Add m-esr52 at 52.6.0

1 files changed, 1351 insertions, 0 deletions

diff --git a/toolkit/components/crashes/CrashManager.jsm b/toolkit/components/crashes/CrashManager.jsm
new file mode 100644
index 000000000..3aac33254
--- /dev/null
+++ b/toolkit/components/crashes/CrashManager.jsm
@@ -0,0 +1,1351 @@
+/* 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 {classes: Cc, interfaces: Ci, utils: Cu} = Components;
+const myScope = this;
+
+Cu.import("resource://gre/modules/Log.jsm", this);
+Cu.import("resource://gre/modules/osfile.jsm", this);
+Cu.import("resource://gre/modules/Promise.jsm", this);
+Cu.import("resource://gre/modules/Services.jsm", this);
+Cu.import("resource://gre/modules/Task.jsm", this);
+Cu.import("resource://gre/modules/Timer.jsm", this);
+Cu.import("resource://gre/modules/XPCOMUtils.jsm", this);
+Cu.import("resource://gre/modules/TelemetryController.jsm");
+Cu.import("resource://gre/modules/KeyValueParser.jsm");
+
+this.EXPORTED_SYMBOLS = [
+  "CrashManager",
+];
+
+/**
+ * How long to wait after application startup before crash event files are
+ * automatically aggregated.
+ *
+ * We defer aggregation for performance reasons, as we don't want too many
+ * services competing for I/O immediately after startup.
+ */
+const AGGREGATE_STARTUP_DELAY_MS = 57000;
+
+const MILLISECONDS_IN_DAY = 24 * 60 * 60 * 1000;
+
+// Converts Date to days since UNIX epoch.
+// This was copied from /services/metrics.storage.jsm. The implementation
+// does not account for leap seconds.
+function dateToDays(date) {
+  return Math.floor(date.getTime() / MILLISECONDS_IN_DAY);
+}
+
+
+/**
+ * A gateway to crash-related data.
+ *
+ * This type is generic and can be instantiated any number of times.
+ * However, most applications will typically only have one instance
+ * instantiated and that instance will point to profile and user appdata
+ * directories.
+ *
+ * Instances are created by passing an object with properties.
+ * Recognized properties are:
+ *
+ *   pendingDumpsDir (string) (required)
+ *     Where dump files that haven't been uploaded are located.
+ *
+ *   submittedDumpsDir (string) (required)
+ *     Where records of uploaded dumps are located.
+ *
+ *   eventsDirs (array)
+ *     Directories (defined as strings) where events files are written. This
+ *     instance will collects events from files in the directories specified.
+ *
+ *   storeDir (string)
+ *     Directory we will use for our data store. This instance will write
+ *     data files into the directory specified.
+ *
+ *   telemetryStoreSizeKey (string)
+ *     Telemetry histogram to report store size under.
+ */
+this.CrashManager = function (options) {
+  for (let k of ["pendingDumpsDir", "submittedDumpsDir", "eventsDirs",
+    "storeDir"]) {
+    if (!(k in options)) {
+      throw new Error("Required key not present in options: " + k);
+    }
+  }
+
+  this._log = Log.repository.getLogger("Crashes.CrashManager");
+
+  for (let k in options) {
+    let v = options[k];
+
+    switch (k) {
+      case "pendingDumpsDir":
+        this._pendingDumpsDir = v;
+        break;
+
+      case "submittedDumpsDir":
+        this._submittedDumpsDir = v;
+        break;
+
+      case "eventsDirs":
+        this._eventsDirs = v;
+        break;
+
+      case "storeDir":
+        this._storeDir = v;
+        break;
+
+      case "telemetryStoreSizeKey":
+        this._telemetryStoreSizeKey = v;
+        break;
+
+      default:
+        throw new Error("Unknown property in options: " + k);
+    }
+  }
+
+  // Promise for in-progress aggregation operation. We store it on the
+  // object so it can be returned for in-progress operations.
+  this._aggregatePromise = null;
+
+  // The CrashStore currently attached to this object.
+  this._store = null;
+
+  // A Task to retrieve the store. This is needed to avoid races when
+  // _getStore() is called multiple times in a short interval.
+  this._getStoreTask = null;
+
+  // The timer controlling the expiration of the CrashStore instance.
+  this._storeTimer = null;
+
+  // This is a semaphore that prevents the store from being freed by our
+  // timer-based resource freeing mechanism.
+  this._storeProtectedCount = 0;
+};
+
+this.CrashManager.prototype = Object.freeze({
+  // A crash in the main process.
+  PROCESS_TYPE_MAIN: "main",
+
+  // A crash in a content process.
+  PROCESS_TYPE_CONTENT: "content",
+
+  // A crash in a plugin process.
+  PROCESS_TYPE_PLUGIN: "plugin",
+
+  // A crash in a Gecko media plugin process.
+  PROCESS_TYPE_GMPLUGIN: "gmplugin",
+
+  // A crash in the GPU process.
+  PROCESS_TYPE_GPU: "gpu",
+
+  // A real crash.
+  CRASH_TYPE_CRASH: "crash",
+
+  // A hang.
+  CRASH_TYPE_HANG: "hang",
+
+  // Submission result values.
+  SUBMISSION_RESULT_OK: "ok",
+  SUBMISSION_RESULT_FAILED: "failed",
+
+  DUMP_REGEX: /^([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})\.dmp$/i,
+  SUBMITTED_REGEX: /^bp-(?:hr-)?([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})\.txt$/i,
+  ALL_REGEX: /^(.*)$/,
+
+  // How long the store object should persist in memory before being
+  // automatically garbage collected.
+  STORE_EXPIRATION_MS: 60 * 1000,
+
+  // Number of days after which a crash with no activity will get purged.
+  PURGE_OLDER_THAN_DAYS: 180,
+
+  // The following are return codes for individual event file processing.
+  // File processed OK.
+  EVENT_FILE_SUCCESS: "ok",
+  // The event appears to be malformed.
+  EVENT_FILE_ERROR_MALFORMED: "malformed",
+  // The type of event is unknown.
+  EVENT_FILE_ERROR_UNKNOWN_EVENT: "unknown-event",
+
+  /**
+   * Obtain a list of all dumps pending upload.
+   *
+   * The returned value is a promise that resolves to an array of objects
+   * on success. Each element in the array has the following properties:
+   *
+   *   id (string)
+   *      The ID of the crash (a UUID).
+   *
+   *   path (string)
+   *      The filename of the crash (<UUID.dmp>)
+   *
+   *   date (Date)
+   *      When this dump was created
+   *
+   * The returned arry is sorted by the modified time of the file backing
+   * the entry, oldest to newest.
+   *
+   * @return Promise<Array>
+   */
+  pendingDumps: function () {
+    return this._getDirectoryEntries(this._pendingDumpsDir, this.DUMP_REGEX);
+  },
+
+  /**
+   * Obtain a list of all dump files corresponding to submitted crashes.
+   *
+   * The returned value is a promise that resolves to an Array of
+   * objects. Each object has the following properties:
+   *
+   *   path (string)
+   *     The path of the file this entry comes from.
+   *
+   *   id (string)
+   *     The crash UUID.
+   *
+   *   date (Date)
+   *     The (estimated) date this crash was submitted.
+   *
+   * The returned array is sorted by the modified time of the file backing
+   * the entry, oldest to newest.
+   *
+   * @return Promise<Array>
+   */
+  submittedDumps: function () {
+    return this._getDirectoryEntries(this._submittedDumpsDir,
+                                     this.SUBMITTED_REGEX);
+  },
+
+  /**
+   * Aggregates "loose" events files into the unified "database."
+   *
+   * This function should be called periodically to collect metadata from
+   * all events files into the central data store maintained by this manager.
+   *
+   * Once events have been stored in the backing store the corresponding
+   * source files are deleted.
+   *
+   * Only one aggregation operation is allowed to occur at a time. If this
+   * is called when an existing aggregation is in progress, the promise for
+   * the original call will be returned.
+   *
+   * @return promise<int> The number of event files that were examined.
+   */
+  aggregateEventsFiles: function () {
+    if (this._aggregatePromise) {
+      return this._aggregatePromise;
+    }
+
+    return this._aggregatePromise = Task.spawn(function* () {
+      if (this._aggregatePromise) {
+        return this._aggregatePromise;
+      }
+
+      try {
+        let unprocessedFiles = yield this._getUnprocessedEventsFiles();
+
+        let deletePaths = [];
+        let needsSave = false;
+
+        this._storeProtectedCount++;
+        for (let entry of unprocessedFiles) {
+          try {
+            let result = yield this._processEventFile(entry);
+
+            switch (result) {
+              case this.EVENT_FILE_SUCCESS:
+                needsSave = true;
+                // Fall through.
+
+              case this.EVENT_FILE_ERROR_MALFORMED:
+                deletePaths.push(entry.path);
+                break;
+
+              case this.EVENT_FILE_ERROR_UNKNOWN_EVENT:
+                break;
+
+              default:
+                Cu.reportError("Unhandled crash event file return code. Please " +
+                               "file a bug: " + result);
+            }
+          } catch (ex) {
+            if (ex instanceof OS.File.Error) {
+              this._log.warn("I/O error reading " + entry.path, ex);
+            } else {
+              // We should never encounter an exception. This likely represents
+              // a coding error because all errors should be detected and
+              // converted to return codes.
+              //
+              // If we get here, report the error and delete the source file
+              // so we don't see it again.
+              Cu.reportError("Exception when processing crash event file: " +
+                             Log.exceptionStr(ex));
+              deletePaths.push(entry.path);
+            }
+          }
+        }
+
+        if (needsSave) {
+          let store = yield this._getStore();
+          yield store.save();
+        }
+
+        for (let path of deletePaths) {
+          try {
+            yield OS.File.remove(path);
+          } catch (ex) {
+            this._log.warn("Error removing event file (" + path + ")", ex);
+          }
+        }
+
+        return unprocessedFiles.length;
+
+      } finally {
+        this._aggregatePromise = false;
+        this._storeProtectedCount--;
+      }
+    }.bind(this));
+  },
+
+  /**
+   * Prune old crash data.
+   *
+   * @param date
+   *        (Date) The cutoff point for pruning. Crashes without data newer
+   *        than this will be pruned.
+   */
+  pruneOldCrashes: function (date) {
+    return Task.spawn(function* () {
+      let store = yield this._getStore();
+      store.pruneOldCrashes(date);
+      yield store.save();
+    }.bind(this));
+  },
+
+  /**
+   * Run tasks that should be periodically performed.
+   */
+  runMaintenanceTasks: function () {
+    return Task.spawn(function* () {
+      yield this.aggregateEventsFiles();
+
+      let offset = this.PURGE_OLDER_THAN_DAYS * MILLISECONDS_IN_DAY;
+      yield this.pruneOldCrashes(new Date(Date.now() - offset));
+    }.bind(this));
+  },
+
+  /**
+   * Schedule maintenance tasks for some point in the future.
+   *
+   * @param delay
+   *        (integer) Delay in milliseconds when maintenance should occur.
+   */
+  scheduleMaintenance: function (delay) {
+    let deferred = Promise.defer();
+
+    setTimeout(() => {
+      this.runMaintenanceTasks().then(deferred.resolve, deferred.reject);
+    }, delay);
+
+    return deferred.promise;
+  },
+
+  /**
+   * Record the occurrence of a crash.
+   *
+   * This method skips event files altogether and writes directly and
+   * immediately to the manager's data store.
+   *
+   * @param processType (string) One of the PROCESS_TYPE constants.
+   * @param crashType (string) One of the CRASH_TYPE constants.
+   * @param id (string) Crash ID. Likely a UUID.
+   * @param date (Date) When the crash occurred.
+   * @param metadata (dictionary) Crash metadata, may be empty.
+   *
+   * @return promise<null> Resolved when the store has been saved.
+   */
+  addCrash: function (processType, crashType, id, date, metadata) {
+    return Task.spawn(function* () {
+      let store = yield this._getStore();
+      if (store.addCrash(processType, crashType, id, date, metadata)) {
+        yield store.save();
+      }
+    }.bind(this));
+  },
+
+  /**
+   * Record the remote ID for a crash.
+   *
+   * @param crashID (string) Crash ID. Likely a UUID.
+   * @param remoteID (Date) Server/Breakpad ID.
+   *
+   * @return boolean True if the remote ID was recorded.
+   */
+  setRemoteCrashID: Task.async(function* (crashID, remoteID) {
+    let store = yield this._getStore();
+    if (store.setRemoteCrashID(crashID, remoteID)) {
+      yield store.save();
+    }
+  }),
+
+  /**
+   * Generate a submission ID for use with addSubmission{Attempt,Result}.
+   */
+  generateSubmissionID() {
+    return "sub-" + Cc["@mozilla.org/uuid-generator;1"]
+                      .getService(Ci.nsIUUIDGenerator)
+                      .generateUUID().toString().slice(1, -1);
+  },
+
+  /**
+   * Record the occurrence of a submission attempt for a crash.
+   *
+   * @param crashID (string) Crash ID. Likely a UUID.
+   * @param submissionID (string) Submission ID. Likely a UUID.
+   * @param date (Date) When the attempt occurred.
+   *
+   * @return boolean True if the attempt was recorded and false if not.
+   */
+  addSubmissionAttempt: Task.async(function* (crashID, submissionID, date) {
+    let store = yield this._getStore();
+    if (store.addSubmissionAttempt(crashID, submissionID, date)) {
+      yield store.save();
+    }
+  }),
+
+  /**
+   * Record the occurrence of a submission result for a crash.
+   *
+   * @param crashID (string) Crash ID. Likely a UUID.
+   * @param submissionID (string) Submission ID. Likely a UUID.
+   * @param date (Date) When the submission result was obtained.
+   * @param result (string) One of the SUBMISSION_RESULT constants.
+   *
+   * @return boolean True if the result was recorded and false if not.
+   */
+  addSubmissionResult: Task.async(function* (crashID, submissionID, date, result) {
+    let store = yield this._getStore();
+    if (store.addSubmissionResult(crashID, submissionID, date, result)) {
+      yield store.save();
+    }
+  }),
+
+  /**
+   * Set the classification of a crash.
+   *
+   * @param crashID (string) Crash ID. Likely a UUID.
+   * @param classifications (array) Crash classifications.
+   *
+   * @return boolean True if the data was recorded and false if not.
+   */
+  setCrashClassifications: Task.async(function* (crashID, classifications) {
+    let store = yield this._getStore();
+    if (store.setCrashClassifications(crashID, classifications)) {
+      yield store.save();
+    }
+  }),
+
+  /**
+   * Obtain the paths of all unprocessed events files.
+   *
+   * The promise-resolved array is sorted by file mtime, oldest to newest.
+   */
+  _getUnprocessedEventsFiles: function () {
+    return Task.spawn(function* () {
+      let entries = [];
+
+      for (let dir of this._eventsDirs) {
+        for (let e of yield this._getDirectoryEntries(dir, this.ALL_REGEX)) {
+          entries.push(e);
+        }
+      }
+
+      entries.sort((a, b) => { return a.date - b.date; });
+
+      return entries;
+    }.bind(this));
+  },
+
+  // See docs/crash-events.rst for the file format specification.
+  _processEventFile: function (entry) {
+    return Task.spawn(function* () {
+      let data = yield OS.File.read(entry.path);
+      let store = yield this._getStore();
+
+      let decoder = new TextDecoder();
+      data = decoder.decode(data);
+
+      let type, time;
+      let start = 0;
+      for (let i = 0; i < 2; i++) {
+        let index = data.indexOf("\n", start);
+        if (index == -1) {
+          return this.EVENT_FILE_ERROR_MALFORMED;
+        }
+
+        let sub = data.substring(start, index);
+        switch (i) {
+          case 0:
+            type = sub;
+            break;
+          case 1:
+            time = sub;
+            try {
+              time = parseInt(time, 10);
+            } catch (ex) {
+              return this.EVENT_FILE_ERROR_MALFORMED;
+            }
+        }
+
+        start = index + 1;
+      }
+      let date = new Date(time * 1000);
+      let payload = data.substring(start);
+
+      return this._handleEventFilePayload(store, entry, type, date, payload);
+    }.bind(this));
+  },
+
+  _handleEventFilePayload: function (store, entry, type, date, payload) {
+      // The payload types and formats are documented in docs/crash-events.rst.
+      // Do not change the format of an existing type. Instead, invent a new
+      // type.
+      // DO NOT ADD NEW TYPES WITHOUT DOCUMENTING!
+      let lines = payload.split("\n");
+
+      switch (type) {
+        case "crash.main.1":
+          if (lines.length > 1) {
+            this._log.warn("Multiple lines unexpected in payload for " +
+                           entry.path);
+            return this.EVENT_FILE_ERROR_MALFORMED;
+          }
+          // fall-through
+        case "crash.main.2":
+          let crashID = lines[0];
+          let metadata = parseKeyValuePairsFromLines(lines.slice(1));
+          store.addCrash(this.PROCESS_TYPE_MAIN, this.CRASH_TYPE_CRASH,
+                         crashID, date, metadata);
+
+          // If we have a saved environment, use it. Otherwise report
+          // the current environment.
+          let crashEnvironment = null;
+          let sessionId = null;
+          let stackTraces = null;
+          let reportMeta = Cu.cloneInto(metadata, myScope);
+          if ('TelemetryEnvironment' in reportMeta) {
+            try {
+              crashEnvironment = JSON.parse(reportMeta.TelemetryEnvironment);
+            } catch (e) {
+              Cu.reportError(e);
+            }
+            delete reportMeta.TelemetryEnvironment;
+          }
+          if ('TelemetrySessionId' in reportMeta) {
+            sessionId = reportMeta.TelemetrySessionId;
+            delete reportMeta.TelemetrySessionId;
+          }
+          if ('StackTraces' in reportMeta) {
+            try {
+              stackTraces = JSON.parse(reportMeta.StackTraces);
+            } catch (e) {
+              Cu.reportError(e);
+            }
+            delete reportMeta.StackTraces;
+          }
+          TelemetryController.submitExternalPing("crash",
+            {
+              version: 1,
+              crashDate: date.toISOString().slice(0, 10), // YYYY-MM-DD
+              sessionId: sessionId,
+              crashId: entry.id,
+              stackTraces: stackTraces,
+              metadata: reportMeta,
+              hasCrashEnvironment: (crashEnvironment !== null),
+            },
+            {
+              retentionDays: 180,
+              addClientId: true,
+              addEnvironment: true,
+              overrideEnvironment: crashEnvironment,
+            });
+          break;
+
+        case "crash.submission.1":
+          if (lines.length == 3) {
+            let [crashID, result, remoteID] = lines;
+            store.addCrash(this.PROCESS_TYPE_MAIN, this.CRASH_TYPE_CRASH,
+                           crashID, date);
+
+            let submissionID = this.generateSubmissionID();
+            let succeeded = result === "true";
+            store.addSubmissionAttempt(crashID, submissionID, date);
+            store.addSubmissionResult(crashID, submissionID, date,
+                                      succeeded ? this.SUBMISSION_RESULT_OK :
+                                                  this.SUBMISSION_RESULT_FAILED);
+            if (succeeded) {
+              store.setRemoteCrashID(crashID, remoteID);
+            }
+          } else {
+            return this.EVENT_FILE_ERROR_MALFORMED;
+          }
+          break;
+
+        default:
+          return this.EVENT_FILE_ERROR_UNKNOWN_EVENT;
+      }
+
+      return this.EVENT_FILE_SUCCESS;
+  },
+
+  /**
+   * The resolved promise is an array of objects with the properties:
+   *
+   *   path -- String filename
+   *   id -- regexp.match()[1] (likely the crash ID)
+   *   date -- Date mtime of the file
+   */
+  _getDirectoryEntries: function (path, re) {
+    return Task.spawn(function* () {
+      try {
+        yield OS.File.stat(path);
+      } catch (ex) {
+        if (!(ex instanceof OS.File.Error) || !ex.becauseNoSuchFile) {
+          throw ex;
+        }
+        return [];
+      }
+
+      let it = new OS.File.DirectoryIterator(path);
+      let entries = [];
+
+      try {
+        yield it.forEach((entry, index, it) => {
+          if (entry.isDir) {
+            return undefined;
+          }
+
+          let match = re.exec(entry.name);
+          if (!match) {
+            return undefined;
+          }
+
+          return OS.File.stat(entry.path).then((info) => {
+            entries.push({
+              path: entry.path,
+              id: match[1],
+              date: info.lastModificationDate,
+            });
+          });
+        });
+      } finally {
+        it.close();
+      }
+
+      entries.sort((a, b) => { return a.date - b.date; });
+
+      return entries;
+    }.bind(this));
+  },
+
+  _getStore: function () {
+    if (this._getStoreTask) {
+      return this._getStoreTask;
+    }
+
+    return this._getStoreTask = Task.spawn(function* () {
+      try {
+        if (!this._store) {
+          yield OS.File.makeDir(this._storeDir, {
+            ignoreExisting: true,
+            unixMode: OS.Constants.libc.S_IRWXU,
+          });
+
+          let store = new CrashStore(this._storeDir,
+                                     this._telemetryStoreSizeKey);
+          yield store.load();
+
+          this._store = store;
+          this._storeTimer = Cc["@mozilla.org/timer;1"]
+                               .createInstance(Ci.nsITimer);
+        }
+
+        // The application can go long periods without interacting with the
+        // store. Since the store takes up resources, we automatically "free"
+        // the store after inactivity so resources can be returned to the
+        // system. We do this via a timer and a mechanism that tracks when the
+        // store is being accessed.
+        this._storeTimer.cancel();
+
+        // This callback frees resources from the store unless the store
+        // is protected from freeing by some other process.
+        let timerCB = function () {
+          if (this._storeProtectedCount) {
+            this._storeTimer.initWithCallback(timerCB, this.STORE_EXPIRATION_MS,
+                                              this._storeTimer.TYPE_ONE_SHOT);
+            return;
+          }
+
+          // We kill the reference that we hold. GC will kill it later. If
+          // someone else holds a reference, that will prevent GC until that
+          // reference is gone.
+          this._store = null;
+          this._storeTimer = null;
+        }.bind(this);
+
+        this._storeTimer.initWithCallback(timerCB, this.STORE_EXPIRATION_MS,
+                                          this._storeTimer.TYPE_ONE_SHOT);
+
+        return this._store;
+      } finally {
+        this._getStoreTask = null;
+      }
+    }.bind(this));
+  },
+
+  /**
+   * Obtain information about all known crashes.
+   *
+   * Returns an array of CrashRecord instances. Instances are read-only.
+   */
+  getCrashes: function () {
+    return Task.spawn(function* () {
+      let store = yield this._getStore();
+
+      return store.crashes;
+    }.bind(this));
+  },
+
+  getCrashCountsByDay: function () {
+    return Task.spawn(function* () {
+      let store = yield this._getStore();
+
+      return store._countsByDay;
+    }.bind(this));
+  },
+});
+
+var gCrashManager;
+
+/**
+ * Interface to storage of crash data.
+ *
+ * This type handles storage of crash metadata. It exists as a separate type
+ * from the crash manager for performance reasons: since all crash metadata
+ * needs to be loaded into memory for access, we wish to easily dispose of all
+ * associated memory when this data is no longer needed. Having an isolated
+ * object whose references can easily be lost faciliates that simple disposal.
+ *
+ * When metadata is updated, the caller must explicitly persist the changes
+ * to disk. This prevents excessive I/O during updates.
+ *
+ * The store has a mechanism for ensuring it doesn't grow too large. A ceiling
+ * is placed on the number of daily events that can occur for events that can
+ * occur with relatively high frequency, notably plugin crashes and hangs
+ * (plugins can enter cycles where they repeatedly crash). If we've reached
+ * the high water mark and new data arrives, it's silently dropped.
+ * However, the count of actual events is always preserved. This allows
+ * us to report on the severity of problems beyond the storage threshold.
+ *
+ * Main process crashes are excluded from limits because they are both
+ * important and should be rare.
+ *
+ * @param storeDir (string)
+ *        Directory the store should be located in.
+ * @param telemetrySizeKey (string)
+ *        The telemetry histogram that should be used to store the size
+ *        of the data file.
+ */
+function CrashStore(storeDir, telemetrySizeKey) {
+  this._storeDir = storeDir;
+  this._telemetrySizeKey = telemetrySizeKey;
+
+  this._storePath = OS.Path.join(storeDir, "store.json.mozlz4");
+
+  // Holds the read data from disk.
+  this._data = null;
+
+  // Maps days since UNIX epoch to a Map of event types to counts.
+  // This data structure is populated when the JSON file is loaded
+  // and is also updated when new events are added.
+  this._countsByDay = new Map();
+}
+
+CrashStore.prototype = Object.freeze({
+  // Maximum number of events to store per day. This establishes a
+  // ceiling on the per-type/per-day records that will be stored.
+  HIGH_WATER_DAILY_THRESHOLD: 100,
+
+  /**
+   * Reset all data.
+   */
+  reset() {
+    this._data = {
+      v: 1,
+      crashes: new Map(),
+      corruptDate: null,
+    };
+    this._countsByDay = new Map();
+  },
+
+  /**
+   * Load data from disk.
+   *
+   * @return Promise
+   */
+  load: function () {
+    return Task.spawn(function* () {
+      // Loading replaces data.
+      this.reset();
+
+      try {
+        let decoder = new TextDecoder();
+        let data = yield OS.File.read(this._storePath, {compression: "lz4"});
+        data = JSON.parse(decoder.decode(data));
+
+        if (data.corruptDate) {
+          this._data.corruptDate = new Date(data.corruptDate);
+        }
+
+        // actualCounts is used to validate that the derived counts by
+        // days stored in the payload matches up to actual data.
+        let actualCounts = new Map();
+
+        // In the past, submissions were stored as separate crash records
+        // with an id of e.g. "someID-submission". If we find IDs ending
+        // with "-submission", we will need to convert the data to be stored
+        // as actual submissions.
+        //
+        // The old way of storing submissions was used from FF33 - FF34. We
+        // drop this old data on the floor.
+        for (let id in data.crashes) {
+          if (id.endsWith("-submission")) {
+            continue;
+          }
+
+          let crash = data.crashes[id];
+          let denormalized = this._denormalize(crash);
+
+          denormalized.submissions = new Map();
+          if (crash.submissions) {
+            for (let submissionID in crash.submissions) {
+              let submission = crash.submissions[submissionID];
+              denormalized.submissions.set(submissionID,
+                                           this._denormalize(submission));
+            }
+          }
+
+          this._data.crashes.set(id, denormalized);
+
+          let key = dateToDays(denormalized.crashDate) + "-" + denormalized.type;
+          actualCounts.set(key, (actualCounts.get(key) || 0) + 1);
+
+          // If we have an OOM size, count the crash as an OOM in addition to
+          // being a main process crash.
+          if (denormalized.metadata &&
+              denormalized.metadata.OOMAllocationSize) {
+            let oomKey = key + "-oom";
+            actualCounts.set(oomKey, (actualCounts.get(oomKey) || 0) + 1);
+          }
+
+        }
+
+        // The validation in this loop is arguably not necessary. We perform
+        // it as a defense against unknown bugs.
+        for (let dayKey in data.countsByDay) {
+          let day = parseInt(dayKey, 10);
+          for (let type in data.countsByDay[day]) {
+            this._ensureCountsForDay(day);
+
+            let count = data.countsByDay[day][type];
+            let key = day + "-" + type;
+
+            // If the payload says we have data for a given day but we
+            // don't, the payload is wrong. Ignore it.
+            if (!actualCounts.has(key)) {
+              continue;
+            }
+
+            // If we encountered more data in the payload than what the
+            // data structure says, use the proper value.
+            count = Math.max(count, actualCounts.get(key));
+
+            this._countsByDay.get(day).set(type, count);
+          }
+        }
+      } catch (ex) {
+        // Missing files (first use) are allowed.
+        if (!(ex instanceof OS.File.Error) || !ex.becauseNoSuchFile) {
+          // If we can't load for any reason, mark a corrupt date in the instance
+          // and swallow the error.
+          //
+          // The marking of a corrupted file is intentionally not persisted to
+          // disk yet. Instead, we wait until the next save(). This is to give
+          // non-permanent failures the opportunity to recover on their own.
+          this._data.corruptDate = new Date();
+        }
+      }
+    }.bind(this));
+  },
+
+  /**
+   * Save data to disk.
+   *
+   * @return Promise<null>
+   */
+  save: function () {
+    return Task.spawn(function* () {
+      if (!this._data) {
+        return;
+      }
+
+      let normalized = {
+        // The version should be incremented whenever the format
+        // changes.
+        v: 1,
+        // Maps crash IDs to objects defining the crash.
+        crashes: {},
+        // Maps days since UNIX epoch to objects mapping event types to
+        // counts. This is a mirror of this._countsByDay. e.g.
+        // {
+        //    15000: {
+        //        "main-crash": 2,
+        //        "plugin-crash": 1
+        //    }
+        // }
+        countsByDay: {},
+
+        // When the store was last corrupted.
+        corruptDate: null,
+      };
+
+      if (this._data.corruptDate) {
+        normalized.corruptDate = this._data.corruptDate.getTime();
+      }
+
+      for (let [id, crash] of this._data.crashes) {
+        let c = this._normalize(crash);
+
+        c.submissions = {};
+        for (let [submissionID, submission] of crash.submissions) {
+          c.submissions[submissionID] = this._normalize(submission);
+        }
+
+        normalized.crashes[id] = c;
+      }
+
+      for (let [day, m] of this._countsByDay) {
+        normalized.countsByDay[day] = {};
+        for (let [type, count] of m) {
+          normalized.countsByDay[day][type] = count;
+        }
+      }
+
+      let encoder = new TextEncoder();
+      let data = encoder.encode(JSON.stringify(normalized));
+      let size = yield OS.File.writeAtomic(this._storePath, data, {
+                                           tmpPath: this._storePath + ".tmp",
+                                           compression: "lz4"});
+      if (this._telemetrySizeKey) {
+        Services.telemetry.getHistogramById(this._telemetrySizeKey).add(size);
+      }
+    }.bind(this));
+  },
+
+  /**
+   * Normalize an object into one fit for serialization.
+   *
+   * This function along with _denormalize() serve to hack around the
+   * default handling of Date JSON serialization because Date serialization
+   * is undefined by JSON.
+   *
+   * Fields ending with "Date" are assumed to contain Date instances.
+   * We convert these to milliseconds since epoch on output and back to
+   * Date on input.
+   */
+  _normalize: function (o) {
+    let normalized = {};
+
+    for (let k in o) {
+      let v = o[k];
+      if (v && k.endsWith("Date")) {
+        normalized[k] = v.getTime();
+      } else {
+        normalized[k] = v;
+      }
+    }
+
+    return normalized;
+  },
+
+  /**
+   * Convert a serialized object back to its native form.
+   */
+  _denormalize: function (o) {
+    let n = {};
+
+    for (let k in o) {
+      let v = o[k];
+      if (v && k.endsWith("Date")) {
+        n[k] = new Date(parseInt(v, 10));
+      } else {
+        n[k] = v;
+      }
+    }
+
+    return n;
+  },
+
+  /**
+   * Prune old crash data.
+   *
+   * Crashes without recent activity are pruned from the store so the
+   * size of the store is not unbounded. If there is activity on a crash,
+   * that activity will keep the crash and all its data around for longer.
+   *
+   * @param date
+   *        (Date) The cutoff at which data will be pruned. If an entry
+   *        doesn't have data newer than this, it will be pruned.
+   */
+  pruneOldCrashes: function (date) {
+    for (let crash of this.crashes) {
+      let newest = crash.newestDate;
+      if (!newest || newest.getTime() < date.getTime()) {
+        this._data.crashes.delete(crash.id);
+      }
+    }
+  },
+
+  /**
+   * Date the store was last corrupted and required a reset.
+   *
+   * May be null (no corruption has ever occurred) or a Date instance.
+   */
+  get corruptDate() {
+    return this._data.corruptDate;
+  },
+
+  /**
+   * The number of distinct crashes tracked.
+   */
+  get crashesCount() {
+    return this._data.crashes.size;
+  },
+
+  /**
+   * All crashes tracked.
+   *
+   * This is an array of CrashRecord.
+   */
+  get crashes() {
+    let crashes = [];
+    for (let [, crash] of this._data.crashes) {
+      crashes.push(new CrashRecord(crash));
+    }
+
+    return crashes;
+  },
+
+  /**
+   * Obtain a particular crash from its ID.
+   *
+   * A CrashRecord will be returned if the crash exists. null will be returned
+   * if the crash is unknown.
+   */
+  getCrash: function (id) {
+    for (let crash of this.crashes) {
+      if (crash.id == id) {
+        return crash;
+      }
+    }
+
+    return null;
+  },
+
+  _ensureCountsForDay: function (day) {
+    if (!this._countsByDay.has(day)) {
+      this._countsByDay.set(day, new Map());
+    }
+  },
+
+  /**
+   * Ensure the crash record is present in storage.
+   *
+   * Returns the crash record if we're allowed to store it or null
+   * if we've hit the high water mark.
+   *
+   * @param processType
+   *        (string) One of the PROCESS_TYPE constants.
+   * @param crashType
+   *        (string) One of the CRASH_TYPE constants.
+   * @param id
+   *        (string) The crash ID.
+   * @param date
+   *        (Date) When this crash occurred.
+   * @param metadata
+   *        (dictionary) Crash metadata, may be empty.
+   *
+   * @return null | object crash record
+   */
+  _ensureCrashRecord: function (processType, crashType, id, date, metadata) {
+    if (!id) {
+      // Crashes are keyed on ID, so it's not really helpful to store crashes
+      // without IDs.
+      return null;
+    }
+
+    let type = processType + "-" + crashType;
+
+    if (!this._data.crashes.has(id)) {
+      let day = dateToDays(date);
+      this._ensureCountsForDay(day);
+
+      let count = (this._countsByDay.get(day).get(type) || 0) + 1;
+      this._countsByDay.get(day).set(type, count);
+
+      if (count > this.HIGH_WATER_DAILY_THRESHOLD &&
+          processType != CrashManager.prototype.PROCESS_TYPE_MAIN) {
+        return null;
+      }
+
+      // If we have an OOM size, count the crash as an OOM in addition to
+      // being a main process crash.
+      if (metadata && metadata.OOMAllocationSize) {
+        let oomType = type + "-oom";
+        let oomCount = (this._countsByDay.get(day).get(oomType) || 0) + 1;
+        this._countsByDay.get(day).set(oomType, oomCount);
+      }
+
+      this._data.crashes.set(id, {
+        id: id,
+        remoteID: null,
+        type: type,
+        crashDate: date,
+        submissions: new Map(),
+        classifications: [],
+        metadata: metadata,
+      });
+    }
+
+    let crash = this._data.crashes.get(id);
+    crash.type = type;
+    crash.crashDate = date;
+
+    return crash;
+  },
+
+  /**
+   * Record the occurrence of a crash.
+   *
+   * @param processType (string) One of the PROCESS_TYPE constants.
+   * @param crashType (string) One of the CRASH_TYPE constants.
+   * @param id (string) Crash ID. Likely a UUID.
+   * @param date (Date) When the crash occurred.
+   * @param metadata (dictionary) Crash metadata, may be empty.
+   *
+   * @return boolean True if the crash was recorded and false if not.
+   */
+  addCrash: function (processType, crashType, id, date, metadata) {
+    return !!this._ensureCrashRecord(processType, crashType, id, date, metadata);
+  },
+
+  /**
+   * @return boolean True if the remote ID was recorded and false if not.
+   */
+  setRemoteCrashID: function (crashID, remoteID) {
+    let crash = this._data.crashes.get(crashID);
+    if (!crash || !remoteID) {
+      return false;
+    }
+
+    crash.remoteID = remoteID;
+    return true;
+  },
+
+  getCrashesOfType: function (processType, crashType) {
+    let crashes = [];
+    for (let crash of this.crashes) {
+      if (crash.isOfType(processType, crashType)) {
+        crashes.push(crash);
+      }
+    }
+
+    return crashes;
+  },
+
+  /**
+   * Ensure the submission record is present in storage.
+   * @returns [submission, crash]
+   */
+  _ensureSubmissionRecord: function (crashID, submissionID) {
+    let crash = this._data.crashes.get(crashID);
+    if (!crash || !submissionID) {
+      return null;
+    }
+
+    if (!crash.submissions.has(submissionID)) {
+      crash.submissions.set(submissionID, {
+        requestDate: null,
+        responseDate: null,
+        result: null,
+      });
+    }
+
+    return [crash.submissions.get(submissionID), crash];
+  },
+
+  /**
+   * @return boolean True if the attempt was recorded.
+   */
+  addSubmissionAttempt: function (crashID, submissionID, date) {
+    let [submission, crash] =
+      this._ensureSubmissionRecord(crashID, submissionID);
+    if (!submission) {
+      return false;
+    }
+
+    submission.requestDate = date;
+    Services.telemetry.getKeyedHistogramById("PROCESS_CRASH_SUBMIT_ATTEMPT")
+      .add(crash.type, 1);
+    return true;
+  },
+
+  /**
+   * @return boolean True if the response was recorded.
+   */
+  addSubmissionResult: function (crashID, submissionID, date, result) {
+    let crash = this._data.crashes.get(crashID);
+    if (!crash || !submissionID) {
+      return false;
+    }
+    let submission = crash.submissions.get(submissionID);
+    if (!submission) {
+      return false;
+    }
+
+    submission.responseDate = date;
+    submission.result = result;
+    Services.telemetry.getKeyedHistogramById("PROCESS_CRASH_SUBMIT_SUCCESS")
+      .add(crash.type, result == "ok");
+    return true;
+  },
+
+  /**
+   * @return boolean True if the classifications were set.
+   */
+  setCrashClassifications: function (crashID, classifications) {
+    let crash = this._data.crashes.get(crashID);
+    if (!crash) {
+      return false;
+    }
+
+    crash.classifications = classifications;
+    return true;
+  },
+});
+
+/**
+ * Represents an individual crash with metadata.
+ *
+ * This is a wrapper around the low-level anonymous JS objects that define
+ * crashes. It exposes a consistent and helpful API.
+ *
+ * Instances of this type should only be constructured inside this module,
+ * not externally. The constructor is not considered a public API.
+ *
+ * @param o (object)
+ *        The crash's entry from the CrashStore.
+ */
+function CrashRecord(o) {
+  this._o = o;
+}
+
+CrashRecord.prototype = Object.freeze({
+  get id() {
+    return this._o.id;
+  },
+
+  get remoteID() {
+    return this._o.remoteID;
+  },
+
+  get crashDate() {
+    return this._o.crashDate;
+  },
+
+  /**
+   * Obtain the newest date in this record.
+   *
+   * This is a convenience getter. The returned value is used to determine when
+   * to expire a record.
+   */
+  get newestDate() {
+    // We currently only have 1 date, so this is easy.
+    return this._o.crashDate;
+  },
+
+  get oldestDate() {
+    return this._o.crashDate;
+  },
+
+  get type() {
+    return this._o.type;
+  },
+
+  isOfType: function (processType, crashType) {
+    return processType + "-" + crashType == this.type;
+  },
+
+  get submissions() {
+    return this._o.submissions;
+  },
+
+  get classifications() {
+    return this._o.classifications;
+  },
+
+  get metadata() {
+    return this._o.metadata;
+  },
+});
+
+/**
+ * Obtain the global CrashManager instance used by the running application.
+ *
+ * CrashManager is likely only ever instantiated once per application lifetime.
+ * The main reason it's implemented as a reusable type is to facilitate testing.
+ */
+XPCOMUtils.defineLazyGetter(this.CrashManager, "Singleton", function () {
+  if (gCrashManager) {
+    return gCrashManager;
+  }
+
+  let crPath = OS.Path.join(OS.Constants.Path.userApplicationDataDir,
+                            "Crash Reports");
+  let storePath = OS.Path.join(OS.Constants.Path.profileDir, "crashes");
+
+  gCrashManager = new CrashManager({
+    pendingDumpsDir: OS.Path.join(crPath, "pending"),
+    submittedDumpsDir: OS.Path.join(crPath, "submitted"),
+    eventsDirs: [OS.Path.join(crPath, "events"), OS.Path.join(storePath, "events")],
+    storeDir: storePath,
+    telemetryStoreSizeKey: "CRASH_STORE_COMPRESSED_BYTES",
+  });
+
+  // Automatically aggregate event files shortly after startup. This
+  // ensures it happens with some frequency.
+  //
+  // There are performance considerations here. While this is doing
+  // work and could negatively impact performance, the amount of work
+  // is kept small per run by periodically aggregating event files.
+  // Furthermore, well-behaving installs should not have much work
+  // here to do. If there is a lot of work, that install has bigger
+  // issues beyond reduced performance near startup.
+  gCrashManager.scheduleMaintenance(AGGREGATE_STARTUP_DELAY_MS);
+
+  return gCrashManager;
+});