What causes "响应超过 %d 字节" in fish2018/pansou?

Use a more specific keyword so the upstream returns a smaller result set

fish2018/pansou · error

响应超过字节

Error message

响应超过 %d 字节

What it means

Returned by doLimitedRequest when the response body exceeds the configured size limit (maxSearchResponseSize = 4MiB for search, maxDiscoveryBodySize = 8MiB for discovery). The LimitReader reads limit+1 bytes, so a body longer than the cap is detected and rejected to protect memory from runaway upstream responses.

Solutions

Use a more specific keyword so the upstream returns a smaller result set
If legitimate responses are being cut off, raise maxSearchResponseSize (trade-off: memory per in-flight request)
If discovery triggers it, check what the homepage actually serves now — an unexpected page means the bundle/layout changed
Keep the limit as a guardrail; prefer fixing the query over disabling the cap

Example fix

// before
maxSearchResponseSize = 4 << 20
// after: raise cap and log when exceeded
maxSearchResponseSize = 8 << 20
if int64(len(body)) > limit {
    return nil, fmt.Errorf("response exceeds %d bytes", limit)
}

Defensive patterns

Strategy: validation

Validate before calling

// use a specific keyword to keep upstream result sets small
if len(keyword) < 3 {
    return errors.New("keyword too broad; expected oversized response, refine the query")
}

Try / catch

if strings.Contains(err.Error(), "响应超过") || strings.Contains(err.Error(), "字节") {
    // oversized response: refine keyword or raise the size cap
    return refineQuery(keyword)
}

Prevention

Prefer narrow, specific search keywords over very common ones
Raise maxSearchResponseSize only if legitimate payloads genuinely exceed 4MiB
Keep maxDiscoveryBodySize (8MiB) in sync with the site's real bundle size

When it happens

Trigger: The xiaokupan search response exceeds 4MiB (e.g. a very broad keyword returning an enormous result set), or the homepage/entry JS bundle fetched during function-ID discovery exceeds 8MiB (site switched to a much larger bundle or began serving an unexpected page, like a giant error/captcha page).

Common situations: Searching an extremely common keyword returns a huge merged result payload; the site's build pipeline outputs index JS >8MiB; the site starts serving a bloated interstitial page instead of the expected content.

Understand the failure class

Background: payload too large / request exceeds maximum size: why libraries cap bytes and how to fix oversize payloads — this error's family across 50 libraries.

Related errors

AI-assisted analysis of fish2018/pansou@beaa561337 (2026-09-07). Data as JSON: /api/errors/ebda68ae143178cd. Report an issue: GitHub.

Appendix: source

Thrown at plugin/xiaokupan/xiaokupan.go:194

	req.Header.Set("x-tsr-serverFn", "true")
}

func doLimitedRequest(client *http.Client, req *http.Request, limit int64) ([]byte, error) {
	resp, err := client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("请求失败: %w", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("HTTP %d", resp.StatusCode)
	}

	body, err := io.ReadAll(io.LimitReader(resp.Body, limit+1))
	if err != nil {
		return nil, fmt.Errorf("读取响应失败: %w", err)
	}
	if int64(len(body)) > limit {
		return nil, fmt.Errorf("响应超过 %d 字节", limit)
	}
	return body, nil
}

func (p *XiaokupanPlugin) currentServerFunctionID() string {
	p.serverFunctionMu.RLock()
	defer p.serverFunctionMu.RUnlock()
	return p.serverFunctionID
}

func (p *XiaokupanPlugin) refreshServerFunctionID(client *http.Client, staleID string) (string, error) {
	p.serverFunctionMu.Lock()
	defer p.serverFunctionMu.Unlock()
	if p.serverFunctionID != "" && p.serverFunctionID != staleID {
		return p.serverFunctionID, nil
	}

	discoveredID, err := p.discoverServerFunctionID(client)

View on GitHub (pinned to beaa561337)

响应超过 字节