zM05Prnu

1import (
2	"database/sql"
3	"log"
4
5	"github.com/go-gorp/gorp"
6)
7
8// go abstract db manipulation layer using gorp
9var (
10	g_dbMap     *gorp.DbMap
11	g_logPrefix string
12	g_logger    *log.Logger
13)
14
15type ModelMap struct {
16	Model       interface{}
17	TableName   string
18	PrimaryKeys []string
19	Autoincr    bool
20}
21
22var g_modelMap = make([]*ModelMap, 0, 10)
23
24// InitializeDatabase try to connect to data source, and
25// create tables if not exists.
26// It should be called after all RegisterModelsToDb.
27func InitializeDatabase(datasrc, driverName string) error {
28	err := initDb(datasrc, driverName)
29	return err
30}
31
32// CloseDatabase close underneath db connection.
33// It returns error if failed.
34func CloseDatabase() error {
35	return GetDbMap().Db.Close()
36}
37
38// RegisterModelsToDb allowes to register a type of object to database persistance
39// layer.
40// keys being nil indicates the table doesn't have a primary key
41// example: RegisterModelsToDb(Solution{}, "solutions", []string{"Id"}, true)
42// autoincr indicates the key is auto incremental. When it's true, there can only one key
43func RegisterModelsToDb(model interface{}, tableName string, keys []string, autoincr bool) {
44	g_modelMap = append(g_modelMap, &ModelMap{model, tableName, keys, autoincr})
45}
46
47// GetDbMap return current gorp.DbMap.
48func GetDbMap() *gorp.DbMap {
49	return g_dbMap
50}
51
52// SetTrace turn on db trace logging to the logger with prefix.
53// If logger is nil, turn it off.
54func SetTrace(prefix string, logger *log.Logger) {
55	if GetDbMap() != nil {
56		if logger == nil {
57			GetDbMap().TraceOff()
58		} else {
59			GetDbMap().TraceOn(prefix, logger)
60		}
61	}
62	g_logPrefix = prefix
63	g_logger = logger
64}
65
66func initDb(datasrc, driverName string) error {
67	db, err := sql.Open(driverName, datasrc)
68	if err != nil {
69		return err
70	}
71
72	g_dbMap = &gorp.DbMap{Db: db, Dialect: gorp.SqliteDialect{}}
73
74	for _, mmap := range g_modelMap {
75		tabMap := g_dbMap.AddTableWithName(mmap.Model, mmap.TableName)
76		if len(mmap.PrimaryKeys) > 0 {
77			tabMap.SetKeys(mmap.Autoincr, mmap.PrimaryKeys...)
78		}
79	}
80
81	SetTrace(g_logPrefix, g_logger)
82
83	err = g_dbMap.CreateTablesIfNotExists()
84
85	return err
86}