Golang storage.VersionedCtx类代码示例

// Deletes an ROI.
func (d *Data) Delete(ctx storage.VersionedCtx) error {
	smalldata, err := storage.SmallDataStore()
	if err != nil {
		return err
	}

	// We only want one PUT on given version for given data to prevent interleaved PUTs.
	putMutex := ctx.Mutex()
	putMutex.Lock()
	defer func() {
		putMutex.Unlock()
	}()

	d.MinZ = math.MaxInt32
	d.MaxZ = math.MinInt32
	if err := datastore.SaveDataByVersion(ctx.VersionID(), d); err != nil {
		return fmt.Errorf("Error in trying to save repo on roi extent change: %v\n", err)
	}

	// Delete all spans for this ROI for just this version.
	if err := smalldata.DeleteAll(ctx, false); err != nil {
		return err
	}
	return nil
}

// versionedRange sends a range of key-value pairs for a particular version down a channel.
func (db *KVAutobus) versionedRange(vctx storage.VersionedCtx, kStart, kEnd storage.TKey, ch chan errorableKV, keysOnly bool) {
	minKey, err := vctx.MinVersionKey(kStart)
	if err != nil {
		ch <- errorableKV{nil, err}
		return
	}
	maxKey, err := vctx.MaxVersionKey(kEnd)
	if err != nil {
		ch <- errorableKV{nil, err}
		return
	}
	maxVersionKey, err := vctx.MaxVersionKey(kStart)
	if err != nil {
		ch <- errorableKV{nil, err}
		return
	}

	kvs, err := db.getRange(minKey, maxKey)
	if err != nil {
		ch <- errorableKV{nil, err}
		return
	}
	versions := []*storage.KeyValue{}
	for _, kv := range kvs {
		if !keysOnly {
			storage.StoreValueBytesRead <- len(kv.V)
		}
		storage.StoreKeyBytesRead <- len(kv.K)
		// Did we pass all versions for last key read?
		if bytes.Compare(kv.K, maxVersionKey) > 0 {
			indexBytes, err := vctx.TKeyFromKey(kv.K)
			if err != nil {
				ch <- errorableKV{nil, err}
				return
			}
			maxVersionKey, err = vctx.MaxVersionKey(indexBytes)
			if err != nil {
				ch <- errorableKV{nil, err}
				return
			}
			// log.Printf("->maxVersionKey %v (transmitting %d values)\n", maxVersionKey, len(values))
			sendKV(vctx, versions, ch)
			versions = []*storage.KeyValue{}
		}
		// Did we pass the final key?
		if bytes.Compare(kv.K, maxKey) > 0 {
			if len(versions) > 0 {
				sendKV(vctx, versions, ch)
			}
			ch <- errorableKV{nil, nil}
			return
		}
		// log.Printf("Appending value with key %v\n", itKey)
		versions = append(versions, kv)
	}
}

func sendKV(vctx storage.VersionedCtx, versions []*storage.KeyValue, ch chan errorableKV) {
	if len(versions) != 0 {
		kv, err := vctx.VersionedKeyValue(versions)
		if err != nil {
			ch <- errorableKV{nil, err}
			return
		}
		if kv != nil {
			// fmt.Printf("Sending kv: %v\n", kv)
			ch <- errorableKV{kv, nil}
		}
	}
}

// getSingleKeyVersions returns all versions of a key.  These key-value pairs will be sorted
// in ascending key order and could include a tombstone key.
func (db *KVAutobus) getSingleKeyVersions(vctx storage.VersionedCtx, k []byte) ([]*storage.KeyValue, error) {
	kStart, err := vctx.MinVersionKey(k)
	if err != nil {
		return nil, err
	}
	kEnd, err := vctx.MaxVersionKey(k)
	if err != nil {
		return nil, err
	}
	kvs, err := db.getRange(vctx, kStart, kEnd)
	if err != nil {
		return nil, err
	}
	return kvs, nil
}

// getSingleKeyVersions returns all versions of a key.  These key-value pairs will be sorted
// in ascending key order and could include a tombstone key.
func (db *LevelDB) getSingleKeyVersions(vctx storage.VersionedCtx, tk []byte) ([]*storage.KeyValue, error) {
	dvid.StartCgo()
	ro := levigo.NewReadOptions()
	it := db.ldb.NewIterator(ro)
	defer func() {
		it.Close()
		dvid.StopCgo()
	}()

	values := []*storage.KeyValue{}
	begKey, err := vctx.MinVersionKey(tk)
	if err != nil {
		return nil, err
	}
	endKey, err := vctx.MaxVersionKey(tk)
	if err != nil {
		return nil, err
	}

	it.Seek(begKey)
	for {
		if it.Valid() {
			itKey := it.Key()
			storage.StoreKeyBytesRead <- len(itKey)
			if bytes.Compare(itKey, endKey) > 0 {
				// log.Printf("key past %v\n", kEnd)
				return values, nil
			}
			itValue := it.Value()
			// log.Printf("got value of length %d\n", len(itValue))
			storage.StoreValueBytesRead <- len(itValue)
			values = append(values, &storage.KeyValue{itKey, itValue})
			it.Next()
		} else {
			err = it.GetError()
			// log.Printf("iteration done, err = %v\n", err)
			if err == nil {
				return values, nil
			}
			return nil, err
		}
	}
}

// versionedRange sends a range of key-value pairs for a particular version down a channel.
func (db *LevelDB) versionedRange(vctx storage.VersionedCtx, begTKey, endTKey storage.TKey, ch chan errorableKV, done <-chan struct{}, keysOnly bool) {
	dvid.StartCgo()
	ro := levigo.NewReadOptions()
	it := db.ldb.NewIterator(ro)
	defer func() {
		it.Close()
		dvid.StopCgo()
	}()

	minKey, err := vctx.MinVersionKey(begTKey)
	if err != nil {
		ch <- errorableKV{nil, err}
		return
	}
	maxKey, err := vctx.MaxVersionKey(endTKey)
	if err != nil {
		ch <- errorableKV{nil, err}
		return
	}

	values := []*storage.KeyValue{}
	maxVersionKey, err := vctx.MaxVersionKey(begTKey)
	if err != nil {
		ch <- errorableKV{nil, err}
		return
	}
	// log.Printf("         minKey %v\n", minKey)
	// log.Printf("         maxKey %v\n", maxKey)
	// log.Printf("  maxVersionKey %v\n", maxVersionKey)

	it.Seek(minKey)
	var itValue []byte
	for {
		select {
		case <-done: // only happens if we don't care about rest of data.
			ch <- errorableKV{nil, nil}
			return
		default:
		}
		if it.Valid() {
			if !keysOnly {
				itValue = it.Value()
				storage.StoreValueBytesRead <- len(itValue)
			}
			itKey := it.Key()
			// log.Printf("   +++valid key %v\n", itKey)
			storage.StoreKeyBytesRead <- len(itKey)

			// Did we pass all versions for last key read?
			if bytes.Compare(itKey, maxVersionKey) > 0 {
				indexBytes, err := storage.TKeyFromKey(itKey)
				if err != nil {
					ch <- errorableKV{nil, err}
					return
				}
				maxVersionKey, err = vctx.MaxVersionKey(indexBytes)
				if err != nil {
					ch <- errorableKV{nil, err}
					return
				}
				// log.Printf("->maxVersionKey %v (transmitting %d values)\n", maxVersionKey, len(values))
				sendKV(vctx, values, ch)
				values = []*storage.KeyValue{}
			}
			// Did we pass the final key?
			if bytes.Compare(itKey, maxKey) > 0 {
				if len(values) > 0 {
					sendKV(vctx, values, ch)
				}
				ch <- errorableKV{nil, nil}
				return
			}
			// log.Printf("Appending value with key %v\n", itKey)
			values = append(values, &storage.KeyValue{K: itKey, V: itValue})
			it.Next()
		} else {
			if err = it.GetError(); err != nil {
				ch <- errorableKV{nil, err}
			} else {
				sendKV(vctx, values, ch)
				ch <- errorableKV{nil, nil}
			}
			return
		}
	}
}

func (db *LevelDB) deleteSingleVersion(vctx storage.VersionedCtx) error {
	dvid.StartCgo()

	minTKey := storage.MinTKey(storage.TKeyMinClass)
	maxTKey := storage.MaxTKey(storage.TKeyMaxClass)
	minKey, err := vctx.MinVersionKey(minTKey)
	if err != nil {
		return err
	}
	maxKey, err := vctx.MaxVersionKey(maxTKey)
	if err != nil {
		return err
	}

	const BATCH_SIZE = 10000
	batch := db.NewBatch(vctx).(*goBatch)

	ro := levigo.NewReadOptions()
	it := db.ldb.NewIterator(ro)
	defer func() {
		it.Close()
		dvid.StopCgo()
	}()

	numKV := 0
	it.Seek(minKey)
	deleteVersion := vctx.VersionID()
	for {
		if err := it.GetError(); err != nil {
			return fmt.Errorf("Error iterating during DeleteAll for %s: %v", vctx, err)
		}
		if it.Valid() {
			itKey := it.Key()
			storage.StoreKeyBytesRead <- len(itKey)
			// Did we pass the final key?
			if bytes.Compare(itKey, maxKey) > 0 {
				break
			}
			_, v, _, err := storage.DataKeyToLocalIDs(itKey)
			if err != nil {
				return fmt.Errorf("Error on DELETE ALL for version %d: %v", vctx.VersionID(), err)
			}
			if v == deleteVersion {
				batch.WriteBatch.Delete(itKey)
				if (numKV+1)%BATCH_SIZE == 0 {
					if err := batch.Commit(); err != nil {
						dvid.Criticalf("Error on batch commit of DeleteAll at key-value pair %d: %v\n", numKV, err)
						return fmt.Errorf("Error on batch commit of DeleteAll at key-value pair %d: %v", numKV, err)
					}
					batch = db.NewBatch(vctx).(*goBatch)
					dvid.Debugf("Deleted %d key-value pairs in ongoing DELETE ALL for %s.\n", numKV+1, vctx)
				}
				numKV++
			}

			it.Next()
		} else {
			break
		}
	}
	if numKV%BATCH_SIZE != 0 {
		if err := batch.Commit(); err != nil {
			dvid.Criticalf("Error on last batch commit of DeleteAll: %v\n", err)
			return fmt.Errorf("Error on last batch commit of DeleteAll: %v", err)
		}
	}
	dvid.Debugf("Deleted %d key-value pairs via DELETE ALL for %s.\n", numKV, vctx)
	return nil
}