You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
300 lines
6.2 KiB
Go
300 lines
6.2 KiB
Go
// Package db exposes a lightweight abstraction over the SQLite code.
|
|
package db
|
|
|
|
import (
|
|
"database/sql/driver"
|
|
"fmt"
|
|
"io"
|
|
"time"
|
|
|
|
"github.com/mattn/go-sqlite3"
|
|
)
|
|
|
|
const bkDelay = 250
|
|
|
|
var DBVersion string
|
|
|
|
func init() {
|
|
DBVersion, _, _ = sqlite3.Version()
|
|
}
|
|
|
|
// Config represents the configuration of the SQLite database.
|
|
type Config struct {
|
|
DSN string // Datasource name
|
|
Memory bool // In-memory database enabled?
|
|
}
|
|
|
|
// NewConfig returns an instance of Config for the database at path.
|
|
func NewConfig() *Config {
|
|
return &Config{}
|
|
}
|
|
|
|
// FQDSN returns the fully-qualified datasource name.
|
|
func (c *Config) FQDSN(path string) string {
|
|
if c.DSN != "" {
|
|
return fmt.Sprintf("file:%s?%s", path, c.DSN)
|
|
}
|
|
return path
|
|
}
|
|
|
|
// DB is the SQL database.
|
|
type DB struct {
|
|
sqlite3conn *sqlite3.SQLiteConn // Driver connection to database.
|
|
path string // Path to database file.
|
|
}
|
|
|
|
// Result represents the outcome of an operation that changes rows.
|
|
type Result struct {
|
|
LastInsertID int64 `json:"last_insert_id,omitempty"`
|
|
RowsAffected int64 `json:"rows_affected,omitempty"`
|
|
Error string `json:"error,omitempty"`
|
|
Time float64 `json:"time,omitempty"`
|
|
}
|
|
|
|
// Rows represents the outcome of an operation that returns query data.
|
|
type Rows struct {
|
|
Columns []string `json:"columns,omitempty"`
|
|
Types []string `json:"types,omitempty"`
|
|
Values [][]interface{} `json:"values,omitempty"`
|
|
Error string `json:"error,omitempty"`
|
|
Time float64 `json:"time,omitempty"`
|
|
}
|
|
|
|
// Open an existing database, creating it if it does not exist.
|
|
func Open(dbPath string) (*DB, error) {
|
|
d := sqlite3.SQLiteDriver{}
|
|
dbc, err := d.Open(dbPath)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &DB{
|
|
sqlite3conn: dbc.(*sqlite3.SQLiteConn),
|
|
path: dbPath,
|
|
}, nil
|
|
}
|
|
|
|
// OpenWithConfiguration an existing database, creating it if it does not exist.
|
|
func OpenWithConfiguration(dbPath string, conf *Config) (*DB, error) {
|
|
return Open(conf.FQDSN(dbPath))
|
|
}
|
|
|
|
// Close closes the underlying database connection.
|
|
func (db *DB) Close() error {
|
|
return db.sqlite3conn.Close()
|
|
}
|
|
|
|
// Execute executes queries that modify the database.
|
|
func (db *DB) Execute(queries []string, tx, xTime bool) ([]*Result, error) {
|
|
type Execer interface {
|
|
Exec(query string, args []driver.Value) (driver.Result, error)
|
|
}
|
|
|
|
var allResults []*Result
|
|
err := func() error {
|
|
var execer Execer
|
|
var rollback bool
|
|
var t driver.Tx
|
|
var err error
|
|
|
|
// Check for the err, if set rollback.
|
|
defer func() {
|
|
if t != nil {
|
|
if rollback {
|
|
t.Rollback()
|
|
return
|
|
}
|
|
t.Commit()
|
|
}
|
|
}()
|
|
|
|
// handleError sets the error field on the given result. It returns
|
|
// whether the caller should continue processing or break.
|
|
handleError := func(result *Result, err error) bool {
|
|
result.Error = err.Error()
|
|
allResults = append(allResults, result)
|
|
if tx {
|
|
rollback = true // Will trigger the rollback.
|
|
return false
|
|
}
|
|
return true
|
|
}
|
|
|
|
execer = db.sqlite3conn
|
|
|
|
// Create the correct execution object, depending on whether a
|
|
// transaction was requested.
|
|
if tx {
|
|
t, err = db.sqlite3conn.Begin()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
// Execute each query.
|
|
for _, q := range queries {
|
|
if q == "" {
|
|
continue
|
|
}
|
|
|
|
result := &Result{}
|
|
start := time.Now()
|
|
|
|
r, err := execer.Exec(q, nil)
|
|
if err != nil {
|
|
if handleError(result, err) {
|
|
continue
|
|
}
|
|
break
|
|
}
|
|
|
|
lid, err := r.LastInsertId()
|
|
if err != nil {
|
|
if handleError(result, err) {
|
|
continue
|
|
}
|
|
break
|
|
}
|
|
result.LastInsertID = lid
|
|
|
|
ra, err := r.RowsAffected()
|
|
if err != nil {
|
|
if handleError(result, err) {
|
|
continue
|
|
}
|
|
break
|
|
}
|
|
result.RowsAffected = ra
|
|
if xTime {
|
|
result.Time = time.Now().Sub(start).Seconds()
|
|
}
|
|
allResults = append(allResults, result)
|
|
}
|
|
|
|
return nil
|
|
}()
|
|
|
|
return allResults, err
|
|
}
|
|
|
|
// Query executes queries that return rows, but don't modify the database.
|
|
func (db *DB) Query(queries []string, tx, xTime bool) ([]*Rows, error) {
|
|
type Queryer interface {
|
|
Query(query string, args []driver.Value) (driver.Rows, error)
|
|
}
|
|
|
|
var allRows []*Rows
|
|
err := func() (err error) {
|
|
var queryer Queryer
|
|
var t driver.Tx
|
|
defer func() {
|
|
// XXX THIS DOESN'T ACTUALLY WORK! Might as WELL JUST COMMIT?
|
|
if t != nil {
|
|
if err != nil {
|
|
t.Rollback()
|
|
return
|
|
}
|
|
t.Commit()
|
|
}
|
|
}()
|
|
|
|
queryer = db.sqlite3conn
|
|
|
|
// Create the correct query object, depending on whether a
|
|
// transaction was requested.
|
|
if tx {
|
|
t, err = db.sqlite3conn.Begin()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
for _, q := range queries {
|
|
if q == "" {
|
|
continue
|
|
}
|
|
|
|
rows := &Rows{}
|
|
start := time.Now()
|
|
|
|
rs, err := queryer.Query(q, nil)
|
|
if err != nil {
|
|
rows.Error = err.Error()
|
|
allRows = append(allRows, rows)
|
|
continue
|
|
}
|
|
defer rs.Close() // This adds to all defers, right? Nothing leaks? XXX Could consume memory. Perhaps anon would be best.
|
|
columns := rs.Columns()
|
|
|
|
rows.Columns = columns
|
|
rows.Types = rs.(*sqlite3.SQLiteRows).DeclTypes()
|
|
dest := make([]driver.Value, len(rows.Columns))
|
|
for {
|
|
err := rs.Next(dest)
|
|
|
|
if err != nil {
|
|
if err != io.EOF {
|
|
rows.Error = err.Error()
|
|
}
|
|
break
|
|
}
|
|
|
|
values := make([]interface{}, len(rows.Columns))
|
|
|
|
// Special case -- convert []uint8 to string. Perhaps this should be a config option.
|
|
for i, v := range dest {
|
|
switch u := v.(type) {
|
|
case []uint8:
|
|
values[i] = string(u)
|
|
default:
|
|
values[i] = u
|
|
}
|
|
}
|
|
rows.Values = append(rows.Values, values)
|
|
}
|
|
if xTime {
|
|
rows.Time = time.Now().Sub(start).Seconds()
|
|
}
|
|
allRows = append(allRows, rows)
|
|
}
|
|
|
|
return nil
|
|
}()
|
|
|
|
return allRows, err
|
|
}
|
|
|
|
// Backup writes a consistent snapshot of the database to the given file.
|
|
func (db *DB) Backup(path string) error {
|
|
dstDB, err := Open(path)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
bk, err := dstDB.sqlite3conn.Backup("main", db.sqlite3conn, "main")
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
for {
|
|
done, err := bk.Step(-1)
|
|
if err != nil {
|
|
bk.Finish()
|
|
return err
|
|
}
|
|
if done {
|
|
break
|
|
}
|
|
time.Sleep(bkDelay * time.Millisecond)
|
|
}
|
|
|
|
if err := bk.Finish(); err != nil {
|
|
return err
|
|
}
|
|
if err := dstDB.Close(); err != nil {
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
}
|