src/storage/Util.cxx

   1 #include<Util.h>
   2 #include<Config.h>
   3
   4 unsigned int Util::hashBinary(char *strVal, int length)
   5 {
   6     unsigned int hval, g;
   7     hval = 0;
   8     char *str =strVal;
   9     int iter = 0;
  10     while (iter != length)
  11     {
  12         hval <<= 4;
  13         hval += (unsigned int) *str++;
  14         g = hval & ((unsigned int) 0xf << (32 - 4));
  15         if (g != 0)
  16             {
  17                 hval ^= g >> (32 - 8);
  18                 hval ^= g;
  19             }
  20         iter++;
  21     }
  22     return hval;
  23 }
  24
  25 unsigned int Util::hashString(char *strVal)
  26 {
  27     unsigned int hval, g;
  28     hval = 0;
  29     char *str =strVal;
  30     while (*str != '\0')
  31     {
  32         hval <<= 4;
  33         hval += (unsigned int) *str++;
  34         g = hval & ((unsigned int) 0xf << (32 - 4));
  35         if (g != 0)
  36         {
  37             hval ^= g >> (32 - 8);
  38             hval ^= g;
  39         }
  40     }
  41     return hval;
  42 }
  43
  44 DbRetVal GlobalUniqueID::create()
  45 {
  46     int key = Conf::config.getShmIDKey();
  47     int id = os::shm_create(key, MAX_UNIQUE_ID *sizeof(int), 0666);
  48     if (-1 == id) {
  49         if (errno != EEXIST)
  50             printError(ErrOS, "Unable to create shared memory");
  51         return ErrOS;
  52     }
  53     ptr = os::shm_attach(id, NULL, 0);
  54     if ((void*)-1 == ptr) {
  55         printError(ErrOS, "Unable to attach shared memory");
  56         return ErrOS;
  57     }
  58     memset(ptr, 0, MAX_UNIQUE_ID *sizeof(int));
  59     return OK;
  60 }
  61
  62 DbRetVal GlobalUniqueID::open()
  63 {
  64     if (ptr != NULL) return OK;
  65     int key = Conf::config.getShmIDKey();
  66     int id = os::shm_open(key, MAX_UNIQUE_ID *sizeof(int), 0666);
  67     if (-1 == id) {
  68         printError(ErrOS, "Unable to create shared memory");
  69     }
  70     ptr = os::shm_attach(id, NULL, 0);
  71     if ((void*)-1 == ptr) {
  72         printError(ErrOS, "Unable to create shared memory");
  73     }
  74     return OK;
  75 }
  76
  77 DbRetVal GlobalUniqueID::destroy()
  78 {
  79     int key = Conf::config.getShmIDKey();
  80     int id = os::shm_open(key, MAX_UNIQUE_ID *sizeof(int), 0666);
  81     if (-1 == id) {
  82 //        printError(ErrOS, "Unable to open shared memory");
  83         return ErrOS;
  84     }
  85     os::shm_remove(id);
  86     return OK;
  87 }
  88
  89 int GlobalUniqueID::getID(UniqueIDType type)
  90 {
  91     InUse *id = (int*)(((char*)ptr) + sizeof(int) * type);
  92     InUse oldVal = *id;
  93     InUse newVal = oldVal + 1;
  94     int ret = Mutex::CASGen(id, oldVal, newVal);
  95     if (ret) return -1;
  96     return *id;
  97 }
  98