logging.js

/* 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/. */
"use strict";

const global = this;

Instances.register("ScriptError", "@mozilla.org/scripterror;1", "nsIScriptError", "init");

var UNKNOWN_STACK = {
  stackMsg: "",
  sourceName: "unknown",
  sourceLine: "",
  lineNumber: 0,
  columnNumber: 0
};
Object.freeze(UNKNOWN_STACK);

function prepareStack(stack) {
  if (!stack || !(stack instanceof Ci.nsIStackFrame)) {
    stack = Components.stack;
    for (let i = 0; stack && i < 2; ++i) {
      stack = stack.caller;
    }
    if (!stack) {
      return UNKNOWN_STACK;
    }
  }
  let rv = {};
  rv.sourceName = stack.filename;
  rv.sourceLine = stack.sourceLine;
  rv.lineNumber = stack.lineNumber;
  let message = [];
  for (let i = 0; stack && i < 6; ++i, stack = stack.caller) {
    if (stack.lineNumber) {
      message.push("\t" + (stack.name || "[anonymous]") + "() @ " + stack.filename + ":" + stack.lineNumber);
    }
    else {
      message.push("\t[native @ " + (stack.languageName || "???" ) + "]");
    }
  }
  rv.stackMsg = message.join("\n");
  rv.prototype = UNKNOWN_STACK;
  return rv;
}

const {
  errorFlag,
  warningFlag,
  exceptionFlag
} = Ci.nsIScriptError;

Object.defineProperties(exports, {
  LOG_DEBUG: {value: 0, enumerable: true},
  LOG_INFO: {value: 1, enumerable: true},
  LOG_ERROR: {value: 2, enumerable: true},
  LOG_NONE: {value: 0x7FFFFFFF},
  PREFIX: {get: function() {return prefix;}},
  setLogLevel: {value: function(l) {global.level = l;}}
});

var prefix = ADDON.name;
var level = exports.LOG_NONE;

exports.log = function(level, message, exception) {
  try {
    if (global.level > level)  {
      return;
    }

    if (message instanceof Ci.nsIScriptError || message instanceof Ci.nsIException || message.fileName) {
      exception = message;
      message = exception.message;
    }
    else if (exception) {
      message = message + " [Exception: " + exception.message + "]";
    }

    let {
      stackMsg,
      sourceName,
      sourceLine,
      lineNumber,
      columnNumber
    } = prepareStack((exception && exception.location) || null);

    if (stackMsg) {
      message += "\n" + stackMsg;
    }

    let category = "component javascript";

    if (exception) {
      if (exception instanceof Ci.nsIScriptError) {
        sourceName = exception.sourceName;
        sourceLine = exception.sourceLine;
        lineNumber = exception.lineNumber;
        columnNumber = exception.columnNumber;
        category = exception.category;
      }
      else if (exception instanceof Ci.nsIException) {
        sourceName = exception.filename;
        lineNumber = exception.lineNumber;
      }
      else {
        sourceName = exception.fileName || sourceName;
        lineNumber = exception.lineNumber || lineNumber;
      }
    }

    let levelMsg;
    switch (level) {
      case exports.LOG_ERROR:
        levelMsg = "error";
        break;
      case exports.LOG_INFO:
        levelMsg = "info";
        break;
      default:
        levelMsg = "debug";
    }

    message = global.prefix + " (" + levelMsg + ") - " + message;

    const scriptError = new Instances.ScriptError(
      message,
      sourceName,
      sourceLine,
      lineNumber,
      columnNumber,
      level >= exports.LOG_ERROR ? errorFlag : warningFlag,
      category);
    Services.console.logMessage(scriptError);
  }
  catch (ex) {
    reportError("failed to log");
    reportError(ex);
    reportError(exception || message);
  }
}

/* vim: set et ts=2 sw=2 : */