From bb1e6536905482c4dedef831304d6324fecc1fd0 Mon Sep 17 00:00:00 2001
From: Albert S <mail@quitesimple.org>
Date: Mon, 30 May 2022 18:35:54 +0200
Subject: [PATCH] gui: PreviewGeneratorPlainText: Truncate dirtily to avoid
 lags

It was possible the text was getting too big. The GUI
was lagging for previews of some text files. The first
assumption was that we would only have a couple of hits,
which is unreasonable for large .txt files and common
words.

We only ever see a handful of previews, it makes no sense
to get all snippets. So just allow 7 snippets, that's it.

Also, just cut after 1000 chars no matter what.
---
 gui/previewgeneratorplaintext.cpp | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/gui/previewgeneratorplaintext.cpp b/gui/previewgeneratorplaintext.cpp
index 4fcaac7..ce39116 100644
--- a/gui/previewgeneratorplaintext.cpp
+++ b/gui/previewgeneratorplaintext.cpp
@@ -23,12 +23,14 @@ QSharedPointer<PreviewResult> PreviewGeneratorPlainText::generate(RenderConfig c
 	int lastWordPos = 0;
 	QHash<QString, int> countmap;
 
+	const unsigned int maxSnippets = 7;
+	unsigned int currentSnippets = 0;
 	for(QString &word : config.wordsToHighlight)
 	{
 
 		int lastPos = 0;
 		int index = content.indexOf(word, lastPos, Qt::CaseInsensitive);
-		while(index != -1)
+		while(index != -1 && currentSnippets < maxSnippets)
 		{
 			countmap[word] = countmap.value(word, 0) + 1;
 
@@ -52,6 +54,7 @@ QSharedPointer<PreviewResult> PreviewGeneratorPlainText::generate(RenderConfig c
 			lastPos = index;
 
 			index = content.indexOf(word, lastPos + 1, Qt::CaseInsensitive);
+			++currentSnippets;
 		}
 		lastWordPos = lastPos;
 	}
@@ -75,8 +78,13 @@ QSharedPointer<PreviewResult> PreviewGeneratorPlainText::generate(RenderConfig c
 	{
 		header += word + ": " + QString::number(countmap[word]) + " ";
 	}
+	if(currentSnippets == maxSnippets)
+	{
+		header += "(truncated)";
+	}
+
 	header += "<hr>";
 
-	result->setText(header + resulText.replace("\n", "<br>"));
+	result->setText(header + resulText.replace("\n", "<br>").mid(0, 1000));
 	return QSharedPointer<PreviewResultPlainText>(result);
 }