woodpecker/server/logging/log.go

156 lines
3.0 KiB
Go

// Copyright 2023 Woodpecker Authors
//
// 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 logging
import (
"context"
"sync"
logger "github.com/rs/zerolog/log"
"go.woodpecker-ci.org/woodpecker/v3/server/model"
)
// TODO: (bradrydzewski) writing to subscribers is currently a blocking
// operation and does not protect against slow clients from locking
// the stream. This should be resolved.
//nolint:godot
// TODO: (bradrydzewski) implement a mux.Info to fetch information and
// statistics for the multiplexer. Streams, subscribers, etc
// mux.Info()
//nolint:godot
// TODO: (bradrydzewski) refactor code to place publisher and subscriber
// operations in separate files with more encapsulated logic.
// sub.push()
// sub.join()
// sub.start()... event loop
type subscriber struct {
receiver LogChan
}
type stream struct {
sync.Mutex
stepID int64
list []*model.LogEntry
subs map[*subscriber]struct{}
done chan struct{}
}
type log struct {
sync.Mutex
streams map[int64]*stream
}
// New returns a new logger.
func New() Log {
return &log{
streams: map[int64]*stream{},
}
}
func (l *log) Open(_ context.Context, stepID int64) error {
l.Lock()
_, ok := l.streams[stepID]
if !ok {
l.streams[stepID] = &stream{
stepID: stepID,
subs: make(map[*subscriber]struct{}),
done: make(chan struct{}),
}
}
l.Unlock()
return nil
}
func (l *log) Write(ctx context.Context, stepID int64, entries []*model.LogEntry) error {
l.Lock()
s, ok := l.streams[stepID]
l.Unlock()
// auto open the stream if it does not exist
if !ok {
err := l.Open(ctx, stepID)
if err != nil {
return err
}
s = l.streams[stepID]
}
s.Lock()
s.list = append(s.list, entries...)
for sub := range s.subs {
select {
case sub.receiver <- entries:
default:
logger.Info().Msgf("subscriber channel is full -- dropping logs for step %d", stepID)
}
}
s.Unlock()
return nil
}
func (l *log) Tail(c context.Context, stepID int64, receiver LogChan) error {
l.Lock()
s, ok := l.streams[stepID]
l.Unlock()
if !ok {
return ErrNotFound
}
sub := &subscriber{
receiver: receiver,
}
s.Lock()
if len(s.list) != 0 {
sub.receiver <- s.list
}
s.subs[sub] = struct{}{}
s.Unlock()
select {
case <-c.Done():
case <-s.done:
}
s.Lock()
delete(s.subs, sub)
s.Unlock()
return nil
}
func (l *log) Close(_ context.Context, stepID int64) error {
l.Lock()
s, ok := l.streams[stepID]
l.Unlock()
if !ok {
return ErrNotFound
}
s.Lock()
close(s.done)
s.Unlock()
l.Lock()
delete(l.streams, stepID)
l.Unlock()
return nil
}