From f76f989b53645136a5e83a9a1a9ab1335e9a2cbf Mon Sep 17 00:00:00 2001
From: ltrk2 <107155950+ltrk2@users.noreply.github.com>
Date: Wed, 24 May 2023 13:33:05 +0000
Subject: [PATCH] Implement a uniform way to query processor core IDs

---
 src/Common/AsynchronousMetrics.cpp | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/src/Common/AsynchronousMetrics.cpp b/src/Common/AsynchronousMetrics.cpp
index ac2180103c5..3753aaca405 100644
--- a/src/Common/AsynchronousMetrics.cpp
+++ b/src/Common/AsynchronousMetrics.cpp
@@ -1041,18 +1041,16 @@ void AsynchronousMetrics::update(TimePoint update_time)
                 // It doesn't read the EOL itself.
                 ++cpuinfo->position();
 
-                if (s.rfind("processor", 0) == 0)
+                static constexpr std::string_view PROCESSOR = "processor";
+                if (s.starts_with(PROCESSOR))
                 {
                     /// s390x example: processor 0: version = FF, identification = 039C88, machine = 3906
                     /// non s390x example: processor : 0
-                    if (auto colon = s.find_first_of(':'))
-                    {
-#ifdef __s390x__
-                        core_id = std::stoi(s.substr(10)); /// 10: length of "processor" plus 1
-#else
-                        core_id = std::stoi(s.substr(colon + 2));
-#endif
-                    }
+                    auto core_id_start = std::ssize(PROCESSOR);
+                    while (core_id_start < std::ssize(s) && !std::isdigit(s[core_id_start]))
+                        ++core_id_start;
+
+                    core_id = std::stoi(s.substr(core_id_start));
                 }
                 else if (s.rfind("cpu MHz", 0) == 0)
                 {