Moves calls to SQL API to its own entity.

Groups affected tables and last updated time for affected tables into one request.
2014-07-30 13:46:46 +02:00
parent 75088c89d3
commit 3af45e1a32
4 changed files with 351 additions and 152 deletions
@@ -0,0 +1,66 @@
+var _       = require('underscore'),
+    request = require('request');
+
+module.exports.query = function (username, api_key, sql, callback) {
+    var api = global.environment.sqlapi;
+
+    // build up api string
+    var sqlapihostname = username;
+    if ( api.domain ) sqlapihostname += '.' + api.domain;
+
+    var sqlapi = api.protocol + '://';
+    if ( api.host && api.host != api.domain ) sqlapi += api.host;
+    else sqlapi += sqlapihostname;
+    sqlapi += ':' + api.port + '/api/' + api.version + '/sql';
+
+    var qs  = { q: sql };
+
+    // add api_key if given
+    if (_.isString(api_key) && api_key != '') { qs.api_key = api_key; }
+
+    // call sql api
+    //
+    // NOTE: using POST to avoid size limits:
+    // See http://github.com/CartoDB/Windshaft-cartodb/issues/111
+    //
+    // NOTE: uses "host" header to allow IP based specification
+    //       of sqlapi address (and avoid a DNS lookup)
+    //
+    // NOTE: allows for keeping up to "maxConnections" concurrent
+    //       sockets opened per SQL-API host.
+    // See http://nodejs.org/api/http.html#http_agent_maxsockets
+    //
+    var maxSockets = global.environment.maxConnections || 128;
+    var maxGetLen = api.max_get_sql_length || 2048;
+    var maxSQLTime = api.timeout || 100; // 1/10 of a second by default
+    var reqSpec = {
+        url:sqlapi,
+        json:true,
+        headers:{host: sqlapihostname}
+        // http://nodejs.org/api/http.html#http_agent_maxsockets
+        ,pool:{maxSockets:maxSockets}
+        // timeout in milliseconds
+        ,timeout:maxSQLTime
+    };
+    if ( sql.length > maxGetLen ) {
+        reqSpec.method = 'POST';
+        reqSpec.body = qs;
+    } else {
+        reqSpec.method = 'GET';
+        reqSpec.qs = qs;
+    }
+    request(reqSpec, function(err, res, body) {
+        if (err){
+            console.log('ERROR connecting to SQL API on ' + sqlapi + ': ' + err);
+            callback(err);
+            return;
+        }
+        if (res.statusCode != 200) {
+            var msg = res.body.error ? res.body.error : res.body;
+            callback(new Error(msg));
+            console.log('unexpected response status (' + res.statusCode + ') for sql query: ' + sql + ': ' + msg);
+            return;
+        }
+        callback(null, body.rows);
+    });
+};