Cacheing

[twomagpi]

Some objects (location being the obvious one) are likely to be repeated multiple times within a dataset. To prevent this duplication we should perhaps permit a cache key on the same level as metadata and records that will contain an object with keys (md5, sha?) that can be referred to later in the file. Eg

"cache": { "e54789a3": {a GeoJSON boject},
                "680f038d": "A base64 encoded file"}
}

Records in the cache could then be referred to in other elements of the file with a cache object

 "location":{"ref$": "e54789a3" }

[thibautjombart]

That sounds like a very good idea. I would go for SHA1 - I think the package 'digest' should do the trick, e.g.:

> library(digest)
> digest("EpiJSON rules!!!", algo="sha1")
[1] "e6e6f50bb3cb5985de0d9b21e5087e047e6aeea6"