1 files changed, 449 insertions, 0 deletions
diff --git a/services/common/logmanager.sys.mjs b/services/common/logmanager.sys.mjs
new file mode 100644
index 0000000000..178228f3e6
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+++ b/services/common/logmanager.sys.mjs
@@ -0,0 +1,449 @@
+/* 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;";
+
+import { Log } from "resource://gre/modules/Log.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  FileUtils: "resource://gre/modules/FileUtils.sys.mjs",
+});
+ChromeUtils.defineModuleGetter(
+  lazy,
+  "NetUtil",
+  "resource://gre/modules/NetUtil.jsm"
+);
+
+import { Preferences } from "resource://gre/modules/Preferences.sys.mjs";
+
+const DEFAULT_MAX_ERROR_AGE = 20 * 24 * 60 * 60; // 20 days
+
+// "shared" logs (ie, where the same log name is used by multiple LogManager
+// instances) are a fact of life here - eg, FirefoxAccounts logs are used by
+// both Sync and Reading List.
+// However, different instances have different pref branches, so we need to
+// handle when one pref branch says "Debug" and the other says "Error"
+// So we (a) keep singleton console and dump appenders and (b) keep track
+// of the minimum (ie, most verbose) level and use that.
+// This avoids (a) the most recent setter winning (as that is indeterminate)
+// and (b) multiple dump/console appenders being added to the same log multiple
+// times, which would cause messages to appear twice.
+
+// Singletons used by each instance.
+var formatter;
+var dumpAppender;
+var consoleAppender;
+
+// A set of all preference roots used by all instances.
+var allBranches = new Set();
+
+const STREAM_SEGMENT_SIZE = 4096;
+const PR_UINT32_MAX = 0xffffffff;
+
+/**
+ * Append to an nsIStorageStream
+ *
+ * This writes logging output to an in-memory stream which can later be read
+ * back as an nsIInputStream. It can be used to avoid expensive I/O operations
+ * during logging. Instead, one can periodically consume the input stream and
+ * e.g. write it to disk asynchronously.
+ */
+class StorageStreamAppender extends Log.Appender {
+  constructor(formatter) {
+    super(formatter);
+    this._name = "StorageStreamAppender";
+
+    this._converterStream = null; // holds the nsIConverterOutputStream
+    this._outputStream = null; // holds the underlying nsIOutputStream
+
+    this._ss = null;
+  }
+
+  get outputStream() {
+    if (!this._outputStream) {
+      // First create a raw stream. We can bail out early if that fails.
+      this._outputStream = this.newOutputStream();
+      if (!this._outputStream) {
+        return null;
+      }
+
+      // Wrap the raw stream in an nsIConverterOutputStream. We can reuse
+      // the instance if we already have one.
+      if (!this._converterStream) {
+        this._converterStream = Cc[
+          "@mozilla.org/intl/converter-output-stream;1"
+        ].createInstance(Ci.nsIConverterOutputStream);
+      }
+      this._converterStream.init(this._outputStream, "UTF-8");
+    }
+    return this._converterStream;
+  }
+
+  newOutputStream() {
+    let ss = (this._ss = Cc["@mozilla.org/storagestream;1"].createInstance(
+      Ci.nsIStorageStream
+    ));
+    ss.init(STREAM_SEGMENT_SIZE, PR_UINT32_MAX, null);
+    return ss.getOutputStream(0);
+  }
+
+  getInputStream() {
+    if (!this._ss) {
+      return null;
+    }
+    return this._ss.newInputStream(0);
+  }
+
+  reset() {
+    if (!this._outputStream) {
+      return;
+    }
+    this.outputStream.close();
+    this._outputStream = null;
+    this._ss = null;
+  }
+
+  doAppend(formatted) {
+    if (!formatted) {
+      return;
+    }
+    try {
+      this.outputStream.writeString(formatted + "\n");
+    } catch (ex) {
+      if (ex.result == Cr.NS_BASE_STREAM_CLOSED) {
+        // The underlying output stream is closed, so let's open a new one
+        // and try again.
+        this._outputStream = null;
+      }
+      try {
+        this.outputStream.writeString(formatted + "\n");
+      } catch (ex) {
+        // Ah well, we tried, but something seems to be hosed permanently.
+      }
+    }
+  }
+}
+
+// A storage appender that is flushable to a file on disk.  Policies for
+// when to flush, to what file, log rotation etc are up to the consumer
+// (although it does maintain a .sawError property to help the consumer decide
+// based on its policies)
+class FlushableStorageAppender extends StorageStreamAppender {
+  constructor(formatter) {
+    super(formatter);
+    this.sawError = false;
+  }
+
+  append(message) {
+    if (message.level >= Log.Level.Error) {
+      this.sawError = true;
+    }
+    StorageStreamAppender.prototype.append.call(this, message);
+  }
+
+  reset() {
+    super.reset();
+    this.sawError = false;
+  }
+
+  // Flush the current stream to a file. Somewhat counter-intuitively, you
+  // must pass a log which will be written to with details of the operation.
+  async flushToFile(subdirArray, filename, log) {
+    let inStream = this.getInputStream();
+    this.reset();
+    if (!inStream) {
+      log.debug("Failed to flush log to a file - no input stream");
+      return;
+    }
+    log.debug("Flushing file log");
+    log.trace("Beginning stream copy to " + filename + ": " + Date.now());
+    try {
+      await this._copyStreamToFile(inStream, subdirArray, filename, log);
+      log.trace("onCopyComplete", Date.now());
+    } catch (ex) {
+      log.error("Failed to copy log stream to file", ex);
+    }
+  }
+
+  /**
+   * Copy an input stream to the named file, doing everything off the main
+   * thread.
+   * subDirArray is an array of path components, relative to the profile
+   * directory, where the file will be created.
+   * outputFileName is the filename to create.
+   * Returns a promise that is resolved on completion or rejected with an error.
+   */
+  async _copyStreamToFile(inputStream, subdirArray, outputFileName, log) {
+    let outputDirectory = PathUtils.join(PathUtils.profileDir, ...subdirArray);
+    await IOUtils.makeDirectory(outputDirectory);
+    let fullOutputFileName = PathUtils.join(outputDirectory, outputFileName);
+
+    let outputStream = Cc[
+      "@mozilla.org/network/file-output-stream;1"
+    ].createInstance(Ci.nsIFileOutputStream);
+
+    outputStream.init(
+      new lazy.FileUtils.File(fullOutputFileName),
+      -1,
+      -1,
+      Ci.nsIFileOutputStream.DEFER_OPEN
+    );
+
+    await new Promise(resolve =>
+      lazy.NetUtil.asyncCopy(inputStream, outputStream, () => resolve())
+    );
+
+    outputStream.close();
+    log.trace("finished copy to", fullOutputFileName);
+  }
+}
+
+// The public LogManager object.
+export function LogManager(prefRoot, logNames, logFilePrefix) {
+  this._prefObservers = [];
+  this.init(prefRoot, logNames, logFilePrefix);
+}
+
+LogManager.StorageStreamAppender = StorageStreamAppender;
+
+LogManager.prototype = {
+  _cleaningUpFileLogs: false,
+
+  init(prefRoot, logNames, logFilePrefix) {
+    if (prefRoot instanceof Preferences) {
+      this._prefs = prefRoot;
+    } else {
+      this._prefs = new Preferences(prefRoot);
+    }
+
+    this.logFilePrefix = logFilePrefix;
+    if (!formatter) {
+      // Create a formatter and various appenders to attach to the logs.
+      formatter = new Log.BasicFormatter();
+      consoleAppender = new Log.ConsoleAppender(formatter);
+      dumpAppender = new Log.DumpAppender(formatter);
+    }
+
+    allBranches.add(this._prefs._branchStr);
+    // We create a preference observer for all our prefs so they are magically
+    // reflected if the pref changes after creation.
+    let setupAppender = (
+      appender,
+      prefName,
+      defaultLevel,
+      findSmallest = false
+    ) => {
+      let observer = newVal => {
+        let level = Log.Level[newVal] || defaultLevel;
+        if (findSmallest) {
+          // As some of our appenders have global impact (ie, there is only one
+          // place 'dump' goes to), we need to find the smallest value from all
+          // prefs controlling this appender.
+          // For example, if consumerA has dump=Debug then consumerB sets
+          // dump=Error, we need to keep dump=Debug so consumerA is respected.
+          for (let branch of allBranches) {
+            let lookPrefBranch = new Preferences(branch);
+            let lookVal = Log.Level[lookPrefBranch.get(prefName)];
+            if (lookVal && lookVal < level) {
+              level = lookVal;
+            }
+          }
+        }
+        appender.level = level;
+      };
+      this._prefs.observe(prefName, observer, this);
+      this._prefObservers.push([prefName, observer]);
+      // and call the observer now with the current pref value.
+      observer(this._prefs.get(prefName));
+      return observer;
+    };
+
+    this._observeConsolePref = setupAppender(
+      consoleAppender,
+      "log.appender.console",
+      Log.Level.Fatal,
+      true
+    );
+    this._observeDumpPref = setupAppender(
+      dumpAppender,
+      "log.appender.dump",
+      Log.Level.Error,
+      true
+    );
+
+    // The file appender doesn't get the special singleton behaviour.
+    let fapp = (this._fileAppender = new FlushableStorageAppender(formatter));
+    // the stream gets a default of Debug as the user must go out of their way
+    // to see the stuff spewed to it.
+    this._observeStreamPref = setupAppender(
+      fapp,
+      "log.appender.file.level",
+      Log.Level.Debug
+    );
+
+    // now attach the appenders to all our logs.
+    for (let logName of logNames) {
+      let log = Log.repository.getLogger(logName);
+      for (let appender of [fapp, dumpAppender, consoleAppender]) {
+        log.addAppender(appender);
+      }
+    }
+    // and use the first specified log as a "root" for our log.
+    this._log = Log.repository.getLogger(logNames[0] + ".LogManager");
+  },
+
+  /**
+   * Cleanup this instance
+   */
+  finalize() {
+    for (let [name, pref] of this._prefObservers) {
+      this._prefs.ignore(name, pref, this);
+    }
+    this._prefObservers = [];
+    try {
+      allBranches.delete(this._prefs._branchStr);
+    } catch (e) {}
+    this._prefs = null;
+  },
+
+  get _logFileSubDirectoryEntries() {
+    // At this point we don't allow a custom directory for the logs, nor allow
+    // it to be outside the profile directory.
+    // This returns an array of the the relative directory entries below the
+    // profile dir, and is the directory about:sync-log uses.
+    return ["weave", "logs"];
+  },
+
+  get sawError() {
+    return this._fileAppender.sawError;
+  },
+
+  // Result values for resetFileLog.
+  SUCCESS_LOG_WRITTEN: "success-log-written",
+  ERROR_LOG_WRITTEN: "error-log-written",
+
+  /**
+   * Possibly generate a log file for all accumulated log messages and refresh
+   * the input & output streams.
+   * Whether a "success" or "error" log is written is determined based on
+   * whether an "Error" log entry was written to any of the logs.
+   * Returns a promise that resolves on completion with either null (for no
+   * file written or on error), SUCCESS_LOG_WRITTEN if a "success" log was
+   * written, or ERROR_LOG_WRITTEN if an "error" log was written.
+   */
+  async resetFileLog() {
+    try {
+      let flushToFile;
+      let reasonPrefix;
+      let reason;
+      if (this._fileAppender.sawError) {
+        reason = this.ERROR_LOG_WRITTEN;
+        flushToFile = this._prefs.get("log.appender.file.logOnError", true);
+        reasonPrefix = "error";
+      } else {
+        reason = this.SUCCESS_LOG_WRITTEN;
+        flushToFile = this._prefs.get("log.appender.file.logOnSuccess", false);
+        reasonPrefix = "success";
+      }
+
+      // might as well avoid creating an input stream if we aren't going to use it.
+      if (!flushToFile) {
+        this._fileAppender.reset();
+        return null;
+      }
+
+      // We have reasonPrefix at the start of the filename so all "error"
+      // logs are grouped in about:sync-log.
+      let filename =
+        reasonPrefix + "-" + this.logFilePrefix + "-" + Date.now() + ".txt";
+      await this._fileAppender.flushToFile(
+        this._logFileSubDirectoryEntries,
+        filename,
+        this._log
+      );
+      // It's not completely clear to markh why we only do log cleanups
+      // for errors, but for now the Sync semantics have been copied...
+      // (one theory is that only cleaning up on error makes it less
+      // likely old error logs would be removed, but that's not true if
+      // there are occasional errors - let's address this later!)
+      if (reason == this.ERROR_LOG_WRITTEN && !this._cleaningUpFileLogs) {
+        this._log.trace("Running cleanup.");
+        try {
+          await this.cleanupLogs();
+        } catch (err) {
+          this._log.error("Failed to cleanup logs", err);
+        }
+      }
+      return reason;
+    } catch (ex) {
+      this._log.error("Failed to resetFileLog", ex);
+      return null;
+    }
+  },
+
+  /**
+   * Finds all logs older than maxErrorAge and deletes them using async I/O.
+   */
+  cleanupLogs() {
+    let maxAge = this._prefs.get(
+      "log.appender.file.maxErrorAge",
+      DEFAULT_MAX_ERROR_AGE
+    );
+    let threshold = Date.now() - 1000 * maxAge;
+    this._log.debug("Log cleanup threshold time: " + threshold);
+
+    let shouldDelete = fileInfo => {
+      return fileInfo.lastModified < threshold;
+    };
+    return this._deleteLogFiles(shouldDelete);
+  },
+
+  /**
+   * Finds all logs and removes them.
+   */
+  removeAllLogs() {
+    return this._deleteLogFiles(() => true);
+  },
+
+  // Delete some log files. A callback is invoked for each found log file to
+  // determine if that file should be removed.
+  async _deleteLogFiles(cbShouldDelete) {
+    this._cleaningUpFileLogs = true;
+    let logDir = lazy.FileUtils.getDir(
+      "ProfD",
+      this._logFileSubDirectoryEntries
+    );
+    for (const path of await IOUtils.getChildren(logDir.path)) {
+      const name = PathUtils.filename(path);
+
+      if (!name.startsWith("error-") && !name.startsWith("success-")) {
+        continue;
+      }
+
+      try {
+        const info = await IOUtils.stat(path);
+        if (!cbShouldDelete(info)) {
+          continue;
+        }
+
+        this._log.trace(` > Cleanup removing ${name} (${info.lastModified})`);
+        await IOUtils.remove(path);
+        this._log.trace(`Deleted ${name}`);
+      } catch (ex) {
+        this._log.debug(
+          `Encountered error trying to clean up old log file ${name}`,
+          ex
+        );
+      }
+    }
+    this._cleaningUpFileLogs = false;
+    this._log.debug("Done deleting files.");
+    // This notification is used only for tests.
+    Services.obs.notifyObservers(
+      null,
+      "services-tests:common:log-manager:cleanup-logs"
+    );
+  },
+};