diff options
| -rw-r--r-- | src/hyperloglog.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/src/hyperloglog.c b/src/hyperloglog.c index f193bee2c..65fbfd06a 100644 --- a/src/hyperloglog.c +++ b/src/hyperloglog.c @@ -1298,6 +1298,7 @@ void pfmergeCommand(client *c) { uint8_t max[HLL_REGISTERS]; struct hllhdr *hdr; int j; + int use_dense = 0; /* Use dense representation as target? */ /* Compute an HLL with M[i] = MAX(M[i]_j). * We store the maximum into the max array of registers. We'll write @@ -1309,6 +1310,11 @@ void pfmergeCommand(client *c) { if (o == NULL) continue; /* Assume empty HLL for non existing var. */ if (isHLLObjectOrReply(c,o) != C_OK) return; + /* If at least one involved HLL is dense, use the dense representation + * as target ASAP to save time and avoid the conversion step. */ + hdr = o->ptr; + if (hdr->encoding == HLL_DENSE) use_dense = 1; + /* Merge with this HLL with our 'max' HHL by setting max[i] * to MAX(max[i],hll[i]). */ if (hllMerge(max,o) == C_ERR) { @@ -1332,8 +1338,9 @@ void pfmergeCommand(client *c) { o = dbUnshareStringValue(c->db,c->argv[1],o); } - /* Only support dense objects as destination. */ - if (hllSparseToDense(o) == C_ERR) { + /* Convert the destination object to dense representation if at least + * one of the inputs was dense. */ + if (use_dense && hllSparseToDense(o) == C_ERR) { addReplySds(c,sdsnew(invalid_hll_err)); return; } @@ -1342,7 +1349,11 @@ void pfmergeCommand(client *c) { * invalidate the cached value. */ hdr = o->ptr; for (j = 0; j < HLL_REGISTERS; j++) { - HLL_DENSE_SET_REGISTER(hdr->registers,j,max[j]); + if (max[j] == 0) continue; + switch(hdr->encoding) { + case HLL_DENSE: hllDenseSet(hdr->registers,j,max[j]); break; + case HLL_SPARSE: hllSparseSet(o,j,max[j]); break; + } } HLL_INVALIDATE_CACHE(hdr); |