mapbox / node-tilejson

Tile source backend for online tile sources

node-tilejson

A javascript implementation of https://github.com/mapbox/tilejson-spec

install

npm install --save @mapbox/tilejson

API

This module mainly provides an API for use by tilelive: it implements methods that allow fetching of tiles and metadata given a TileJSON object.

Provides a metadata for online tile sources in json format.

node-tilejson's Issues

Failing to get a lock doesn't retry

Encountered an issue while running http://github.com/mapbox/unpacker tests where tilelive.load(tilejson_url) wouldn't return, causing the tests to hang at https://github.com/mapbox/tilelive.js/blob/master/lib/tilelive.js#L97 and eventually time out.

Traced this back to the Locking function, where it appears that failed attempts at getting a lock aren't handled properly. It seems that the lock doesn't actually prevent subsequent listeners still being bound to the done event, only ensures that the first listener to respond takes the lock, blocking others. Triggered listeners that encounter !locks[id].io fail silently rather than retrying.

Added logging around this issue at https://github.com/mapbox/node-tilejson/blob/broken-locking/lib/tilejson.js#L226-252, this is what I'm seeing.

3 Dec 17:54:25 - 33403d98-bc58-4f2c-92e3-bfc5c96c79c0 test.test-5331-valid-tilejson - Downloaded file from http://tilestream-tilesets-testing.s3.amazonaws.com/_pending/test/test-5331-valid-tilejson
TILELIVE handler { filename: '/tmp/unpacker/33403d98-bc58-4f2c-92e3-bfc5c96c79c0' }
PRE-EMIT listeners.length 1
LOCKED
TILELIVE handler {}
EMIT listeners.length 2
LOCK RELEASED

Is this a dupe of #4? Is a lock necessary here?

/cc @yhahn @willwhite

README

lol https://github.com/mapbox/node-tilejson/blob/master/README.md

Changelog

This module needs a changelog.

Update agentkeepalive

To prevent agentkeepalive error

TypeError: this._evictSession is not a function

Dependency version should be updated

needs first tag and npm publish

Retry downloads after failure

Tests failing in master branch

It looks like something changed causing tests to start failing in master without any code changes: https://travis-ci.org/mapbox/node-tilejson/builds/105263252

Add configurable retry

Allow node-retry configuration to be passed in, similar to to carmen. Default to 0 retries.

support for HiDPI

The module doesn't seem to works with HiDPI screens like Retina.

Example:
save following under config.json, then run /usr/bin/nodejs /usr/bin/tessera -c . -p 28089

{
 "/toner": {
   "source": "tilejson+http://staging.tile.stamen.com/toner-background/index.json"
  },
 "/toner-http": {
   "source": "http://toner-elb-3vaew2i23b6d-1666871272.us-east-1.elb.amazonaws.com/toner-background/{z}/{x}/{y}.png"
  }
}

http://127.0.0.1:28089/toner-http/6/11/[email protected] returns a 512x512 image. Fine.

http://toner-elb-3vaew2i23b6d-1666871272.us-east-1.elb.amazonaws.com/toner-background/6/11/[email protected] returns a 512x512 image (it's the link described in the tilejson file). Fine.

http://127.0.0.1:28089/toner/6/11/[email protected] returns a 256x256 image. Wrong :-(.

The solution is probably as simple as integrating the modifications proposed in https://github.com/mapbox/node-tilejson/pull/26/files.

Use "request" instead of "get"

Can the dependency on https://github.com/mapbox/node-get be replaced with https://github.com/request/request ?

As get is not fully supporting proxies (e.g. HTTPS url and HTTP proxy or authentication), which request already has (request#proxies), it seems that this is the only roadblock on unleashing proxy support with Mapbox Studio.

Also, tile-json is the only Mapbox Studio dependency that uses get, all others already use request.

Add caching

• Save to disk or to file system
• Respect HTTP headers
• Cache both grids and tiles

Use locking cache to prevent duplicate parallel downloads

npm owner add

Gotta roll a release for a small bugfix:

a4fd8e1