2.0.4 • Published 7 years ago

osm-p2p-db-importer v2.0.4

Weekly downloads
3
License
ISC
Repository
github
Last release
7 years ago

osm-p2p-db-importer

Fast imports from OSM XML into a fresh osm-p2p-db

This is useful if you have a very large OSM dataset that would otherwise be too slow to insert directly into osm-p2p-db.

How much faster?

smaller.xml: 1.4mb

  • osm-p2p-server: 10.5s
  • osm-p2p-db-importer: 7.3s

6.xml: 18mb

  • osm-p2p-server: 720+ seconds (stopped recording)
  • osm-p2p-db-importer: 73.3s

How does it work?

A fresh import is a special case that lets us make a key assumption:

  1. No historic data (no data in the import is an earlier revision of other data)

There is a lot of cost in ensuring consistency across the layers of osm-p2p-*, which can be potentially skipped if we know we don't need to worry about inconsistent data coming in.

This module skips multiple layers, accepting OSM XML data and generating LevelDB batch operations directly, without the osm-p2p-db, hyperkv, and hyperlog layers of processing in between. This isn't very stable in the long-term (since the things under the blankets of these modules may change), but for now it makes for some very quick data insertions into a fresh DB.

Usage

var importer = require('osm-p2p-db-importer')
var fs = require('fs')

var xml = fs.createReadStream('./hawaii.xml')

var dbPath = '/tmp/osm-p2p-ex'

importer(dbPath, xml, function (err) {
  console.log(err ? err : 'import done!')

  // OPTIONAL: wait for indexes to be generated
  var osmdb = require('osm-p2p')
  var osm = osmdb(dbPath)
  osm.ready(function () {
    console.log('indexes generated')
  })
})

outputs

done!

API

var importer = require('osm-p2p-db-importer')

importer(osmDir, xmlStream, opts, done)

  • osmDir: path to a directory where the osm-p2p-db will be located.
  • xmlStream: a readable stream of OSM XML data.
  • opts: options object. Currently accepts slow: true|false.
  • done: a callback function, receiving an error err or null.

importer.toLevel(db, xmlStream, done)

Like the above, except operating on a user-specified LevelUP instance, db. This is useful if you aren't using a filesystem-backed LevelDOWN as your back-end.

CLI Usage

USAGE: osm-p2p-db-importer [--slow] DBDIR [XMLFILE]

  Import OSM XML into an osm-p2p-db located at DBDIR. XMLFILE is a file
  containing OSM XML. If not specified, OSM XML is read from standard input.

  --slow, -s: skip fragile optimizations; import using the normal osm-p2p-db
              process.

XML Formatting

Anything that would be an acceptable upload to OSM v0.6's POST /api/0.6/changeset/:id/upload should work here.

Caveat: Changeset ID

Note that this module doesn't create a changeset for you. You will need to create one first, an ensure your XML has that changeset set.

Install

With npm installed, run

As a Library

$ npm install osm-p2p-db-importer

As a Command Line Utility

$ npm install --global osm-p2p-db-importer

License

ISC