Jeffail / jc

Prints the cardinalities of value paths in a stream of JSON blobs.

jc

jc prints the cardinalities of JSON value paths for a stream of JSON blobs.

Use it like this:

cat ./a_bunch_of_line_delim.json | jc

Or, like this:

$ jc
{"foo":{"bar":1}}
{"foo":{"bar":2}}
{"foo":{"bar":[3,4,5]}}
<CTRL+D>
{"foo.bar":5}

Build it like this:

cargo build

HyperLogLog

By default jc is a type aware exact count, but this can potentially use up a lot of memory when the cardinalities are high. Alternatively, you can use the HyperLogLog algorithm for approximating cardinalities with the --hll flag. However, using HLL means type information is lost, as all values are parsed into string types.