コード例 #1
0
ファイル: prmjtime.cpp プロジェクト: Anachid/mozilla-central
int64_t
DSTOffsetCache::getDSTOffsetMilliseconds(int64_t localTimeMilliseconds, JSContext *cx)
{
    sanityCheck();

    int64_t localTimeSeconds = localTimeMilliseconds / MILLISECONDS_PER_SECOND;

    if (localTimeSeconds > MAX_UNIX_TIMET) {
        localTimeSeconds = MAX_UNIX_TIMET;
    } else if (localTimeSeconds < 0) {
        /* Go ahead a day to make localtime work (does not work with 0). */
        localTimeSeconds = SECONDS_PER_DAY;
    }

    /*
     * NB: Be aware of the initial range values when making changes to this
     *     code: the first call to this method, with those initial range
     *     values, must result in a cache miss.
     */

    if (rangeStartSeconds <= localTimeSeconds &&
        localTimeSeconds <= rangeEndSeconds) {
        return offsetMilliseconds;
    }

    if (oldRangeStartSeconds <= localTimeSeconds &&
        localTimeSeconds <= oldRangeEndSeconds) {
        return oldOffsetMilliseconds;
    }

    oldOffsetMilliseconds = offsetMilliseconds;
    oldRangeStartSeconds = rangeStartSeconds;
    oldRangeEndSeconds = rangeEndSeconds;

    if (rangeStartSeconds <= localTimeSeconds) {
        int64_t newEndSeconds = JS_MIN(rangeEndSeconds + RANGE_EXPANSION_AMOUNT, MAX_UNIX_TIMET);
        if (newEndSeconds >= localTimeSeconds) {
            int64_t endOffsetMilliseconds = computeDSTOffsetMilliseconds(newEndSeconds);
            if (endOffsetMilliseconds == offsetMilliseconds) {
                rangeEndSeconds = newEndSeconds;
                return offsetMilliseconds;
            }

            offsetMilliseconds = computeDSTOffsetMilliseconds(localTimeSeconds);
            if (offsetMilliseconds == endOffsetMilliseconds) {
                rangeStartSeconds = localTimeSeconds;
                rangeEndSeconds = newEndSeconds;
            } else {
                rangeEndSeconds = localTimeSeconds;
            }
            return offsetMilliseconds;
        }

        offsetMilliseconds = computeDSTOffsetMilliseconds(localTimeSeconds);
        rangeStartSeconds = rangeEndSeconds = localTimeSeconds;
        return offsetMilliseconds;
    }

    int64_t newStartSeconds = JS_MAX(rangeStartSeconds - RANGE_EXPANSION_AMOUNT, 0);
    if (newStartSeconds <= localTimeSeconds) {
        int64_t startOffsetMilliseconds = computeDSTOffsetMilliseconds(newStartSeconds);
        if (startOffsetMilliseconds == offsetMilliseconds) {
            rangeStartSeconds = newStartSeconds;
            return offsetMilliseconds;
        }

        offsetMilliseconds = computeDSTOffsetMilliseconds(localTimeSeconds);
        if (offsetMilliseconds == startOffsetMilliseconds) {
            rangeStartSeconds = newStartSeconds;
            rangeEndSeconds = localTimeSeconds;
        } else {
            rangeStartSeconds = localTimeSeconds;
        }
        return offsetMilliseconds;
    }

    rangeStartSeconds = rangeEndSeconds = localTimeSeconds;
    offsetMilliseconds = computeDSTOffsetMilliseconds(localTimeSeconds);
    return offsetMilliseconds;
}
コード例 #2
0
JSInt64
DSTOffsetCache::getDSTOffsetMilliseconds(JSInt64 localTimeMilliseconds, JSContext *cx)
{
    sanityCheck();
    noteOffsetCalculation();

    JSInt64 localTimeSeconds = localTimeMilliseconds / MILLISECONDS_PER_SECOND;

    if (localTimeSeconds > MAX_UNIX_TIMET) {
        localTimeSeconds = MAX_UNIX_TIMET;
    } else if (localTimeSeconds < 0) {
        /* Go ahead a day to make localtime work (does not work with 0). */
        localTimeSeconds = SECONDS_PER_DAY;
    }

    /*
     * NB: Be aware of the initial range values when making changes to this
     *     code: the first call to this method, with those initial range
     *     values, must result in a cache miss.
     */

    if (rangeStartSeconds <= localTimeSeconds &&
        localTimeSeconds <= rangeEndSeconds) {
        noteCacheHit();
        return offsetMilliseconds;
    }

    if (oldRangeStartSeconds <= localTimeSeconds &&
        localTimeSeconds <= oldRangeEndSeconds) {
        noteCacheHit();
        return oldOffsetMilliseconds;
    }

    oldOffsetMilliseconds = offsetMilliseconds;
    oldRangeStartSeconds = rangeStartSeconds;
    oldRangeEndSeconds = rangeEndSeconds;

    if (rangeStartSeconds <= localTimeSeconds) {
        JSInt64 newEndSeconds = JS_MIN(rangeEndSeconds + RANGE_EXPANSION_AMOUNT, MAX_UNIX_TIMET);
        if (newEndSeconds >= localTimeSeconds) {
            JSInt64 endOffsetMilliseconds = computeDSTOffsetMilliseconds(newEndSeconds);
            if (endOffsetMilliseconds == offsetMilliseconds) {
                noteCacheMissIncrease();
                rangeEndSeconds = newEndSeconds;
                return offsetMilliseconds;
            }

            offsetMilliseconds = computeDSTOffsetMilliseconds(localTimeSeconds);
            if (offsetMilliseconds == endOffsetMilliseconds) {
                noteCacheMissIncreasingOffsetChangeUpper();
                rangeStartSeconds = localTimeSeconds;
                rangeEndSeconds = newEndSeconds;
            } else {
                noteCacheMissIncreasingOffsetChangeExpand();
                rangeEndSeconds = localTimeSeconds;
            }
            return offsetMilliseconds;
        }

        noteCacheMissLargeIncrease();
        offsetMilliseconds = computeDSTOffsetMilliseconds(localTimeSeconds);
        rangeStartSeconds = rangeEndSeconds = localTimeSeconds;
        return offsetMilliseconds;
    }

    JSInt64 newStartSeconds = JS_MAX(rangeStartSeconds - RANGE_EXPANSION_AMOUNT, 0);
    if (newStartSeconds <= localTimeSeconds) {
        JSInt64 startOffsetMilliseconds = computeDSTOffsetMilliseconds(newStartSeconds);
        if (startOffsetMilliseconds == offsetMilliseconds) {
            noteCacheMissDecrease();
            rangeStartSeconds = newStartSeconds;
            return offsetMilliseconds;
        }

        offsetMilliseconds = computeDSTOffsetMilliseconds(localTimeSeconds);
        if (offsetMilliseconds == startOffsetMilliseconds) {
            noteCacheMissDecreasingOffsetChangeLower();
            rangeStartSeconds = newStartSeconds;
            rangeEndSeconds = localTimeSeconds;
        } else {
            noteCacheMissDecreasingOffsetChangeExpand();
            rangeStartSeconds = localTimeSeconds;
        }
        return offsetMilliseconds;
    }

    noteCacheMissLargeDecrease();
    rangeStartSeconds = rangeEndSeconds = localTimeSeconds;
    offsetMilliseconds = computeDSTOffsetMilliseconds(localTimeSeconds);
    return offsetMilliseconds;
}