/* Decompresses sparse counters */
static HLLCounter
hll_decompress_dense_V1(HLLCounter hloglog)
{
char * dest;
int m,i;
HLLCounter htemp;
/* reset b to positive value for calcs and to indicate data is
* decompressed */
hloglog->b = -1 * (hloglog->b);
/* allocate and zero an array large enough to hold all the decompressed
* bins */
m = (int) pow(2,hloglog->b);
dest = malloc(m);
memset(dest,0,m);
/* decompress the data */
pglz_decompress((PGLZ_Header *)hloglog->data,dest);
/* copy the struct internals but not the data into a counter with enough
* space for the uncompressed data */
htemp = palloc(sizeof(HLLData) + (int)ceil((m * hloglog->binbits / 8.0)));
memcpy(htemp,hloglog,sizeof(HLLData));
hloglog = htemp;
/* set the registers to the appropriate value based on the decompressed
* data */
for (i=0; i<m; i++){
HLL_DENSE_SET_REGISTER(hloglog->data,i,dest[i],hloglog->binbits);
}
/* set the varsize to the appropriate length */
SET_VARSIZE(hloglog,sizeof(HLLData) + (int)ceil((m * hloglog->binbits / 8.0)) );
/* free allocated memory */
if (dest){
free(dest);
}
return hloglog;
}
static int hll_merge(lua_State *lua)
{
hyperloglog *dest = check_hll(lua, 2);
hyperloglog *src = luaL_checkudata(lua, 2, mozsvc_hyperloglog);
if (dest == src) {
return 1;
}
int i;
uint8_t sval, dval;
for (i = 0; i < HLL_REGISTERS; i++) {
HLL_DENSE_GET_REGISTER(dval, dest->registers, i);
HLL_DENSE_GET_REGISTER(sval, src->registers, i);
if (sval > dval) {
HLL_DENSE_SET_REGISTER(dest->registers, i, sval);
}
}
HLL_INVALIDATE_CACHE(dest);
lua_pushvalue(lua, 1);
return 1;
}