/
query.go
173 lines (146 loc) · 3.91 KB
/
query.go
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// Copyright JAMF Software, LLC
package fsm
import (
"encoding/binary"
"errors"
"io"
"github.com/cockroachdb/pebble"
"github.com/jamf/regatta/regattapb"
"github.com/jamf/regatta/storage/table/key"
"github.com/jamf/regatta/util/iter"
sm "github.com/lni/dragonboat/v4/statemachine"
)
const maxRangeSize uint64 = (4 * 1024 * 1024) - 1024 // 4MiB - 1KiB sentinel.
func commandSnapshot(reader pebble.Reader, tableName string, w io.Writer, stopc <-chan struct{}) (uint64, error) {
iter := reader.NewIter(nil)
defer iter.Close()
idx, err := readLocalIndex(reader, sysLocalIndex)
if err != nil {
return 0, err
}
var buffer []byte
for iter.First(); iter.Valid(); iter.Next() {
select {
case <-stopc:
return 0, sm.ErrSnapshotStopped
default:
k, err := key.DecodeBytes(iter.Key())
if err != nil {
return 0, err
}
if k.KeyType == key.TypeUser {
buffer, err = writeCommand(tableName, k.Key, iter.Value(), buffer)
if err != nil {
return 0, err
}
if _, err := w.Write(buffer); err != nil {
return 0, err
}
}
}
}
return idx, nil
}
// writeCommand writes KV pair as PUT proto.Command into (optionally provided) buffer.
func writeCommand(tableName string, key []byte, val []byte, buffer []byte) ([]byte, error) {
cmd := regattapb.CommandFromVTPool()
defer cmd.ReturnToVTPool()
cmd.Table = []byte(tableName)
cmd.Type = regattapb.Command_PUT
cmd.Kv = ®attapb.KeyValue{
Key: key,
Value: val,
}
size := cmd.SizeVT()
if cap(buffer) < size {
buffer = make([]byte, size*2)
}
n, err := cmd.MarshalToSizedBufferVT(buffer[:size])
if err != nil {
return buffer, err
}
return buffer[:n], err
}
func readLocalIndex(db pebble.Reader, indexKey []byte) (idx uint64, err error) {
indexVal, closer, err := db.Get(indexKey)
if err != nil {
if !errors.Is(err, pebble.ErrNotFound) {
return 0, err
}
return 0, nil
}
defer func() {
err = closer.Close()
}()
return binary.LittleEndian.Uint64(indexVal), nil
}
func lookup(reader pebble.Reader, req *regattapb.RequestOp_Range) (*regattapb.ResponseOp_Range, error) {
if req.RangeEnd != nil {
return rangeLookup(reader, req)
}
return singleLookup(reader, req)
}
func rangeLookup(reader pebble.Reader, req *regattapb.RequestOp_Range) (*regattapb.ResponseOp_Range, error) {
it, err := iterate(reader, req)
if err != nil {
return nil, err
}
return iter.First(it), nil
}
func singleLookup(reader pebble.Reader, req *regattapb.RequestOp_Range) (*regattapb.ResponseOp_Range, error) {
keyBuf := bufferPool.Get()
defer bufferPool.Put(keyBuf)
err := encodeUserKey(keyBuf, req.Key)
if err != nil {
return nil, err
}
iter := reader.NewIter(nil)
defer func() {
_ = iter.Close()
}()
found := iter.SeekPrefixGE(keyBuf.Bytes())
if !found {
return ®attapb.ResponseOp_Range{}, nil
}
kv := ®attapb.KeyValue{Key: req.Key}
value := iter.Value()
if !(req.KeysOnly || req.CountOnly) && len(value) > 0 {
kv.Value = make([]byte, len(value))
copy(kv.Value, value)
}
var kvs []*regattapb.KeyValue
if !req.CountOnly {
kvs = append(kvs, kv)
}
return ®attapb.ResponseOp_Range{
Kvs: kvs,
Count: 1,
}, nil
}
// IteratorRequest returns open pebble.Iterator it is an API consumer responsibility to close it.
type IteratorRequest struct {
RangeOp *regattapb.RequestOp_Range
}
// SnapshotRequest to write Command snapshot into provided writer.
type SnapshotRequest struct {
Writer io.Writer
Stopper <-chan struct{}
}
// SnapshotResponse returns local index to which the snapshot was created.
type SnapshotResponse struct {
Index uint64
}
// LocalIndexRequest to read local index.
type LocalIndexRequest struct{}
// LeaderIndexRequest to read leader index.
type LeaderIndexRequest struct{}
// IndexResponse returns local index.
type IndexResponse struct {
Index uint64
}
// PathRequest request data disk paths.
type PathRequest struct{}
// PathResponse returns SM data paths.
type PathResponse struct {
Path string
}