Browser Console code snippet to Decompress Firefox 56 jsonlz4 Session History file

decompress-jsonlz4-session-history.txt

/* 
FOR FIREFOX 66+, USE THE FOLLOWING SCRIPT INSTEAD:
https://gist.github.com/jscher2000/4403507e33df0918289619edb83f8193

NOTE: BEFORE RUNNING THIS SCRIPT, CHECK THIS SETTING:
Type or paste about:config into the address bar and press Enter
Click the button promising to be careful
In the search box type devt and pause while Firefox filters the list
If devtools.chrome.enabled is false, double-click it to toggle to true

Paste this entire script into the command line at the bottom of the Browser Console (Windows: Ctrl+Shift+j)
Then press Enter to run the script. A file picker should promptly open.

See: http://forums.mozillazine.org/viewtopic.php?p=14111285#p14111285
*/
var {utils:Cu} = Components;
function decompressBookmarksFile(oFilePath,nFilePath){
	Cu.import("resource://gre/modules/Task.jsm");
	Cu.import("resource://gre/modules/osfile.jsm");
	return Task.spawn(function* () {
		var jsonString = yield OS.File.read(oFilePath,{compression:"lz4"}); 
		yield OS.File.writeAtomic(nFilePath, jsonString);})
}
// Set up file chooser
var fp = Components.classes["@mozilla.org/filepicker;1"].createInstance(Components.interfaces.nsIFilePicker);
var fu = Cu.import("resource://gre/modules/FileUtils.jsm").FileUtils
fp.init(window, "Open File", Components.interfaces.nsIFilePicker.modeOpen);
fp.appendFilter("Session History Files", "*.jsonlz4*");
fp.displayDirectory = fu.File(OS.Path.join(OS.Constants.Path.profileDir, "\sessionstore-backups"));
// Call file chooser
fp.open((aResult) => {
  if (aResult == Components.interfaces.nsIFilePicker.returnOK) {
	if (fp.file.exists() && fp.file.isFile() && fp.file.isReadable()) {
		var oldfile = fp.file.path;
		// Construct output file name
		var newfile = oldfile + "_converted.json";
		try {
			decompressBookmarksFile(oldfile, newfile);
			console.log("Saved as: \"" + newfile + "\"");
			if(confirm("Open JSON file in a Firefox tab?")){
				var uri="file:///"+newfile.replace(/\\/g, "/");
				window.open(uri, "_blank");
			}
		}
		catch (err) {
			console.log(err);
		}
	}
  }
});

I created a webapp that is simpler to use:

• Session History: https://www.jeffersonscher.com/res/scrounger.html

Just saying thanks for the webapp. Saved my hide.