/* -*- 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, uuid(de54f594-4c20-4968-a27a-83b38ff952b9)]
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;

  /*
   * 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;

  /*
   * 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 object whose properties are the names of histograms defined in
   * TelemetryHistograms.h and whose corresponding values are the textual
   * comments associated with said histograms.
   */
  [implicit_jscontext]
  readonly attribute jsval registeredHistograms;

  /** 
   * Create and return a histogram.  Parameters:
   *
   * @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 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 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;
};
