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<html lang="en-US">
  <head>
    <meta charset="UTF-8" />
    <title>Leak Gauge</title>

    <style type="text/css">
      pre {
        margin: 0;
      }
      pre.output {
        border: medium solid;
        padding: 1em;
        margin: 1em;
      }
    </style>
    <script>
      function runfile(file) {
        var result = "Results of processing log " + file.fileName + " :\n";

        var fileReader = new FileReader();
        fileReader.onload = function (e) {
          runContents(result, e.target.result);
        };
        fileReader.readAsText(file, "iso-8859-1");
      }

      function runContents(result, contents) {
        // A hash of objects (keyed by the first word of the line in the log)
        // that have two public methods, handle_line and dump (to be called using
        // call, above), along with any private data they need.
        var handlers = {
          DOMWINDOW: {
            count: 0,
            windows: {},
            handle_line(line) {
              var match = line.match(/^([0-9a-f]*) (\S*)(.*)/);
              if (match) {
                var addr = match[1];
                var verb = match[2];
                var rest = match[3];
                if (verb == "created") {
                  let m = rest.match(/ outer=([0-9a-f]*)$/);
                  if (!m) throw new Error("outer expected");
                  this.windows[addr] = { outer: m[1] };
                  ++this.count;
                } else if (verb == "destroyed") {
                  delete this.windows[addr];
                } else if (verb == "SetNewDocument") {
                  let m = rest.match(/^ (.*)$/);
                  if (!m) throw new Error("URI expected");
                  this.windows[addr][m[1]] = true;
                }
              }
            },
            dump() {
              for (var addr in this.windows) {
                var winobj = this.windows[addr];
                var outer = winobj.outer;
                delete winobj.outer;
                result +=
                  "Leaked " +
                  (outer == "0" ? "outer" : "inner") +
                  " window " +
                  addr +
                  " " +
                  (outer == "0" ? "" : "(outer " + outer + ") ") +
                  "at address " +
                  addr +
                  ".\n";
                for (var uri in winobj) {
                  result += ' ... with URI "' + uri + '".\n';
                }
              }
            },
            summary() {
              result +=
                "Leaked " +
                Object.keys(this.windows).length +
                " out of " +
                this.count +
                " DOM Windows\n";
            },
          },
          DOCUMENT: {
            count: 0,
            docs: {},
            handle_line(line) {
              var match = line.match(/^([0-9a-f]*) (\S*)(.*)/);
              if (match) {
                var addr = match[1];
                var verb = match[2];
                var rest = match[3];
                if (verb == "created") {
                  this.docs[addr] = {};
                  ++this.count;
                } else if (verb == "destroyed") {
                  delete this.docs[addr];
                } else if (
                  verb == "ResetToURI" ||
                  verb == "StartDocumentLoad"
                ) {
                  var m = rest.match(/^ (.*)$/);
                  if (!m) throw new Error("URI expected");
                  var uri = m[1];
                  var doc_info = this.docs[addr];
                  doc_info[uri] = true;
                  if ("nim" in doc_info) {
                    doc_info.nim[uri] = true;
                  }
                }
              }
            },
            dump() {
              for (var addr in this.docs) {
                var doc = this.docs[addr];
                result += "Leaked document at address " + addr + ".\n";
                for (var uri in doc) {
                  if (uri != "nim") {
                    result += ' ... with URI "' + uri + '".\n';
                  }
                }
              }
            },
            summary() {
              result +=
                "Leaked " +
                Object.keys(this.docs).length +
                " out of " +
                this.count +
                " documents\n";
            },
          },
          DOCSHELL: {
            count: 0,
            shells: {},
            handle_line(line) {
              var match = line.match(/^([0-9a-f]*) (\S*)(.*)/);
              if (match) {
                var addr = match[1];
                var verb = match[2];
                var rest = match[3];
                if (verb == "created") {
                  this.shells[addr] = {};
                  ++this.count;
                } else if (verb == "destroyed") {
                  delete this.shells[addr];
                } else if (verb == "InternalLoad" || verb == "SetCurrentURI") {
                  var m = rest.match(/^ (.*)$/);
                  if (!m) throw new Error("URI expected");
                  this.shells[addr][m[1]] = true;
                }
              }
            },
            dump() {
              for (var addr in this.shells) {
                var doc = this.shells[addr];
                result += "Leaked docshell at address " + addr + ".\n";
                for (var uri in doc) {
                  result += ' ... which loaded URI "' + uri + '".\n';
                }
              }
            },
            summary() {
              result +=
                "Leaked " +
                Object.keys(this.shells).length +
                " out of " +
                this.count +
                " docshells\n";
            },
          },
          NODEINFOMANAGER: {
            count: 0,
            nims: {},
            handle_line(line) {
              var match = line.match(/^([0-9a-f]*) (\S*)(.*)/);
              if (match) {
                var addr = match[1];
                var verb = match[2];
                var rest = match[3];
                if (verb == "created") {
                  this.nims[addr] = {};
                  ++this.count;
                } else if (verb == "destroyed") {
                  delete this.nims[addr];
                } else if (verb == "Init") {
                  var m = rest.match(/^ document=(.*)$/);
                  if (!m) throw new Error("document pointer expected");
                  var nim_info = this.nims[addr];
                  var doc = m[1];
                  if (doc != "0") {
                    var doc_info = handlers.DOCUMENT.docs[doc];
                    for (var uri in doc_info) {
                      nim_info[uri] = true;
                    }
                    doc_info.nim = nim_info;
                  }
                }
              }
            },
            dump() {
              for (var addr in this.nims) {
                var nim = this.nims[addr];
                result +=
                  "Leaked content nodes associated with node info manager at address " +
                  addr +
                  ".\n";
                for (var uri in nim) {
                  result += ' ... with document URI "' + uri + '".\n';
                }
              }
            },
            summary() {
              result +=
                "Leaked content nodes in " +
                Object.keys(this.nims).length +
                " out of " +
                this.count +
                " documents\n";
            },
          },
        };

        var lines = contents.split(/[\r\n]+/);
        for (var j in lines) {
          var line = lines[j];
          // strip off initial "-", thread id, and thread pointer; separate
          // first word and rest
          var matches = line.match(/^\-?[0-9]*\[[0-9a-f]*\]: (\S*) (.*)$/);
          if (matches) {
            let handler = matches[1];
            var data = matches[2];
            if (typeof handlers[handler] != "undefined") {
              handlers[handler].handle_line(data);
            }
          }
        }

        for (let handler in handlers) handlers[handler].dump();
        if (result.length) result += "\n";
        result += "Summary:\n";
        for (let handler in handlers) handlers[handler].summary();
        result += "\n";

        var out = document.createElement("pre");
        out.className = "output";
        out.appendChild(document.createTextNode(result));
        document.body.appendChild(out);
      }

      function run() {
        var input = document.getElementById("fileinput");
        var files = input.files;
        for (var i = 0; i < files.length; ++i) runfile(files[i]);
        // So the user can process the same filename again (after
        // overwriting the log), clear the value on the form input so we
        // will always get an onchange event.
        input.value = "";
      }
    </script>
  </head>
  <body>
    <h1>Leak Gauge</h1>

    <pre>
$Id: leak-gauge.html,v 1.8 2008/02/08 19:55:34 dbaron%dbaron.org Exp $</pre
    >

    <p>
      This script is designed to help testers isolate and simplify testcases for
      many classes of leaks (those that involve large graphs of core data
      structures) in Mozilla-based browsers. It is designed to print information
      about what has leaked by processing a log taken while running the browser.
      Such a log can be taken over a long session of normal browsing and then
      the log can be processed to find sites that leak. Once a site is known to
      leak, the logging can then be repeated to figure out under what conditions
      the leak occurs.
    </p>

    <p>The way to create this log is to set the environment variables:</p>
    <pre>  MOZ_LOG=DOMLeak:5,DocumentLeak:5,nsDocShellLeak:5,NodeInfoManagerLeak:5
  MOZ_LOG_FILE=nspr.log     <i>(or any other filename of your choice)</i></pre>
    <p>in your shell and then run the program.</p>
    <ul>
      <li>
        In a Windows command prompt, set environment variables with
        <pre>    set VAR=value</pre>
      </li>
      <li>
        In an sh-based shell such as bash, set environment variables with
        <pre>    export VAR=value</pre>
      </li>
      <li>
        In a csh-based shell such as tcsh, set environment variables with
        <pre>    setenv VAR value</pre>
      </li>
    </ul>

    <p>
      Once you have this log from a complete run of the browser (you have to
      exit; otherwise it will look like everything leaked), you can load this
      page (be careful not to overwrite the log when starting the browser to
      load this page) and enter the filename of the log:
    </p>

    <p><input type="file" id="fileinput" onchange="run()" /></p>

    <p>
      Then you'll see the output below, which will tell you which of certain
      core objects leaked and the URLs associated with those objects.
    </p>
  </body>
</html>
