From 4bd023fd9801d73de7dc1f13fbd47f49faabd967 Mon Sep 17 00:00:00 2001
From: Andrew Howden <hello@andrewhowden.com>
Date: Sat, 12 May 2018 14:10:36 +0200
Subject: [PATCH 1/2] AD-HOC feat (Profiler): Allow supplying complex profiler
 configuration

Magento 2 provides a primitive creating profiles of the application,
similar to those esposed by the transaction tracing community. These
allow getting a granular view of the application based on a custom set
of metrics, rather than relying on PHP callgraph profilers to determine
how an application is behaving.

It is currently possible to modify the *output* of a transaction trace.
However, it is not currently possible to modify *the transaction trace
driver*. This commit seeks to extend the configuration such that the
driver itself can be replaced, rather than simply the output.

This allows replacing the driver entirely with something like the
OpenTracing API, which can then use its own exporters to express the
code to something like the CNCF Jaeger project.

This, in turn, allows getting a granular view of the transactions in an
application.

== Design Notes ==

=== Minimal changes ===

Considerable additional work is bring prototyped with the alpha
OpenCensus APIs, however at this time this is inappropriate to be merged
into the core. The APIs are immature, and the approach for reading
transaction traces not finalised.

This allows continued experimentation up to and including deployment to
production infrastructure without committing early to supporting this
model of profiling.

=== Variables prefixed with "profiler" ===

At first glace, the variables appear to be unnecessarily verbose.
However, they are declared in the global context, and are thus
namespaced to avoid collisions.
---
 app/bootstrap.php | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/app/bootstrap.php b/app/bootstrap.php
index e77c6d432c816..b3f2c71f0f85b 100644
--- a/app/bootstrap.php
+++ b/app/bootstrap.php
@@ -54,12 +54,18 @@
     && isset($_SERVER['HTTP_ACCEPT'])
     && strpos($_SERVER['HTTP_ACCEPT'], 'text/html') !== false
 ) {
-    $profilerFlag = isset($_SERVER['MAGE_PROFILER']) && strlen($_SERVER['MAGE_PROFILER'])
+    $profilerString = isset($_SERVER['MAGE_PROFILER']) && strlen($_SERVER['MAGE_PROFILER'])
         ? $_SERVER['MAGE_PROFILER']
         : trim(file_get_contents(BP . '/var/profiler.flag'));
 
-    \Magento\Framework\Profiler::applyConfig(
-        $profilerFlag,
+    if ($profilerString && $profilerArray = json_decode($profilerString, true)) {
+        $profilerConfig = $profilerArray;
+    } else {
+        $profilerConfig = $profilerString;
+    }
+
+    Magento\Framework\Profiler::applyConfig(
+        $profilerConfig,
         BP,
         !empty($_SERVER['HTTP_X_REQUESTED_WITH']) && $_SERVER['HTTP_X_REQUESTED_WITH'] == 'XMLHttpRequest'
     );

From fa1667643c35815c082b3576d2b7f8de9eb5971a Mon Sep 17 00:00:00 2001
From: Stanislav Idolov <sidolov@magento.com>
Date: Thu, 9 Aug 2018 11:06:03 +0300
Subject: [PATCH 2/2] Small refactoring for better readability

---
 app/bootstrap.php | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/app/bootstrap.php b/app/bootstrap.php
index b3f2c71f0f85b..70b632537a75b 100644
--- a/app/bootstrap.php
+++ b/app/bootstrap.php
@@ -54,14 +54,12 @@
     && isset($_SERVER['HTTP_ACCEPT'])
     && strpos($_SERVER['HTTP_ACCEPT'], 'text/html') !== false
 ) {
-    $profilerString = isset($_SERVER['MAGE_PROFILER']) && strlen($_SERVER['MAGE_PROFILER'])
+    $profilerConfig = isset($_SERVER['MAGE_PROFILER']) && strlen($_SERVER['MAGE_PROFILER'])
         ? $_SERVER['MAGE_PROFILER']
         : trim(file_get_contents(BP . '/var/profiler.flag'));
 
-    if ($profilerString && $profilerArray = json_decode($profilerString, true)) {
-        $profilerConfig = $profilerArray;
-    } else {
-        $profilerConfig = $profilerString;
+    if ($profilerConfig) {
+        $profilerConfig = json_decode($profilerConfig, true) ?: $profilerConfig;
     }
 
     Magento\Framework\Profiler::applyConfig(