Add utility iterfaces to vertexmap, and revisit the hebaviour of `emp…

…lace()` in HashmapMVCC. (#1446) Signed-off-by: Tao He <[email protected]>
v6d-io · Jul 3, 2023 · 6570406 · 6570406
1 parent 21fc39e
commit 6570406
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Showing 6 changed files with 23 additions and 4 deletions.
diff --git a/modules/basic/ds/hashmap_mvcc.h b/modules/basic/ds/hashmap_mvcc.h
@@ -234,15 +234,17 @@ class HashmapMVCC
   /**
    * @brief Emplace key-value pair into the hashmap.
    *
+   * @param out If the emplace finished without rehash, the `out` will
+   *        be nullptr, otherwise will be the new hashmap after rehash.
    */
   template <class... Args>
   inline Status emplace(std::shared_ptr<hashmap_t>& out, Args&&... args) {
-    out = this->shared_from_this();
-    if (try_emplace(const_cast<MutEntryPointer>(out->entries_),
-                    out->hash_policy_, out->num_buckets_,
-                    std::forward<Args>(args)...)) {
+    if (try_emplace(const_cast<MutEntryPointer>(entries_), hash_policy_,
+                    num_buckets_, std::forward<Args>(args)...)) {
+      out = nullptr;
       return Status::OK();
     }
+    out = this->shared_from_this();
     size_t new_num_buckets = compute_next_num_buckets(out->num_buckets_);
     while (true) {
       DVLOG(100) << "trigger rehash when emplace: " << new_num_buckets;

diff --git a/modules/graph/fragment/arrow_fragment.vineyard-mod b/modules/graph/fragment/arrow_fragment.vineyard-mod
@@ -129,6 +129,8 @@ class [[vineyard]] ArrowFragment
 
   bool compact_edges() const override { return compact_edges_; }
 
+  bool use_perfect_hash() const override { return vm_ptr_->use_perfect_hash(); }
+
   bool directed() const override { return directed_; }
 
   const PropertyGraphSchema& schema() const override { return schema_; }

diff --git a/modules/graph/fragment/arrow_fragment_base.h b/modules/graph/fragment/arrow_fragment_base.h
@@ -167,6 +167,8 @@ class ArrowFragmentBase : public vineyard::Object {
 
   virtual bool compact_edges() const = 0;
 
+  virtual bool use_perfect_hash() const = 0;
+
   virtual const PropertyGraphSchema& schema() const = 0;
 
   virtual bool directed() const = 0;

diff --git a/modules/graph/vertex_map/arrow_local_vertex_map.h b/modules/graph/vertex_map/arrow_local_vertex_map.h
@@ -80,6 +80,8 @@ class ArrowLocalVertexMap
 
   fid_t fnum() { return fnum_; }
 
+  bool use_perfect_hash() const { return false; }
+
   size_t GetTotalNodesNum() const;
 
   size_t GetTotalNodesNum(label_id_t label) const;

diff --git a/modules/graph/vertex_map/arrow_vertex_map.h b/modules/graph/vertex_map/arrow_vertex_map.h
@@ -74,6 +74,8 @@ class ArrowVertexMap
 
   fid_t fnum() const { return fnum_; }
 
+  bool use_perfect_hash() const { return use_perfect_hash_; }
+
   size_t GetTotalNodesNum() const;
 
   size_t GetTotalNodesNum(label_id_t label) const;

diff --git a/test/hashmap_mvcc_test.cc b/test/hashmap_mvcc_test.cc
@@ -43,6 +43,9 @@ void testHashmapMVCC(Client& client) {
   for (int i = 1; i <= n; ++i) {
     std::shared_ptr<hashmap_t> hmap;
     VINEYARD_CHECK_OK(hashmaps[i - 1]->emplace(hmap, i, i * 100.0));
+    if (hmap == nullptr) {
+      hmap = hashmaps[i - 1];
+    }
     hashmaps.emplace_back(hmap);
   }
 
@@ -71,6 +74,9 @@ void testHashmapMVCCLarge(Client& client) {
   for (int i = 1; i <= n; ++i) {
     std::shared_ptr<hashmap_t> hmap;
     VINEYARD_CHECK_OK(hashmaps[i - 1]->emplace(hmap, i, i * 100.0));
+    if (hmap == nullptr) {
+      hmap = hashmaps[i - 1];
+    }
     hashmaps.emplace_back(hmap);
   }
 
@@ -97,6 +103,9 @@ void testHashmapMVCCView(Client& client) {
   for (int i = 1; i <= n; ++i) {
     std::shared_ptr<hashmap_t> hmap;
     VINEYARD_CHECK_OK(hashmaps[i - 1]->emplace(hmap, i, i * 100.0));
+    if (hmap == nullptr) {
+      hmap = hashmaps[i - 1];
+    }
     hashmaps.emplace_back(hmap);
   }