PeerTable
class PeerTable
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
static func tableSpec(_ id: Int32) -> ValueBoxTable {
return ValueBoxTable(id: id, keyType: .int64, compactValuesOnCreation: false)
}
private let reverseAssociatedTable: ReverseAssociatedPeerTable
private let sharedEncoder = PostboxEncoder()
private let sharedKey = ValueBoxKey(length: 8)
private var cachedPeers: [PeerId: Peer] = [:]
private var updatedInitialPeers: [PeerId: Peer?] = [:]
private func key(_ id: PeerId) -> ValueBoxKey {
self.sharedKey.setInt64(0, value: id.toInt64())
return self.sharedKey
}
// set
func set(_ peer: Peer) {
let previous = self.get(peer.id)
// update cache
self.cachedPeers[peer.id] = peer
if self.updatedInitialPeers[peer.id] == nil {// update only when cache is nil
self.updatedInitialPeers[peer.id] = previous
}
}
// get
func get(_ id: PeerId) -> Peer? {
if let peer = self.cachedPeers[id] {// from cache
return peer
}
// from db in disk
if let value = self.valueBox.get(self.table, key: self.key(id)) {
if let peer = PostboxDecoder(buffer: value).decodeRootObject() as? Peer {
self.cachedPeers[id] = peer
return peer
}
}
return nil
}
// clearMemoryCache
override func clearMemoryCache() {
self.cachedPeers.removeAll()
assert(self.updatedInitialPeers.isEmpty)
}
// transaction update peers
func transactionUpdatedPeers(contactsTable: ContactTable) -> [((Peer, Bool)?, (Peer, Bool))] {
var result: [((Peer, Bool)?, (Peer, Bool))] = []
for (peerId, initialPeer) in self.updatedInitialPeers {
if let peer = self.get(peerId) {
let isContact = contactsTable.isContact(peerId: peerId)
result.append((initialPeer.flatMap { ($0, isContact) }, (peer, isContact)))
} else {
assertionFailure()
}
}
return result
}
// before commit
override func beforeCommit() {
if !self.updatedInitialPeers.isEmpty {
for (peerId, previousPeer) in self.updatedInitialPeers {
if let peer = self.cachedPeers[peerId] {
self.sharedEncoder.reset()
self.sharedEncoder.encodeRootObject(peer)
self.valueBox.set(self.table, key: self.key(peerId), value: self.sharedEncoder.readBufferNoCopy())
// update reverse associated peer
let previousAssociation = previousPeer?.associatedPeerId
if previousAssociation != peer.associatedPeerId {
if let previousAssociation = previousAssociation {
self.reverseAssociatedTable.removeReverseAssociation(target: previousAssociation, from: peerId)
}
if let associatedPeerId = peer.associatedPeerId {
self.reverseAssociatedTable.addReverseAssociation(target: associatedPeerId, from: peerId)
}
}
} else {
assertionFailure()
}
}
self.updatedInitialPeers.removeAll()
if !self.useCaches {
self.cachedPeers.removeAll()
}
}
}