Repository: etcd-io/etcd
File: clientv3/watch.go (Go)

Code before:
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package clientv3

import (
	"context"
	"errors"
	"fmt"
	"sync"
	"time"

	v3rpc "go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
	mvccpb "go.etcd.io/etcd/mvcc/mvccpb"

	"github.com/coreos/pkg/capnslog"
	"google.golang.org/grpc"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/metadata"
	"google.golang.org/grpc/status"
)

var (
	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "clientv3")
)

const (
	EventTypeDelete = mvccpb.DELETE
	EventTypePut    = mvccpb.PUT

	closeSendErrTimeout = 250 * time.Millisecond
)

type Event mvccpb.Event

type WatchChan <-chan WatchResponse

type Watcher interface {
	// Watch watches on a key or prefix. The watched events will be returned
	// through the returned channel. If revisions waiting to be sent over the
	// watch are compacted, then the watch will be canceled by the server, the

Review comment (suggestion):
We are deprecating this logger in next release (and current master branch). Let's pass clientv3's logger to watcher and use that.
cc @gyuho 

Code after:
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package clientv3

import (
	"context"
	"errors"
	"fmt"
	"sync"
	"time"

	v3rpc "go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
	mvccpb "go.etcd.io/etcd/mvcc/mvccpb"

	"go.uber.org/zap"
	"google.golang.org/grpc"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/metadata"
	"google.golang.org/grpc/status"
)

const (
	EventTypeDelete = mvccpb.DELETE
	EventTypePut    = mvccpb.PUT

	closeSendErrTimeout = 250 * time.Millisecond
)

type Event mvccpb.Event

type WatchChan <-chan WatchResponse

type Watcher interface {
	// Watch watches on a key or prefix. The watched events will be returned
	// through the returned channel. If revisions waiting to be sent over the
	// watch are compacted, then the watch will be canceled by the server, the
	// client will post a compacted error watch response, and the channel will close.
	// If the context "ctx" is canceled or timed out, returned "WatchChan" is closed,
	// and "WatchResponse" from this closed channel has zero events and nil "Err()".
	// The context "ctx" MUST be canceled, as soon as watcher is no longer being used,