github.com/livekit/protocol@v1.39.3/webhook/resource_queue.go (about)

     1  // Copyright 2023 LiveKit, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package webhook
    16  
    17  import (
    18  	"context"
    19  	"errors"
    20  	"sync"
    21  	"time"
    22  
    23  	"github.com/gammazero/deque"
    24  
    25  	"github.com/livekit/protocol/livekit"
    26  )
    27  
    28  var (
    29  	errQueueFull   = errors.New("queue is full")
    30  	errQueueClosed = errors.New("queue is closed")
    31  )
    32  
    33  type item struct {
    34  	ctx      context.Context
    35  	queuedAt time.Time
    36  	event    *livekit.WebhookEvent
    37  	params   *ResourceURLNotifierParams
    38  }
    39  
    40  type resourceQueueParams struct {
    41  	MaxDepth int
    42  
    43  	Poster poster
    44  }
    45  
    46  type resourceQueue struct {
    47  	params resourceQueueParams
    48  
    49  	mu    sync.Mutex
    50  	items deque.Deque[*item]
    51  	cond  *sync.Cond
    52  
    53  	closed bool
    54  	drain  bool
    55  }
    56  
    57  func newResourceQueue(params resourceQueueParams) *resourceQueue {
    58  	r := &resourceQueue{
    59  		params: params,
    60  	}
    61  	r.items.SetBaseCap(int(min(params.MaxDepth, 16)))
    62  	r.cond = sync.NewCond(&r.mu)
    63  
    64  	go r.worker()
    65  	return r
    66  }
    67  
    68  func (r *resourceQueue) Stop(force bool) {
    69  	r.mu.Lock()
    70  	defer r.mu.Unlock()
    71  
    72  	if !r.closed {
    73  		r.closed = true
    74  		r.drain = !force
    75  
    76  		r.cond.Broadcast()
    77  	}
    78  }
    79  
    80  func (r *resourceQueue) Enqueue(ctx context.Context, whEvent *livekit.WebhookEvent, params *ResourceURLNotifierParams) (int, error) {
    81  	return r.EnqueueAt(ctx, time.Now(), whEvent, params)
    82  }
    83  
    84  func (r *resourceQueue) EnqueueAt(ctx context.Context, at time.Time, whEvent *livekit.WebhookEvent, params *ResourceURLNotifierParams) (int, error) {
    85  	r.mu.Lock()
    86  	defer r.mu.Unlock()
    87  
    88  	if r.closed {
    89  		return r.items.Len(), errQueueClosed
    90  	}
    91  
    92  	if r.items.Len() >= r.params.MaxDepth {
    93  		return r.items.Len(), errQueueFull
    94  	}
    95  
    96  	r.items.PushBack(&item{ctx, at, whEvent, params})
    97  	r.cond.Broadcast()
    98  	return r.items.Len(), nil
    99  }
   100  
   101  func (r *resourceQueue) worker() {
   102  	for {
   103  		r.mu.Lock()
   104  		for {
   105  			if r.closed && (!r.drain || r.items.Len() == 0) {
   106  				r.mu.Unlock()
   107  				return
   108  			}
   109  
   110  			if r.items.Len() != 0 {
   111  				break
   112  			}
   113  			r.cond.Wait()
   114  		}
   115  
   116  		item := r.items.PopFront()
   117  		qLen := r.items.Len()
   118  		r.mu.Unlock()
   119  
   120  		r.params.Poster.Process(item.ctx, item.queuedAt, item.event, item.params, qLen)
   121  	}
   122  }