/* -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 8 -*- */
/* 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/. */

#include "nsISupports.idl"
#include "nsIFile.idl"

[scriptable,function, uuid(3d3b9075-5549-4244-9c08-b64fefa1dd60)]
interface nsIFetchTelemetryDataCallback : nsISupports
{
  void complete();
};

[scriptable, uuid(4e4bfc35-dac6-4b28-ade4-7e45760051d5)]
interface nsITelemetry : nsISupports
{
  /**
   * Histogram types:
   * HISTOGRAM_EXPONENTIAL - buckets increase exponentially
   * HISTOGRAM_LINEAR - buckets increase linearly
   * HISTOGRAM_BOOLEAN - For storing 0/1 values
   * HISTOGRAM_FLAG - For storing a single value; its count is always == 1.
   */
  const unsigned long HISTOGRAM_EXPONENTIAL = 0;
  const unsigned long HISTOGRAM_LINEAR = 1;
  const unsigned long HISTOGRAM_BOOLEAN = 2;
  const unsigned long HISTOGRAM_FLAG = 3;

  /*
   * An object containing a snapshot from all of the currently registered histograms.
   * { name1: {data1}, name2:{data2}...}
   * where data is consists of the following properties:
   *   min - Minimal bucket size
   *   max - Maximum bucket size
   *   histogram_type - HISTOGRAM_EXPONENTIAL, HISTOGRAM_LINEAR, or HISTOGRAM_BOOLEAN
   *   counts - array representing contents of the buckets in the histogram
   *   ranges -  an array with calculated bucket sizes
   *   sum - sum of the bucket contents
   *   static - true for histograms defined in TelemetryHistograms.h, false for ones defined with newHistogram
   */
  [implicit_jscontext]
  readonly attribute jsval histogramSnapshots;

  /**
   * The amount of time, in milliseconds, that the last session took
   * to shutdown.  Reads as 0 to indicate failure.
   */
  readonly attribute uint32_t lastShutdownDuration;

  /**
   * The number of failed profile lock attempts that have occurred prior to 
   * successfully locking the profile
   */
  readonly attribute uint32_t failedProfileLockCount;

  /*
   * An object containing information about slow SQL statements.
   *
   * {
   *   mainThread: { "sqlString1": [<hit count>, <total time>], "sqlString2": [...], ... },
   *   otherThreads: { "sqlString3": [<hit count>, <total time>], "sqlString4": [...], ... }
   * }
   *
   * where:
   *   mainThread: Slow statements that executed on the main thread
   *   otherThreads: Slow statements that executed on a non-main thread
   *   sqlString - String of the offending statement (see note)
   *   hit count - The number of times this statement required longer than the threshold time to execute
   *   total time - The sum of all execution times above the threshold time for this statement
   *
   * Note that dynamic SQL strings and SQL strings executed against addon DBs could contain private information.
   * This property represents such SQL as aggregate database-level stats and the sqlString contains the database
   * filename instead.
   */
  [implicit_jscontext]
  readonly attribute jsval slowSQL;

  /*
   * See slowSQL above.
   *
   * An object containing full strings of every slow SQL statement if toolkit.telemetry.debugSlowSql = true
   * The returned SQL strings may contain private information and should not be reported to Telemetry.
   */
  [implicit_jscontext]
  readonly attribute jsval debugSlowSQL;

  /**
   * A number representing the highest number of concurrent threads
   * reached during this session.
   */
  readonly attribute uint32_t maximalNumberOfConcurrentThreads;

  /*
   * An array of chrome hang reports. Each element is a hang report represented
   * as an object containing the hang duration, call stack PCs and information
   * about modules in memory.
   */
  [implicit_jscontext]
  readonly attribute jsval chromeHangs;

  /*
   * An array of thread hang stats,
   *   [<thread>, <thread>, ...]
   * <thread> represents a single thread,
   *   {"name": "<name>",
   *    "activity": <time>,
   *    "hangs": [<hang>, <hang>, ...]}
   * <time> represents a histogram of time intervals in milliseconds,
   *   with the same format as histogramSnapshots
   * <hang> represents a particular hang,
   *   {"stack": <stack>, "nativeStack": <stack>, "histogram": <time>}
   * <stack> represents the hang's stack,
   *   ["<frame_0>", "<frame_1>", ...]
   */
  [implicit_jscontext]
  readonly attribute jsval threadHangStats;

  /*
   * An object with two fields: memoryMap and stacks.
   * * memoryMap is a list of loaded libraries.
   * * stacks is a list of stacks. Each stack is a list of pairs of the form
   *   [moduleIndex, offset]. The moduleIndex is an index into the memoryMap and
   *   offset is an offset in the library at memoryMap[moduleIndex].
   * This format is used to make it easier to send the stacks to the
   * symbolication server.
   */
  [implicit_jscontext]
  readonly attribute jsval lateWrites;

  /**
   * Returns an array whose values are the names of histograms defined
   * in Histograms.json.
   */
  void registeredHistograms(out uint32_t count,
                            [retval, array, size_is(count)] out string histograms);

  /** 
   * Create and return a histogram.  Parameters:
   *
   * @param name Unique histogram name
   * @param expiration Expiration version
   * @param min - Minimal bucket size
   * @param max - Maximum bucket size
   * @param bucket_count - number of buckets in the histogram.
   * @param type - HISTOGRAM_EXPONENTIAL, HISTOGRAM_LINEAR or HISTOGRAM_BOOLEAN
   * The returned object has the following functions:
   *   add(int) - Adds an int value to the appropriate bucket
   *   snapshot() - Returns a snapshot of the histogram with the same data fields as in histogramSnapshots()
   *   clear() - Zeros out the histogram's buckets and sum
   */
  [implicit_jscontext]
  jsval newHistogram(in ACString name, in ACString expiration, in uint32_t min, in uint32_t max, in uint32_t bucket_count, in unsigned long histogram_type);

  /**
   * Create a histogram using the current state of an existing histogram.  The
   * existing histogram must be registered in TelemetryHistograms.h.
   *
   * @param name Unique histogram name
   * @param existing_name Existing histogram name
   * The returned object has the same functions as a histogram returned from newHistogram.
   */
  [implicit_jscontext]
  jsval histogramFrom(in ACString name, in ACString existing_name);

  /**
   * Same as newHistogram above, but for histograms registered in TelemetryHistograms.h.
   *
   * @param id - unique identifier from TelemetryHistograms.h
   */
  [implicit_jscontext]
  jsval getHistogramById(in ACString id);

  /**
   * Set this to false to disable gathering of telemetry statistics.
   */
  attribute boolean canRecord;

  /**
   * A flag indicating whether Telemetry can submit official results.
   */
  readonly attribute boolean canSend;

  /** Addon telemetry hooks */

  /**
   * Register a histogram for an addon.  Throws an error if the
   * histogram name has been registered previously.
   *
   * @param addon_id - Unique ID of the addon
   * @param name - Unique histogram name
   * @param min - Minimal bucket size
   * @param max - Maximum bucket size
   * @param bucket_count - number of buckets in the histogram
   * @param histogram_type - HISTOGRAM_EXPONENTIAL, HISTOGRAM_LINEAR, or
   *        HISTOGRAM_BOOLEAN
   */
  void registerAddonHistogram(in ACString addon_id, in ACString name,
                              in uint32_t min, in uint32_t max,
                              in uint32_t bucket_count,
                              in unsigned long histogram_type);

  /**
   * Return a histogram previously registered via
   * registerAddonHistogram.  Throws an error if the id/name combo has
   * not been registered via registerAddonHistogram.
   *
   * @param addon_id - Unique ID of the addon
   * @param name - Registered histogram name
   *
   * The returned object has the same functions as a histogram returned
   * from newHistogram.
   */
  [implicit_jscontext]
  jsval getAddonHistogram(in ACString addon_id, in ACString name);

  /**
   * Delete all histograms associated with the given addon id.
   *
   * @param addon_id - Unique ID of the addon
   */
  void unregisterAddonHistograms(in ACString addon_id);

  /**
   * An object containing a snapshot from all of the currently
   * registered addon histograms.
   * { addon-id1 : data1, ... }
   *
   * where data is an object whose properties are the names of the
   * addon's histograms and whose corresponding values are as in
   * histogramSnapshots.
   */
  [implicit_jscontext]
  readonly attribute jsval addonHistogramSnapshots;

  /**
   * Read data from the previous run. After the callback is called, the last
   * shutdown time is available in lastShutdownDuration and any late
   * writes in lateWrites.
   */
  void asyncFetchTelemetryData(in nsIFetchTelemetryDataCallback aCallback);

  /**
   * Get statistics of file IO reports, null, if not recorded.
   *
   * The statistics are returned as an object whose propoerties are the names
   * of the files that have been accessed and whose corresponding values are
   * arrays of size three, representing startup, normal, and shutdown stages.
   * Each stage's entry is either null or an array with the layout
   * [total_time, #creates, #reads, #writes, #fsyncs, #stats]
   */
  [implicit_jscontext]
  readonly attribute jsval fileIOReports;

  /**
   * Return the number of seconds since process start using monotonic
   * timestamps (unaffected by system clock changes).
   * @throws NS_ERROR_NOT_AVAILABLE if TimeStamp doesn't have the data.
   */
  double msSinceProcessStart();
};
