Method evalCmp

kv/etcd/mock.go:397–423

evalCmp executes the given comparison between some field of a key-value pair stored in mockKV and a provided value. The field may be the value stored or one of the various version numbers associated with it.

(cmp clientv3.Cmp)

// pair stored in mockKV and a provided value. The field may be the value
// stored or one of the various version numbers associated with it.
func (m *mockKV) evalCmp(cmp clientv3.Cmp) bool {
	// Note that we're not checking if there was an existing entry for this
	// key/value pair since we'll get one with all zero values in that case.
	// This allows transactions to compare a '0' version so that they can be
	// used to only create an entry if there previously was none.
	entry := m.values[string(cmp.KeyBytes())]

	switch cmp.Target {
	case etcdserverpb.Compare_VALUE:
		v, _ := cmp.TargetUnion.(*etcdserverpb.Compare_Value)
		return m.evalEntryBytes(entry.Value, v.Value, cmp)
	case etcdserverpb.Compare_CREATE:
		v, _ := cmp.TargetUnion.(*etcdserverpb.Compare_CreateRevision)
		return m.evalEntryInt64(entry.CreateRevision, v.CreateRevision, cmp)
	case etcdserverpb.Compare_LEASE:
		v, _ := cmp.TargetUnion.(*etcdserverpb.Compare_Lease)
		return m.evalEntryInt64(entry.Lease, v.Lease, cmp)
	case etcdserverpb.Compare_VERSION:
		v, _ := cmp.TargetUnion.(*etcdserverpb.Compare_Version)
		return m.evalEntryInt64(entry.Version, v.Version, cmp)
	case etcdserverpb.Compare_MOD:
		v, _ := cmp.TargetUnion.(*etcdserverpb.Compare_ModRevision)
		return m.evalEntryInt64(entry.ModRevision, v.ModRevision, cmp)
	default:
		panic(fmt.Sprintf("unsupported target for cmp: %+v", cmp))
	}
}

// evalEntryBytes returns true if the provided comparison between two
// byte slices is true, false otherwise. This is used to compare values