fix(driver-adapters): Ensure transaction metrics do not get negative (#…

…4417)

* fix(driver-adapters): Ensure transaction metrics do not get negative

Current dispatcher for a thread gets lost somewhere within napi-rs/napi
`ThreadsafeFunction` nad thearfore, gauge increment in `Transaction::new` is not registered. That in turn means that when the same gauge is decremented in `commit`/`rollback`, it's value will get negative.

Moving increment to proxy fixes the problem.

Unblocks prisma/prisma-orm#21746

* clippy

query-engine/driver-adapters/src/proxy.rs

@@ -4,6 +4,7 @@ use std::str::FromStr;
 use crate::async_js_function::AsyncJsFunction;
 use crate::conversion::JSArg;
 use crate::transaction::JsTransaction;
+use metrics::increment_gauge;
 use napi::bindgen_prelude::{FromNapiValue, ToNapiValue};
 use napi::threadsafe_function::{ErrorStrategy, ThreadsafeFunction};
 use napi::{JsObject, JsString};
@@ -555,6 +556,12 @@ impl DriverProxy {
 
     pub async fn start_transaction(&self) -> quaint::Result<Box<JsTransaction>> {
         let tx = self.start_transaction.call(()).await?;
+
+        // Decrement for this gauge is done in JsTransaction::commit/JsTransaction::rollback
+        // Previously, it was done in JsTransaction::new, similar to the native Transaction.
+        // However, correct Dispatcher is lost there and increment does not register, so we moved
+        // it here instead.
+        increment_gauge!("prisma_client_queries_active", 1.0);
         Ok(Box::new(tx))
     }
 }

query-engine/driver-adapters/src/transaction.rs

@@ -1,5 +1,5 @@
 use async_trait::async_trait;
-use metrics::{decrement_gauge, increment_gauge};
+use metrics::decrement_gauge;
 use napi::{bindgen_prelude::FromNapiValue, JsObject};
 use quaint::{
     connector::{IsolationLevel, Transaction as QuaintTransaction},
@@ -22,8 +22,6 @@ pub(crate) struct JsTransaction {
 
 impl JsTransaction {
     pub(crate) fn new(inner: JsBaseQueryable, tx_proxy: TransactionProxy) -> Self {
-        increment_gauge!("prisma_client_queries_active", 1.0);
-
         Self { inner, tx_proxy }
     }
 
@@ -40,6 +38,7 @@ impl JsTransaction {
 #[async_trait]
 impl QuaintTransaction for JsTransaction {
     async fn commit(&self) -> quaint::Result<()> {
+        // increment of this gauge is done in DriverProxy::startTransaction
         decrement_gauge!("prisma_client_queries_active", 1.0);
 
         let commit_stmt = "COMMIT";
@@ -55,6 +54,7 @@ impl QuaintTransaction for JsTransaction {
     }
 
     async fn rollback(&self) -> quaint::Result<()> {
+        // increment of this gauge is done in DriverProxy::startTransaction
         decrement_gauge!("prisma_client_queries_active", 1.0);
 
         let rollback_stmt = "ROLLBACK";