src/inlined.h

   1 #ifndef NETDATA_INLINED_H
   2 #define NETDATA_INLINED_H
   3
   4 #include "common.h"
   5
   6 #ifdef HAVE_STMT_EXPR
   7 // GCC extension to define a function as a preprocessor macro
   8
   9 #define simple_hash(name) ({                                         \
  10     register unsigned char *__hash_source = (unsigned char *)(name); \
  11     register uint32_t __hash_value = 0x811c9dc5;                     \
  12     while (*__hash_source) {                                         \
  13         __hash_value *= 16777619;                                    \
  14         __hash_value ^= (uint32_t) *__hash_source++;                 \
  15     }                                                                \
  16     __hash_value;                                                    \
  17 })
  18
  19 #define simple_uhash(name) ({                                        \
  20     register unsigned char *__hash_source = (unsigned char *)(name); \
  21     register uint32_t __hash_value = 0x811c9dc5, __hash_char;        \
  22     while ((__hash_char = *__hash_source++)) {                       \
  23         if (unlikely(__hash_char >= 'A' && __hash_char <= 'Z'))      \
  24             __hash_char += 'a' - 'A';                                \
  25         __hash_value *= 16777619;                                    \
  26         __hash_value ^= __hash_char;                                 \
  27     }                                                                \
  28     __hash_value;                                                    \
  29 })
  30
  31 #else /* ! HAVE_STMT_EXPR */
  32
  33 // for faster execution, allow the compiler to inline
  34 // these functions that are called to hash strings
  35 static inline uint32_t simple_hash(const char *name) {
  36     register unsigned char *s = (unsigned char *) name;
  37     register uint32_t hval = 0x811c9dc5;
  38     while (*s) {
  39         hval *= 16777619;
  40         hval ^= (uint32_t) *s++;
  41     }
  42     return hval;
  43 }
  44
  45 static inline uint32_t simple_uhash(const char *name) {
  46     register unsigned char *s = (unsigned char *) name;
  47     register uint32_t hval = 0x811c9dc5, c;
  48     while ((c = *s++)) {
  49         if (unlikely(c >= 'A' && c <= 'Z')) c += 'a' - 'A';
  50         hval *= 16777619;
  51         hval ^= c;
  52     }
  53     return hval;
  54 }
  55
  56 #endif /* HAVE_STMT_EXPR */
  57
  58 static inline int read_single_number_file(const char *filename, unsigned long long *result) {
  59     char buffer[1024 + 1];
  60
  61     int fd = open(filename, O_RDONLY, 0666);
  62     if(unlikely(fd == -1)) {
  63         *result = 0;
  64         return 1;
  65     }
  66
  67     ssize_t r = read(fd, buffer, 1024);
  68     if(unlikely(r == -1)) {
  69         *result = 0;
  70         close(fd);
  71         return 2;
  72     }
  73
  74     close(fd);
  75     *result = strtoull(buffer, NULL, 0);
  76     return 0;
  77 }
  78
  79 #endif //NETDATA_INLINED_H