memos/store/db/db.go
2023-08-26 07:33:45 +08:00

271 lines
8.4 KiB
Go

package db
import (
"context"
"database/sql"
"embed"
"errors"
"fmt"
"io/fs"
"os"
"regexp"
"sort"
"time"
"github.com/usememos/memos/server/profile"
"github.com/usememos/memos/server/version"
)
//go:embed migration
var migrationFS embed.FS
//go:embed seed
var seedFS embed.FS
type DB struct {
// sqlite db connection instance
DBInstance *sql.DB
profile *profile.Profile
}
// NewDB returns a new instance of DB associated with the given datasource name.
func NewDB(profile *profile.Profile) *DB {
db := &DB{
profile: profile,
}
return db
}
// Open opens a database specified by its database driver name and a
// driver-specific data source name, usually consisting of at least a
// database name and connection information.
func (db *DB) Open() error {
// Ensure a DSN is set before attempting to open the database.
if db.profile.DSN == "" {
return fmt.Errorf("dsn required")
}
// Connect to the database with some sane settings:
// - No shared-cache: it's obsolete; WAL journal mode is a better solution.
// - No foreign key constraints: it's currently disabled by default, but it's a
// good practice to be explicit and prevent future surprises on SQLite upgrades.
// - Journal mode set to WAL: it's the recommended journal mode for most applications
// as it prevents locking issues.
//
// Notes:
// - When using the `modernc.org/sqlite` driver, each pragma must be prefixed with `_pragma=`.
//
// References:
// - https://pkg.go.dev/modernc.org/sqlite#Driver.Open
// - https://www.sqlite.org/sharedcache.html
// - https://www.sqlite.org/pragma.html
sqliteDB, err := sql.Open("sqlite", db.profile.DSN+"?_pragma=foreign_keys(0)&_pragma=busy_timeout(10000)&_pragma=journal_mode(WAL)")
if err != nil {
return fmt.Errorf("failed to open db with dsn: %s, err: %w", db.profile.DSN, err)
}
db.DBInstance = sqliteDB
return nil
}
// Migrate applies the latest schema to the database.
func (db *DB) Migrate(ctx context.Context) error {
if db.profile.Mode == "prod" {
_, err := os.Stat(db.profile.DSN)
if err != nil {
// If db file not exists, we should create a new one with latest schema.
if errors.Is(err, os.ErrNotExist) {
if err := db.applyLatestSchema(ctx); err != nil {
return fmt.Errorf("failed to apply latest schema, err: %w", err)
}
} else {
return fmt.Errorf("failed to get db file stat, err: %w", err)
}
} else {
// If db file exists, we should check if we need to migrate the database.
currentVersion := version.GetCurrentVersion(db.profile.Mode)
migrationHistoryList, err := db.FindMigrationHistoryList(ctx, &MigrationHistoryFind{})
if err != nil {
return fmt.Errorf("failed to find migration history, err: %w", err)
}
if len(migrationHistoryList) == 0 {
_, err := db.UpsertMigrationHistory(ctx, &MigrationHistoryUpsert{
Version: currentVersion,
})
if err != nil {
return fmt.Errorf("failed to upsert migration history, err: %w", err)
}
return nil
}
migrationHistoryVersionList := []string{}
for _, migrationHistory := range migrationHistoryList {
migrationHistoryVersionList = append(migrationHistoryVersionList, migrationHistory.Version)
}
sort.Sort(version.SortVersion(migrationHistoryVersionList))
latestMigrationHistoryVersion := migrationHistoryVersionList[len(migrationHistoryVersionList)-1]
if version.IsVersionGreaterThan(version.GetSchemaVersion(currentVersion), latestMigrationHistoryVersion) {
minorVersionList := getMinorVersionList()
// backup the raw database file before migration
rawBytes, err := os.ReadFile(db.profile.DSN)
if err != nil {
return fmt.Errorf("failed to read raw database file, err: %w", err)
}
backupDBFilePath := fmt.Sprintf("%s/memos_%s_%d_backup.db", db.profile.Data, db.profile.Version, time.Now().Unix())
if err := os.WriteFile(backupDBFilePath, rawBytes, 0644); err != nil {
return fmt.Errorf("failed to write raw database file, err: %w", err)
}
println("succeed to copy a backup database file")
println("start migrate")
for _, minorVersion := range minorVersionList {
normalizedVersion := minorVersion + ".0"
if version.IsVersionGreaterThan(normalizedVersion, latestMigrationHistoryVersion) && version.IsVersionGreaterOrEqualThan(currentVersion, normalizedVersion) {
println("applying migration for", normalizedVersion)
if err := db.applyMigrationForMinorVersion(ctx, minorVersion); err != nil {
return fmt.Errorf("failed to apply minor version migration: %w", err)
}
}
}
println("end migrate")
// remove the created backup db file after migrate succeed
if err := os.Remove(backupDBFilePath); err != nil {
println(fmt.Sprintf("Failed to remove temp database file, err %v", err))
}
}
}
} else {
// In non-prod mode, we should always migrate the database.
if _, err := os.Stat(db.profile.DSN); errors.Is(err, os.ErrNotExist) {
if err := db.applyLatestSchema(ctx); err != nil {
return fmt.Errorf("failed to apply latest schema: %w", err)
}
// In demo mode, we should seed the database.
if db.profile.Mode == "demo" {
if err := db.seed(ctx); err != nil {
return fmt.Errorf("failed to seed: %w", err)
}
}
}
}
return nil
}
const (
latestSchemaFileName = "LATEST__SCHEMA.sql"
)
func (db *DB) applyLatestSchema(ctx context.Context) error {
schemaMode := "dev"
if db.profile.Mode == "prod" {
schemaMode = "prod"
}
latestSchemaPath := fmt.Sprintf("%s/%s/%s", "migration", schemaMode, latestSchemaFileName)
buf, err := migrationFS.ReadFile(latestSchemaPath)
if err != nil {
return fmt.Errorf("failed to read latest schema %q, error %w", latestSchemaPath, err)
}
stmt := string(buf)
if err := db.execute(ctx, stmt); err != nil {
return fmt.Errorf("migrate error: statement:%s err=%w", stmt, err)
}
return nil
}
func (db *DB) applyMigrationForMinorVersion(ctx context.Context, minorVersion string) error {
filenames, err := fs.Glob(migrationFS, fmt.Sprintf("%s/%s/*.sql", "migration/prod", minorVersion))
if err != nil {
return fmt.Errorf("failed to read ddl files, err: %w", err)
}
sort.Strings(filenames)
migrationStmt := ""
// Loop over all migration files and execute them in order.
for _, filename := range filenames {
buf, err := migrationFS.ReadFile(filename)
if err != nil {
return fmt.Errorf("failed to read minor version migration file, filename=%s err=%w", filename, err)
}
stmt := string(buf)
migrationStmt += stmt
if err := db.execute(ctx, stmt); err != nil {
return fmt.Errorf("migrate error: statement:%s err=%w", stmt, err)
}
}
// Upsert the newest version to migration_history.
version := minorVersion + ".0"
if _, err = db.UpsertMigrationHistory(ctx, &MigrationHistoryUpsert{
Version: version,
}); err != nil {
return fmt.Errorf("failed to upsert migration history with version: %s, err: %w", version, err)
}
return nil
}
func (db *DB) seed(ctx context.Context) error {
filenames, err := fs.Glob(seedFS, fmt.Sprintf("%s/*.sql", "seed"))
if err != nil {
return fmt.Errorf("failed to read seed files, err: %w", err)
}
sort.Strings(filenames)
// Loop over all seed files and execute them in order.
for _, filename := range filenames {
buf, err := seedFS.ReadFile(filename)
if err != nil {
return fmt.Errorf("failed to read seed file, filename=%s err=%w", filename, err)
}
stmt := string(buf)
if err := db.execute(ctx, stmt); err != nil {
return fmt.Errorf("seed error: statement:%s err=%w", stmt, err)
}
}
return nil
}
// execute runs a single SQL statement within a transaction.
func (db *DB) execute(ctx context.Context, stmt string) error {
tx, err := db.DBInstance.Begin()
if err != nil {
return err
}
defer tx.Rollback()
if _, err := tx.ExecContext(ctx, stmt); err != nil {
return fmt.Errorf("failed to execute statement, err: %w", err)
}
return tx.Commit()
}
// minorDirRegexp is a regular expression for minor version directory.
var minorDirRegexp = regexp.MustCompile(`^migration/prod/[0-9]+\.[0-9]+$`)
func getMinorVersionList() []string {
minorVersionList := []string{}
if err := fs.WalkDir(migrationFS, "migration", func(path string, file fs.DirEntry, err error) error {
if err != nil {
return err
}
if file.IsDir() && minorDirRegexp.MatchString(path) {
minorVersionList = append(minorVersionList, file.Name())
}
return nil
}); err != nil {
panic(err)
}
sort.Sort(version.SortVersion(minorVersionList))
return minorVersionList
}