Simple blogging system written in Go https://goblog.app
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

284 lines
6.7 KiB

package main
import (
"context"
"database/sql"
"errors"
"log"
"os"
"strings"
"sync"
"github.com/dgraph-io/ristretto"
"github.com/google/uuid"
sqlite "github.com/mattn/go-sqlite3"
"github.com/schollz/sqlite3dump"
"golang.org/x/sync/singleflight"
)
type database struct {
// Basic things
db *sql.DB // database
em sync.Mutex // command execution (insert, update, delete ...)
sg singleflight.Group // singleflight group for prepared statements
psc *ristretto.Cache // prepared statement cache
// Other things
pc singleflight.Group // persistant cache
pcm sync.Mutex // post creation
sp singleflight.Group // singleflight group for short path requests
spc *ristretto.Cache // shortpath cache
debug bool
}
func (a *goBlog) initDatabase(logging bool) (err error) {
if logging {
log.Println("Initialize database...")
}
// Setup db
db, err := a.openDatabase(a.cfg.Db.File, logging)
if err != nil {
return err
}
// Create appDB
a.db = db
a.shutdown.Add(func() {
if err := db.close(); err != nil {
log.Printf("Failed to close database: %v", err)
} else {
log.Println("Closed database")
}
})
if a.cfg.Db.DumpFile != "" {
a.hourlyHooks = append(a.hourlyHooks, func() {
db.dump(a.cfg.Db.DumpFile)
})
db.dump(a.cfg.Db.DumpFile)
}
if logging {
log.Println("Initialized database")
}
return nil
}
func (a *goBlog) openDatabase(file string, logging bool) (*database, error) {
// Register driver
dbDriverName := "goblog_db_" + uuid.NewString()
sql.Register(dbDriverName, &sqlite.SQLiteDriver{
ConnectHook: func(c *sqlite.SQLiteConn) error {
// Register functions
for n, f := range map[string]any{
"mdtext": a.renderText,
"tolocal": toLocalSafe,
"toutc": toUTCSafe,
"wordcount": wordCount,
"charcount": charCount,
"urlize": urlize,
"lowerx": strings.ToLower,
"lowerunescaped": lowerUnescapedPath,
} {
if err := c.RegisterFunc(n, f, true); err != nil {
return err
}
}
return nil
},
})
// Open db
db, err := sql.Open(dbDriverName, file+"?mode=rwc&_journal=WAL&_timeout=100&cache=shared&_fk=1")
if err != nil {
return nil, err
}
numConns := 5
db.SetMaxOpenConns(numConns)
db.SetMaxIdleConns(numConns)
err = db.Ping()
if err != nil {
return nil, err
}
// Check available SQLite features
rows, err := db.Query("pragma compile_options")
if err != nil {
return nil, err
}
cos := map[string]bool{}
var co string
for rows.Next() {
err = rows.Scan(&co)
if err != nil {
return nil, err
}
cos[co] = true
}
if _, ok := cos["ENABLE_FTS5"]; !ok {
return nil, errors.New("sqlite not compiled with FTS5")
}
// Migrate DB
err = migrateDb(db, logging)
if err != nil {
return nil, err
}
// Debug
debug := false
if c := a.cfg.Db; c != nil && c.Debug {
debug = true
}
psc, err := ristretto.NewCache(&ristretto.Config{
NumCounters: 1000,
MaxCost: 100,
BufferItems: 64,
IgnoreInternalCost: true,
})
if err != nil {
return nil, err
}
spc, err := ristretto.NewCache(&ristretto.Config{
NumCounters: 5000,
MaxCost: 500,
BufferItems: 64,
IgnoreInternalCost: true,
})
if err != nil {
return nil, err
}
return &database{
db: db,
debug: debug,
psc: psc,
spc: spc,
}, nil
}
// Main features
func (db *database) dump(file string) {
if db == nil || db.db == nil {
return
}
// Lock execution
db.em.Lock()
defer db.em.Unlock()
// Dump database
f, err := os.Create(file)
if err != nil {
log.Println("Error while dump db:", err.Error())
return
}
if err = sqlite3dump.DumpDB(db.db, f, sqlite3dump.WithTransaction(true)); err != nil {
log.Println("Error while dump db:", err.Error())
}
}
func (db *database) close() error {
if db == nil || db.db == nil {
return nil
}
return db.db.Close()
}
func (db *database) prepare(query string, args ...any) (*sql.Stmt, []any, error) {
if db == nil || db.db == nil {
return nil, nil, errors.New("database not initialized")
}
if len(args) > 0 && args[0] == dbNoCache {
return nil, args[1:], nil
}
stmt, err, _ := db.sg.Do(query, func() (any, error) {
// Look if statement already exists
st, ok := db.psc.Get(query)
if ok {
return st, nil
}
// ... otherwise prepare ...
st, err := db.db.Prepare(query)
if err != nil {
return nil, err
}
// ... and store it
db.psc.Set(query, st, 1)
return st, nil
})
if err != nil {
if db.debug {
log.Printf(`Failed to prepare query "%s": %s`, query, err.Error())
}
return nil, args, err
}
return stmt.(*sql.Stmt), args, nil
}
const dbNoCache = "nocache"
func (db *database) exec(query string, args ...any) (sql.Result, error) {
return db.execContext(context.Background(), query, args...)
}
func (db *database) execContext(c context.Context, query string, args ...any) (sql.Result, error) {
if db == nil || db.db == nil {
return nil, errors.New("database not initialized")
}
// Maybe prepare
st, args, _ := db.prepare(query, args...)
// Lock execution
db.em.Lock()
defer db.em.Unlock()
// Prepare context, call hook
ctx := db.dbBefore(c, query, args...)
defer db.dbAfter(ctx, query, args...)
// Execute
if st != nil {
return st.ExecContext(ctx, args...)
}
return db.db.ExecContext(ctx, query, args...)
}
func (db *database) query(query string, args ...any) (*sql.Rows, error) {
return db.queryContext(context.Background(), query, args...)
}
func (db *database) queryContext(c context.Context, query string, args ...any) (rows *sql.Rows, err error) {
if db == nil || db.db == nil {
return nil, errors.New("database not initialized")
}
// Maybe prepare
st, args, _ := db.prepare(query, args...)
// Prepare context, call hook
ctx := db.dbBefore(c, query, args...)
// Query
if st != nil {
rows, err = st.QueryContext(ctx, args...)
} else {
rows, err = db.db.QueryContext(ctx, query, args...)
}
// Call hook
db.dbAfter(ctx, query, args...)
return
}
func (db *database) queryRow(query string, args ...any) (*sql.Row, error) {
return db.queryRowContext(context.Background(), query, args...)
}
func (db *database) queryRowContext(c context.Context, query string, args ...any) (row *sql.Row, err error) {
if db == nil || db.db == nil {
return nil, errors.New("database not initialized")
}
// Maybe prepare
st, args, _ := db.prepare(query, args...)
// Prepare context, call hook
ctx := db.dbBefore(c, query, args...)
// Query
if st != nil {
row = st.QueryRowContext(ctx, args...)
} else {
row = db.db.QueryRowContext(ctx, query, args...)
}
// Call hook
db.dbAfter(ctx, query, args...)
return
}
// Other things
func (d *database) rebuildFTSIndex() {
_, _ = d.exec("insert into posts_fts(posts_fts) values ('rebuild')")
}