Function start

packages/trailbase-db-collection/src/trailbase.ts:296–341

()

      }

      async function start() {
        const eventStream = await config.recordApi.subscribe(`*`)
        const reader = (eventReader = eventStream.getReader())

        // Start listening for subscriptions first. Otherwise, we'd risk a gap
        // between the initial fetch and starting to listen.
        listen(reader)

        try {
          // Eager mode: perform initial fetch to populate everything
          if (internalSyncMode === `eager`) {
            // Load everything on initial load.
            await load({})
            fullSyncCompleted = true
          }
        } catch (e) {
          cancelEventReader()
          throw e
        } finally {
          // Mark ready both if everything went well or if there's an error to
          // avoid blocking apps waiting for `.preload()` to finish.
          markReady()
        }

        // Lastly, start a periodic cleanup task that will be removed when the
        // reader closes.
        const periodicCleanupTask = setInterval(() => {
          seenIds.setState((curr) => {
            const now = Date.now()
            let anyExpired = false

            const notExpired = Array.from(curr.entries()).filter(([_, v]) => {
              const expired = now - v > 300 * 1000
              anyExpired = anyExpired || expired
              return !expired
            })

            if (anyExpired) {
              return new Map(notExpired)
            }
            return curr
          })
        }, 120 * 1000)

        reader.closed.finally(() => clearInterval(periodicCleanupTask))
      }

      start()