From f490ac671267438d8a539f4639c9e987861924cf Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@kdab.com>
Date: Sat, 9 May 2020 16:36:08 +0200
Subject: QXmlStreamReader: avoid double QHash lookups

Replace

  if (hash.contains(x)) { // lookup #1
     ~~~ hash[x];         // lookup #2

with

  if (auto it = hash.find(x); it != hash.end()) { // lookup
      ~~~ *it;                                    // no lookup

halving the number of QHash lookups. The container is not shared, so
there's no danger of a detach when going directly to the non-const
function.

Change-Id: Ifae409f98e0be972b31a24326ad548723831fda8
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
---
 src/corelib/serialization/qxmlstream.g   | 12 ++++++------
 src/corelib/serialization/qxmlstream_p.h | 12 ++++++------
 2 files changed, 12 insertions(+), 12 deletions(-)

(limited to 'src/corelib/serialization')

diff --git a/src/corelib/serialization/qxmlstream.g b/src/corelib/serialization/qxmlstream.g
index b623de9505..e630366822 100644
--- a/src/corelib/serialization/qxmlstream.g
+++ b/src/corelib/serialization/qxmlstream.g
@@ -1642,8 +1642,8 @@ entity_ref ::= AMPERSAND name SEMICOLON;
         case $rule_number: {
             sym(1).len += sym(2).len + 1;
             QStringView reference = symView(2);
-            if (entityHash.contains(reference)) {
-                Entity &entity = entityHash[reference];
+            if (const auto it = entityHash.find(reference); it != entityHash.end()) {
+                Entity &entity = *it;
                 if (entity.unparsed) {
                     raiseWellFormedError(QXmlStream::tr("Reference to unparsed entity '%1'.").arg(reference));
                 } else {
@@ -1684,9 +1684,9 @@ pereference ::= PERCENT name SEMICOLON;
         case $rule_number: {
             sym(1).len += sym(2).len + 1;
             QStringView reference = symView(2);
-            if (parameterEntityHash.contains(reference)) {
+            if (const auto it = parameterEntityHash.find(reference); it != parameterEntityHash.end()) {
                 referenceToParameterEntityDetected = true;
-                Entity &entity = parameterEntityHash[reference];
+                Entity &entity = *it;
                 if (entity.unparsed || entity.external) {
                     referenceToUnparsedEntityDetected = true;
                 } else {
@@ -1715,8 +1715,8 @@ entity_ref_in_attribute_value ::= AMPERSAND name SEMICOLON;
         case $rule_number: {
             sym(1).len += sym(2).len + 1;
             QStringView reference = symView(2);
-            if (entityHash.contains(reference)) {
-                Entity &entity = entityHash[reference];
+            if (const auto it = entityHash.find(reference); it != entityHash.end()) {
+                Entity &entity = *it;
                 if (entity.unparsed || entity.value.isNull()) {
                     raiseWellFormedError(QXmlStream::tr("Reference to external entity '%1' in attribute value.").arg(reference));
                     break;
diff --git a/src/corelib/serialization/qxmlstream_p.h b/src/corelib/serialization/qxmlstream_p.h
index 103b123b10..0ffe57e403 100644
--- a/src/corelib/serialization/qxmlstream_p.h
+++ b/src/corelib/serialization/qxmlstream_p.h
@@ -1814,8 +1814,8 @@ bool QXmlStreamReaderPrivate::parse()
         case 240: {
             sym(1).len += sym(2).len + 1;
             QStringView reference = symView(2);
-            if (entityHash.contains(reference)) {
-                Entity &entity = entityHash[reference];
+            if (const auto it = entityHash.find(reference); it != entityHash.end()) {
+                Entity &entity = *it;
                 if (entity.unparsed) {
                     raiseWellFormedError(QXmlStream::tr("Reference to unparsed entity '%1'.").arg(reference));
                 } else {
@@ -1853,9 +1853,9 @@ bool QXmlStreamReaderPrivate::parse()
         case 241: {
             sym(1).len += sym(2).len + 1;
             QStringView reference = symView(2);
-            if (parameterEntityHash.contains(reference)) {
+            if (const auto it = parameterEntityHash.find(reference); it != parameterEntityHash.end()) {
                 referenceToParameterEntityDetected = true;
-                Entity &entity = parameterEntityHash[reference];
+                Entity &entity = *it;
                 if (entity.unparsed || entity.external) {
                     referenceToUnparsedEntityDetected = true;
                 } else {
@@ -1876,8 +1876,8 @@ bool QXmlStreamReaderPrivate::parse()
         case 243: {
             sym(1).len += sym(2).len + 1;
             QStringView reference = symView(2);
-            if (entityHash.contains(reference)) {
-                Entity &entity = entityHash[reference];
+            if (const auto it = entityHash.find(reference); it != entityHash.end()) {
+                Entity &entity = *it;
                 if (entity.unparsed || entity.value.isNull()) {
                     raiseWellFormedError(QXmlStream::tr("Reference to external entity '%1' in attribute value.").arg(reference));
                     break;
-- 
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