app source code

1 // Written in D programming language
2 /**
3 *   Copyright: © 2014 DSoftOut
4 *   License: Subject to the terms of the MIT license, as written in the included LICENSE file.
5 *   Authors: NCrashed <ncrashed@gmail.com>
6 */
7 module app;
8 
9 import std.getopt;
10 import std.stdio;
11 import std.datetime;
12 import dlogg.strict;
13 import pgator.db.pq.libpq;
14 import pgator.db.pq.connection;
15 import pgator.db.async.pool;    
16 
17 void main(string[] args)
18 {
19     string logName = "app.log";
20     string connString = "port=5432";
21     bool help = false;
22     
23     args.getopt("l|log", &logName,
24                 "c|conn", &connString,
25                 "h|help", &help
26                 );
27     
28     if(help)
29     {
30         writeln("pgator-backend-example-onerow [options]\n\n",
31           "\t-l|--log=path\t - path to log, default 'app.log'\n",
32           "\t-c|--conn=string - connection string to PostgreSQL\n",
33           "\t-h|--help\t - prints this message"
34         );
35         return;
36     }
37     
38     // Initializing concurrent logger
39     auto logger = new shared StrictLogger(logName);
40     scope(exit) logger.finalize();
41 
42     // Intitializing PostgreSQL bindings and Connection factory
43     auto api = new shared PostgreSQL(logger);
44     auto connProvider = new shared PQConnProvider(logger, api);
45 
46     // Creating pool
47     auto pool = new shared AsyncPool(logger, connProvider
48         , dur!"seconds"(1) // time between reconnection tries
49         , dur!"seconds"(5) // maximum time to wait for free connection appearing in the pool while quering
50         , dur!"seconds"(3) // every 3 seconds check connection
51         );
52     scope(failure) pool.finalize();
53 
54     // Adding server to the pool
55     pool.addServer(connString, 1);
56 
57     // Quering a server from pool
58     auto bsonRange = pool.execTransaction(["select 10 as field"],
59                                           [], // no parameters
60                                           [], // no parameters
61                                           null, // no vars
62                                           [true] // indicates that first query should be one-row query
63                                           );
64     foreach(bson; bsonRange) writeln(bson);
65     
66     // Invalid query with rollback
67     auto bsonRange2 = pool.execTransaction(["select 10 as field union select 11 as field"],
68                                           [], // no parameters
69                                           [], // no parameters
70                                           null, // no vars
71                                           [true] // indicates that first query should be one-row query
72                                           );
73     foreach(bson; bsonRange2) writeln(bson);
74 }