Method #tick

src/utils/task/TaskOutput.ts:109–164

* Shared tick: reads the file tail for every actively-polled task. * Non-async body (.then) to avoid stacking if I/O is slow.

()

   * Non-async body (.then) to avoid stacking if I/O is slow.
   */
  static #tick(): void {
    for (const [, entry] of TaskOutput.#activePolling) {
      if (!entry.#onProgress) {
        continue
      }
      void tailFile(entry.path, PROGRESS_TAIL_BYTES).then(
        ({ content, bytesRead, bytesTotal }) => {
          if (!entry.#onProgress) {
            return
          }
          // Always call onProgress even when content is empty, so the
          // progress loop wakes up and can check for backgrounding.
          // Commands like `git log -S` produce no output for long periods.
          if (!content) {
            entry.#onProgress('', '', entry.#totalLines, bytesTotal, false)
            return
          }
          // Count all newlines in the tail and capture slice points for the
          // last 5 and last 100 lines. Uncapped so extrapolation stays accurate
          // for dense output (short lines → >100 newlines in 4KB).
          let pos = content.length
          let n5 = 0
          let n100 = 0
          let lineCount = 0
          while (pos > 0) {
            pos = content.lastIndexOf('\n', pos - 1)
            lineCount++
            if (lineCount === 5) n5 = pos <= 0 ? 0 : pos + 1
            if (lineCount === 100) n100 = pos <= 0 ? 0 : pos + 1
          }
          // lineCount is exact when the whole file fits in PROGRESS_TAIL_BYTES.
          // Otherwise extrapolate from the tail sample; monotone max keeps the
          // counter from going backwards when the tail has longer lines on one tick.
          const totalLines =
            bytesRead >= bytesTotal
              ? lineCount
              : Math.max(
                  entry.#totalLines,
                  Math.round((bytesTotal / bytesRead) * lineCount),
                )
          entry.#totalLines = totalLines
          entry.#totalBytes = bytesTotal
          entry.#onProgress(
            content.slice(n5),
            content.slice(n100),
            totalLines,
            bytesTotal,
            bytesRead < bytesTotal,
          )
        },
        () => {
          // File may not exist yet
        },
      )
    }
  }

  /** Write stdout data (pipe mode only — used by hooks). */