// txnKVS handles all KV-related operations.
func (s *StateStore) txnKVS(tx *memdb.Txn, idx uint64, op *structs.TxnKVOp) (structs.TxnResults, error) {
var entry *structs.DirEntry
var err error
switch op.Verb {
case structs.KVSSet:
entry = &op.DirEnt
err = s.kvsSetTxn(tx, idx, entry, false)
case structs.KVSDelete:
err = s.kvsDeleteTxn(tx, idx, op.DirEnt.Key)
case structs.KVSDeleteCAS:
var ok bool
ok, err = s.kvsDeleteCASTxn(tx, idx, op.DirEnt.ModifyIndex, op.DirEnt.Key)
if !ok && err == nil {
err = fmt.Errorf("failed to delete key %q, index is stale", op.DirEnt.Key)
}
case structs.KVSDeleteTree:
err = s.kvsDeleteTreeTxn(tx, idx, op.DirEnt.Key)
case structs.KVSCAS:
var ok bool
entry = &op.DirEnt
ok, err = s.kvsSetCASTxn(tx, idx, entry)
if !ok && err == nil {
err = fmt.Errorf("failed to set key %q, index is stale", op.DirEnt.Key)
}
case structs.KVSLock:
var ok bool
entry = &op.DirEnt
ok, err = s.kvsLockTxn(tx, idx, entry)
if !ok && err == nil {
err = fmt.Errorf("failed to lock key %q, lock is already held", op.DirEnt.Key)
}
case structs.KVSUnlock:
var ok bool
entry = &op.DirEnt
ok, err = s.kvsUnlockTxn(tx, idx, entry)
if !ok && err == nil {
err = fmt.Errorf("failed to unlock key %q, lock isn't held, or is held by another session", op.DirEnt.Key)
}
case structs.KVSGet:
_, entry, err = s.kvsGetTxn(tx, op.DirEnt.Key)
if entry == nil && err == nil {
err = fmt.Errorf("key %q doesn't exist", op.DirEnt.Key)
}
case structs.KVSGetTree:
var entries structs.DirEntries
_, entries, err = s.kvsListTxn(tx, op.DirEnt.Key)
if err == nil {
results := make(structs.TxnResults, 0, len(entries))
for _, e := range entries {
result := structs.TxnResult{KV: e}
results = append(results, &result)
}
return results, nil
}
case structs.KVSCheckSession:
entry, err = s.kvsCheckSessionTxn(tx, op.DirEnt.Key, op.DirEnt.Session)
case structs.KVSCheckIndex:
entry, err = s.kvsCheckIndexTxn(tx, op.DirEnt.Key, op.DirEnt.ModifyIndex)
default:
err = fmt.Errorf("unknown KV verb %q", op.Verb)
}
if err != nil {
return nil, err
}
// For a GET we keep the value, otherwise we clone and blank out the
// value (we have to clone so we don't modify the entry being used by
// the state store).
if entry != nil {
if op.Verb == structs.KVSGet {
result := structs.TxnResult{KV: entry}
return structs.TxnResults{&result}, nil
}
clone := entry.Clone()
clone.Value = nil
result := structs.TxnResult{KV: clone}
return structs.TxnResults{&result}, nil
}
return nil, nil
}
