c_cpp/lib/cstring/cstring.h

   1 #ifndef cstring_h
   2 #define cstring_h
   3
   4 #include <stdint.h>
   5 #include <stddef.h>
   6
   7 #define CSTRING_PERMANENT 1
   8 #define CSTRING_INTERNING 2
   9 #define CSTRING_ONSTACK 4
  10
  11 #define CSTRING_INTERNING_SIZE 32
  12 #define CSTRING_STACK_SIZE 128
  13
  14 struct cstring_data {
  15         char * cstr;
  16         uint32_t hash_size;
  17         uint16_t type;
  18         uint16_t ref;
  19 };
  20
  21 typedef struct _cstring_buffer {
  22         struct cstring_data * str;
  23 } cstring_buffer[1];
  24
  25 typedef struct cstring_data * cstring;
  26
  27 #define CSTRING_BUFFER(var) \
  28         char var##_cstring [CSTRING_STACK_SIZE] = { '\0' };     \
  29         struct cstring_data var##_cstring_data = { var##_cstring , 0, CSTRING_ONSTACK, 0 };     \
  30         cstring_buffer var;     \
  31         var->str = &var##_cstring_data;
  32
  33 #define CSTRING_LITERAL(var, cstr)      \
  34         static cstring var = NULL;      \
  35         if (var) {} else {      \
  36                 cstring tmp = cstring_persist(""cstr, (sizeof(cstr)/sizeof(char))-1);   \
  37                 if (!__sync_bool_compare_and_swap(&var, NULL, tmp)) {   \
  38                         cstring_free_persist(tmp);      \
  39                 }       \
  40         }
  41
  42 #define CSTRING(s) ((s)->str)
  43
  44 #define CSTRING_CLOSE(var) \
  45         if ((var)->str->type != 0) {} else \
  46                 cstring_release((var)->str);
  47
  48 /* low level api, don't use directly */
  49 cstring cstring_persist(const char * cstr, size_t sz);
  50 void cstring_free_persist(cstring s);
  51
  52 /* public api */
  53 cstring cstring_grab(cstring s);
  54 void cstring_release(cstring s);
  55 cstring cstring_cat(cstring_buffer sb, const char * str);
  56 cstring cstring_printf(cstring_buffer sb, const char * format, ...)
  57 #ifdef __GNUC__
  58         __attribute__((format(printf, 2, 3)))
  59 #endif
  60 ;
  61 int cstring_equal(cstring a, cstring b);
  62 uint32_t cstring_hash(cstring s);
  63
  64 #endif
  65
  66