Function initialFetch

packages/rxdb-db-collection/src/rxdb.ts:130–196

()

      let ready = false
      async function initialFetch() {
        /**
         * RxDB stores a last-write-time
         * which can be used to "sort" document writes,
         * so for initial sync we iterate over that.
         */
        let cursor: RxDocumentData<Row> | undefined = undefined
        const syncBatchSize = config.syncBatchSize ? config.syncBatchSize : 1000
        begin()

        while (!ready) {
          let query: FilledMangoQuery<Row>
          if (cursor) {
            query = {
              selector: {
                $or: [
                  { '_meta.lwt': { $gt: cursor._meta.lwt } },
                  {
                    '_meta.lwt': cursor._meta.lwt,
                    [primaryPath]: {
                      $gt: getKey(cursor),
                    },
                  },
                ],
                _deleted: false,
              },
              sort: [{ '_meta.lwt': `asc` }, { [primaryPath]: `asc` }],
              limit: syncBatchSize,
              skip: 0,
            }
          } else {
            query = {
              selector: { _deleted: false },
              sort: [{ '_meta.lwt': `asc` }, { [primaryPath]: `asc` }],
              limit: syncBatchSize,
              skip: 0,
            }
          }

          /**
           * Instead of doing a RxCollection.query(),
           * we directly query the storage engine of the RxCollection so we do not use the
           * RxCollection document cache because it likely wont be used anyway
           * since most queries will run directly on the tanstack-db side.
           */
          const preparedQuery = prepareQuery<Row>(
            rxCollection.storageInstance.schema,
            query,
          )
          const result = await rxCollection.storageInstance.query(preparedQuery)
          const docs = result.documents

          cursor = lastOfArray(docs)
          if (docs.length === 0) {
            ready = true
            break
          }