Add MySQL backend

backend/mysql/mysql_storage.go

@@ -0,0 +1,96 @@
+package mysql
+
+import (
+	"database/sql"
+	"time"
+
+	_ "github.com/go-sql-driver/mysql"
+	"github.com/localhots/steward/steward"
+)
+
+type (
+	MysqlStorage struct {
+		db    *sql.DB
+		state map[string]*steward.State
+
+		importStmt    *sql.Stmt
+		saveStateStmt *sql.Stmt
+		loadStateStmt *sql.Stmt
+	}
+)
+
+const (
+	importQuery    = "replace into commits (sha1, author, repo, ts) values (?, ?, ?, ?)"
+	saveStateQuery = "replace into state (repo, sha1, ts) values (?, ?, ?)"
+	loadStateQuery = "select repo, sha1, ts from state"
+)
+
+func New() *MysqlStorage {
+	var (
+		s = &MysqlStorage{
+			state: map[string]*steward.State{},
+		}
+		err error
+	)
+
+	if s.db, err = sql.Open("mysql", "root@/steward?parseTime=true"); err != nil {
+		panic(err)
+	}
+	if s.importStmt, err = s.db.Prepare(importQuery); err != nil {
+		panic(err)
+	}
+	if s.saveStateStmt, err = s.db.Prepare(saveStateQuery); err != nil {
+		panic(err)
+	}
+
+	s.loadGlobalState()
+
+	return s
+}
+
+func (ms *MysqlStorage) Import(repo string, hist map[string]*steward.Commit) {
+	var (
+		lastTimestamp *time.Time
+		lastSha1      string
+	)
+
+	for sha1, c := range hist {
+		if _, err := ms.importStmt.Exec(sha1, c.Author, repo, c.Timestamp); err != nil {
+			panic(err)
+		}
+		if lastTimestamp == nil || lastTimestamp.After(c.Timestamp) {
+			lastTimestamp = &c.Timestamp
+			lastSha1 = sha1
+		}
+	}
+
+	ms.saveRepoState(repo, lastSha1, *lastTimestamp)
+}
+
+func (ms *MysqlStorage) saveRepoState(repo string, sha1 string, ts time.Time) {
+	if _, err := ms.saveStateStmt.Exec(repo, sha1, ts); err != nil {
+		panic(err)
+	}
+}
+
+func (ms *MysqlStorage) loadGlobalState() {
+	var (
+		repo string
+		sha1 string
+		ts   time.Time
+	)
+
+	rows, err := ms.db.Query(loadStateQuery)
+	if err != nil {
+		panic(err)
+	}
+	for rows.Next() {
+		if err := rows.Scan(&repo, &sha1, &ts); err != nil {
+			panic(err)
+		}
+		ms.state[repo] = &steward.State{
+			Sha1:      sha1,
+			Timestamp: ts,
+		}
+	}
+}