planetNodes.js

// just store the coordinates of every node

var osmium = require('osmium'),
    levelup = require('levelup'),
    args = require('minimist')(process.argv.slice(2));

var db;
var reader;
var batch = [];
var batchSize = args.batch || 50000;

if (process.argv[2] === undefined) {
    return console.log('specify a file: `node planetNodes.js [planet pbf or bz2]`');
}

createDB(args._[0], function() {
    readFile(args._[0]);
});

function createDB(name, cb) {
    db = levelup('./planet-nodes.ldb', cb);
}

function readFile(file) {
    reader = new osmium.Reader(file, {
        'node': true
    });
    readOSM();
}

function readOSM() {
    var buffer = reader.read();
    if (!buffer) return pushBatch();

    while (object = buffer.next()) {
        batch.push({
            type: "put",
            key: 'n' + object.id,
            value: JSON.stringify(object.lat + ',' + object.lon)
        });
    }

    if (batch.length > batchSize) {
        pushBatch(function() {
            readOSM();
        });
    } else {
        readOSM();
    }
}

function pushBatch(callback) {
    db.batch(batch, function(err) {
        if (err) return console.log(err);
        batch = [];
        return callback ? callback() : false;
    });
}