From 36ef2c3fd706bfae7b873081dd43b33a1ab00e5a Mon Sep 17 00:00:00 2001
From: D050513 <sebastian.van.syckel@sap.com>
Date: Wed, 8 Jan 2025 14:51:20 +0100
Subject: [PATCH] feat: support driver self-wrapping (for Dynatrace)

---
 hana/lib/drivers/dynatrace.js   | 12 +++++++++---
 hana/lib/drivers/hana-client.js |  4 ++--
 hana/lib/drivers/hdb.js         |  4 ++--
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/hana/lib/drivers/dynatrace.js b/hana/lib/drivers/dynatrace.js
index 64451a3da..d506c2cdd 100644
--- a/hana/lib/drivers/dynatrace.js
+++ b/hana/lib/drivers/dynatrace.js
@@ -8,7 +8,7 @@ try {
   // If module was not required, do not do anything
 }
 
-const isDynatraceEnabled = () => {
+const _shall_wrap = () => {
   return dynatrace.sdk !== undefined && !process.env.CDS_SKIP_DYNATRACE
 }
 
@@ -65,7 +65,7 @@ const _preparedStmtUsingDynatrace = function (client, prepareFn, dbInfo) {
   }
 }
 
-const dynatraceClient = (client, credentials, tenant) => {
+const _wrapped = (client, credentials, tenant) => {
   const dbInfo = {
     name: `SAPHANA${tenant ? `-${tenant}` : ''}`,
     vendor: dynatrace.sdk.DatabaseVendor.HANADB,
@@ -88,4 +88,10 @@ const dynatraceClient = (client, credentials, tenant) => {
   return client
 }
 
-module.exports = { dynatraceClient, isDynatraceEnabled }
+module.exports = {
+  wrap_client: (client, credentials, tenant) => {
+    if (client.isDynatraceSupported) return client //> client will wrap itself
+    if (!_shall_wrap()) return client
+    return _wrapped(client, credentials, tenant)
+  }
+}
diff --git a/hana/lib/drivers/hana-client.js b/hana/lib/drivers/hana-client.js
index d6291b753..ab669fbd3 100644
--- a/hana/lib/drivers/hana-client.js
+++ b/hana/lib/drivers/hana-client.js
@@ -3,7 +3,7 @@ const { Readable, Stream } = require('stream')
 const cds = require('@sap/cds')
 const hdb = require('@sap/hana-client')
 const { driver, prom, handleLevel } = require('./base')
-const { isDynatraceEnabled: dt_sdk_is_present, dynatraceClient: wrap_client } = require('./dynatrace')
+const { wrap_client } = require('./dynatrace')
 const LOG = cds.log('@sap/hana-client')
 if (process.env.NODE_ENV === 'production' && !process.env.HDB_NODEJS_THREADPOOL_SIZE && !process.env.UV_THREADPOOL_SIZE) LOG.warn("When using @sap/hana-client, it's strongly recommended to adjust its thread pool size with environment variable `HDB_NODEJS_THREADPOOL_SIZE`, otherwise it might lead to performance issues.\nLearn more: https://help.sap.com/docs/SAP_HANA_CLIENT/f1b440ded6144a54ada97ff95dac7adf/31a8c93a574b4f8fb6a8366d2c758f21.html")
 
@@ -44,7 +44,7 @@ class HANAClientDriver extends driver {
 
     super(creds)
     this._native = hdb.createConnection(creds)
-    if (dt_sdk_is_present()) this._native = wrap_client(this._native, creds, creds.tenant)
+    this._native = wrap_client(this._native, creds, creds.tenant)
     this._native.setAutoCommit(false)
   }
 
diff --git a/hana/lib/drivers/hdb.js b/hana/lib/drivers/hdb.js
index 23d2d339d..39d7a9fb8 100644
--- a/hana/lib/drivers/hdb.js
+++ b/hana/lib/drivers/hdb.js
@@ -7,7 +7,7 @@ const hdb = require('hdb')
 const iconv = require('iconv-lite')
 
 const { driver, prom, handleLevel } = require('./base')
-const { isDynatraceEnabled: dt_sdk_is_present, dynatraceClient: wrap_client } = require('./dynatrace')
+const { wrap_client } = require('./dynatrace')
 
 if (cds.env.features.sql_simple_queries === 3) {
   // Make hdb return true / false
@@ -44,7 +44,7 @@ class HDBDriver extends driver {
 
     super(creds)
     this._native = hdb.createClient(creds)
-    if (dt_sdk_is_present()) this._native = wrap_client(this._native, creds, creds.tenant)
+    this._native = wrap_client(this._native, creds, creds.tenant)
     this._native.setAutoCommit(false)
     this._native.on('close', () => this.destroy?.())