93 lines
1.9 KiB
Go
93 lines
1.9 KiB
Go
package adapter
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import (
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"database/sql"
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"fmt"
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"time"
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)
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/**
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* DBAdapter
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* Automatically creates connections for each database URL.
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* Executes queries on the specified database.
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* TODO: Closes connections older than 2 minutes.
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**/
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type DBAdapter struct {
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Type string
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MaxAttempts int
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_db map[string]*sql.DB
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_connect_attempts map[string]int
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_connect_time map[string]int64
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}
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func (a *DBAdapter) Open(url string) (*sql.DB, error) {
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if a._db == nil {
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a._db = make(map[string]*sql.DB)
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}
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if a._connect_attempts == nil {
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a._connect_attempts = make(map[string]int)
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}
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if a._connect_time == nil {
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a._connect_time = make(map[string]int64)
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}
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if a.MaxAttempts == 0 {
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a.MaxAttempts = 6
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}
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if _, ok := a._db[url]; !ok {
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a._db[url], _ = sql.Open(a.Type, url)
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} else {
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err := a._db[url].Ping()
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if err != nil {
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a._db[url] = nil
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a._connect_attempts[url]++
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time.Sleep(time.Duration(5) * time.Second)
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if a._connect_attempts[url] > a.MaxAttempts {
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return nil, fmt.Errorf(`failed to connect to "%s"`, url)
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}
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return a.Open(url)
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}
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}
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a._connect_attempts[url] = 0
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a._connect_time[url] = time.Now().Unix()
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return a._db[url], nil
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}
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func (a *DBAdapter) GetDB(url string) *sql.DB {
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if a._db == nil {
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return nil
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}
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return a._db[url]
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}
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func (a *DBAdapter) Close() {
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for _, db := range a._db {
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db.Close()
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}
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a._db = nil
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a._connect_attempts = nil
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}
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func (a *DBAdapter) Query(req Query) (*sql.Rows, error) {
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db, err := a.Open(req.Db)
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if err != nil {
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return nil, err
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}
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sfmt, err := db.Prepare(req.Expression)
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if err != nil {
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return nil, err
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}
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return sfmt.Query(req.Data...)
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}
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func (a *DBAdapter) Exec(req Query) (sql.Result, error) {
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db, err := a.Open(req.Db)
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if err != nil {
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return nil, err
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}
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sfmt, err := db.Prepare(req.Expression)
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if err != nil {
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return nil, err
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}
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return sfmt.Exec(req.Data...)
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}
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