1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/tests/ecma/Date/shell.js Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,149 @@
1.4 +
1.5 +var BUGNUMBER;
1.6 +var summary;
1.7 +
1.8 +function runDSTOffsetCachingTestsFraction(part, parts)
1.9 +{
1.10 + BUGNUMBER = 563938;
1.11 + summary = 'Cache DST offsets to improve SunSpider score';
1.12 +
1.13 + print(BUGNUMBER + ": " + summary);
1.14 +
1.15 + var MAX_UNIX_TIMET = 2145859200;
1.16 + var RANGE_EXPANSION_AMOUNT = 30 * 24 * 60 * 60;
1.17 +
1.18 + /**
1.19 + * Computes the time zone offset in minutes at the given timestamp.
1.20 + */
1.21 + function tzOffsetFromUnixTimestamp(timestamp)
1.22 + {
1.23 + var d = new Date(NaN);
1.24 + d.setTime(timestamp); // local slot = NaN, UTC slot = timestamp
1.25 + return d.getTimezoneOffset(); // get UTC, calculate local => diff in minutes
1.26 + }
1.27 +
1.28 + /**
1.29 + * Clear the DST offset cache, leaving it initialized to include a timestamp
1.30 + * completely unlike the provided one (i.e. one very, very far away in time
1.31 + * from it). Thus an immediately following lookup for the provided timestamp
1.32 + * will cache-miss and compute a clean value.
1.33 + */
1.34 + function clearDSTOffsetCache(undesiredTimestamp)
1.35 + {
1.36 + var opposite = (undesiredTimestamp + MAX_UNIX_TIMET / 2) % MAX_UNIX_TIMET;
1.37 +
1.38 + // Generic purge to known, but not necessarily desired, state
1.39 + tzOffsetFromUnixTimestamp(0);
1.40 + tzOffsetFromUnixTimestamp(MAX_UNIX_TIMET);
1.41 +
1.42 + // Purge to desired state. Cycle 2x in case opposite or undesiredTimestamp
1.43 + // is close to 0 or MAX_UNIX_TIMET.
1.44 + tzOffsetFromUnixTimestamp(opposite);
1.45 + tzOffsetFromUnixTimestamp(undesiredTimestamp);
1.46 + tzOffsetFromUnixTimestamp(opposite);
1.47 + tzOffsetFromUnixTimestamp(undesiredTimestamp);
1.48 + }
1.49 +
1.50 + function computeCanonicalTZOffset(timestamp)
1.51 + {
1.52 + clearDSTOffsetCache(timestamp);
1.53 + return tzOffsetFromUnixTimestamp(timestamp);
1.54 + }
1.55 +
1.56 + var TEST_TIMESTAMPS_SECONDS =
1.57 + [
1.58 + // Special-ish timestamps
1.59 + 0,
1.60 + RANGE_EXPANSION_AMOUNT,
1.61 + MAX_UNIX_TIMET,
1.62 + ];
1.63 +
1.64 + var ONE_DAY = 24 * 60 * 60;
1.65 + var EIGHTY_THREE_HOURS = 83 * 60 * 60;
1.66 + var NINETY_EIGHT_HOURS = 98 * 60 * 60;
1.67 + function nextIncrement(i)
1.68 + {
1.69 + return i === EIGHTY_THREE_HOURS ? NINETY_EIGHT_HOURS : EIGHTY_THREE_HOURS;
1.70 + }
1.71 +
1.72 + // Now add a long sequence of non-special timestamps, from a fixed range, that
1.73 + // overlaps a DST change by "a bit" on each side. 67 days should be enough
1.74 + // displacement that we can occasionally exercise the implementation's
1.75 + // thirty-day expansion and the DST-offset-change logic. Use two different
1.76 + // increments just to be safe and catch something a single increment might not.
1.77 + var DST_CHANGE_DATE = 1268553600; // March 14, 2010
1.78 + for (var t = DST_CHANGE_DATE - 67 * ONE_DAY,
1.79 + i = nextIncrement(NINETY_EIGHT_HOURS),
1.80 + end = DST_CHANGE_DATE + 67 * ONE_DAY;
1.81 + t < end;
1.82 + i = nextIncrement(i), t += i)
1.83 + {
1.84 + TEST_TIMESTAMPS_SECONDS.push(t);
1.85 + }
1.86 +
1.87 + var TEST_TIMESTAMPS =
1.88 + TEST_TIMESTAMPS_SECONDS.map(function(v) { return v * 1000; });
1.89 +
1.90 + /**************
1.91 + * BEGIN TEST *
1.92 + **************/
1.93 +
1.94 + // Compute the correct time zone offsets for all timestamps to be tested.
1.95 + var CORRECT_TZOFFSETS = TEST_TIMESTAMPS.map(computeCanonicalTZOffset);
1.96 +
1.97 + // Intentionally and knowingly invoking every single logic path in the cache
1.98 + // isn't easy for a human to get right (and know he's gotten it right), so
1.99 + // let's do it the easy way: exhaustively try all possible four-date sequences
1.100 + // selecting from our array of possible timestamps.
1.101 +
1.102 + var sz = TEST_TIMESTAMPS.length;
1.103 + var start = Math.floor((part - 1) / parts * sz);
1.104 + var end = Math.floor(part / parts * sz);
1.105 +
1.106 + print("Exhaustively testing timestamps " +
1.107 + "[" + start + ", " + end + ") of " + sz + "...");
1.108 +
1.109 + try
1.110 + {
1.111 + for (var i = start; i < end; i++)
1.112 + {
1.113 + print("Testing timestamp " + i + "...");
1.114 +
1.115 + var t1 = TEST_TIMESTAMPS[i];
1.116 + for (var j = 0; j < sz; j++)
1.117 + {
1.118 + var t2 = TEST_TIMESTAMPS[j];
1.119 + for (var k = 0; k < sz; k++)
1.120 + {
1.121 + var t3 = TEST_TIMESTAMPS[k];
1.122 + for (var w = 0; w < sz; w++)
1.123 + {
1.124 + var t4 = TEST_TIMESTAMPS[w];
1.125 +
1.126 + clearDSTOffsetCache(t1);
1.127 +
1.128 + var tzo1 = tzOffsetFromUnixTimestamp(t1);
1.129 + var tzo2 = tzOffsetFromUnixTimestamp(t2);
1.130 + var tzo3 = tzOffsetFromUnixTimestamp(t3);
1.131 + var tzo4 = tzOffsetFromUnixTimestamp(t4);
1.132 +
1.133 + assertEq(tzo1, CORRECT_TZOFFSETS[i]);
1.134 + assertEq(tzo2, CORRECT_TZOFFSETS[j]);
1.135 + assertEq(tzo3, CORRECT_TZOFFSETS[k]);
1.136 + assertEq(tzo4, CORRECT_TZOFFSETS[w]);
1.137 + }
1.138 + }
1.139 + }
1.140 + }
1.141 + }
1.142 + catch (e)
1.143 + {
1.144 + assertEq(true, false,
1.145 + "Error when testing with timestamps " +
1.146 + i + ", " + j + ", " + k + ", " + w +
1.147 + " (" + t1 + ", " + t2 + ", " + t3 + ", " + t4 + ")!");
1.148 + }
1.149 +
1.150 + reportCompare(true, true);
1.151 + print("All tests passed!");
1.152 +}
