gecko-dev/toolkit/crashreporter/KeyValueParser.jsm

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

ChromeUtils.defineModuleGetter(this, "OS", "resource://gre/modules/osfile.jsm");

var EXPORTED_SYMBOLS = [
  "parseKeyValuePairsFromLines",
  "parseKeyValuePairs",
  "parseKeyValuePairsFromFile",
  "parseKeyValuePairsFromFileAsync",
];

var parseKeyValuePairsFromLines = function(lines) {
  let data = {};
  for (let line of lines) {
    if (line == "") {
      continue;
    }

    // can't just .split() because the value might contain = characters
    let eq = line.indexOf("=");
    if (eq != -1) {
      let [key, value] = [line.substring(0, eq), line.substring(eq + 1)];
      if (key && value) {
        data[key] = value.replace(/\\n/g, "\n").replace(/\\\\/g, "\\");
      }
    }
  }
  return data;
};

function parseKeyValuePairs(text) {
  let lines = text.split("\n");
  return parseKeyValuePairsFromLines(lines);
}

// some test setup still uses this sync version
function parseKeyValuePairsFromFile(file) {
  let fstream = Cc["@mozilla.org/network/file-input-stream;1"].createInstance(
    Ci.nsIFileInputStream
  );
  fstream.init(file, -1, 0, 0);
  let is = Cc["@mozilla.org/intl/converter-input-stream;1"].createInstance(
    Ci.nsIConverterInputStream
  );
  is.init(
    fstream,
    "UTF-8",
    1024,
    Ci.nsIConverterInputStream.DEFAULT_REPLACEMENT_CHARACTER
  );
  let str = {};
  let contents = "";
  while (is.readString(4096, str) != 0) {
    contents += str.value;
  }
  is.close();
  fstream.close();
  return parseKeyValuePairs(contents);
}

async function parseKeyValuePairsFromFileAsync(file) {
  let contents = await OS.File.read(file, { encoding: "utf-8" });
  return parseKeyValuePairs(contents);
}