Download size count switching from KiB to MiB only after 2MiB

Question

I was using pacman to update my Manjaro system on the commandline. I noticed that the progress uses KiB to measure the amount of downloaded data. This changes to MiB after it reaches 2048 KiB (most probably; the time switching from the previous to the next is very small and not completely verifiable by observation). My question is this: What is the reasoning of changing it to MiB only at 2048 KiB and not 1024 KiB? It could very well have been presented as 1 MiB.

Answer 1

What is the reasoning of changing it to MiB only at 2048 KiB and not 1024 KiB?

The developers decided to code it that way:

/** Converts sizes in bytes into human readable units.
 *
 * @param bytes the size in bytes
 * @param target_unit '\0' or a short label. If equal to one of the short unit
 * labels ('B', 'K', ...) bytes is converted to target_unit; if '\0', the first
 * unit which will bring the value to below a threshold of 2048 will be chosen.
 * @param precision number of decimal places, ensures -0.00 gets rounded to
 * 0.00; -1 if no rounding desired
 * @param label will be set to the appropriate unit label
 *
 * @return the size in the appropriate unit
 */
double humanize_size(off_t bytes, const char target_unit, int precision,
        const char **label)
{
    static const char *labels[] = {"B", "KiB", "MiB", "GiB",
        "TiB", "PiB", "EiB", "ZiB", "YiB"};
    static const int unitcount = ARRAYSIZE(labels);

    double val = (double)bytes;
    int index;

    for(index = 0; index < unitcount - 1; index++) {
        if(target_unit != '\0' && labels[index][0] == target_unit) {
            break;
        } else if(target_unit == '\0' && val <= 2048.0 && val >= -2048.0) {
            break;
        }
        val /= 1024.0;
    }

    if(label) {
        *label = labels[index];
    }

    /* do not display negative zeroes */
    if(precision >= 0 && val < 0.0 &&
            val > (-0.5 / simple_pow(10, precision))) {
        val = 0.0;
    }

    return val;
}

Source util.c\pacman\src - pacman.git - The official pacman repository

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It could very well have been presented as 1 MiB.

It is an open source project. You can add a feature request to change the behavior or clone the project and change it yourself.