annotate contrib/packaging/inno/modpath.iss @ 52284:f4aede0f01af

rust-manifest: use `memchr` crate for all byte-finding needs

While writing a very dumb manifest diffing algorithm for a proof-of-concept
I saw that `Manifest::find_by_path` was much slower than I was expecting.

It turns out that the Rust stdlib uses slow (all is relative) code when
searching for byte positions for reasons ranging from portability, SIMD
API stability, nobody doing the work, etc. `memch` is much faster for these
purposes, so let's use it.

I was measuring ~670ms of profile time in `find_by_path`, after this patch
it went down to ~230ms.

// ----------------------------------------------------------------------------
//
// Inno Setup Ver:	5.4.2
// Script Version:	1.4.2
// Author:			Jared Breland <[e-mail]>
// Homepage:		http://www.legroom.net/software
// License:			GNU Lesser General Public License (LGPL), version 3
//						http://www.gnu.org/licenses/lgpl.html
//
// Script Function:
//	Allow modification of environmental path directly from Inno Setup installers
//
// Instructions:
//	Copy modpath.iss to the same directory as your setup script
//
//	Add this statement to your [Setup] section
//		ChangesEnvironment=true
//
//	Add this statement to your [Tasks] section
//	You can change the Description or Flags
//	You can change the Name, but it must match the ModPathName setting below
//		Name: modifypath; Description: &Add application directory to your environmental path; Flags: unchecked
//
//	Add the following to the end of your [Code] section
//	ModPathName defines the name of the task defined above
//	ModPathType defines whether the 'user' or 'system' path will be modified;
//		this will default to user if anything other than system is set
//	setArrayLength must specify the total number of dirs to be added
//	Result[0] contains first directory, Result[1] contains second, etc.
//		const
//			ModPathName = 'modifypath';
//			ModPathType = 'user';
//
//		function ModPathDir(): TArrayOfString;
//		begin
//			setArrayLength(Result, 1);
//			Result[0] := ExpandConstant('{app}');
//		end;
//		#include "modpath.iss"
// ----------------------------------------------------------------------------

procedure ModPath();
var
	oldpath:	String;
	newpath:	String;
	updatepath:	Boolean;
	pathArr:	TArrayOfString;
	aExecFile:	String;
	aExecArr:	TArrayOfString;
	i, d:		Integer;
	pathdir:	TArrayOfString;
	regroot:	Integer;
	regpath:	String;

begin
	// Get constants from main script and adjust behavior accordingly
	// ModPathType MUST be 'system' or 'user'; force 'user' if invalid
	if ModPathType = 'system' then begin
		regroot := HKEY_LOCAL_MACHINE;
		regpath := 'SYSTEM\CurrentControlSet\Control\Session Manager\Environment';
	end else begin
		regroot := HKEY_CURRENT_USER;
		regpath := 'Environment';
	end;

	// Get array of new directories and act on each individually
	pathdir := ModPathDir();
	for d := 0 to GetArrayLength(pathdir)-1 do begin
		updatepath := true;

		// Get current path, split into an array
		RegQueryStringValue(regroot, regpath, 'Path', oldpath);
		oldpath := oldpath + ';';
		i := 0;

		while (Pos(';', oldpath) > 0) do begin
			SetArrayLength(pathArr, i+1);
			pathArr[i] := Copy(oldpath, 0, Pos(';', oldpath)-1);
			oldpath := Copy(oldpath, Pos(';', oldpath)+1, Length(oldpath));
			i := i + 1;

			// Check if current directory matches app dir
			if pathdir[d] = pathArr[i-1] then begin
				// if uninstalling, remove dir from path
				if IsUninstaller() = true then begin
					continue;
				// if installing, flag that dir already exists in path
				end else begin
					updatepath := false;
				end;
			end;

			// Add current directory to new path
			if i = 1 then begin
				newpath := pathArr[i-1];
			end else begin
				newpath := newpath + ';' + pathArr[i-1];
			end;
		end;

		// Append app dir to path if not already included
		if (IsUninstaller() = false) AND (updatepath = true) then
			newpath := newpath + ';' + pathdir[d];

		// Write new path
		RegWriteStringValue(regroot, regpath, 'Path', newpath);
	end;
end;

// Split a string into an array using passed delimeter
procedure MPExplode(var Dest: TArrayOfString; Text: String; Separator: String);
var
	i: Integer;
begin
	i := 0;
	repeat
		SetArrayLength(Dest, i+1);
		if Pos(Separator,Text) > 0 then	begin
			Dest[i] := Copy(Text, 1, Pos(Separator, Text)-1);
			Text := Copy(Text, Pos(Separator,Text) + Length(Separator), Length(Text));
			i := i + 1;
		end else begin
			 Dest[i] := Text;
			 Text := '';
		end;
	until Length(Text)=0;
end;


procedure CurStepChanged(CurStep: TSetupStep);
var
	taskname:	String;
begin
	taskname := ModPathName;
	if CurStep = ssPostInstall then
		if IsTaskSelected(taskname) then
			ModPath();
end;

procedure CurUninstallStepChanged(CurUninstallStep: TUninstallStep);
var
	aSelectedTasks:	TArrayOfString;
	i:				Integer;
	taskname:		String;
	regpath:		String;
	regstring:		String;
	appid:			String;
begin
	// only run during actual uninstall
	if CurUninstallStep = usUninstall then begin
		// get list of selected tasks saved in registry at install time
		appid := '{#emit SetupSetting("AppId")}';
		if appid = '' then appid := '{#emit SetupSetting("AppName")}';
		regpath := ExpandConstant('Software\Microsoft\Windows\CurrentVersion\Uninstall\'+appid+'_is1');
		RegQueryStringValue(HKLM, regpath, 'Inno Setup: Selected Tasks', regstring);
		if regstring = '' then RegQueryStringValue(HKCU, regpath, 'Inno Setup: Selected Tasks', regstring);

		// check each task; if matches modpath taskname, trigger patch removal
		if regstring <> '' then begin
			taskname := ModPathName;
			MPExplode(aSelectedTasks, regstring, ',');
			if GetArrayLength(aSelectedTasks) > 0 then begin
				for i := 0 to GetArrayLength(aSelectedTasks)-1 do begin
					if comparetext(aSelectedTasks[i], taskname) = 0 then
						ModPath();
				end;
			end;
		end;
	end;
end;

function NeedRestart(): Boolean;
begin
	Result := False;
end;