Add range reads to server_bench

ServerBench.cpp

@@ -66,13 +66,14 @@ template <class... Ts> std::string tupleKey(const Ts &...ts) {
 
 constexpr int kTotalKeyRange = 1'000'000'000;
 constexpr int kWindowSize = 1'000'000;
-constexpr int kNumKeys = 10;
+constexpr int kNumReadKeysPerTx = 10;
+constexpr int kNumWriteKeysPerTx = 5;
 
 void workload(weaselab::ConflictSet *cs) {
   int64_t version = kWindowSize;
   for (;; transactions.fetch_add(1, std::memory_order_relaxed)) {
     std::vector<int64_t> keyIndices;
-    for (int i = 0; i < kNumKeys; ++i) {
+    for (int i = 0; i < std::max(kNumReadKeysPerTx, kNumWriteKeysPerTx); ++i) {
       keyIndices.push_back(rand() % kTotalKeyRange);
     }
     std::sort(keyIndices.begin(), keyIndices.end());
@@ -80,7 +81,7 @@ void workload(weaselab::ConflictSet *cs) {
     constexpr std::string_view fullString =
         "this is a string, where a prefix of it is used as an element of the "
         "tuple forming the key";
-    for (int i = 0; i < kNumKeys; ++i) {
+    for (int i = 0; i < int(keyIndices.size()); ++i) {
       keys.push_back(
           tupleKey(0x100, keyIndices[i] / fullString.size(),
                    fullString.substr(0, keyIndices[i] % fullString.size())));
@@ -90,21 +91,22 @@ void workload(weaselab::ConflictSet *cs) {
     std::vector<weaselab::ConflictSet::ReadRange> reads;
     std::vector<weaselab::ConflictSet::WriteRange> writes;
     std::vector<weaselab::ConflictSet::Result> results;
-    for (int i = 0; i < kNumKeys; ++i) {
+    for (int i = 0; i < kNumWriteKeysPerTx; ++i) {
       writes.push_back({{(const uint8_t *)keys[i].data(), int(keys[i].size())},
                         {nullptr, 0}});
+    }
+    reads.push_back({{(const uint8_t *)keys[0].data(), int(keys[0].size())},
+                     {(const uint8_t *)keys[1].data(), int(keys[1].size())},
+                     version - kWindowSize});
+    static_assert(kNumReadKeysPerTx >= 3);
+    for (int i = 2; i < kNumReadKeysPerTx; ++i) {
       reads.push_back({{(const uint8_t *)keys[i].data(), int(keys[i].size())},
                        {nullptr, 0},
                        version - kWindowSize});
     }
     results.resize(reads.size());
-
     cs->check(reads.data(), results.data(), reads.size());
-    bool ok = true;
-    for (auto result : results) {
-      ok &= result == weaselab::ConflictSet::Commit;
-    }
-    cs->addWrites(writes.data(), ok ? writes.size() : 0, version);
+    cs->addWrites(writes.data(), writes.size(), version);
     cs->setOldestVersion(version - kWindowSize);
     ++version;
   }