json2lines v1.0.1

json2lines

This package is designed to take JSON files of any size with multiple sub-documents and produce a JSONL or JSON Lines file from the data. Take the example document:

{
    "fruits": [
        {
            "name": "Apple",
            "color": "red"
        },
        {
            "name": "Orange",
            "color": "red"
        }
    ]
}

Run it through json2lines package:

# npx json2lines --input input.json --output output.jsonl --filter fruits.*

Will result in the following JSON Lines to the output.jsonl file:

{"name":"Apple","color":"red"}
{"name":"Orange","color":"orange"}

Filtering

In the example above, you can see we passed the filter foods.*. This tells us to extract the object in the foods array in the root object. For this functionality we make use of JSONStream. For more information on filters, you can visit the documentation here:

https://github.com/dominictarr/JSONStream#jsonstreamparsepath

Performance

Memory wise the program stays near baseline for Node.JS, with a 2.6GB file with 374k entries running at <50MB in the Task Manager on a Windows 10 x64 machine. The file took roughly 6m40s on a AMD FX-8120 and Budget SSD doing both reads and writes.