Method healOversizedWal

src/db/index.ts:556–567

* Shrink a leftover oversized WAL (#1431). A SIGKILL'd session — the #850 * liveness watchdog, OOM, a crash — leaves its WAL on disk, the next session * appends to the same file, and (pre-#1431) nothing ever truncated it: * PASSIVE checkpoints fold frames but keep the file at its high-water

()

   * next open retries rather than a stall.
   */
  async healOversizedWal(): Promise<{ healed: boolean; beforeBytes: number; afterBytes: number }> {
    const beforeBytes = this.getWalSizeBytes();
    if (beforeBytes <= WAL_HEAL_THRESHOLD_BYTES) {
      return { healed: false, beforeBytes, afterBytes: beforeBytes };
    }
    // Single-flight: open() fires this fire-and-forget and callers may also
    // invoke it explicitly. Two concurrent passes DEFEAT each other — each
    // checkpoint worker sees the other as a busy reader and no-ops — so share
    // one in-flight pass instead of racing.
    this.walHeal ??= this.runWalHeal(beforeBytes).finally(() => { this.walHeal = null; });
    return this.walHeal;
  }

  private walHeal: Promise<{ healed: boolean; beforeBytes: number; afterBytes: number }> | null = null;