func applyDeleteRange(txnID int64, kv mvcc.KV, req *etcdserverpb.DeleteRangeRequest) (*etcdserverpb.DeleteRangeResponse, error) {
resp := &etcdserverpb.DeleteRangeResponse{}
resp.Header = &etcdserverpb.ResponseHeader{}
var (
n int64
rev int64
err error
)
if isGteRange(req.RangeEnd) {
req.RangeEnd = []byte{}
}
if txnID != noTxn {
n, rev, err = kv.TxnDeleteRange(txnID, req.Key, req.RangeEnd)
if err != nil {
return nil, err
}
} else {
n, rev = kv.DeleteRange(req.Key, req.RangeEnd)
}
resp.Deleted = n
resp.Header.Revision = rev
return resp, nil
}
func applyCompaction(kv mvcc.KV, req *etcdserverpb.CompactionRequest) (*etcdserverpb.CompactionResponse, error) {
resp := &etcdserverpb.CompactionResponse{}
resp.Header = &etcdserverpb.ResponseHeader{}
_, err := kv.Compact(req.Revision)
if err != nil {
return nil, err
}
// get the current revision. which key to get is not important.
_, resp.Header.Revision, _ = kv.Range([]byte("compaction"), nil, 1, 0)
return resp, err
}
func applyTransaction(kv mvcc.KV, lessor lease.Lessor, req *etcdserverpb.TxnRequest) (*etcdserverpb.TxnResponse, error) {
var revision int64
ok := true
for _, c := range req.Compare {
if revision, ok = applyCompare(kv, c); !ok {
break
}
}
var reqs []*etcdserverpb.RequestUnion
if ok {
reqs = req.Success
} else {
reqs = req.Failure
}
if err := checkRequestLeases(lessor, reqs); err != nil {
return nil, err
}
if err := checkRequestRange(kv, reqs); err != nil {
return nil, err
}
// When executing the operations of txn, we need to hold the txn lock.
// So the reader will not see any intermediate results.
txnID := kv.TxnBegin()
defer func() {
err := kv.TxnEnd(txnID)
if err != nil {
panic(fmt.Sprint("unexpected error when closing txn", txnID))
}
}()
resps := make([]*etcdserverpb.ResponseUnion, len(reqs))
for i := range reqs {
resps[i] = applyUnion(txnID, kv, reqs[i])
}
if len(resps) != 0 {
revision++
}
txnResp := &etcdserverpb.TxnResponse{}
txnResp.Header = &etcdserverpb.ResponseHeader{}
txnResp.Header.Revision = revision
txnResp.Responses = resps
txnResp.Succeeded = ok
return txnResp, nil
}
func checkRequestRange(kv mvcc.KV, reqs []*etcdserverpb.RequestUnion) error {
for _, requ := range reqs {
tv, ok := requ.Request.(*etcdserverpb.RequestUnion_RequestRange)
if !ok {
continue
}
greq := tv.RequestRange
if greq == nil || greq.Revision == 0 {
continue
}
if greq.Revision > kv.Rev() {
return mvcc.ErrFutureRev
}
if greq.Revision < kv.FirstRev() {
return mvcc.ErrCompacted
}
}
return nil
}
func applyPut(txnID int64, kv mvcc.KV, lessor lease.Lessor, req *etcdserverpb.PutRequest) (*etcdserverpb.PutResponse, error) {
resp := &etcdserverpb.PutResponse{}
resp.Header = &etcdserverpb.ResponseHeader{}
var (
rev int64
err error
)
if txnID != noTxn {
rev, err = kv.TxnPut(txnID, req.Key, req.Value, lease.LeaseID(req.Lease))
if err != nil {
return nil, err
}
} else {
leaseID := lease.LeaseID(req.Lease)
if leaseID != lease.NoLease {
if l := lessor.Lookup(leaseID); l == nil {
return nil, lease.ErrLeaseNotFound
}
}
rev = kv.Put(req.Key, req.Value, leaseID)
}
resp.Header.Revision = rev
return resp, nil
}
// applyCompare applies the compare request.
// It returns the revision at which the comparison happens. If the comparison
// succeeds, the it returns true. Otherwise it returns false.
func applyCompare(kv mvcc.KV, c *etcdserverpb.Compare) (int64, bool) {
ckvs, rev, err := kv.Range(c.Key, nil, 1, 0)
if err != nil {
if err == mvcc.ErrTxnIDMismatch {
panic("unexpected txn ID mismatch error")
}
return rev, false
}
var ckv mvccpb.KeyValue
if len(ckvs) != 0 {
ckv = ckvs[0]
} else {
// Use the zero value of ckv normally. However...
if c.Target == etcdserverpb.Compare_VALUE {
// Always fail if we're comparing a value on a key that doesn't exist.
// We can treat non-existence as the empty set explicitly, such that
// even a key with a value of length 0 bytes is still a real key
// that was written that way
return rev, false
}
}
// -1 is less, 0 is equal, 1 is greater
var result int
switch c.Target {
case etcdserverpb.Compare_VALUE:
tv, _ := c.TargetUnion.(*etcdserverpb.Compare_Value)
if tv != nil {
result = bytes.Compare(ckv.Value, tv.Value)
}
case etcdserverpb.Compare_CREATE:
tv, _ := c.TargetUnion.(*etcdserverpb.Compare_CreateRevision)
if tv != nil {
result = compareInt64(ckv.CreateRevision, tv.CreateRevision)
}
case etcdserverpb.Compare_MOD:
tv, _ := c.TargetUnion.(*etcdserverpb.Compare_ModRevision)
if tv != nil {
result = compareInt64(ckv.ModRevision, tv.ModRevision)
}
case etcdserverpb.Compare_VERSION:
tv, _ := c.TargetUnion.(*etcdserverpb.Compare_Version)
if tv != nil {
result = compareInt64(ckv.Version, tv.Version)
}
}
switch c.Result {
case etcdserverpb.Compare_EQUAL:
if result != 0 {
return rev, false
}
case etcdserverpb.Compare_GREATER:
if result != 1 {
return rev, false
}
case etcdserverpb.Compare_LESS:
if result != -1 {
return rev, false
}
}
return rev, true
}
func applyRange(txnID int64, kv mvcc.KV, r *etcdserverpb.RangeRequest) (*etcdserverpb.RangeResponse, error) {
resp := &etcdserverpb.RangeResponse{}
resp.Header = &etcdserverpb.ResponseHeader{}
var (
kvs []mvccpb.KeyValue
rev int64
err error
)
if isGteRange(r.RangeEnd) {
r.RangeEnd = []byte{}
}
limit := r.Limit
if r.SortOrder != etcdserverpb.RangeRequest_NONE {
// fetch everything; sort and truncate afterwards
limit = 0
}
if limit > 0 {
// fetch one extra for 'more' flag
limit = limit + 1
}
if txnID != noTxn {
kvs, rev, err = kv.TxnRange(txnID, r.Key, r.RangeEnd, limit, r.Revision)
if err != nil {
return nil, err
}
} else {
kvs, rev, err = kv.Range(r.Key, r.RangeEnd, limit, r.Revision)
if err != nil {
return nil, err
}
}
if r.SortOrder != etcdserverpb.RangeRequest_NONE {
var sorter sort.Interface
switch {
case r.SortTarget == etcdserverpb.RangeRequest_KEY:
sorter = &kvSortByKey{&kvSort{kvs}}
case r.SortTarget == etcdserverpb.RangeRequest_VERSION:
sorter = &kvSortByVersion{&kvSort{kvs}}
case r.SortTarget == etcdserverpb.RangeRequest_CREATE:
sorter = &kvSortByCreate{&kvSort{kvs}}
case r.SortTarget == etcdserverpb.RangeRequest_MOD:
sorter = &kvSortByMod{&kvSort{kvs}}
case r.SortTarget == etcdserverpb.RangeRequest_VALUE:
sorter = &kvSortByValue{&kvSort{kvs}}
}
switch {
case r.SortOrder == etcdserverpb.RangeRequest_ASCEND:
sort.Sort(sorter)
case r.SortOrder == etcdserverpb.RangeRequest_DESCEND:
sort.Sort(sort.Reverse(sorter))
}
}
if r.Limit > 0 && len(kvs) > int(r.Limit) {
kvs = kvs[:r.Limit]
resp.More = true
}
resp.Header.Revision = rev
for i := range kvs {
resp.Kvs = append(resp.Kvs, &kvs[i])
}
return resp, nil
}