migration_helpers.go

package migrations

import (
	"database/sql"
	"fmt"
	"os"
	"path"
	"strconv"
)

func OpenDB(repoPath string, dbPassword string, testnet bool) (*sql.DB, error) {
	var dbPath string
	if testnet {
		dbPath = path.Join(repoPath, "datastore", "testnet.db")
	} else {
		dbPath = path.Join(repoPath, "datastore", "mainnet.db")
	}
	db, err := sql.Open("sqlite3", dbPath)
	if err != nil {
		return nil, err
	}
	if dbPassword != "" {
		p := "pragma key='" + dbPassword + "';"
		_, err = db.Exec(p)
		if err != nil {
			return nil, err
		}
	}
	return db, nil
}

func withTransaction(db *sql.DB, handler func(tx *sql.Tx) error) error {
	tx, err := db.Begin()
	if err != nil {
		return fmt.Errorf("beginning transaction: %s", err.Error())
	}

	handleErr := handler(tx)
	if handleErr != nil {
		if err := tx.Rollback(); err != nil {
			return fmt.Errorf("handler AND rollback failed: %s (rollback error: %s)", handleErr.Error(), err.Error())
		}
		return fmt.Errorf("handler failed: %s", handleErr.Error())
	}

	if err := tx.Commit(); err != nil {
		return fmt.Errorf("commit failed: %s", err.Error())
	}

	return nil
}

func writeRepoVer(repoPath string, version int) error {
	f1, err := os.Create(path.Join(repoPath, "repover"))
	if err != nil {
		return err
	}
	_, err = f1.Write([]byte(strconv.Itoa(version)))
	if err != nil {
		return err
	}
	return f1.Close()
}

func writeIPFSVer(repoPath string, version int) error {
	f1, err := os.Create(path.Join(repoPath, "version"))
	if err != nil {
		return err
	}
	_, err = f1.Write([]byte(strconv.Itoa(version)))
	if err != nil {
		return err
	}
	return f1.Close()
}