Issue with decodeRunRepeated

[aizard-trackinsight]

Hi,

I think there is an issue here:

parquetjs/lib/codec/rle.js

Line 114 in 07fb2fd

value << 8;

I worked on a parquet file where decodeRunRepeated was basically supposed to convert a [18, 1] buffer into 274 as the repeated value but yielded 19 instead.

[18,1] is supposed to be interpreted as 18 * 2^(8 * 0) + 1 * 2^(8 * 1) = 18 + 256 = 274, which would lead to something like this:

value += (cursor.buffer[cursor.offset] << 8*i)

The current code yields the correct result if there is only one byte needed: [18, 0] yields 18 which is expected.

The issue is only visible if the parquet file has some repeated values above 256, as those repeated values will need more than 1 bytes to be encoded, and the current code would yield incorrect values.

I think value << 8 without affectation has no effect. There might be a similar problem in the encoding function but I haven't used it so far:

parquetjs/lib/codec/rle.js

Line 26 in 07fb2fd

value >> 8;