From 1e8ce453a5efb535a7dd131fa32b4c883cad8c8c Mon Sep 17 00:00:00 2001
From: Yang Jun <harttleharttle@gmail.com>
Date: Sat, 9 May 2026 22:06:06 +0800
Subject: [PATCH] docs: merge DoS details into security-model docs

Move the detailed parseLimit/renderLimit/memoryLimit explanations and examples into the English and Chinese security-model pages so content from the removed dos pages is preserved.

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 docs/source/tutorials/security-model.md       | 35 +++++++++++++++++++
 docs/source/zh-cn/tutorials/security-model.md | 35 +++++++++++++++++++
 2 files changed, 70 insertions(+)

diff --git a/docs/source/tutorials/security-model.md b/docs/source/tutorials/security-model.md
index 838d8cbac..fc6da6c74 100644
--- a/docs/source/tutorials/security-model.md
+++ b/docs/source/tutorials/security-model.md
@@ -39,6 +39,41 @@ LiquidJS provides 3 DoS-oriented options:
 
 For heavy single-template operations, process-level isolation is still recommended (for example with [paralleljs][paralleljs]).
 
+## DoS limits details
+
+### parseLimit
+
+[parseLimit][parseLimit] restricts the size (character length) of templates parsed in each `.parse()` call, including referenced partials and layouts. Since LiquidJS parses template strings in near O(n) time, limiting total template length is usually sufficient.
+
+A typical PC handles `1e8` (100M) characters without issues.
+
+### renderLimit
+
+Restricting template size alone is insufficient because dynamic loops with large counts can occur in render time. [renderLimit][renderLimit] mitigates this by limiting the time consumed by each `render()` call.
+
+```liquid
+{%- for i in (1..10000000) -%}
+    order: {{i}}
+{%- endfor -%}
+```
+
+Render time is checked on a per-template basis (before rendering each template). In the above example, there are 2 templates in the loop: `order: ` and `{{i}}`, render time will be checked 10000000x2 times.
+
+For time-consuming tags and filters within a single template, the process can still hang.
+
+### memoryLimit
+
+Even with small number of templates and iterations, memory usage can grow exponentially. In the following example, memory doubles with each iteration:
+
+```liquid
+{% assign array = "1,2,3" | split: "," %}
+{% for i in (1..32) %}
+    {% assign array = array | concat: array %}
+{% endfor %}
+```
+
+[memoryLimit][memoryLimit] restricts memory-sensitive filters to prevent excessive memory allocation. As [JavaScript uses GC to manage memory](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Memory_management), `memoryLimit` limits only the total number of objects allocated by memory-sensitive operations in LiquidJS and may not reflect the actual memory footprint.
+
 [paralleljs]: https://www.npmjs.com/package/paralleljs
 [parseLimit]: /api/interfaces/LiquidOptions.html#parseLimit
 [renderLimit]: /api/interfaces/LiquidOptions.html#renderLimit
diff --git a/docs/source/zh-cn/tutorials/security-model.md b/docs/source/zh-cn/tutorials/security-model.md
index bb6a20f0b..be9cc7764 100644
--- a/docs/source/zh-cn/tutorials/security-model.md
+++ b/docs/source/zh-cn/tutorials/security-model.md
@@ -39,6 +39,41 @@ LiquidJS 提供 3 个 DoS 相关选项：
 
 对于单个模板中的重型操作，仍建议使用进程级隔离（例如 [paralleljs][paralleljs]）。
 
+## DoS 限制详解
+
+### parseLimit
+
+[parseLimit][parseLimit] 限制每次 `.parse()` 调用中解析的模板大小（字符长度），包括引用的 partials 和 layouts。由于 LiquidJS 解析模板字符串的时间复杂度接近 O(n)，限制模板总长度通常就足够了。
+
+普通电脑可以很容易处理 `1e8`（100M）个字符的模板。
+
+### renderLimit
+
+仅限制模板大小是不够的，因为在渲染时可能会出现动态的数组和循环。[renderLimit][renderLimit] 通过限制每次 `render()` 调用的时间来缓解这些问题。
+
+```liquid
+{%- for i in (1..10000000) -%}
+    order: {{i}}
+{%- endfor -%}
+```
+
+渲染时间是在渲染每个模板之前检查的。在上面的例子中，循环中有两个模板：`order: ` 和 `{{i}}`，因此会检查 2x10000000 次。
+
+单个模板内的标签和过滤器仍然可能把进程挂起。
+
+### memoryLimit
+
+即使模板和迭代次数较少，内存使用量也可能呈指数增长。在下面的示例中，内存会在每次迭代中翻倍：
+
+```liquid
+{% assign array = "1,2,3" | split: "," %}
+{% for i in (1..32) %}
+    {% assign array = array | concat: array %}
+{% endfor %}
+```
+
+[memoryLimit][memoryLimit] 限制内存敏感操作，以防止过度的内存分配。由于 [JavaScript 使用 GC 来管理内存](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Memory_management)，`memoryLimit` 仅限制 LiquidJS 中已记账对象的总数，因此可能无法反映实际的内存占用。
+
 [paralleljs]: https://www.npmjs.com/package/paralleljs
 [parseLimit]: /api/interfaces/LiquidOptions.html#parseLimit
 [renderLimit]: /api/interfaces/LiquidOptions.html#renderLimit