From 3070efb64a628f5c61fc5870ee4a8791942f6699 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Tue, 11 Feb 2025 16:34:13 +0100
Subject: QCbor/JsonValue: add toStringView()

This is like toString(), but returns a view on the underlying string
data (which may be US-ASCII (= L1), UTF-8, or UTF-16, so the return
value is QASV).

Use it around the code a bit.

Benchmark results on my machine (with -perf -iterations 1000):

  PASS   : BenchmarkQtJson::iteratorKey()
  RESULT : BenchmarkQtJson::iteratorKey():
     78,268.426 nsecs per iteration (total: 78,268,427, iterations: 1000)
     349,458.080 CPU cycles per iteration, 4,46 GHz (total: 349,458,080, iterations: 1000)
     780,327.957 instructions per iteration, 2,233 instr/cycle (total: 780,327,957, iterations: 1000)
     173,511.019 branch instructions per iteration, 2,22 G/sec (total: 173,511,020, iterations: 1000)
  PASS   : BenchmarkQtJson::iteratorKeyValueView()
  RESULT : BenchmarkQtJson::iteratorKeyValueView():
     58,424.756 nsecs per iteration (total: 58,424,756, iterations: 1000)
     267,176.603 CPU cycles per iteration, 4,57 GHz (total: 267,176,604, iterations: 1000)
     614,805.388 instructions per iteration, 2,301 instr/cycle (total: 614,805,389, iterations: 1000)
     140,681.105 branch instructions per iteration, 2,41 G/sec (total: 140,681,106, iterations: 1000)
  PASS   : BenchmarkQtJson::iteratorKeyView()
  RESULT : BenchmarkQtJson::iteratorKeyView():
     44,060.925 nsecs per iteration (total: 44,060,925, iterations: 1000)
     196,344.233 CPU cycles per iteration, 4,46 GHz (total: 196,344,233, iterations: 1000)
     426,631.322 instructions per iteration, 2,173 instr/cycle (total: 426,631,323, iterations: 1000)
     93,703.100 branch instructions per iteration, 2,13 G/sec (total: 93,703,101, iterations: 1000)
  PASS   : BenchmarkQtJson::iteratorKeyViewValueView()
  RESULT : BenchmarkQtJson::iteratorKeyViewValueView():
     29,205.569 nsecs per iteration (total: 29,205,570, iterations: 1000)
     131,089.040 CPU cycles per iteration, 4,49 GHz (total: 131,089,041, iterations: 1000)
     258,529.469 instructions per iteration, 1,972 instr/cycle (total: 258,529,469, iterations: 1000)
     60,875.631 branch instructions per iteration, 2,08 G/sec (total: 60,875,631, iterations: 1000)

[ChangeLog][QtCore][QCborValue/QJsonValue] Add toStringView() method.

Fixes: QTBUG-133688
Change-Id: I4200035e995426f1cce46a73a429921a0cd56c85
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 src/gui/opengl/qopengl.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'src/gui/opengl/qopengl.cpp')

diff --git a/src/gui/opengl/qopengl.cpp b/src/gui/opengl/qopengl.cpp
index 587975085ad..021c3964219 100644
--- a/src/gui/opengl/qopengl.cpp
+++ b/src/gui/opengl/qopengl.cpp
@@ -176,8 +176,8 @@ VersionTerm VersionTerm::fromJson(const QJsonValue &v)
     if (!v.isObject())
         return result;
     const QJsonObject o = v.toObject();
-    result.number = QVersionNumber::fromString(o.value("value"_L1).toString());
-    const QString opS = o.value("op"_L1).toString();
+    result.number = QVersionNumber::fromString(o.value("value"_L1).toStringView());
+    const auto opS = o.value("op"_L1).toStringView();
     for (size_t i = 0; i < sizeof(operators) / sizeof(operators[0]); ++i) {
         if (opS == QLatin1StringView(operators[i])) {
             result.op = static_cast<Operator>(i);
-- 
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