feat(treansaction): Use single hop in squashing when possible

Signed-off-by: Vladislav Oleshko <[email protected]>

Author: dranikpg

src/server/command_registry.h

@@ -93,6 +93,10 @@ class CommandId : public facade::CommandId {
 
   bool IsTransactional() const;
 
+  bool IsMultiTransactional() const {
+    return CO::IsTransKind(name()) || CO::IsEvalKind(name());
+  }
+
   bool IsReadOnly() const {
     return opt_mask_ & CO::READONLY;
   }

src/server/conn_context.cc

@@ -93,7 +93,7 @@ ConnectionContext::ConnectionContext(const ConnectionContext* owner, Transaction
   if (tx) {  // If we have a carrier transaction, this context is used for squashing
     DCHECK(owner);
     conn_state.db_index = owner->conn_state.db_index;
-    conn_state.squashing_info = {owner};
+    conn_state.squashing_info = {owner, owner->transaction};
   }
   auto* prev_reply_builder = Inject(crb);
   CHECK_EQ(prev_reply_builder, nullptr);
@@ -234,7 +234,7 @@ size_t ConnectionState::ExecInfo::UsedMemory() const {
 }
 
 size_t ConnectionState::ScriptInfo::UsedMemory() const {
-  return dfly::HeapSize(keys) + async_cmds_heap_mem;
+  return async_cmds_heap_mem;
 }
 
 size_t ConnectionState::SubscribeInfo::UsedMemory() const {

src/server/conn_context.h

@@ -101,8 +101,6 @@ struct ConnectionState {
   struct ScriptInfo {
     size_t UsedMemory() const;
 
-    absl::flat_hash_set<std::string_view> keys;  // declared keys
-
     size_t async_cmds_heap_mem = 0;     // bytes used by async_cmds
     size_t async_cmds_heap_limit = 0;   // max bytes allowed for async_cmds
     std::vector<StoredCmd> async_cmds;  // aggregated by acall
@@ -135,10 +133,11 @@ struct ConnectionState {
   };
 
   struct SquashingInfo {
-    // Pointer to the original underlying context of the base command.
-    // Only const access it possible for reading from multiple threads,
-    // each squashing thread has its own proxy context that contains this info.
+    // Underlying context of the base command, should be used for state checks.
+    // Note: some squashing mechanisms re-use the context (single shard eval).
     const ConnectionContext* owner = nullptr;
+    // Underlying base transaction of squashing mechanism.
+    const Transaction* transaction = nullptr;
   };
 
   enum MCGetMask {

src/server/journal/tx_executor.cc

@@ -117,7 +117,7 @@ std::optional<TransactionData> TransactionReader::NextTxData(JournalReader* read
 
     // Otherwise, continue building multi command.
     DCHECK(res->opcode == journal::Op::MULTI_COMMAND || res->opcode == journal::Op::EXEC);
-    DCHECK(res->txid > 0);
+    // DCHECK(res->txid > 0);
 
     auto txid = res->txid;
     auto& txdata = current_[txid];