Windshaft-cartodb/lib/cartodb/carto_data.js
2011-09-05 00:00:41 +01:00

134 lines
3.7 KiB
JavaScript

/**
* User: simon
* Date: 30/08/2011
* Time: 21:10
* Desc: CartoDB helper.
* Retrieves dbname (based on subdomain/username)
* and geometry type from the redis stores of cartodb
*/
var RedisPool = require("./redis_pool")
, _ = require('underscore')
, Step = require('step');
module.exports = function() {
var redis_pool = new RedisPool();
var me = {
user_metadata_db: 5,
table_metadata_db: 0,
user_key: "rails:users:<%= username %>",
table_key: "rails:<%= database_name %>:<%= table_name %>"
};
/**
* Get the database name for this particular subdomain/username
*
* @param req - standard express req object. importantly contains host information
* @param callback
*/
me.getDatabase = function(req, callback) {
// strip subdomain from header host
var username = req.headers.host.split('.')[0]
var redisKey = _.template(this.user_key, {username: username});
this.retrieve(this.user_metadata_db, redisKey, 'database_name', callback);
};
/**
* Get the user id for this particular subdomain/username
*
* @param req - standard express req object. importantly contains host information
* @param callback
*/
me.getId= function(req, callback) {
// strip subdomain from header host
var username = req.headers.host.split('.')[0]
var redisKey = _.template(this.user_key, {username: username});
this.retrieve(this.user_metadata_db, redisKey, 'id', callback);
};
/**
* Get the geometry type for this particular table;
* @param req - standard req object. Importantly contains table and host information
* @param callback
*/
me.getGeometryType = function(req, callback){
var that = this;
Step(
function(){
that.getDatabase(req, this)
},
function(err, data){
if (err) throw err;
var redisKey = _.template(that.table_key, {database_name: data, table_name: req.params.table});
that.retrieve(that.table_metadata_db, redisKey, 'the_geom_type', this);
},
function(err, data){
if (err) throw err;
callback(err, data);
}
);
};
me.getInfowindow = function(req, callback){
var that = this;
Step(
function(){
that.getDatabase(req, this);
},
function(err, data){
if (err) throw err;
var redisKey = _.template(that.table_key, {database_name: data, table_name: req.params.table});
that.retrieve(that.table_metadata_db, redisKey, 'infowindow', this);
},
function(err, data){
if (err) throw err;
callback(err, data);
}
);
};
/**
* Make a HASH data access call to Redis
*
* @param redisKey - the base redis key where the metadata hash lives
* @param hashKey - the specific metadata you want to retrieve
* @param callback - function to pass metadata too. err,data args
*/
me.retrieve = function(db, redisKey, hashKey, callback) {
var redisClient;
Step(
function getRedisClient() {
redis_pool.acquire(db, this);
},
function lookupMetadata(err, data) {
redisClient = data;
redisClient.HGET(redisKey, hashKey, this);
},
function releaseRedisClient(err, data) {
if (err) throw err;
redis_pool.release(db, redisClient);
callback(err, data);
}
);
};
return me;
}();