characters are not generated uniformly

[mbican]

numbers 0-7 are generated more often then other characters. Because the number of characters is 62. The random number from generator is 0-255. 256 is not multiple of 62.

You should replace

var index = bf.readUInt8(i) % chars.length;

with something like this:

while((random = bf.readUInt8(i++))>=248); // 248 = 4*62
index = random % 62;

to throw away the nonuniform remainder

[eliaskg]

I would totally merge this if you had a working fork 😉

[dchest]

@mbican could you please review #18.

[weisjohn]

👍

[eliaskg]

I tested this function wise and it works. Could anyone check whether characters now are really generated uniformly?

[dchest]

@eliaskg there's a test for uniformness included:

dchest@15ce2fd#diff-910eb6f57886ca16c136101fb1699231R79

If you want to see/graph the distribution, insert a few console.log's there.