Freezing when pasting large amount of text between quotes or heredoc (language PHP)

Min Liu

Hi,
I’ve been using Notepad++ for several years however one of the later updates v8.7 and above (currently running 8.9 64bit) is causing the app to hang when pasting large amounts of text in.

This only occurs when:

language is set to PHP
text is pasted between quotes or a heredoc

Does not occur if language is switched to something else, data pasted, then changed back.

Does not occur if language is set to PHP and the entire file contents is pasted in.

Example:
Start with a blank file, set language to PHP.
Paste in:
<?php

$a =<<< AAA

AAA

then paste in 15000 lines of
AAAAAA 9999

Plugins installed:
Mime tools
Npp converter
NppExport

Alan Kilborn

@Min-Liu

You should post your Debug Info.

Does it hang forever or does it just take what seems like a really long time?

Min Liu

@Alan-Kilborn
It hangs for a long time, and seems to increase exponentially with the number of lines.

Notepad++ v8.9 (64-bit)
Build time: Dec 27 2025 - 14:28:33
Scintilla/Lexilla included: 5.5.8/5.4.6
Boost Regex included: 1_85
TinyXML-2 included: 11.0.0
nlohmann JSON included: 3.12.0
Path: C:\Program Files\Notepad++\notepad++.exe
Command Line: “C:\inetpub\wwwroot\minzliu\test3.php”
Admin mode: OFF
Local Conf mode: OFF
Cloud Config: OFF
Periodic Backup: ON
Placeholders: OFF
Scintilla Rendering Mode: SC_TECHNOLOGY_DIRECTWRITE (1)
Multi-instance Mode: monoInst
asNotepad: OFF
File Status Auto-Detection: cdEnabledNew (for current file/tab only)
Dark Mode: OFF
Display Info:
primary monitor: 2560x1440, scaling 100%
visible monitors count: 2
installed Display Class adapters:
0000: Description - Intel® UHD Graphics 770
0000: DriverVersion - 32.0.101.7079
0001: Description - Microsoft Remote Display Adapter
0001: DriverVersion - 10.0.26100.7019
0002: Description - Microsoft Remote Display Adapter
0002: DriverVersion - 10.0.26100.3624
0003: Description - Microsoft Remote Display Adapter
0003: DriverVersion - 10.0.26100.3624
- warning, search has been limited to maximum number of adapter records: 4
OS Name: Windows 11 Pro (64-bit)
OS Version: 25H2
OS Build: 26200.7462
Current ANSI codepage: 1252
Plugins:
mimeTools (3.1)
NppConverter (4.7)
NppExport (0.4)

PeterJones

@Min-Liu ,

I can confirm:

Create C:\usr\local\share\TempData\Npp\heredoc.php:
```
<?php

$a =<<< AAA

AAA
?>
```
Create C:\usr\local\share\TempData\Npp\16k lines.txt: enter text AZAZAZAZ 123456789[NEWLINE] then Ctrl+A Ctrl+D until 16k lines, and save.

For each listed below, Ctrl+A Ctrl+C to copy from 16k lines.txt and paste in the empty line between the two AAA lines of heredoc.php

Search for change in behavior: use a fresh unzip (no additional plugins, etc)

SciTE 5.6.8 = near-instantaneous paste
v8.7 = near-instantaneous paste
v8.9 = more than a minute to paste: confirmed there’s a difference in behavior; see Resource Monitor CPU screenshot
v8.8 = >1min
v8.7.5 = near-instantaneous paste
v8.7.9 = >1min
v8.7.6 = >1min

Debug info for the v8.7.5 (last fast), v8.7.6 (first slow), and v8.9 (showing it’s still a problem)

v8.7.5 = Fast

Notepad++ v8.7.5   (64-bit)
Build time : Dec 21 2024 - 05:13:03
Path : C:\usr\local\apps\npp\npp.8.7.5-php\notepad++.exe
Command Line : 
Admin mode : OFF
Local Conf mode : ON
Cloud Config : OFF
Periodic Backup : ON
Placeholders : OFF
DirectWrite : ON
Multi-instance Mode : monoInst
File Status Auto-Detection : cdEnabledNew (for current file/tab only)
Dark Mode : OFF
OS Name : Windows 11 Home (64-bit)
OS Version : 24H2
OS Build : 26100.7171
Current ANSI codepage : 1252
Plugins : 
    mimeTools (3.1)
    NppConverter (4.6)
    NppExport (0.4)

v8.7.6 = Slow

Notepad++ v8.7.6   (64-bit)
Build time : Jan 24 2025 - 08:27:33
Path : C:\usr\local\apps\npp\npp.8.7.6-php\notepad++.exe
Command Line : 
Admin mode : OFF
Local Conf mode : ON
Cloud Config : OFF
Periodic Backup : ON
Placeholders : OFF
DirectWrite : ON
Multi-instance Mode : monoInst
File Status Auto-Detection : cdEnabledNew (for current file/tab only)
Dark Mode : OFF
OS Name : Windows 11 Home (64-bit)
OS Version : 24H2
OS Build : 26100.7171
Current ANSI codepage : 1252
Plugins : 
    mimeTools (3.1)
    NppConverter (4.6)
    NppExport (0.4)

v8.9 = Slow

Notepad++ v8.9   (64-bit)
Build time: Dec 27 2025 - 14:28:33
Scintilla/Lexilla included: 5.5.8/5.4.6
Boost Regex included: 1_85
TinyXML-2 included: 11.0.0
nlohmann JSON included: 3.12.0
Path: C:\usr\local\apps\npp\npp.8.9-php\notepad++.exe
Command Line: 
Admin mode: OFF
Local Conf mode: ON
Cloud Config: OFF
Periodic Backup: ON
Placeholders: OFF
Scintilla Rendering Mode: SC_TECHNOLOGY_DIRECTWRITE (1)
Multi-instance Mode: monoInst
asNotepad: OFF
File Status Auto-Detection: cdEnabledNew (for current file/tab only)
Dark Mode: OFF
Display Info:
    primary monitor: 1920x1080, scaling 100%
    visible monitors count: 1
    installed Display Class adapters: 
        0000: Description - Intel(R) UHD Graphics 770
        0000: DriverVersion - 32.0.101.7026
OS Name: Windows 11 Home (64-bit)
OS Version: 24H2
OS Build: 26100.7171
Current ANSI codepage: 1252
Plugins: 
    mimeTools (3.1)
    NppConverter (4.7)
    NppExport (0.4)

update: oddly, I think that means that the “enhance performance of syntax highlighting for large files” fix in v8.7.6 might have slowed things down when pasting into the PHP heredoc…

mpheath

@Min-Liu

This is related to the change of idle styling. Note SCI_SETIDLESTYLING = 0 (default) to now = 3 in Notepad++.

When the paste action occurs, 50,000 lines is styled before being shown which you regard the issue as being frozen with the Gui. The Gui is waiting for the styling to finish. If you interact with the Gui while the program is busy processing then the Gui will signal with not responding as the Gui message loop is not processing messages at that time. Takes about 30 seconds in my testing to style, though can take longer if you interact with the Gui too much to confuse it and make it worse. Switching tabs is just as tormenting as full restyling is requested.

If you want the old “just in time” aka JIT with only what is visual processing behavior, then install LuaScript/PythonScript/… plugin and change the idle styling setting.

PythonScript: editor.setIdleStyling(0)

Lua: editor.IdleStyling = 0

This might be enough in a startup script. If you want to manage it then this might Lua code help:

local function ModIdleStyling(modType, _, length)
    -- Big insert will set IdleStyling to 0.
    -- Small insert will set IdleStyling to 3.
    -- Big is larger than 100 lines at 80 characters.

    if modType & SC_MOD_BEFOREINSERT then
        if length > 8000 then
            editor.IdleStyling = SC_IDLESTYLING_NONE
        else
            editor.IdleStyling = SC_IDLESTYLING_ALL
        end
    end
end


local function FileIdleStyling()
    -- Big file will set IdleStyling to 0.
    -- Small file will set IdleStyling to 3.
    -- Big is larger than 1000 lines at 80 characters.

    if editor.Length > 80000 then
        editor.IdleStyling = SC_IDLESTYLING_NONE
    else
        editor.IdleStyling = SC_IDLESTYLING_ALL
    end
end


local function EventReady()
    -- User option.
    local useIdleStylingHandlers = true

    -- Set IdleStyling setting.
    if useIdleStylingHandlers ~= nil then
        editor.IdleStyling = SC_IDLESTYLING_NONE
    end

    -- Register IdleStyling event handlers.
    if useIdleStylingHandlers then
        npp.AddEventHandler('OnOpen', FileIdleStyling)
        npp.AddEventHandler('OnSwitchFile', FileIdleStyling)
        npp.AddEventHandler('OnModification', ModIdleStyling)
    end
end


npp.AddEventHandler('OnReady', EventReady)

It mostly works OK though sometimes it does the 30 second styling so has it’s faults.

The difference of identifier of AAA to 'AAA' made little difference with the lexer speed of processing as the later is simple string and yet took about the same amount of time to finish. Double quoted strings and here-doc string are interpreted with special characters so single quoted strings should be faster to process, seems not that much difference in time with my testing.

PeterJones

@mpheath,

If you want the old “just in time” aka JIT with only what is visual processing behavior, then install LuaScript/PythonScript/… plugin and change the idle styling setting.

… That originally prompted me to think, “then we should ask Don to setIdleStyling(0) (NONE) before a paste and back to 3 (ALL) after the paste”. But then it hit me that keyboard-shortcut or menu paste are just calling the SCI_PASTE directly, AFAIR. So is that something that N++ can inject? Or would Scintilla itself have to be edited to redefine SCI_PASTE to temporarily disable SetIdleStyling during paste? (if the latter, do you know how to change SetIdleStyling in SciTE, so the behavioral difference can be made obvious to the Scintilla team?)

I also confirmed that it was the commit to address “Enhance performance of syntax highlighting for large files. (Fix #15952)” in v8.7.6 that changed the setIdleStyling to ALL=3, so our concurrent investigations found the same cause. :-)

mpheath

@PeterJones If PythonScript can do it with SC_MOD_BEFOREINSERT message then so can Notepad++. It is hard to know what the user may do to aggravate the current idle styling setting. If Scintilla knew best then there would not be multiple settings, rather a leave it with me and I will handle it, OK, no worries.

SCI_PASTE should send a SC_MOD_BEFOREINSERT message which is why the Lua code posted uses it. It is before text is inserted so it knows that the paste is going to happen which if large, changes the idle setting.

I like the 1 liner to set to 0. I think the opposite, small file = 3, larger files = 0. Larger files are always going to be proportional with processing problems when time is the measurement. Larger files need like a super computer to match the processing speed of small files.

P.S. good tracing to the commit.