yvbolt/db_bolt.go

255 lines
6.1 KiB
Go

package main
import (
"fmt"
"path/filepath"
"sort"
"strings"
"time"
"unsafe"
"github.com/ying32/govcl/vcl"
"go.etcd.io/bbolt"
"go.etcd.io/bbolt/version"
)
type boltLoadedDatabase struct {
displayName string
path string
db *bbolt.DB
nav *vcl.TTreeNode
arena []*navData // keepalive
}
func (ld *boltLoadedDatabase) DisplayName() string {
return ld.displayName
}
func (ld *boltLoadedDatabase) DriverName() string {
return "Bolt " + version.Version
}
func (ld *boltLoadedDatabase) RootElement() *vcl.TTreeNode {
return ld.nav
}
func (ld *boltLoadedDatabase) Keepalive(ndata *navData) {
ld.arena = append(ld.arena, ndata)
}
func (ld *boltLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
// Load properties
bucketDisplayName := strings.Join(ndata.bucketPath, `/`)
content := fmt.Sprintf("Selected database: %#v\n\n\nSelected bucket: %q\n", ld.db.Stats(), bucketDisplayName)
f.propertiesBox.SetText(content)
// Load data
// Bolt always uses Key + Value as the columns
colKey := f.contentBox.Columns().Add()
colKey.Title().SetCaption("Key")
colVal := f.contentBox.Columns().Add()
colVal.Title().SetCaption("Value")
err := ld.db.View(func(tx *bbolt.Tx) error {
b := boltTargetBucket(tx, ndata.bucketPath)
if b == nil {
// no such bucket
return nil
}
// Valid
c := b.Cursor()
for k, v := c.First(); k != nil; k, v = c.Next() {
rpos := f.contentBox.RowCount()
f.contentBox.SetRowCount(rpos + 1)
f.contentBox.SetCells(0, rpos, formatUtf8(k))
f.contentBox.SetCells(1, rpos, formatUtf8(v))
}
return nil
})
if err != nil {
vcl.ShowMessage(fmt.Sprintf("Failed to load data for bucket %q: %s", bucketDisplayName, err.Error()))
return
}
// Valid
vcl_stringgrid_columnwidths(f.contentBox)
f.contentBox.SetEnabled(true)
}
func (ld *boltLoadedDatabase) NavChildren(ndata *navData) ([]string, error) {
// In the bolt implementation, the nav is a recursive tree of child buckets
return boltChildBucketNames(ld.db, ndata.bucketPath)
}
func (ld *boltLoadedDatabase) NavContext(ndata *navData) (ret []contextAction, err error) {
ret = append(ret, contextAction{"Add bucket...", ld.AddChildBucket})
if len(ndata.bucketPath) > 0 {
ret = append(ret, contextAction{"Delete bucket", ld.DeleteBucket})
}
return
}
func (ld *boltLoadedDatabase) AddChildBucket(ndata *navData) {
bucketName := ""
if !vcl.InputQuery(APPNAME, "Enter a name for the new bucket:", &bucketName) {
return // cancel
}
err := ld.db.Update(func(tx *bbolt.Tx) error {
parent := boltTargetBucket(tx, ndata.bucketPath)
if parent != nil {
_, err := parent.CreateBucket([]byte(bucketName))
return err
}
// Top-level
_, err := tx.CreateBucket([]byte(bucketName))
return err
})
if err != nil {
vcl.ShowMessageFmt("Error adding bucket: %v", err)
}
}
func (ld *boltLoadedDatabase) DeleteBucket(ndata *navData) {
err := ld.db.Update(func(tx *bbolt.Tx) error {
// Find parent of this bucket.
if len(ndata.bucketPath) >= 2 {
// child bucket
parent := boltTargetBucket(tx, ndata.bucketPath[0:len(ndata.bucketPath)-1])
return parent.DeleteBucket([]byte(ndata.bucketPath[len(ndata.bucketPath)-1]))
} else {
// top-level bucket
return tx.DeleteBucket([]byte(ndata.bucketPath[0]))
}
})
if err != nil {
vcl.ShowMessageFmt("Error deleting bucket %q: %v", strings.Join(ndata.bucketPath, `/`), err)
}
}
func (ld *boltLoadedDatabase) ExecQuery(query string, resultArea *vcl.TStringGrid) {
vcl.ShowMessage("Bolt doesn't support querying")
}
func (ld *boltLoadedDatabase) Close() {
_ = ld.db.Close()
ld.arena = nil
}
var _ loadedDatabase = &boltLoadedDatabase{} // interface assertion
//
func (f *TMainForm) boltAddDatabaseFromFile(path string, readonly bool) {
// TODO load in background thread to stop blocking the UI
opts := bbolt.Options{
Timeout: 1 * time.Second,
ReadOnly: readonly,
}
db, err := bbolt.Open(path, 0644, &opts)
if err != nil {
vcl.ShowMessage(fmt.Sprintf("Failed to load database '%s': %s", path, err.Error()))
return
}
ld := &boltLoadedDatabase{
path: path,
displayName: filepath.Base(path),
db: db,
}
if readonly {
ld.displayName += " (read-only)"
}
ld.nav = f.Buckets.Items().Add(nil, ld.displayName)
ld.nav.SetHasChildren(true) // dynamically populate in OnNavExpanding
ld.nav.SetImageIndex(imgDatabase)
ld.nav.SetSelectedIndex(imgDatabase)
navData := &navData{
ld: ld,
childrenLoaded: false, // will be loaded dynamically
bucketPath: []string{}, // empty = root
}
ld.nav.SetData(unsafe.Pointer(navData))
f.dbs = append(f.dbs, ld)
f.Buckets.SetSelected(ld.nav) // Select new element
ld.Keepalive(navData)
}
func boltTargetBucket(tx *bbolt.Tx, path []string) *bbolt.Bucket {
// If we are already deep in buckets, go directly there to find children
if len(path) == 0 {
return nil
}
b := tx.Bucket([]byte(path[0]))
if b == nil {
return nil // unexpectedly missing
}
for i := 1; i < len(path); i += 1 {
b = b.Bucket([]byte(path[i]))
if b == nil {
return nil // unexpectedly missing
}
}
return b // OK
}
func boltChildBucketNames(db *bbolt.DB, path []string) ([]string, error) {
var nextBucketNames []string
err := db.View(func(tx *bbolt.Tx) error {
// If we are already deep in buckets, go directly there to find children
if len(path) > 0 {
b := tx.Bucket([]byte(path[0]))
if b == nil {
return fmt.Errorf("Root bucket %q: %w", path[0], ErrNavNotExist)
}
for i := 1; i < len(path); i += 1 {
b = b.Bucket([]byte(path[i]))
if b == nil {
return fmt.Errorf("Bucket %q: %w", strings.Join(path[0:i], `/`), ErrNavNotExist)
}
}
// Find child buckets of this bucket
b.ForEachBucket(func(bucketName []byte) error {
nextBucketNames = append(nextBucketNames, string(bucketName))
return nil
})
} else {
// Find root bucket names
return tx.ForEach(func(bucketName []byte, _ *bbolt.Bucket) error {
nextBucketNames = append(nextBucketNames, string(bucketName))
return nil
})
}
// OK
return nil
})
if err != nil {
return nil, err
}
sort.Strings(nextBucketNames)
return nextBucketNames, nil
}