error handling in async loop

This commit is contained in:
Ryan Clark
2015-01-05 10:32:10 -05:00
parent 18a9d50e2f
commit 5e8f1375f5

View File

@@ -31,7 +31,7 @@ MBTiles.schema = fs.readFileSync(__dirname + '/schema.sql', 'utf8');
// - callback: Will be called when the resources have been acquired
// or acquisition failed.
require('util').inherits(MBTiles, require('events').EventEmitter)
function MBTiles(uri, callback) {
function MBTiles(uri, callback) {
if (typeof uri === 'string') {
uri = url.parse(uri, true);
uri.pathname = qs.unescape(uri.pathname);
@@ -274,17 +274,29 @@ MBTiles.prototype.getInfo = function(callback) {
var zooms = [];
var query = mbtiles._db.prepare('SELECT zoom_level FROM tiles WHERE zoom_level = ? LIMIT 1', function(err) {
if (err) return callback(err.errno === 1 ? null : err, info);
for (var i = 0; i < remaining; i++) query.get(i, function(err, row) {
if (err) return (remaining = 0) && callback(err);
if (row) zooms.push(row.zoom_level);
if (--remaining === 0) {
if (!zooms.length) return callback(null, info);
zooms.sort(function(a,b) { return a < b ? -1 : 1 });
info.minzoom = zooms[0];
info.maxzoom = zooms.pop();
return callback(null, info);
}
});
function done(err, info) {
if (done.sent) return;
callback(err, info);
done.sent = true;
}
done.sent = false;
for (var i = 0; i < remaining; i++) {
query.get(i, function(err, row) {
if (err) return done(err);
if (row) zooms.push(row.zoom_level);
if (--remaining === 0) {
if (!zooms.length) return callback(null, info);
zooms.sort(function(a,b) { return a < b ? -1 : 1; });
info.minzoom = zooms[0];
info.maxzoom = zooms.pop();
return done(null, info);
}
});
}
query.finalize();
});
};
@@ -752,4 +764,3 @@ MBTiles.prototype.geocoderCentroid = function(id, zxy, callback) {
MBTiles.prototype.createZXYStream = function(options) {
return new ZXYStream(this, options);
};