| 1 | package sessioncatalog |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "strings" |
| 6 | "time" |
| 7 | ) |
| 8 | |
| 9 | // RequestReconcile makes the channel a wake signal while the maps retain the |
| 10 | // newest target. Session saves never wait for catalog work. |
| 11 | func (c *Catalog) RequestReconcile(target DirectoryTarget) bool { |
| 12 | if c == nil || strings.TrimSpace(target.Path) == "" { |
| 13 | return false |
| 14 | } |
| 15 | target.Path = cleanCatalogAccessPath(target.Path) |
| 16 | key := queuePathKey(target.Path) |
| 17 | if key == "" { |
| 18 | return false |
| 19 | } |
| 20 | target.mutationSeq = c.mutationSeq.Add(1) |
| 21 | if _, loaded := c.reconcileQueued.LoadOrStore(key, target); loaded { |
| 22 | c.markReconcileDirty(target) |
| 23 | return true |
| 24 | } |
| 25 | select { |
| 26 | case c.reconcileCh <- target: |
| 27 | return true |
| 28 | case <-c.stop: |
| 29 | c.reconcileQueued.Delete(key) |
| 30 | return false |
| 31 | default: |
| 32 | c.reconcileQueued.Delete(key) |
| 33 | c.markReconcileDirty(target) |
| 34 | return false |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | func (c *Catalog) markReconcileDirty(target DirectoryTarget) { |
| 39 | key := queuePathKey(target.Path) |
| 40 | c.reconcileDirtyMu.Lock() |
| 41 | if queued, ok := c.reconcileQueued.Load(key); ok { |
| 42 | target = newestReconcileTarget(queued.(DirectoryTarget), target) |
| 43 | } |
| 44 | if dirty, ok := c.reconcileDirty[key]; ok { |
| 45 | target = newestReconcileTarget(dirty, target) |
| 46 | } |
| 47 | c.reconcileDirty[key] = target |
| 48 | c.reconcileQueued.Store(key, target) |
| 49 | c.reconcileDirtyMu.Unlock() |
| 50 | } |
| 51 | |
| 52 | func (c *Catalog) resolveReconcileToken(target DirectoryTarget) (DirectoryTarget, bool) { |
| 53 | key := queuePathKey(target.Path) |
| 54 | c.reconcileDirtyMu.Lock() |
| 55 | defer c.reconcileDirtyMu.Unlock() |
| 56 | queued, owned := c.reconcileQueued.Load(key) |
| 57 | if !owned { |
| 58 | return DirectoryTarget{}, false |
| 59 | } |
| 60 | target = newestReconcileTarget(target, queued.(DirectoryTarget)) |
| 61 | if latest, dirty := c.reconcileDirty[key]; dirty { |
| 62 | target = newestReconcileTarget(target, latest) |
| 63 | delete(c.reconcileDirty, key) |
| 64 | } |
| 65 | c.reconcileQueued.Store(key, target) |
| 66 | return target, true |
| 67 | } |
| 68 | |
| 69 | func newestReconcileTarget(current, candidate DirectoryTarget) DirectoryTarget { |
| 70 | if candidate.mutationSeq > current.mutationSeq { |
| 71 | return candidate |
| 72 | } |
| 73 | return current |
| 74 | } |
| 75 | |
| 76 | func (c *Catalog) takeReconcileDirty() (DirectoryTarget, bool) { |
| 77 | c.reconcileDirtyMu.Lock() |
| 78 | defer c.reconcileDirtyMu.Unlock() |
| 79 | for key, target := range c.reconcileDirty { |
| 80 | delete(c.reconcileDirty, key) |
| 81 | c.reconcileQueued.Store(key, target) |
| 82 | return target, true |
| 83 | } |
| 84 | return DirectoryTarget{}, false |
| 85 | } |
| 86 | |
| 87 | func (c *Catalog) reconcileLoop() { |
| 88 | defer c.workers.Done() |
| 89 | ticker := time.NewTicker(250 * time.Millisecond) |
| 90 | defer ticker.Stop() |
| 91 | for { |
| 92 | select { |
| 93 | case token := <-c.reconcileCh: |
| 94 | if target, ok := c.resolveReconcileToken(token); ok { |
| 95 | c.runQueuedReconcile(target) |
| 96 | } |
| 97 | continue |
| 98 | default: |
| 99 | } |
| 100 | if target, ok := c.takeReconcileDirty(); ok { |
| 101 | c.runQueuedReconcile(target) |
| 102 | continue |
| 103 | } |
| 104 | select { |
| 105 | case token := <-c.reconcileCh: |
| 106 | if target, ok := c.resolveReconcileToken(token); ok { |
| 107 | c.runQueuedReconcile(target) |
| 108 | } |
| 109 | case <-ticker.C: |
| 110 | case <-c.stop: |
| 111 | return |
| 112 | } |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | func (c *Catalog) runQueuedReconcile(target DirectoryTarget) { |
| 117 | key := queuePathKey(target.Path) |
| 118 | for { |
| 119 | if c.testReconcileStartHook != nil { |
| 120 | c.testReconcileStartHook(target) |
| 121 | } |
| 122 | ctx, cancel := context.WithTimeout(c.workerCtx, 2*time.Minute) |
| 123 | _ = c.reconcileDirectory(ctx, target, target.mutationSeq) |
| 124 | cancel() |
| 125 | |
| 126 | c.reconcileDirtyMu.Lock() |
| 127 | followUp, dirty := c.reconcileDirty[key] |
| 128 | if dirty { |
| 129 | delete(c.reconcileDirty, key) |
| 130 | c.reconcileQueued.Store(key, followUp) |
| 131 | c.reconcileDirtyMu.Unlock() |
| 132 | target = followUp |
| 133 | continue |
| 134 | } |
| 135 | c.reconcileQueued.Delete(key) |
| 136 | c.reconcileDirtyMu.Unlock() |
| 137 | return |
| 138 | } |
| 139 | } |
| 140 |