open-consul/agent/consul/state/txn.go
Daniel Nephin f9b2834171 state: convert the remaining functions to ReadTxn
Required also converting some of the transaction functions to WriteTxn
because TxnRO() called the same helper as TxnRW.

This change allows us to return a memdb.Txn for read-only txn instead of
wrapping them with state.txn.
2020-10-23 14:29:22 -04:00

424 lines
12 KiB
Go

package state
import (
"fmt"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/api"
)
// txnKVS handles all KV-related operations.
func (s *Store) txnKVS(tx WriteTxn, idx uint64, op *structs.TxnKVOp) (structs.TxnResults, error) {
var entry *structs.DirEntry
var err error
switch op.Verb {
case api.KVSet:
entry = &op.DirEnt
err = kvsSetTxn(tx, idx, entry, false)
case api.KVDelete:
err = s.kvsDeleteTxn(tx, idx, op.DirEnt.Key, &op.DirEnt.EnterpriseMeta)
case api.KVDeleteCAS:
var ok bool
ok, err = s.kvsDeleteCASTxn(tx, idx, op.DirEnt.ModifyIndex, op.DirEnt.Key, &op.DirEnt.EnterpriseMeta)
if !ok && err == nil {
err = fmt.Errorf("failed to delete key %q, index is stale", op.DirEnt.Key)
}
case api.KVDeleteTree:
err = s.kvsDeleteTreeTxn(tx, idx, op.DirEnt.Key, &op.DirEnt.EnterpriseMeta)
case api.KVCAS:
var ok bool
entry = &op.DirEnt
ok, err = kvsSetCASTxn(tx, idx, entry)
if !ok && err == nil {
err = fmt.Errorf("failed to set key %q, index is stale", op.DirEnt.Key)
}
case api.KVLock:
var ok bool
entry = &op.DirEnt
ok, err = kvsLockTxn(tx, idx, entry)
if !ok && err == nil {
err = fmt.Errorf("failed to lock key %q, lock is already held", op.DirEnt.Key)
}
case api.KVUnlock:
var ok bool
entry = &op.DirEnt
ok, err = 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 api.KVGet:
_, entry, err = kvsGetTxn(tx, nil, op.DirEnt.Key, &op.DirEnt.EnterpriseMeta)
if entry == nil && err == nil {
err = fmt.Errorf("key %q doesn't exist", op.DirEnt.Key)
}
case api.KVGetTree:
var entries structs.DirEntries
_, entries, err = s.kvsListTxn(tx, nil, op.DirEnt.Key, &op.DirEnt.EnterpriseMeta)
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 api.KVCheckSession:
entry, err = kvsCheckSessionTxn(tx, op.DirEnt.Key, op.DirEnt.Session, &op.DirEnt.EnterpriseMeta)
case api.KVCheckIndex:
entry, err = kvsCheckIndexTxn(tx, op.DirEnt.Key, op.DirEnt.ModifyIndex, &op.DirEnt.EnterpriseMeta)
case api.KVCheckNotExists:
_, entry, err = kvsGetTxn(tx, nil, op.DirEnt.Key, &op.DirEnt.EnterpriseMeta)
if entry != nil && err == nil {
err = fmt.Errorf("key %q exists", op.DirEnt.Key)
}
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 == api.KVGet {
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
}
// txnSession handles all Session-related operations.
func txnSession(tx WriteTxn, idx uint64, op *structs.TxnSessionOp) error {
var err error
switch op.Verb {
case api.SessionDelete:
err = sessionDeleteWithSession(tx, &op.Session, idx)
default:
err = fmt.Errorf("unknown Session verb %q", op.Verb)
}
if err != nil {
return fmt.Errorf("failed to delete session: %v", err)
}
return nil
}
// txnLegacyIntention handles all Intention-related operations.
//
// Deprecated: see TxnOp.Intention description
func txnLegacyIntention(tx WriteTxn, idx uint64, op *structs.TxnIntentionOp) error {
switch op.Op {
case structs.IntentionOpCreate, structs.IntentionOpUpdate:
return legacyIntentionSetTxn(tx, idx, op.Intention)
case structs.IntentionOpDelete:
return legacyIntentionDeleteTxn(tx, idx, op.Intention.ID)
case structs.IntentionOpDeleteAll:
fallthrough // deliberately not available via this api
case structs.IntentionOpUpsert:
fallthrough // deliberately not available via this api
default:
return fmt.Errorf("unknown Intention op %q", op.Op)
}
}
// txnNode handles all Node-related operations.
func (s *Store) txnNode(tx WriteTxn, idx uint64, op *structs.TxnNodeOp) (structs.TxnResults, error) {
var entry *structs.Node
var err error
getNode := func() (*structs.Node, error) {
if op.Node.ID != "" {
return getNodeIDTxn(tx, op.Node.ID)
} else {
return getNodeTxn(tx, op.Node.Node)
}
}
switch op.Verb {
case api.NodeGet:
entry, err = getNode()
if entry == nil && err == nil {
err = fmt.Errorf("node %q doesn't exist", op.Node.Node)
}
case api.NodeSet:
err = s.ensureNodeTxn(tx, idx, false, &op.Node)
if err == nil {
entry, err = getNode()
}
case api.NodeCAS:
var ok bool
ok, err = s.ensureNodeCASTxn(tx, idx, &op.Node)
if !ok && err == nil {
err = fmt.Errorf("failed to set node %q, index is stale", op.Node.Node)
break
}
entry, err = getNode()
case api.NodeDelete:
err = s.deleteNodeTxn(tx, idx, op.Node.Node)
case api.NodeDeleteCAS:
var ok bool
ok, err = s.deleteNodeCASTxn(tx, idx, op.Node.ModifyIndex, op.Node.Node)
if !ok && err == nil {
err = fmt.Errorf("failed to delete node %q, index is stale", op.Node.Node)
}
default:
err = fmt.Errorf("unknown Node 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 == api.NodeGet {
result := structs.TxnResult{Node: entry}
return structs.TxnResults{&result}, nil
}
clone := *entry
result := structs.TxnResult{Node: &clone}
return structs.TxnResults{&result}, nil
}
return nil, nil
}
// txnService handles all Service-related operations.
func (s *Store) txnService(tx WriteTxn, idx uint64, op *structs.TxnServiceOp) (structs.TxnResults, error) {
switch op.Verb {
case api.ServiceGet:
entry, err := getNodeServiceTxn(tx, op.Node, op.Service.ID, &op.Service.EnterpriseMeta)
switch {
case err != nil:
return nil, err
case entry == nil:
return nil, fmt.Errorf("service %q on node %q doesn't exist", op.Service.ID, op.Node)
default:
return structs.TxnResults{&structs.TxnResult{Service: entry}}, nil
}
case api.ServiceSet:
if err := ensureServiceTxn(tx, idx, op.Node, false, &op.Service); err != nil {
return nil, err
}
entry, err := getNodeServiceTxn(tx, op.Node, op.Service.ID, &op.Service.EnterpriseMeta)
return newTxnResultFromNodeServiceEntry(entry), err
case api.ServiceCAS:
err := ensureServiceCASTxn(tx, idx, op.Node, &op.Service)
switch {
case err == errCASCompareFailed:
err := fmt.Errorf("failed to set service %q on node %q, index is stale", op.Service.ID, op.Node)
return nil, err
case err != nil:
return nil, err
}
entry, err := getNodeServiceTxn(tx, op.Node, op.Service.ID, &op.Service.EnterpriseMeta)
return newTxnResultFromNodeServiceEntry(entry), err
case api.ServiceDelete:
err := s.deleteServiceTxn(tx, idx, op.Node, op.Service.ID, &op.Service.EnterpriseMeta)
return nil, err
case api.ServiceDeleteCAS:
ok, err := s.deleteServiceCASTxn(tx, idx, op.Service.ModifyIndex, op.Node, op.Service.ID, &op.Service.EnterpriseMeta)
if !ok && err == nil {
return nil, fmt.Errorf("failed to delete service %q on node %q, index is stale", op.Service.ID, op.Node)
}
return nil, err
default:
return nil, fmt.Errorf("unknown Service verb %q", op.Verb)
}
}
// newTxnResultFromNodeServiceEntry returns a TxnResults with a single result,
// a copy of entry. The entry is copied to prevent modification of the state
// store.
func newTxnResultFromNodeServiceEntry(entry *structs.NodeService) structs.TxnResults {
if entry == nil {
return nil
}
clone := *entry
result := structs.TxnResult{Service: &clone}
return structs.TxnResults{&result}
}
// txnCheck handles all Check-related operations.
func (s *Store) txnCheck(tx WriteTxn, idx uint64, op *structs.TxnCheckOp) (structs.TxnResults, error) {
var entry *structs.HealthCheck
var err error
switch op.Verb {
case api.CheckGet:
_, entry, err = getNodeCheckTxn(tx, op.Check.Node, op.Check.CheckID, &op.Check.EnterpriseMeta)
if entry == nil && err == nil {
err = fmt.Errorf("check %q on node %q doesn't exist", op.Check.CheckID, op.Check.Node)
}
case api.CheckSet:
err = s.ensureCheckTxn(tx, idx, false, &op.Check)
if err == nil {
_, entry, err = getNodeCheckTxn(tx, op.Check.Node, op.Check.CheckID, &op.Check.EnterpriseMeta)
}
case api.CheckCAS:
var ok bool
entry = &op.Check
ok, err = s.ensureCheckCASTxn(tx, idx, entry)
if !ok && err == nil {
err = fmt.Errorf("failed to set check %q on node %q, index is stale", entry.CheckID, entry.Node)
break
}
_, entry, err = getNodeCheckTxn(tx, op.Check.Node, op.Check.CheckID, &op.Check.EnterpriseMeta)
case api.CheckDelete:
err = s.deleteCheckTxn(tx, idx, op.Check.Node, op.Check.CheckID, &op.Check.EnterpriseMeta)
case api.CheckDeleteCAS:
var ok bool
ok, err = s.deleteCheckCASTxn(tx, idx, op.Check.ModifyIndex, op.Check.Node, op.Check.CheckID, &op.Check.EnterpriseMeta)
if !ok && err == nil {
err = fmt.Errorf("failed to delete check %q on node %q, index is stale", op.Check.CheckID, op.Check.Node)
}
default:
err = fmt.Errorf("unknown Check 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 == api.CheckGet {
result := structs.TxnResult{Check: entry}
return structs.TxnResults{&result}, nil
}
clone := entry.Clone()
result := structs.TxnResult{Check: clone}
return structs.TxnResults{&result}, nil
}
return nil, nil
}
// txnDispatch runs the given operations inside the state store transaction.
func (s *Store) txnDispatch(tx WriteTxn, idx uint64, ops structs.TxnOps) (structs.TxnResults, structs.TxnErrors) {
results := make(structs.TxnResults, 0, len(ops))
errors := make(structs.TxnErrors, 0, len(ops))
for i, op := range ops {
var ret structs.TxnResults
var err error
// Dispatch based on the type of operation.
switch {
case op.KV != nil:
ret, err = s.txnKVS(tx, idx, op.KV)
case op.Node != nil:
ret, err = s.txnNode(tx, idx, op.Node)
case op.Service != nil:
ret, err = s.txnService(tx, idx, op.Service)
case op.Check != nil:
ret, err = s.txnCheck(tx, idx, op.Check)
case op.Session != nil:
err = txnSession(tx, idx, op.Session)
case op.Intention != nil:
// NOTE: this branch is deprecated and exists for backwards
// compatibility with pre-1.9.0 raft logs and during upgrades.
err = txnLegacyIntention(tx, idx, op.Intention)
default:
err = fmt.Errorf("no operation specified")
}
// Accumulate the results.
results = append(results, ret...)
// Capture any error along with the index of the operation that
// failed.
if err != nil {
errors = append(errors, &structs.TxnError{
OpIndex: i,
What: err.Error(),
})
}
}
if len(errors) > 0 {
return nil, errors
}
return results, nil
}
// TxnRW tries to run the given operations all inside a single transaction. If
// any of the operations fail, the entire transaction will be rolled back. This
// is done in a full write transaction on the state store, so reads and writes
// are possible
func (s *Store) TxnRW(idx uint64, ops structs.TxnOps) (structs.TxnResults, structs.TxnErrors) {
tx := s.db.WriteTxn(idx)
defer tx.Abort()
results, errors := s.txnDispatch(tx, idx, ops)
if len(errors) > 0 {
return nil, errors
}
err := tx.Commit()
if err != nil {
return nil, structs.TxnErrors{
{What: err.Error(), OpIndex: 0},
}
}
return results, nil
}
// TxnRO runs the given operations inside a single read transaction in the state
// store. You must verify outside this function that no write operations are
// present, otherwise you'll get an error from the state store.
func (s *Store) TxnRO(ops structs.TxnOps) (structs.TxnResults, structs.TxnErrors) {
tx := s.db.Txn(false)
defer tx.Abort()
results, errors := s.txnDispatch(tx, 0, ops)
if len(errors) > 0 {
return nil, errors
}
return results, nil
}