_RESERVE (2);
+ memcpy (q, "\\b", 2);
+ q += 2;
break;
case '\n':
- *q++ = '\\';
- *q++ = 'n';
+ BUFFER_RESERVE (2);
+ memcpy (q, "\\n", 2);
+ q += 2;
break;
case '\r':
- *q++ = '\\';
- *q++ = 'r';
+ BUFFER_RESERVE (2);
+ memcpy (q, "\\r", 2);
+ q += 2;
break;
case '\t':
- *q++ = '\\';
- *q++ = 't';
+ BUFFER_RESERVE (2);
+ memcpy (q, "\\t", 2);
+ q += 2;
break;
case '\\':
- *q++ = '\\';
- *q++ = '\\';
+ BUFFER_RESERVE (2);
+ memcpy (q, "\\\\", 2);
+ q += 2;
break;
case '"':
- *q++ = '\\';
- *q++ = '"';
+ BUFFER_RESERVE (2);
+ memcpy (q, "\\\"", 2);
+ q += 2;
break;
default:
- if ((*p < ' ') || (*p >= 0177))
- {
- const char *json_hex_chars = "0123456789abcdef";
-
- *q++ = '\\';
- *q++ = 'u';
- *q++ = '0';
- *q++ = '0';
- *q++ = json_hex_chars[(*p) >> 4];
- *q++ = json_hex_chars[(*p) & 0xf];
- }
- else
- *q++ = *p;
- break;
+ {
+ static const char json_hex_chars[16] = "0123456789abcdef";
+
+ BUFFER_RESERVE (6);
+ *q++ = '\\';
+ *q++ = 'u';
+ *q++ = '0';
+ *q++ = '0';
+ *q++ = json_hex_chars[(*p) >> 4];
+ *q++ = json_hex_chars[(*p) & 0xf];
+ break;
+ }
}
}
p++;
}
+ dest->ptr = q;
- *q = 0;
- if (length)
- *length = q - dest;
- return dest;
+ return 0;
}
-static inline ul_buffer_t *
-_ul_buffer_ensure_size (ul_buffer_t *buffer, size_t size)
-{
- if (buffer->alloc < size)
- {
- buffer->alloc += size * 2;
- buffer->msg = realloc (buffer->msg, buffer->alloc);
- if (!buffer->msg)
- return NULL;
- }
- return buffer;
-}
-
-ul_buffer_t *
+int
ul_buffer_reset (ul_buffer_t *buffer)
{
- buffer->len = 1;
- _ul_buffer_ensure_size (buffer, 512);
- buffer->msg[0] = '{';
- return buffer;
+ buffer->ptr = buffer->msg;
+ if (_ul_buffer_reserve_size (buffer, 512) != 0)
+ return -1;
+ *buffer->ptr++ = '{';
+ return 0;
}
ul_buffer_t *
ul_buffer_append (ul_buffer_t *buffer, const char *key, const char *value)
{
- char *k, *v;
- size_t lk, lv;
- size_t orig_len = buffer->len;
+ size_t orig_len = buffer->ptr - buffer->msg;
/* Append the key to the buffer */
- escape_buffer.len = 0;
- _ul_buffer_ensure_size (&escape_buffer, strlen (key) * 6 + 1);
- k = _ul_str_escape (key, escape_buffer.msg, &lk);
- if (!k)
- return NULL;
+ if (_ul_buffer_reserve_size (buffer, 1) != 0)
+ goto err;
+ *buffer->ptr++ = '"';
- buffer = _ul_buffer_ensure_size (buffer, buffer->len + lk + 4);
- if (!buffer)
- return NULL;
+ if (_ul_str_escape (buffer, key) != 0)
+ goto err;
- memcpy (buffer->msg + buffer->len, "\"", 1);
- memcpy (buffer->msg + buffer->len + 1, k, lk);
- memcpy (buffer->msg + buffer->len + 1 + lk, "\":\"", 3);
+ if (_ul_buffer_reserve_size (buffer, 3) != 0)
+ goto err;
+ memcpy (buffer->ptr, "\":\"", 3);
+ buffer->ptr += 3;
/* Append the value to the buffer */
- escape_buffer.len = 0;
- _ul_buffer_ensure_size (&escape_buffer, strlen (value) * 6 + 1);
- v = _ul_str_escape (value, escape_buffer.msg, &lv);
- if (!v)
- {
- buffer->len = orig_len;
- return NULL;
- }
-
- buffer = _ul_buffer_ensure_size (buffer, buffer->len + lk + lv + 6);
- if (!buffer)
- {
- buffer->len = orig_len;
- return NULL;
- }
+ if (_ul_str_escape (buffer, value) != 0)
+ goto err;
- memcpy (buffer->msg + buffer->len + 1 + lk + 3, v, lv);
- memcpy (buffer->msg + buffer->len + 1 + lk + 3 + lv, "\",", 2);
- buffer->len += lk + lv + 6;
+ if (_ul_buffer_reserve_size (buffer, 2) != 0)
+ goto err;
+ memcpy (buffer->ptr, "\",", 2);
+ buffer->ptr += 2;
return buffer;
+
+ err:
+ buffer->ptr = buffer->msg + orig_len;
+ return NULL;
}
char *
ul_buffer_finalize (ul_buffer_t *buffer)
{
- if (buffer->msg[buffer->len - 1] == ',')
- buffer->msg[buffer->len - 1] = '}';
+ if (buffer->ptr[-1] == ',')
+ {
+ if (_ul_buffer_reserve_size (buffer, 1) != 0)
+ return NULL;
+ buffer->ptr[-1] = '}';
+ }
else
{
- if (!_ul_buffer_ensure_size (buffer, buffer->len + 1))
+ if (_ul_buffer_reserve_size (buffer, 2) != 0)
return NULL;
- buffer->msg[buffer->len++] = '}';
+ *buffer->ptr++ = '}';
}
- buffer->msg[buffer->len] = '\0';
+ *buffer->ptr++ = '\0';
return buffer->msg;
}
generated by cgit (git 2.34.1) at 2026-03-07 14:53:05 +0000