throw IOException(
          "unexpected journal header: [$magic, $version, $valueCountString, $blank]",
        )
      }

      var lineCount = 0
      while (true) {
        try {
          readJournalLine(readUtf8LineStrict())
          lineCount++
        } catch (_: EOFException) {
          break // End of journal.
        }
      }

      redundantOpCount = lineCount - lruEntries.size