DBImpl::GetApproximateSizes: speed up by new func SetInternalKey(char…

…* buf, ...)
topling · Sep 2, 2022 · e63de81 · e63de81
1 parent 719af44
commit e63de81
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Showing 2 changed files with 35 additions and 6 deletions.
diff --git a/db/db_impl/db_impl.cc b/db/db_impl/db_impl.cc
@@ -4127,6 +4127,9 @@ Status DBImpl::GetApproximateSizes(const SizeApproximationOptions& options,
   if (!options.include_memtables && !options.include_files) {
     return Status::InvalidArgument("Invalid options");
   }
+  if (UNLIKELY(n <= 0)) {
+    return Status::OK();
+  }
 
 #if defined(TOPLINGDB_WITH_TIMESTAMP)
   const Comparator* const ucmp = column_family->GetComparator();
@@ -4140,7 +4143,19 @@ Status DBImpl::GetApproximateSizes(const SizeApproximationOptions& options,
   SuperVersion* sv = GetAndRefSuperVersion(cfd);
   v = sv->current;
 
-  InternalKey k1, k2;
+  size_t len1 = range[0].start.size_;
+  size_t len2 = range[0].limit.size_;
+  for (int i = 1; i < n; i++) {
+    len1 = std::max(len1, range[i].start.size_);
+    len2 = std::max(len2, range[i].limit.size_);
+  }
+#if defined(TOPLINGDB_WITH_TIMESTAMP)
+  len1 += ts_sz;
+  len2 += ts_sz;
+#endif
+  char* k1 = (char*)alloca(len1 + 8);
+  char* k2 = (char*)alloca(len2 + 8);
+
   for (int i = 0; i < n; i++) {
     Slice start = range[i].start;
     Slice limit = range[i].limit;
@@ -4159,17 +4174,19 @@ Status DBImpl::GetApproximateSizes(const SizeApproximationOptions& options,
     }
   #endif
     // Convert user_key into a corresponding internal key.
-    SetInternalKey(k1.rep(), start, kMaxSequenceNumber, kValueTypeForSeek);
-    SetInternalKey(k2.rep(), limit, kMaxSequenceNumber, kValueTypeForSeek);
+    SetInternalKey(k1, start, kMaxSequenceNumber, kValueTypeForSeek);
+    SetInternalKey(k2, limit, kMaxSequenceNumber, kValueTypeForSeek);
     sizes[i] = 0;
+    Slice ik1(k1, start.size_ + 8);
+    Slice ik2(k2, limit.size_ + 8);
     if (options.include_files) {
       sizes[i] += versions_->ApproximateSize(
-          options, v, k1.Encode(), k2.Encode(), /*start_level=*/0,
+          options, v, ik1, ik2, /*start_level=*/0,
           /*end_level=*/-1, TableReaderCaller::kUserApproximateSize);
     }
     if (options.include_memtables) {
-      sizes[i] += sv->mem->ApproximateStats(k1.Encode(), k2.Encode()).size;
-      sizes[i] += sv->imm->ApproximateStats(k1.Encode(), k2.Encode()).size;
+      sizes[i] += sv->mem->ApproximateStats(ik1, ik2).size;
+      sizes[i] += sv->imm->ApproximateStats(ik1, ik2).size;
     }
   }
 

diff --git a/db/dbformat.h b/db/dbformat.h
@@ -170,6 +170,18 @@ inline void SetInternalKey(std::string* result, Slice ukey,
   PutFixed64(result, PackSequenceAndType(seq, vt));
 }
 
+// user code should ensure buf size is at least ukey.size() + 8
+inline void SetInternalKey(char* buf, Slice ukey,
+                           SequenceNumber seq, ValueType vt) {
+  memcpy(buf, ukey.data_, ukey.size_);
+  auto value = PackSequenceAndType(seq, vt);
+  if (port::kLittleEndian) {
+    memcpy(buf + ukey.size_, &value, sizeof(value));
+  } else {
+    EncodeFixed64(buf + ukey.size_, value);
+  }
+}
+
 // Append the serialization of "key" to *result.
 extern void AppendInternalKey(std::string* result,
                               const ParsedInternalKey& key);