gecko/toolkit/mozapps/downloads/DownloadUtils.jsm
2012-05-21 12:12:37 +01:00

494 lines
17 KiB
JavaScript

/* vim: sw=2 ts=2 sts=2 expandtab filetype=javascript
* 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/. */
var EXPORTED_SYMBOLS = [ "DownloadUtils" ];
/**
* This module provides the DownloadUtils object which contains useful methods
* for downloads such as displaying file sizes, transfer times, and download
* locations.
*
* List of methods:
*
* [string status, double newLast]
* getDownloadStatus(int aCurrBytes, [optional] int aMaxBytes,
* [optional] double aSpeed, [optional] double aLastSec)
*
* string progress
* getTransferTotal(int aCurrBytes, [optional] int aMaxBytes)
*
* [string timeLeft, double newLast]
* getTimeLeft(double aSeconds, [optional] double aLastSec)
*
* [string dateCompact, string dateComplete]
* getReadableDates(Date aDate, [optional] Date aNow)
*
* [string displayHost, string fullHost]
* getURIHost(string aURIString)
*
* [string convertedBytes, string units]
* convertByteUnits(int aBytes)
*
* [int time, string units, int subTime, string subUnits]
* convertTimeUnits(double aSecs)
*/
const Cc = Components.classes;
const Ci = Components.interfaces;
const Cu = Components.utils;
__defineGetter__("PluralForm", function() {
delete this.PluralForm;
Cu.import("resource://gre/modules/PluralForm.jsm");
return PluralForm;
});
__defineGetter__("gDecimalSymbol", function() {
delete this.gDecimalSymbol;
return this.gDecimalSymbol = Number(5.4).toLocaleString().match(/\D/);
});
const kDownloadProperties =
"chrome://mozapps/locale/downloads/downloads.properties";
let gStr = {
statusFormat: "statusFormat3",
transferSameUnits: "transferSameUnits2",
transferDiffUnits: "transferDiffUnits2",
transferNoTotal: "transferNoTotal2",
timePair: "timePair2",
timeLeftSingle: "timeLeftSingle2",
timeLeftDouble: "timeLeftDouble2",
timeFewSeconds: "timeFewSeconds",
timeUnknown: "timeUnknown",
monthDate: "monthDate2",
yesterday: "yesterday",
doneScheme: "doneScheme2",
doneFileScheme: "doneFileScheme",
units: ["bytes", "kilobyte", "megabyte", "gigabyte"],
// Update timeSize in convertTimeUnits if changing the length of this array
timeUnits: ["seconds", "minutes", "hours", "days"],
};
// This lazily initializes the string bundle upon first use.
__defineGetter__("gBundle", function() {
delete gBundle;
return this.gBundle = Cc["@mozilla.org/intl/stringbundle;1"].
getService(Ci.nsIStringBundleService).
createBundle(kDownloadProperties);
});
// Keep track of at most this many second/lastSec pairs so that multiple calls
// to getTimeLeft produce the same time left
const kCachedLastMaxSize = 10;
let gCachedLast = [];
let DownloadUtils = {
/**
* Generate a full status string for a download given its current progress,
* total size, speed, last time remaining
*
* @param aCurrBytes
* Number of bytes transferred so far
* @param [optional] aMaxBytes
* Total number of bytes or -1 for unknown
* @param [optional] aSpeed
* Current transfer rate in bytes/sec or -1 for unknown
* @param [optional] aLastSec
* Last time remaining in seconds or Infinity for unknown
* @return A pair: [download status text, new value of "last seconds"]
*/
getDownloadStatus: function DU_getDownloadStatus(aCurrBytes, aMaxBytes,
aSpeed, aLastSec)
{
if (aMaxBytes == null)
aMaxBytes = -1;
if (aSpeed == null)
aSpeed = -1;
if (aLastSec == null)
aLastSec = Infinity;
// Calculate the time remaining if we have valid values
let seconds = (aSpeed > 0) && (aMaxBytes > 0) ?
(aMaxBytes - aCurrBytes) / aSpeed : -1;
let transfer = DownloadUtils.getTransferTotal(aCurrBytes, aMaxBytes);
let [rate, unit] = DownloadUtils.convertByteUnits(aSpeed);
let [timeLeft, newLast] = DownloadUtils.getTimeLeft(seconds, aLastSec);
let params = [transfer, rate, unit, timeLeft];
let status = gBundle.formatStringFromName(gStr.statusFormat, params,
params.length);
return [status, newLast];
},
/**
* Generate the transfer progress string to show the current and total byte
* size. Byte units will be as large as possible and the same units for
* current and max will be suppressed for the former.
*
* @param aCurrBytes
* Number of bytes transferred so far
* @param [optional] aMaxBytes
* Total number of bytes or -1 for unknown
* @return The transfer progress text
*/
getTransferTotal: function DU_getTransferTotal(aCurrBytes, aMaxBytes)
{
if (aMaxBytes == null)
aMaxBytes = -1;
let [progress, progressUnits] = DownloadUtils.convertByteUnits(aCurrBytes);
let [total, totalUnits] = DownloadUtils.convertByteUnits(aMaxBytes);
// Figure out which byte progress string to display
let name, values;
if (aMaxBytes < 0) {
name = gStr.transferNoTotal;
values = [
progress,
progressUnits,
];
} else if (progressUnits == totalUnits) {
name = gStr.transferSameUnits;
values = [
progress,
total,
totalUnits,
];
} else {
name = gStr.transferDiffUnits;
values = [
progress,
progressUnits,
total,
totalUnits,
];
}
return gBundle.formatStringFromName(name, values, values.length);
},
/**
* Generate a "time left" string given an estimate on the time left and the
* last time. The extra time is used to give a better estimate on the time to
* show. Both the time values are doubles instead of integers to help get
* sub-second accuracy for current and future estimates.
*
* @param aSeconds
* Current estimate on number of seconds left for the download
* @param [optional] aLastSec
* Last time remaining in seconds or Infinity for unknown
* @return A pair: [time left text, new value of "last seconds"]
*/
getTimeLeft: function DU_getTimeLeft(aSeconds, aLastSec)
{
if (aLastSec == null)
aLastSec = Infinity;
if (aSeconds < 0)
return [gBundle.GetStringFromName(gStr.timeUnknown), aLastSec];
// Try to find a cached lastSec for the given second
aLastSec = gCachedLast.reduce(function(aResult, aItem)
aItem[0] == aSeconds ? aItem[1] : aResult, aLastSec);
// Add the current second/lastSec pair unless we have too many
gCachedLast.push([aSeconds, aLastSec]);
if (gCachedLast.length > kCachedLastMaxSize)
gCachedLast.shift();
// Apply smoothing only if the new time isn't a huge change -- e.g., if the
// new time is more than half the previous time; this is useful for
// downloads that start/resume slowly
if (aSeconds > aLastSec / 2) {
// Apply hysteresis to favor downward over upward swings
// 30% of down and 10% of up (exponential smoothing)
let (diff = aSeconds - aLastSec) {
aSeconds = aLastSec + (diff < 0 ? .3 : .1) * diff;
}
// If the new time is similar, reuse something close to the last seconds,
// but subtract a little to provide forward progress
let diff = aSeconds - aLastSec;
let diffPct = diff / aLastSec * 100;
if (Math.abs(diff) < 5 || Math.abs(diffPct) < 5)
aSeconds = aLastSec - (diff < 0 ? .4 : .2);
}
// Decide what text to show for the time
let timeLeft;
if (aSeconds < 4) {
// Be friendly in the last few seconds
timeLeft = gBundle.GetStringFromName(gStr.timeFewSeconds);
} else {
// Convert the seconds into its two largest units to display
let [time1, unit1, time2, unit2] =
DownloadUtils.convertTimeUnits(aSeconds);
let pair1 =
gBundle.formatStringFromName(gStr.timePair, [time1, unit1], 2);
let pair2 =
gBundle.formatStringFromName(gStr.timePair, [time2, unit2], 2);
// Only show minutes for under 1 hour unless there's a few minutes left;
// or the second pair is 0.
if ((aSeconds < 3600 && time1 >= 4) || time2 == 0) {
timeLeft = gBundle.formatStringFromName(gStr.timeLeftSingle,
[pair1], 1);
} else {
// We've got 2 pairs of times to display
timeLeft = gBundle.formatStringFromName(gStr.timeLeftDouble,
[pair1, pair2], 2);
}
}
return [timeLeft, aSeconds];
},
/**
* Converts a Date object to two readable formats, one compact, one complete.
* The compact format is relative to the current date, and is not an accurate
* representation. For example, only the time is displayed for today. The
* complete format always includes both the date and the time, excluding the
* seconds, and is often shown when hovering the cursor over the compact
* representation.
*
* @param aDate
* Date object representing the date and time to format. It is assumed
* that this value represents a past date.
* @param [optional] aNow
* Date object representing the current date and time. The real date
* and time of invocation is used if this parameter is omitted.
* @return A pair: [compact text, complete text]
*/
getReadableDates: function DU_getReadableDates(aDate, aNow)
{
if (!aNow) {
aNow = new Date();
}
let dts = Cc["@mozilla.org/intl/scriptabledateformat;1"]
.getService(Ci.nsIScriptableDateFormat);
// Figure out when today begins
let today = new Date(aNow.getFullYear(), aNow.getMonth(), aNow.getDate());
// Figure out if the time is from today, yesterday, this week, etc.
let dateTimeCompact;
if (aDate >= today) {
// After today started, show the time
dateTimeCompact = dts.FormatTime("",
dts.timeFormatNoSeconds,
aDate.getHours(),
aDate.getMinutes(),
0);
} else if (today - aDate < (24 * 60 * 60 * 1000)) {
// After yesterday started, show yesterday
dateTimeCompact = gBundle.GetStringFromName(gStr.yesterday);
} else if (today - aDate < (6 * 24 * 60 * 60 * 1000)) {
// After last week started, show day of week
dateTimeCompact = aDate.toLocaleFormat("%A");
} else {
// Show month/day
let month = aDate.toLocaleFormat("%B");
// Remove leading 0 by converting the date string to a number
let date = Number(aDate.toLocaleFormat("%d"));
dateTimeCompact = gBundle.formatStringFromName(gStr.monthDate, [month, date], 2);
}
let dateTimeFull = dts.FormatDateTime("",
dts.dateFormatLong,
dts.timeFormatNoSeconds,
aDate.getFullYear(),
aDate.getMonth() + 1,
aDate.getDate(),
aDate.getHours(),
aDate.getMinutes(),
0);
return [dateTimeCompact, dateTimeFull];
},
/**
* Get the appropriate display host string for a URI string depending on if
* the URI has an eTLD + 1, is an IP address, a local file, or other protocol
*
* @param aURIString
* The URI string to try getting an eTLD + 1, etc.
* @return A pair: [display host for the URI string, full host name]
*/
getURIHost: function DU_getURIHost(aURIString)
{
let ioService = Cc["@mozilla.org/network/io-service;1"].
getService(Ci.nsIIOService);
let eTLDService = Cc["@mozilla.org/network/effective-tld-service;1"].
getService(Ci.nsIEffectiveTLDService);
let idnService = Cc["@mozilla.org/network/idn-service;1"].
getService(Ci.nsIIDNService);
// Get a URI that knows about its components
let uri = ioService.newURI(aURIString, null, null);
// Get the inner-most uri for schemes like jar:
if (uri instanceof Ci.nsINestedURI)
uri = uri.innermostURI;
let fullHost;
try {
// Get the full host name; some special URIs fail (data: jar:)
fullHost = uri.host;
} catch (e) {
fullHost = "";
}
let displayHost;
try {
// This might fail if it's an IP address or doesn't have more than 1 part
let baseDomain = eTLDService.getBaseDomain(uri);
// Convert base domain for display; ignore the isAscii out param
displayHost = idnService.convertToDisplayIDN(baseDomain, {});
} catch (e) {
// Default to the host name
displayHost = fullHost;
}
// Check if we need to show something else for the host
if (uri.scheme == "file") {
// Display special text for file protocol
displayHost = gBundle.GetStringFromName(gStr.doneFileScheme);
fullHost = displayHost;
} else if (displayHost.length == 0) {
// Got nothing; show the scheme (data: about: moz-icon:)
displayHost =
gBundle.formatStringFromName(gStr.doneScheme, [uri.scheme], 1);
fullHost = displayHost;
} else if (uri.port != -1) {
// Tack on the port if it's not the default port
let port = ":" + uri.port;
displayHost += port;
fullHost += port;
}
return [displayHost, fullHost];
},
/**
* Converts a number of bytes to the appropriate unit that results in an
* internationalized number that needs fewer than 4 digits.
*
* @param aBytes
* Number of bytes to convert
* @return A pair: [new value with 3 sig. figs., its unit]
*/
convertByteUnits: function DU_convertByteUnits(aBytes)
{
let unitIndex = 0;
// Convert to next unit if it needs 4 digits (after rounding), but only if
// we know the name of the next unit
while ((aBytes >= 999.5) && (unitIndex < gStr.units.length - 1)) {
aBytes /= 1024;
unitIndex++;
}
// Get rid of insignificant bits by truncating to 1 or 0 decimal points
// 0 -> 0; 1.2 -> 1.2; 12.3 -> 12.3; 123.4 -> 123; 234.5 -> 235
// added in bug 462064: (unitIndex != 0) makes sure that no decimal digit for bytes appears when aBytes < 100
aBytes = aBytes.toFixed((aBytes > 0) && (aBytes < 100) && (unitIndex != 0) ? 1 : 0);
if (gDecimalSymbol != ".")
aBytes = aBytes.replace(".", gDecimalSymbol);
return [aBytes, gBundle.GetStringFromName(gStr.units[unitIndex])];
},
/**
* Converts a number of seconds to the two largest units. Time values are
* whole numbers, and units have the correct plural/singular form.
*
* @param aSecs
* Seconds to convert into the appropriate 2 units
* @return 4-item array [first value, its unit, second value, its unit]
*/
convertTimeUnits: function DU_convertTimeUnits(aSecs)
{
// These are the maximum values for seconds, minutes, hours corresponding
// with gStr.timeUnits without the last item
let timeSize = [60, 60, 24];
let time = aSecs;
let scale = 1;
let unitIndex = 0;
// Keep converting to the next unit while we have units left and the
// current one isn't the largest unit possible
while ((unitIndex < timeSize.length) && (time >= timeSize[unitIndex])) {
time /= timeSize[unitIndex];
scale *= timeSize[unitIndex];
unitIndex++;
}
let value = convertTimeUnitsValue(time);
let units = convertTimeUnitsUnits(value, unitIndex);
let extra = aSecs - value * scale;
let nextIndex = unitIndex - 1;
// Convert the extra time to the next largest unit
for (let index = 0; index < nextIndex; index++)
extra /= timeSize[index];
let value2 = convertTimeUnitsValue(extra);
let units2 = convertTimeUnitsUnits(value2, nextIndex);
return [value, units, value2, units2];
},
};
/**
* Private helper for convertTimeUnits that gets the display value of a time
*
* @param aTime
* Time value for display
* @return An integer value for the time rounded down
*/
function convertTimeUnitsValue(aTime)
{
return Math.floor(aTime);
}
/**
* Private helper for convertTimeUnits that gets the display units of a time
*
* @param aTime
* Time value for display
* @param aIndex
* Index into gStr.timeUnits for the appropriate unit
* @return The appropriate plural form of the unit for the time
*/
function convertTimeUnitsUnits(aTime, aIndex)
{
// Negative index would be an invalid unit, so just give empty
if (aIndex < 0)
return "";
return PluralForm.get(aTime, gBundle.GetStringFromName(gStr.timeUnits[aIndex]));
}
/**
* Private helper function to log errors to the error console and command line
*
* @param aMsg
* Error message to log or an array of strings to concat
*/
function log(aMsg)
{
let msg = "DownloadUtils.jsm: " + (aMsg.join ? aMsg.join("") : aMsg);
Cc["@mozilla.org/consoleservice;1"].getService(Ci.nsIConsoleService).
logStringMessage(msg);
dump(msg + "\n");
}