|
| 1 | +package metricscache |
| 2 | + |
| 3 | +import ( |
| 4 | + "context" |
| 5 | + "os" |
| 6 | + "strconv" |
| 7 | + "sync/atomic" |
| 8 | + "time" |
| 9 | + |
| 10 | + "golang.org/x/xerrors" |
| 11 | + |
| 12 | + "cdr.dev/slog" |
| 13 | + "github.com/coder/coder/coderd/database" |
| 14 | + "github.com/coder/coder/codersdk" |
| 15 | + "github.com/coder/retry" |
| 16 | +) |
| 17 | + |
| 18 | +type Cache struct { |
| 19 | + database database.Store |
| 20 | + log slog.Logger |
| 21 | + |
| 22 | + dausResponse atomic.Pointer[codersdk.DAUsResponse] |
| 23 | + |
| 24 | + doneCh chan struct{} |
| 25 | + cancel func() |
| 26 | +} |
| 27 | + |
| 28 | +func New(db database.Store, log slog.Logger) *Cache { |
| 29 | + ctx, cancel := context.WithCancel(context.Background()) |
| 30 | + |
| 31 | + c := &Cache{ |
| 32 | + database: db, |
| 33 | + log: log, |
| 34 | + doneCh: make(chan struct{}), |
| 35 | + cancel: cancel, |
| 36 | + } |
| 37 | + go c.run(ctx) |
| 38 | + return c |
| 39 | +} |
| 40 | + |
| 41 | +const CacheRefreshIntervalEnv = "CODER_METRICS_CACHE_INTERVAL_MS" |
| 42 | + |
| 43 | +func fillEmptyDAUDays(rows []database.GetDAUsFromAgentStatsRow) []database.GetDAUsFromAgentStatsRow { |
| 44 | + var newRows []database.GetDAUsFromAgentStatsRow |
| 45 | + |
| 46 | + for i, row := range rows { |
| 47 | + if i == 0 { |
| 48 | + newRows = append(newRows, row) |
| 49 | + continue |
| 50 | + } |
| 51 | + |
| 52 | + last := rows[i-1] |
| 53 | + |
| 54 | + const day = time.Hour * 24 |
| 55 | + diff := row.Date.Sub(last.Date) |
| 56 | + for diff > day { |
| 57 | + if diff <= day { |
| 58 | + break |
| 59 | + } |
| 60 | + last.Date = last.Date.Add(day) |
| 61 | + last.Daus = 0 |
| 62 | + newRows = append(newRows, last) |
| 63 | + diff -= day |
| 64 | + } |
| 65 | + |
| 66 | + newRows = append(newRows, row) |
| 67 | + continue |
| 68 | + } |
| 69 | + |
| 70 | + return newRows |
| 71 | +} |
| 72 | + |
| 73 | +func (c *Cache) refresh(ctx context.Context) error { |
| 74 | + err := c.database.DeleteOldAgentStats(ctx) |
| 75 | + if err != nil { |
| 76 | + return xerrors.Errorf("delete old stats: %w", err) |
| 77 | + } |
| 78 | + |
| 79 | + daus, err := c.database.GetDAUsFromAgentStats(ctx) |
| 80 | + if err != nil { |
| 81 | + return err |
| 82 | + } |
| 83 | + |
| 84 | + var resp codersdk.DAUsResponse |
| 85 | + for _, ent := range fillEmptyDAUDays(daus) { |
| 86 | + resp.Entries = append(resp.Entries, codersdk.DAUEntry{ |
| 87 | + Date: ent.Date, |
| 88 | + DAUs: int(ent.Daus), |
| 89 | + }) |
| 90 | + } |
| 91 | + |
| 92 | + c.dausResponse.Store(&resp) |
| 93 | + return nil |
| 94 | +} |
| 95 | + |
| 96 | +func (c *Cache) run(ctx context.Context) { |
| 97 | + defer close(c.doneCh) |
| 98 | + |
| 99 | + interval := time.Hour |
| 100 | + |
| 101 | + intervalEnv, ok := os.LookupEnv(CacheRefreshIntervalEnv) |
| 102 | + if ok { |
| 103 | + intervalMs, err := strconv.Atoi(intervalEnv) |
| 104 | + if err != nil { |
| 105 | + c.log.Error( |
| 106 | + ctx, |
| 107 | + "could not parse interval from env", |
| 108 | + slog.F("interval", intervalEnv), |
| 109 | + ) |
| 110 | + } else { |
| 111 | + interval = time.Duration(intervalMs) * time.Millisecond |
| 112 | + } |
| 113 | + } |
| 114 | + |
| 115 | + ticker := time.NewTicker(interval) |
| 116 | + defer ticker.Stop() |
| 117 | + |
| 118 | + for { |
| 119 | + for r := retry.New(time.Millisecond*100, time.Minute); r.Wait(ctx); { |
| 120 | + start := time.Now() |
| 121 | + err := c.refresh(ctx) |
| 122 | + if err != nil { |
| 123 | + c.log.Error(ctx, "refresh", slog.Error(err)) |
| 124 | + continue |
| 125 | + } |
| 126 | + c.log.Debug( |
| 127 | + ctx, |
| 128 | + "metrics refreshed", |
| 129 | + slog.F("took", time.Since(start)), |
| 130 | + slog.F("interval", interval), |
| 131 | + ) |
| 132 | + break |
| 133 | + } |
| 134 | + |
| 135 | + select { |
| 136 | + case <-ticker.C: |
| 137 | + case <-c.doneCh: |
| 138 | + return |
| 139 | + case <-ctx.Done(): |
| 140 | + return |
| 141 | + } |
| 142 | + } |
| 143 | +} |
| 144 | + |
| 145 | +func (c *Cache) Close() error { |
| 146 | + c.cancel() |
| 147 | + <-c.doneCh |
| 148 | + return nil |
| 149 | +} |
| 150 | + |
| 151 | +// DAUs returns the DAUs or nil if they aren't ready yet. |
| 152 | +func (c *Cache) DAUs() codersdk.DAUsResponse { |
| 153 | + r := c.dausResponse.Load() |
| 154 | + if r == nil { |
| 155 | + return codersdk.DAUsResponse{} |
| 156 | + } |
| 157 | + return *r |
| 158 | +} |
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