package clientv3
import pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
type opType int
const (
// A default Op has opType 0, which is invalid.
tRange opType = iota + 1
tPut
tDeleteRange
)
var (
noPrefixEnd = []byte{0}
)
// Op represents an Operation that kv can execute.
type Op struct {
t opType
key []byte
end []byte
// for range
limit int64
sort *SortOption
serializable bool
keysOnly bool
countOnly bool
minModRev int64
maxModRev int64
minCreateRev int64
maxCreateRev int64
// for range, watch
rev int64
// for watch, put, delete
prevKV bool
// progressNotify is for progress updates.
progressNotify bool
// createdNotify is for created event
createdNotify bool
// filters for watchers
filterPut bool
filterDelete bool
// for put
val []byte
leaseID LeaseID
}
func (op Op) toRangeRequest() *pb.RangeRequest {
if op.t != tRange {
panic("op.t != tRange")
}
r := &pb.RangeRequest{
Key: op.key,
RangeEnd: op.end,
Limit: op.limit,
Revision: op.rev,
Serializable: op.serializable,
KeysOnly: op.keysOnly,
CountOnly: op.countOnly,
MinModRevision: op.minModRev,
MaxModRevision: op.maxModRev,
MinCreateRevision: op.minCreateRev,
MaxCreateRevision: op.maxCreateRev,
}
if op.sort != nil {
r.SortOrder = pb.RangeRequest_SortOrder(op.sort.Order)
r.SortTarget = pb.RangeRequest_SortTarget(op.sort.Target)
}
return r
}
func (op Op) toRequestOp() *pb.RequestOp {
switch op.t {
case tRange:
return &pb.RequestOp{Request: &pb.RequestOp_RequestRange{RequestRange: op.toRangeRequest()}}
case tPut:
r := &pb.PutRequest{Key: op.key, Value: op.val, Lease: int64(op.leaseID), PrevKv: op.prevKV}
return &pb.RequestOp{Request: &pb.RequestOp_RequestPut{RequestPut: r}}
case tDeleteRange:
r := &pb.DeleteRangeRequest{Key: op.key, RangeEnd: op.end, PrevKv: op.prevKV}
return &pb.RequestOp{Request: &pb.RequestOp_RequestDeleteRange{RequestDeleteRange: r}}
default:
panic("Unknown Op")
}
}
func (op Op) isWrite() bool {
return op.t != tRange
}
func OpGet(key string, opts ...OpOption) Op {
ret := Op{t: tRange, key: []byte(key)}
ret.applyOpts(opts)
return ret
}
func OpDelete(key string, opts ...OpOption) Op {
ret := Op{t: tDeleteRange, key: []byte(key)}
ret.applyOpts(opts)
switch {
case ret.leaseID != 0:
panic("unexpected lease in delete")
case ret.limit != 0:
panic("unexpected limit in delete")
case ret.rev != 0:
panic("unexpected revision in delete")
case ret.sort != nil:
panic("unexpected sort in delete")
case ret.serializable:
panic("unexpected serializable in delete")
case ret.countOnly:
panic("unexpected countOnly in delete")
case ret.minModRev != 0, ret.maxModRev != 0:
panic("unexpected mod revision filter in delete")
case ret.minCreateRev != 0, ret.maxCreateRev != 0:
panic("unexpected create revision filter in delete")
case ret.filterDelete, ret.filterPut:
panic("unexpected filter in delete")
case ret.createdNotify:
panic("unexpected createdNotify in delete")
}
return ret
}
func OpPut(key, val string, opts ...OpOption) Op {
ret := Op{t: tPut, key: []byte(key), val: []byte(val)}
ret.applyOpts(opts)
switch {
case ret.end != nil:
panic("unexpected range in put")
case ret.limit != 0:
panic("unexpected limit in put")
case ret.rev != 0:
panic("unexpected revision in put")
case ret.sort != nil:
panic("unexpected sort in put")
case ret.serializable:
panic("unexpected serializable in put")
case ret.countOnly:
panic("unexpected countOnly in put")
case ret.minModRev != 0, ret.maxModRev != 0:
panic("unexpected mod revision filter in put")
case ret.minCreateRev != 0, ret.maxCreateRev != 0:
panic("unexpected create revision filter in put")
case ret.filterDelete, ret.filterPut:
panic("unexpected filter in put")
case ret.createdNotify:
panic("unexpected createdNotify in put")
}
return ret
}
func opWatch(key string, opts ...OpOption) Op {
ret := Op{t: tRange, key: []byte(key)}
ret.applyOpts(opts)
switch {
case ret.leaseID != 0:
panic("unexpected lease in watch")
case ret.limit != 0:
panic("unexpected limit in watch")
case ret.sort != nil:
panic("unexpected sort in watch")
case ret.serializable:
panic("unexpected serializable in watch")
case ret.countOnly:
panic("unexpected countOnly in watch")
case ret.minModRev != 0, ret.maxModRev != 0:
panic("unexpected mod revision filter in watch")
case ret.minCreateRev != 0, ret.maxCreateRev != 0:
panic("unexpected create revision filter in watch")
}
return ret
}
func (op *Op) applyOpts(opts []OpOption) {
for _, opt := range opts {
opt(op)
}
}
// OpOption configures Operations like Get, Put, Delete.
type OpOption func(*Op)
// WithLease attaches a lease ID to a key in ‘Put‘ request.
func WithLease(leaseID LeaseID) OpOption {
return func(op *Op) { op.leaseID = leaseID }
}
// WithLimit limits the number of results to return from ‘Get‘ request.
func WithLimit(n int64) OpOption { return func(op *Op) { op.limit = n } }
// WithRev specifies the store revision for ‘Get‘ request.
// Or the start revision of ‘Watch‘ request.
func WithRev(rev int64) OpOption { return func(op *Op) { op.rev = rev } }
// WithSort specifies the ordering in ‘Get‘ request. It requires
// ‘WithRange‘ and/or ‘WithPrefix‘ to be specified too.
// ‘target‘ specifies the target to sort by: key, version, revisions, value.
// ‘order‘ can be either ‘SortNone‘, ‘SortAscend‘, ‘SortDescend‘.
func WithSort(target SortTarget, order SortOrder) OpOption {
return func(op *Op) {
if target == SortByKey && order == SortAscend {
// If order != SortNone, server fetches the entire key-space,
// and then applies the sort and limit, if provided.
// Since current mvcc.Range implementation returns results
// sorted by keys in lexicographically ascending order,
// client should ignore SortOrder if the target is SortByKey.
order = SortNone
}
op.sort = &SortOption{target, order}
}
}
// GetPrefixRangeEnd gets the range end of the prefix.
// ‘Get(foo, WithPrefix())‘ is equal to ‘Get(foo, WithRange(GetPrefixRangeEnd(foo))‘.
func GetPrefixRangeEnd(prefix string) string {
return string(getPrefix([]byte(prefix)))
}
func getPrefix(key []byte) []byte {
end := make([]byte, len(key))
copy(end, key)
for i := len(end) - 1; i >= 0; i-- {
if end[i] < 0xff {
end[i] = end[i] + 1
end = end[:i+1]
return end
}
}
// next prefix does not exist (e.g., 0xffff);
// default to WithFromKey policy
return noPrefixEnd
}
// WithPrefix enables ‘Get‘, ‘Delete‘, or ‘Watch‘ requests to operate
// on the keys with matching prefix. For example, ‘Get(foo, WithPrefix())‘
// can return ‘foo1‘, ‘foo2‘, and so on.
func WithPrefix() OpOption {
return func(op *Op) {
op.end = getPrefix(op.key)
}
}
// WithRange specifies the range of ‘Get‘, ‘Delete‘, ‘Watch‘ requests.
// For example, ‘Get‘ requests with ‘WithRange(end)‘ returns
// the keys in the range [key, end).
// endKey must be lexicographically greater than start key.
func WithRange(endKey string) OpOption {
return func(op *Op) { op.end = []byte(endKey) }
}
// WithFromKey specifies the range of ‘Get‘, ‘Delete‘, ‘Watch‘ requests
// to be equal or greater than the key in the argument.
func WithFromKey() OpOption { return WithRange("\x00") }
// WithSerializable makes ‘Get‘ request serializable. By default,
// it‘s linearizable. Serializable requests are better for lower latency
// requirement.
func WithSerializable() OpOption {
return func(op *Op) { op.serializable = true }
}
// WithKeysOnly makes the ‘Get‘ request return only the keys and the corresponding
// values will be omitted.
func WithKeysOnly() OpOption {
return func(op *Op) { op.keysOnly = true }
}
// WithCountOnly makes the ‘Get‘ request return only the count of keys.
func WithCountOnly() OpOption {
return func(op *Op) { op.countOnly = true }
}
// WithMinModRev filters out keys for Get with modification revisions less than the given revision.
func WithMinModRev(rev int64) OpOption { return func(op *Op) { op.minModRev = rev } }
// WithMaxModRev filters out keys for Get with modification revisions greater than the given revision.
func WithMaxModRev(rev int64) OpOption { return func(op *Op) { op.maxModRev = rev } }
// WithMinCreateRev filters out keys for Get with creation revisions less than the given revision.
func WithMinCreateRev(rev int64) OpOption { return func(op *Op) { op.minCreateRev = rev } }
// WithMaxCreateRev filters out keys for Get with creation revisions greater than the given revision.
func WithMaxCreateRev(rev int64) OpOption { return func(op *Op) { op.maxCreateRev = rev } }
// WithFirstCreate gets the key with the oldest creation revision in the request range.
func WithFirstCreate() []OpOption { return withTop(SortByCreateRevision, SortAscend) }
// WithLastCreate gets the key with the latest creation revision in the request range.
func WithLastCreate() []OpOption { return withTop(SortByCreateRevision, SortDescend) }
// WithFirstKey gets the lexically first key in the request range.
func WithFirstKey() []OpOption { return withTop(SortByKey, SortAscend) }
// WithLastKey gets the lexically last key in the request range.
func WithLastKey() []OpOption { return withTop(SortByKey, SortDescend) }
// WithFirstRev gets the key with the oldest modification revision in the request range.
func WithFirstRev() []OpOption { return withTop(SortByModRevision, SortAscend) }
// WithLastRev gets the key with the latest modification revision in the request range.
func WithLastRev() []OpOption { return withTop(SortByModRevision, SortDescend) }
// withTop gets the first key over the get‘s prefix given a sort order
func withTop(target SortTarget, order SortOrder) []OpOption {
return []OpOption{WithPrefix(), WithSort(target, order), WithLimit(1)}
}
// WithProgressNotify makes watch server send periodic progress updates
// every 10 minutes when there is no incoming events.
// Progress updates have zero events in WatchResponse.
func WithProgressNotify() OpOption {
return func(op *Op) {
op.progressNotify = true
}
}
// WithCreatedNotify makes watch server sends the created event.
func WithCreatedNotify() OpOption {
return func(op *Op) {
op.createdNotify = true
}
}
// WithFilterPut discards PUT events from the watcher.
func WithFilterPut() OpOption {
return func(op *Op) { op.filterPut = true }
}
// WithFilterDelete discards DELETE events from the watcher.
func WithFilterDelete() OpOption {
return func(op *Op) { op.filterDelete = true }
}
// WithPrevKV gets the previous key-value pair before the event happens. If the previous KV is already compacted,
// nothing will be returned.
func WithPrevKV() OpOption {
return func(op *Op) {
op.prevKV = true
}
}
// LeaseOp represents an Operation that lease can execute.
type LeaseOp struct {
id LeaseID
// for TimeToLive
attachedKeys bool
}
// LeaseOption configures lease operations.
type LeaseOption func(*LeaseOp)
func (op *LeaseOp) applyOpts(opts []LeaseOption) {
for _, opt := range opts {
opt(op)
}
}
// WithAttachedKeys requests lease timetolive API to return
// attached keys of given lease ID.
func WithAttachedKeys() LeaseOption {
return func(op *LeaseOp) { op.attachedKeys = true }
}
func toLeaseTimeToLiveRequest(id LeaseID, opts ...LeaseOption) *pb.LeaseTimeToLiveRequest {
ret := &LeaseOp{id: id}
ret.applyOpts(opts)
return &pb.LeaseTimeToLiveRequest{ID: int64(id), Keys: ret.attachedKeys}
}
时间： 2024-08-29 11:24:38