From ebdf7344d8b1e16e06284cef0e2a6727f7b99eb1 Mon Sep 17 00:00:00 2001
From: gvolfing <gabor.volfinger@memgraph.io>
Date: Thu, 2 Mar 2023 11:07:40 +0100
Subject: [PATCH] Make a split_threshold stub

---
 src/coordinator/shard_map.hpp   |  5 ++++-
 src/query/v2/request_router.hpp | 21 +++++++++++++++++----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/coordinator/shard_map.hpp b/src/coordinator/shard_map.hpp
index fc408e965..4177c3403 100644
--- a/src/coordinator/shard_map.hpp
+++ b/src/coordinator/shard_map.hpp
@@ -1,4 +1,4 @@
-// Copyright 2022 Memgraph Ltd.
+// Copyright 2023 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -128,6 +128,9 @@ struct LabelSpace {
   // Maps between the smallest primary key stored in the shard and the shard
   std::map<PrimaryKey, ShardMetadata> shards;
   size_t replication_factor;
+  // TODO
+  // Stub value. Should be replaced once the shard-split logic is in place.
+  int64_t split_threshold{10000};
 
   friend std::ostream &operator<<(std::ostream &in, const LabelSpace &label_space) {
     using utils::print_helpers::operator<<;
diff --git a/src/query/v2/request_router.hpp b/src/query/v2/request_router.hpp
index 6e23a494f..2a3c10baf 100644
--- a/src/query/v2/request_router.hpp
+++ b/src/query/v2/request_router.hpp
@@ -419,15 +419,28 @@ class RequestRouter : public RequestRouterInterface {
     return shards_map_.GetLabelId(name);
   }
 
-  int64_t GetApproximateVertexCount() const override { return 1; }
+  int64_t GetApproximateVertexCount() const override {
+    int64_t vertex_count = 0;
+
+    for (const auto &label_space : shards_map_.label_spaces) {
+      const auto split_threshold = label_space.second.split_threshold;
+      const auto shard_count = static_cast<int64_t>(label_space.second.shards.size());
+      vertex_count += split_threshold * shard_count;
+    }
+
+    return vertex_count;
+  }
 
   int64_t GetApproximateVertexCount(storage::v3::LabelId label) const override {
     const auto &label_space = shards_map_.label_spaces.at(label);
-    return 1;
+    return label_space.split_threshold * label_space.shards.size();
   }
 
-  int64_t GetApproximateVertexCount(storage::v3::LabelId label, storage::v3::PropertyId property) const override {
-    return 1;
+  int64_t GetApproximateVertexCount(storage::v3::LabelId label, storage::v3::PropertyId /*property*/) const override {
+    // TODO
+    // Once we have reliable metadata to approximate the
+    // vertex count -based on properties- rework this function.
+    return GetApproximateVertexCount(label);
   }
 
  private: