github.com/vmware/govmomi@v0.43.0/event/processor.go (about)

     1  /*
     2  Copyright (c) 2016-2017 VMware, Inc. All Rights Reserved.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package event
    18  
    19  import (
    20  	"context"
    21  	"fmt"
    22  
    23  	"github.com/vmware/govmomi/property"
    24  	"github.com/vmware/govmomi/view"
    25  	"github.com/vmware/govmomi/vim25/types"
    26  )
    27  
    28  type tailInfo struct {
    29  	t         *eventTailer
    30  	obj       types.ManagedObjectReference
    31  	collector *HistoryCollector
    32  }
    33  
    34  type eventProcessor struct {
    35  	mgr      Manager
    36  	pageSize int32
    37  	kind     []string
    38  	tailers  map[types.ManagedObjectReference]*tailInfo // tailers by collector ref
    39  	callback func(types.ManagedObjectReference, []types.BaseEvent) error
    40  }
    41  
    42  func newEventProcessor(mgr Manager, pageSize int32, callback func(types.ManagedObjectReference, []types.BaseEvent) error, kind []string) *eventProcessor {
    43  	return &eventProcessor{
    44  		mgr:      mgr,
    45  		tailers:  make(map[types.ManagedObjectReference]*tailInfo),
    46  		callback: callback,
    47  		pageSize: pageSize,
    48  		kind:     kind,
    49  	}
    50  }
    51  
    52  func (p *eventProcessor) addObject(ctx context.Context, obj types.ManagedObjectReference) error {
    53  	filter := types.EventFilterSpec{
    54  		Entity: &types.EventFilterSpecByEntity{
    55  			Entity:    obj,
    56  			Recursion: types.EventFilterSpecRecursionOptionAll,
    57  		},
    58  		EventTypeId: p.kind,
    59  	}
    60  
    61  	collector, err := p.mgr.CreateCollectorForEvents(ctx, filter)
    62  	if err != nil {
    63  		return fmt.Errorf("[%#v] %s", obj, err)
    64  	}
    65  
    66  	err = collector.SetPageSize(ctx, p.pageSize)
    67  	if err != nil {
    68  		return err
    69  	}
    70  
    71  	p.tailers[collector.Reference()] = &tailInfo{
    72  		t:         newEventTailer(),
    73  		obj:       obj,
    74  		collector: collector,
    75  	}
    76  
    77  	return nil
    78  }
    79  
    80  func (p *eventProcessor) destroy() {
    81  	for _, info := range p.tailers {
    82  		_ = info.collector.Destroy(context.Background())
    83  	}
    84  }
    85  
    86  func (p *eventProcessor) run(ctx context.Context, tail bool) error {
    87  	if len(p.tailers) == 0 {
    88  		return nil
    89  	}
    90  
    91  	var collectors []types.ManagedObjectReference
    92  	for ref := range p.tailers {
    93  		collectors = append(collectors, ref)
    94  	}
    95  
    96  	c := property.DefaultCollector(p.mgr.Client())
    97  	props := []string{"latestPage"}
    98  
    99  	if len(collectors) == 1 {
   100  		// only one object to follow, don't bother creating a view
   101  		return property.Wait(ctx, c, collectors[0], props, func(pc []types.PropertyChange) bool {
   102  			if err := p.process(collectors[0], pc); err != nil {
   103  				return false
   104  			}
   105  
   106  			return !tail
   107  		})
   108  	}
   109  
   110  	// create and populate a ListView
   111  	m := view.NewManager(p.mgr.Client())
   112  
   113  	list, err := m.CreateListView(ctx, collectors)
   114  	if err != nil {
   115  		return err
   116  	}
   117  
   118  	defer func() {
   119  		_ = list.Destroy(context.Background())
   120  	}()
   121  
   122  	ref := list.Reference()
   123  	filter := new(property.WaitFilter).Add(ref, collectors[0].Type, props, list.TraversalSpec())
   124  
   125  	return property.WaitForUpdates(ctx, c, filter, func(updates []types.ObjectUpdate) bool {
   126  		for _, update := range updates {
   127  			if err := p.process(update.Obj, update.ChangeSet); err != nil {
   128  				return false
   129  			}
   130  		}
   131  
   132  		return !tail
   133  	})
   134  }
   135  
   136  func (p *eventProcessor) process(c types.ManagedObjectReference, pc []types.PropertyChange) error {
   137  	t := p.tailers[c]
   138  	if t == nil {
   139  		return fmt.Errorf("unknown collector %s", c.String())
   140  	}
   141  
   142  	for _, u := range pc {
   143  		evs := t.t.newEvents(u.Val.(types.ArrayOfEvent).Event)
   144  		if len(evs) == 0 {
   145  			continue
   146  		}
   147  
   148  		if err := p.callback(t.obj, evs); err != nil {
   149  			return err
   150  		}
   151  	}
   152  
   153  	return nil
   154  }
   155  
   156  const invalidKey = int32(-1)
   157  
   158  type eventTailer struct {
   159  	lastKey int32
   160  }
   161  
   162  func newEventTailer() *eventTailer {
   163  	return &eventTailer{
   164  		lastKey: invalidKey,
   165  	}
   166  }
   167  
   168  func (t *eventTailer) newEvents(evs []types.BaseEvent) []types.BaseEvent {
   169  	var ret []types.BaseEvent
   170  	if t.lastKey == invalidKey {
   171  		ret = evs
   172  	} else {
   173  		found := false
   174  		for i := range evs {
   175  			if evs[i].GetEvent().Key != t.lastKey {
   176  				continue
   177  			}
   178  
   179  			found = true
   180  			ret = evs[:i]
   181  			break
   182  		}
   183  
   184  		if !found {
   185  			ret = evs
   186  		}
   187  	}
   188  
   189  	if len(ret) > 0 {
   190  		t.lastKey = ret[0].GetEvent().Key
   191  	}
   192  
   193  	return ret
   194  }