-
Notifications
You must be signed in to change notification settings - Fork 176
/
pending_receipts.go
222 lines (197 loc) · 6.55 KB
/
pending_receipts.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
package stdmap
import (
"fmt"
"github.com/onflow/flow-go/model/flow"
"github.com/onflow/flow-go/module/mempool"
"github.com/onflow/flow-go/storage"
)
type receiptsSet map[flow.Identifier]struct{}
// PendingReceipts stores pending receipts indexed by the id.
// It also maintains a secondary index on the previous result id.
// in order to allow to find receipts by the previous result id.
type PendingReceipts struct {
*Backend
headers storage.Headers // used to query headers of executed blocks
// secondary index by parent result id, since multiple receipts could
// have the same parent result, (even if they have different result)
byPreviousResultID map[flow.Identifier]receiptsSet
// secondary index by height, we need this to prune pending receipts to some height
// it's safe to cleanup this index only when pruning. Even if some receipts are deleted manually,
// eventually index will be cleaned up.
byHeight map[uint64]receiptsSet
lowestHeight uint64
}
func indexByPreviousResultID(receipt *flow.ExecutionReceipt) flow.Identifier {
return receipt.ExecutionResult.PreviousResultID
}
func (r *PendingReceipts) indexByHeight(receipt *flow.ExecutionReceipt) (uint64, error) {
header, err := r.headers.ByBlockID(receipt.ExecutionResult.BlockID)
if err != nil {
return 0, fmt.Errorf("could not retreieve block by ID %v: %w", receipt.ExecutionResult.BlockID, err)
}
return header.Height, nil
}
// NewPendingReceipts creates a new memory pool for execution receipts.
func NewPendingReceipts(headers storage.Headers, limit uint) *PendingReceipts {
// create the receipts memory pool with the lookup maps
r := &PendingReceipts{
Backend: NewBackend(WithLimit(limit)),
headers: headers,
byPreviousResultID: make(map[flow.Identifier]receiptsSet),
byHeight: make(map[uint64]receiptsSet),
}
// TODO: there is smarter eject exists. For instance:
// if the mempool fills up, we want to eject the receipts for the highest blocks
// See https://github.com/onflow/flow-go/pull/387/files#r574228078
r.RegisterEjectionCallbacks(func(entity flow.Entity) {
receipt := entity.(*flow.ExecutionReceipt)
removeReceipt(receipt, r.backData, r.byPreviousResultID)
})
return r
}
func removeReceipt(
receipt *flow.ExecutionReceipt,
entities mempool.BackData,
byPreviousResultID map[flow.Identifier]receiptsSet) {
receiptID := receipt.ID()
entities.Remove(receiptID)
index := indexByPreviousResultID(receipt)
siblings := byPreviousResultID[index]
delete(siblings, receiptID)
if len(siblings) == 0 {
delete(byPreviousResultID, index)
}
}
// Add adds an execution receipt to the mempool.
func (r *PendingReceipts) Add(receipt *flow.ExecutionReceipt) bool {
added := false
err := r.Backend.Run(func(backData mempool.BackData) error {
receiptID := receipt.ID()
_, exists := backData.ByID(receiptID)
if exists {
// duplication
return nil
}
height, err := r.indexByHeight(receipt)
if err != nil {
return err
}
// skip elements below the pruned
if height < r.lowestHeight {
return nil
}
backData.Add(receiptID, receipt)
// update index AND the backdata in one "transaction"
previousResultID := indexByPreviousResultID(receipt)
siblings, ok := r.byPreviousResultID[previousResultID]
if !ok {
siblings = make(receiptsSet)
r.byPreviousResultID[previousResultID] = siblings
}
siblings[receiptID] = struct{}{}
sameHeight, ok := r.byHeight[height]
if !ok {
sameHeight = make(receiptsSet)
r.byHeight[height] = sameHeight
}
sameHeight[receiptID] = struct{}{}
added = true
return nil
})
if err != nil {
panic(err)
}
return added
}
// Remove will remove a receipt by ID.
func (r *PendingReceipts) Remove(receiptID flow.Identifier) bool {
removed := false
err := r.Backend.Run(func(backData mempool.BackData) error {
entity, ok := backData.ByID(receiptID)
if ok {
receipt := entity.(*flow.ExecutionReceipt)
removeReceipt(receipt, r.backData, r.byPreviousResultID)
removed = true
}
return nil
})
if err != nil {
panic(err)
}
return removed
}
// ByPreviousResultID returns receipts whose previous result ID matches the given ID
func (r *PendingReceipts) ByPreviousResultID(previousResultID flow.Identifier) []*flow.ExecutionReceipt {
var receipts []*flow.ExecutionReceipt
err := r.Backend.Run(func(backData mempool.BackData) error {
siblings, foundIndex := r.byPreviousResultID[previousResultID]
if !foundIndex {
return nil
}
for receiptID := range siblings {
entity, ok := backData.ByID(receiptID)
if !ok {
return fmt.Errorf("inconsistent index. can not find entity by id: %v", receiptID)
}
receipt, ok := entity.(*flow.ExecutionReceipt)
if !ok {
return fmt.Errorf("could not convert entity to receipt: %v", receiptID)
}
receipts = append(receipts, receipt)
}
return nil
})
if err != nil {
panic(err)
}
return receipts
}
// Size will return the total number of pending receipts
func (r *PendingReceipts) Size() uint {
return r.Backend.Size()
}
// PruneUpToHeight remove all receipts for blocks whose height is strictly
// smaller that height. Note: receipts for blocks at height are retained.
// After pruning, receipts below for blocks below the given height are dropped.
//
// Monotonicity Requirement:
// The pruned height cannot decrease, as we cannot recover already pruned elements.
// If `height` is smaller than the previous value, the previous value is kept
// and the sentinel mempool.BelowPrunedThresholdError is returned.
func (r *PendingReceipts) PruneUpToHeight(height uint64) error {
return r.Backend.Run(func(backData mempool.BackData) error {
if height < r.lowestHeight {
return mempool.NewBelowPrunedThresholdErrorf(
"pruning height: %d, existing height: %d", height, r.lowestHeight)
}
if backData.Size() == 0 {
r.lowestHeight = height
return nil
}
// Optimization: if there are less height in the index than the height range to prune,
// range to prune, then just go through each seal.
// Otherwise, go through each height to prune.
if uint64(len(r.byHeight)) < height-r.lowestHeight {
for h := range r.byHeight {
if h < height {
r.removeByHeight(h, backData)
}
}
} else {
for h := r.lowestHeight; h < height; h++ {
r.removeByHeight(h, backData)
}
}
r.lowestHeight = height
return nil
})
}
func (r *PendingReceipts) removeByHeight(height uint64, backData mempool.BackData) {
for receiptID := range r.byHeight[height] {
entity, ok := backData.ByID(receiptID)
if ok {
removeReceipt(entity.(*flow.ExecutionReceipt), r.backData, r.byPreviousResultID)
}
}
delete(r.byHeight, height)
}