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Diffstat (limited to 'search.xml')
| -rw-r--r-- | search.xml | 91 |
1 files changed, 77 insertions, 14 deletions
@@ -3431,20 +3431,6 @@ NestJS 依赖其底层 HTTP 适配器（默认为 Express）来解析传入的� </tags> </entry> <entry> - <title>使用 [@poll error] 实现线程安全的数据结构</title> - <url>/2023/08/15/poll-error-attribute-in-OCaml/</url> - <content><![CDATA[<p>OCaml的标准库提供了许多mutable的数据结构，比如Hashtbl, Queue, Stack之类的，但是这些数据结构都不是线程安全的。在 OCaml 4 和 OCaml 5 中，单个Domain中一次只能运行一个线程。换句话说，单个Domain中的线程仍然不会并行运行，除非在不同所的Domain中。</p> -<p>而在单个Domain中 OCaml 的 runtime 是通过在safe point期间半抢占式的切换线程。也就是说，线程切换只会发生在safe point期间。例如内存分配就是是safe point。这意味着在没有safe point的代码块内，可以在Domain内原子性地进行多次读写或访问操作，因为线程没被切换。</p> -<p>OCaml 编译器提供了一个名为 <a href="https://github.com/ocaml/ocaml/pull/10462"><code>[@poll error]</code></a> 的annotation，可以在函数中使用它来确保该函数不包含safe point。</p> -<p>所以通过使用 <code>[@poll error]</code> 就可以创建在Domain内原子性执行的函数，也就是说，基于此特性可以实现单个Domain内线程安全的数据结构，例如 thread-table 便是使用这个特性实现的 Hash Table。可以看看它的 add 函数的实现:</p> -<figure class="highlight ocaml"><table><tr><td class="code"><pre><span class="line"><span class="keyword">let</span>[@poll error] add_atomically t buckets n i before after =</span><br><span class="line"> t.rehash = <span class="number">0</span> && buckets == t.buckets</span><br><span class="line"> && before == <span class="type">Array</span>.unsafe_get buckets i</span><br><span class="line"> && <span class="keyword">begin</span></span><br><span class="line"> <span class="type">Array</span>.unsafe_set buckets i after;</span><br><span class="line"> <span class="keyword">let</span> length = t.length + <span class="number">1</span> <span class="keyword">in</span></span><br><span class="line"> t.length <- length;</span><br><span class="line"> <span class="keyword">if</span> n < length && n < max_buckets_div_2 <span class="keyword">then</span> t.rehash <- n * <span class="number">2</span>;</span><br><span class="line"> <span class="literal">true</span></span><br><span class="line"> <span class="keyword">end</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">let</span> <span class="keyword">rec</span> add t k' v' =</span><br><span class="line"> <span class="keyword">let</span> h = <span class="type">Mix</span>.<span class="built_in">int</span> k' <span class="keyword">in</span></span><br><span class="line"> maybe_rehash t;</span><br><span class="line"> <span class="keyword">let</span> buckets = t.buckets <span class="keyword">in</span></span><br><span class="line"> <span class="keyword">let</span> n = <span class="type">Array</span>.length buckets <span class="keyword">in</span></span><br><span class="line"> <span class="keyword">let</span> i = h <span class="keyword">land</span> (n - <span class="number">1</span>) <span class="keyword">in</span></span><br><span class="line"> <span class="keyword">let</span> before = <span class="type">Array</span>.unsafe_get buckets i <span class="keyword">in</span></span><br><span class="line"> <span class="keyword">let</span> after = <span class="type">Cons</span> (k', v', before) <span class="keyword">in</span></span><br><span class="line"> <span class="keyword">if</span> not (add_atomically t buckets n i before after) <span class="keyword">then</span> add t k' v'</span><br></pre></td></tr></table></figure> -<p>相比使用 Stdlib.Mutex，这种无锁实现会有更好的性能（特别是对于只读操作），并且还允许例如信号处理之类的上下文操作。</p> -]]></content> - <tags> - <tag>Technique</tag> - </tags> - </entry> - <entry> <title>除权除息日，股价调整与分红</title> <url>/2025/07/11/rep-date/</url> <content><![CDATA[<p>例如：</p> @@ -3492,6 +3478,20 @@ NestJS 依赖其底层 HTTP 适配器（默认为 Express）来解析传入的� </tags> </entry> <entry> + <title>使用 [@poll error] 实现线程安全的数据结构</title> + <url>/2023/08/15/poll-error-attribute-in-OCaml/</url> + <content><![CDATA[<p>OCaml的标准库提供了许多mutable的数据结构，比如Hashtbl, Queue, Stack之类的，但是这些数据结构都不是线程安全的。在 OCaml 4 和 OCaml 5 中，单个Domain中一次只能运行一个线程。换句话说，单个Domain中的线程仍然不会并行运行，除非在不同所的Domain中。</p> +<p>而在单个Domain中 OCaml 的 runtime 是通过在safe point期间半抢占式的切换线程。也就是说，线程切换只会发生在safe point期间。例如内存分配就是是safe point。这意味着在没有safe point的代码块内，可以在Domain内原子性地进行多次读写或访问操作，因为线程没被切换。</p> +<p>OCaml 编译器提供了一个名为 <a href="https://github.com/ocaml/ocaml/pull/10462"><code>[@poll error]</code></a> 的annotation，可以在函数中使用它来确保该函数不包含safe point。</p> +<p>所以通过使用 <code>[@poll error]</code> 就可以创建在Domain内原子性执行的函数，也就是说，基于此特性可以实现单个Domain内线程安全的数据结构，例如 thread-table 便是使用这个特性实现的 Hash Table。可以看看它的 add 函数的实现:</p> +<figure class="highlight ocaml"><table><tr><td class="code"><pre><span class="line"><span class="keyword">let</span>[@poll error] add_atomically t buckets n i before after =</span><br><span class="line"> t.rehash = <span class="number">0</span> && buckets == t.buckets</span><br><span class="line"> && before == <span class="type">Array</span>.unsafe_get buckets i</span><br><span class="line"> && <span class="keyword">begin</span></span><br><span class="line"> <span class="type">Array</span>.unsafe_set buckets i after;</span><br><span class="line"> <span class="keyword">let</span> length = t.length + <span class="number">1</span> <span class="keyword">in</span></span><br><span class="line"> t.length <- length;</span><br><span class="line"> <span class="keyword">if</span> n < length && n < max_buckets_div_2 <span class="keyword">then</span> t.rehash <- n * <span class="number">2</span>;</span><br><span class="line"> <span class="literal">true</span></span><br><span class="line"> <span class="keyword">end</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">let</span> <span class="keyword">rec</span> add t k' v' =</span><br><span class="line"> <span class="keyword">let</span> h = <span class="type">Mix</span>.<span class="built_in">int</span> k' <span class="keyword">in</span></span><br><span class="line"> maybe_rehash t;</span><br><span class="line"> <span class="keyword">let</span> buckets = t.buckets <span class="keyword">in</span></span><br><span class="line"> <span class="keyword">let</span> n = <span class="type">Array</span>.length buckets <span class="keyword">in</span></span><br><span class="line"> <span class="keyword">let</span> i = h <span class="keyword">land</span> (n - <span class="number">1</span>) <span class="keyword">in</span></span><br><span class="line"> <span class="keyword">let</span> before = <span class="type">Array</span>.unsafe_get buckets i <span class="keyword">in</span></span><br><span class="line"> <span class="keyword">let</span> after = <span class="type">Cons</span> (k', v', before) <span class="keyword">in</span></span><br><span class="line"> <span class="keyword">if</span> not (add_atomically t buckets n i before after) <span class="keyword">then</span> add t k' v'</span><br></pre></td></tr></table></figure> +<p>相比使用 Stdlib.Mutex，这种无锁实现会有更好的性能（特别是对于只读操作），并且还允许例如信号处理之类的上下文操作。</p> +]]></content> + <tags> + <tag>Technique</tag> + </tags> + </entry> + <entry> <title>shadow-cljs 怎么设置代理</title> <url>/2024/04/03/shadow-cljs-proxy/</url> <content><![CDATA[<p>The library pomegranate used for retrieving maven dependencies does not read <code>.m2/settings.xml</code>. You can however set the :proxy config either in <code>shadow-cljs.edn</code> directly or <code>~/.shadow-cljs/config.edn</code>.</p> @@ -5398,6 +5398,69 @@ NestJS 依赖其底层 HTTP 适配器（默认为 Express）来解析传入的� </tags> </entry> <entry> + <title>如何在 DDD + CQRS 中处理跨聚合的事务</title> + <url>/2026/05/28/%E5%A6%82%E4%BD%95%E5%9C%A8-DDD-CQRS-%E4%B8%AD%E5%A4%84%E7%90%86%E8%B7%A8%E8%81%9A%E5%90%88%E7%9A%84%E4%BA%8B%E5%8A%A1/</url> + <content><![CDATA[<p>假设系统里有一个模块，用来管理化合物从 hit、lead 到 candidate 的推进。</p> +<p>药化团队合成了一批化合物。生物团队上传活性、选择性、ADME、早期毒理等实验结果。项目负责人看完某个化合物的数据包后，要做一个决策：</p> +<ul> +<li>推进为候选化合物。</li> +<li>退回继续优化。</li> +<li>暂停该方向。</li> +</ul> +<p>提交这个决策时，系统通常要做这些事：</p> +<ul> +<li>写入一条候选化合物推进决策。</li> +<li>改变化合物当前研发阶段。</li> +<li>如果推进成功，创建候选药物档案。</li> +<li>关闭当前评审责任。</li> +<li>锁定本次使用的实验数据包版本。</li> +<li>写入审计事件，说明阶段变化依据哪一次数据评审。</li> +</ul> +<p>这些写入必须一起成功。不能出现决策已经提交，但化合物阶段没变, 或是候选药物档案已创建，但数据包没有锁定等问题。</p> +<p>最直接的实现，是在 Command Handler 里注入 Prisma，然后开事务：</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">SubmitCompoundPromotionDecisionHandler</span> {</span><br><span class="line"> <span class="title function_">constructor</span>(<span class="params"><span class="keyword">private</span> <span class="keyword">readonly</span> <span class="attr">prisma</span>: <span class="title class_">PrismaClient</span></span>) {}</span><br><span class="line"></span><br><span class="line"> <span class="keyword">async</span> <span class="title function_">execute</span>(<span class="params"><span class="attr">command</span>: <span class="title class_">SubmitCompoundPromotionDecision</span></span>) {</span><br><span class="line"> <span class="keyword">return</span> <span class="variable language_">this</span>.<span class="property">prisma</span>.$transaction(<span class="title function_">async</span> (tx) => {</span><br><span class="line"> <span class="keyword">const</span> decision = <span class="keyword">await</span> tx.<span class="property">compoundDecision</span>.<span class="title function_">create</span>({</span><br><span class="line"> <span class="attr">data</span>: {</span><br><span class="line"> <span class="attr">compoundId</span>: command.<span class="property">compoundId</span>,</span><br><span class="line"> <span class="attr">result</span>: command.<span class="property">result</span>,</span><br><span class="line"> <span class="attr">reason</span>: command.<span class="property">reason</span>,</span><br><span class="line"> <span class="attr">decidedBy</span>: command.<span class="property">actorUserId</span>,</span><br><span class="line"> },</span><br><span class="line"> });</span><br><span class="line"></span><br><span class="line"> <span class="keyword">await</span> tx.<span class="property">compound</span>.<span class="title function_">update</span>({</span><br><span class="line"> <span class="attr">where</span>: { <span class="attr">id</span>: command.<span class="property">compoundId</span> },</span><br><span class="line"> <span class="attr">data</span>: { <span class="attr">stage</span>: command.<span class="property">result</span> === <span class="string">"promote"</span> ? <span class="string">"candidate"</span> : <span class="string">"lead"</span> },</span><br><span class="line"> });</span><br><span class="line"></span><br><span class="line"> <span class="keyword">if</span> (command.<span class="property">result</span> === <span class="string">"promote"</span>) {</span><br><span class="line"> <span class="keyword">await</span> tx.<span class="property">developmentCandidate</span>.<span class="title function_">create</span>({</span><br><span class="line"> <span class="attr">data</span>: { <span class="attr">compoundId</span>: command.<span class="property">compoundId</span> },</span><br><span class="line"> });</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="keyword">await</span> tx.<span class="property">reviewAssignment</span>.<span class="title function_">update</span>(...);</span><br><span class="line"> <span class="keyword">await</span> tx.<span class="property">auditEvent</span>.<span class="title function_">create</span>(...);</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> decision;</span><br><span class="line"> });</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure> +<p>但它把几个层次混在了一起。</p> +<p>Command Handler 本来应该编排业务流程，但现在它编排了数据库表的更新顺序。</p> +<p>化合物阶段变化本来应该由 <code>Compound</code> 聚合判断。比如只有 <code>lead_optimization</code> 阶段的化合物才能推进到 <code>candidate</code>，已经暂停的化合物不能直接推进。现在这条规则可能散落在 <code>tx.compound.update</code> 前后的 if 判断里。</p> +<p>事务边界本来属于用例。现在它由具体 ORM 的 <code>$transaction</code> 暴露在 Command Handler 里。换 ORM、拆 outbox、改审计事件写法，Command Handler 都要动。</p> +<hr> +<p>如果把这段逻辑挪到 repository 里：</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line">compoundRepository.<span class="title function_">submitPromotionDecision</span>(command);</span><br></pre></td></tr></table></figure> +<p>这看起来把 Prisma 从 Command Handler 里拿掉了。但如果 <code>compoundRepository</code> 内部仍然创建决策、更新化合物、创建候选药物档案、关闭责任、写审计事件，那只是把混乱换了一个地方，因为 Repository 的核心职责应该只是持久化聚合，例如：</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line">compoundRepository.<span class="title function_">findById</span>(id);</span><br><span class="line">compoundRepository.<span class="title function_">save</span>(compound);</span><br><span class="line">compoundDecisionRepository.<span class="title function_">save</span>(decision);</span><br><span class="line">developmentCandidateRepository.<span class="title function_">save</span>(candidate);</span><br></pre></td></tr></table></figure> +<p>如果一个 <code>CompoundRepository</code> 开始保存 <code>CompoundDecision</code>、<code>DevelopmentCandidate</code>、<code>ReviewAssignment</code>、<code>AuditEvent</code>，它就不再只是 Compound 的 repository。它变成了一个跨模块事务服务，只是名字还叫 repository。</p> +<hr> +<p>所以这里我的解决方案之一是在 application 层定义一个 Unit of Work port，它表达的是一个具体业务动作：提交候选化合物推进决策。</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line"><span class="keyword">export</span> <span class="keyword">interface</span> <span class="title class_">SubmitCompoundPromotionDecisionUnitOfWork</span> {</span><br><span class="line"> <span class="title function_">submit</span>(<span class="attr">input</span>: {</span><br><span class="line"> <span class="attr">compoundId</span>: <span class="built_in">string</span>;</span><br><span class="line"> <span class="attr">dataPackageId</span>: <span class="built_in">string</span>;</span><br><span class="line"> <span class="attr">result</span>: <span class="string">"promote"</span> | <span class="string">"optimize"</span> | <span class="string">"pause"</span>;</span><br><span class="line"> <span class="attr">reason</span>?: <span class="built_in">string</span>;</span><br><span class="line"> <span class="attr">actorUserId</span>: <span class="built_in">string</span>;</span><br><span class="line"> }): <span class="title class_">Promise</span><<span class="title class_">CompoundPromotionDecisionDto</span>>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure> +<p>Command Handler 依赖这个端口，而不是依赖 Prisma。</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">SubmitCompoundPromotionDecisionHandler</span> {</span><br><span class="line"> <span class="title function_">constructor</span>(<span class="params"></span></span><br><span class="line"><span class="params"> <span class="keyword">private</span> <span class="keyword">readonly</span> <span class="attr">unitOfWork</span>: <span class="title class_">SubmitCompoundPromotionDecisionUnitOfWork</span>,</span></span><br><span class="line"><span class="params"> </span>) {}</span><br><span class="line"></span><br><span class="line"> <span class="keyword">async</span> <span class="title function_">execute</span>(<span class="params"><span class="attr">command</span>: <span class="title class_">SubmitCompoundPromotionDecision</span></span>) {</span><br><span class="line"> <span class="keyword">return</span> <span class="variable language_">this</span>.<span class="property">unitOfWork</span>.<span class="title function_">submit</span>({</span><br><span class="line"> <span class="attr">compoundId</span>: command.<span class="property">compoundId</span>,</span><br><span class="line"> <span class="attr">dataPackageId</span>: command.<span class="property">dataPackageId</span>,</span><br><span class="line"> <span class="attr">result</span>: command.<span class="property">result</span>,</span><br><span class="line"> <span class="attr">reason</span>: command.<span class="property">reason</span>,</span><br><span class="line"> <span class="attr">actorUserId</span>: command.<span class="property">actorUserId</span>,</span><br><span class="line"> });</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure> +<p>这段代码没有事务细节。它只转交命令意图。</p> +<p>具体事务放在 infrastructure：</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">PrismaSubmitCompoundPromotionDecisionUnitOfWork</span></span><br><span class="line"> <span class="keyword">implements</span> <span class="title class_">SubmitCompoundPromotionDecisionUnitOfWork</span></span><br><span class="line">{</span><br><span class="line"> <span class="title function_">constructor</span>(<span class="params"><span class="keyword">private</span> <span class="keyword">readonly</span> <span class="attr">prisma</span>: <span class="title class_">PrismaClient</span></span>) {}</span><br><span class="line"></span><br><span class="line"> <span class="keyword">async</span> <span class="title function_">submit</span>(<span class="params"><span class="attr">input</span>: <span class="title class_">SubmitCompoundPromotionDecisionInput</span></span>) {</span><br><span class="line"> <span class="keyword">return</span> <span class="variable language_">this</span>.<span class="property">prisma</span>.$transaction(<span class="title function_">async</span> (tx) => {</span><br><span class="line"> <span class="comment">// 在这里组合 tx-bound store / repository</span></span><br><span class="line"> });</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure> +<p>这样就把“业务事务边界”和“命令入口”分开，Command Handler 不需要知道用 Prisma 还是别的 ORM。它也不需要知道事务里要调用哪些表。它只知道这个命令由一个原子用例完成。</p> +<p>但聚合仍然要负责状态规则，Unit of Work 不能变成新的数据库脚本，在事务内部，仍然应该先读取聚合，让聚合执行状态变化，再保存聚合。</p> +<p>例如 <code>Compound</code> 聚合可以这样表达规则：</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">Compound</span> {</span><br><span class="line"> <span class="title function_">promoteToCandidate</span>(<span class="params"><span class="attr">input</span>: {</span></span><br><span class="line"><span class="params"> dataPackageId: <span class="built_in">string</span>;</span></span><br><span class="line"><span class="params"> actorUserId: <span class="built_in">string</span>;</span></span><br><span class="line"><span class="params"> }</span>) {</span><br><span class="line"> <span class="keyword">if</span> (<span class="variable language_">this</span>.<span class="property">stage</span> !== <span class="string">"lead_optimization"</span>) {</span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> <span class="title class_">DomainError</span>(<span class="string">"只有先导优化阶段的化合物才能推进为候选化合物"</span>);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="keyword">if</span> (<span class="variable language_">this</span>.<span class="property">lockedDataPackageId</span> !== <span class="literal">null</span>) {</span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> <span class="title class_">DomainError</span>(<span class="string">"已锁定数据包的化合物不能重复推进"</span>);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="variable language_">this</span>.<span class="property">stage</span> = <span class="string">"candidate"</span>;</span><br><span class="line"> <span class="variable language_">this</span>.<span class="property">lockedDataPackageId</span> = input.<span class="property">dataPackageId</span>;</span><br><span class="line"> <span class="variable language_">this</span>.<span class="property">updatedByUserId</span> = input.<span class="property">actorUserId</span>;</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="title function_">returnToOptimization</span>(<span class="params"><span class="attr">input</span>: { reason: <span class="built_in">string</span>; actorUserId: <span class="built_in">string</span> }</span>) {</span><br><span class="line"> <span class="keyword">if</span> (<span class="variable language_">this</span>.<span class="property">stage</span> !== <span class="string">"lead_optimization"</span>) {</span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> <span class="title class_">DomainError</span>(<span class="string">"只有评审中的化合物才能退回优化"</span>);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="variable language_">this</span>.<span class="property">stage</span> = <span class="string">"lead_optimization"</span>;</span><br><span class="line"> <span class="variable language_">this</span>.<span class="property">optimizationReason</span> = input.<span class="property">reason</span>;</span><br><span class="line"> <span class="variable language_">this</span>.<span class="property">updatedByUserId</span> = input.<span class="property">actorUserId</span>;</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure> +<p>Unit of Work 在事务里调用这些方法：</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line"><span class="keyword">await</span> prisma.$transaction(<span class="title function_">async</span> (tx) => {</span><br><span class="line"> <span class="keyword">const</span> compoundStore = <span class="keyword">new</span> <span class="title class_">PrismaCompoundStore</span>(tx);</span><br><span class="line"> <span class="keyword">const</span> compound = <span class="keyword">await</span> compoundStore.<span class="title function_">findById</span>(input.<span class="property">compoundId</span>);</span><br><span class="line"></span><br><span class="line"> <span class="keyword">if</span> (input.<span class="property">result</span> === <span class="string">"promote"</span>) {</span><br><span class="line"> compound.<span class="title function_">promoteToCandidate</span>({</span><br><span class="line"> <span class="attr">dataPackageId</span>: input.<span class="property">dataPackageId</span>,</span><br><span class="line"> <span class="attr">actorUserId</span>: input.<span class="property">actorUserId</span>,</span><br><span class="line"> });</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="keyword">if</span> (input.<span class="property">result</span> === <span class="string">"optimize"</span>) {</span><br><span class="line"> compound.<span class="title function_">returnToOptimization</span>({</span><br><span class="line"> <span class="attr">reason</span>: input.<span class="property">reason</span> ?? <span class="string">"需要补充结构优化"</span>,</span><br><span class="line"> <span class="attr">actorUserId</span>: input.<span class="property">actorUserId</span>,</span><br><span class="line"> });</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="keyword">await</span> compoundStore.<span class="title function_">save</span>(compound);</span><br><span class="line"> <span class="keyword">await</span> decisionStore.<span class="title function_">save</span>(decision);</span><br><span class="line"> <span class="keyword">await</span> candidateStore.<span class="title function_">createIfPromoted</span>(...);</span><br><span class="line"> <span class="keyword">await</span> assignmentStore.<span class="title function_">closeCurrent</span>(...);</span><br><span class="line"> <span class="keyword">await</span> auditStore.<span class="title function_">append</span>(...);</span><br><span class="line">});</span><br></pre></td></tr></table></figure> +<p>而为了让事务里的代码复用聚合持久化逻辑，我们需要一种 tx-bound repository 或 store。</p> +<p>最粗暴的写法是在领域 repository interface 里加一个可选事务参数：</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line"><span class="keyword">interface</span> <span class="title class_">CompoundRepository</span> {</span><br><span class="line"> <span class="title function_">findById</span>(<span class="attr">id</span>: <span class="built_in">string</span>, <span class="attr">tx</span>?: <span class="title class_">Prisma</span>.<span class="property">TransactionClient</span>): <span class="title class_">Promise</span><<span class="title class_">Compound</span> | <span class="literal">null</span>>;</span><br><span class="line"> <span class="title function_">save</span>(<span class="attr">compound</span>: <span class="title class_">Compound</span>, <span class="attr">tx</span>?: <span class="title class_">Prisma</span>.<span class="property">TransactionClient</span>): <span class="title class_">Promise</span><<span class="built_in">void</span>>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure> +<p>但它又把 Prisma 带进了领域层。就算把 <code>Prisma.TransactionClient</code> 包成 <code>TransactionClient</code> 类型别名，领域接口仍然在为基础设施妥协。</p> +<p>我更倾向于把 tx-bound 能力留在 infrastructure，领域层只定义干净的 repository port：</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line"><span class="keyword">export</span> <span class="keyword">interface</span> <span class="title class_">CompoundRepository</span> {</span><br><span class="line"> <span class="title function_">findById</span>(<span class="attr">id</span>: <span class="built_in">string</span>): <span class="title class_">Promise</span><<span class="title class_">Compound</span> | <span class="literal">null</span>>;</span><br><span class="line"> <span class="title function_">save</span>(<span class="attr">compound</span>: <span class="title class_">Compound</span>): <span class="title class_">Promise</span><<span class="built_in">void</span>>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure> +<p>infrastructure 层拆一个 store，接收最小持久化客户端：</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line"><span class="keyword">type</span> <span class="title class_">CompoundStoreClient</span> = {</span><br><span class="line"> <span class="attr">compound</span>: {</span><br><span class="line"> <span class="title function_">findUnique</span>(<span class="attr">args</span>: <span class="built_in">unknown</span>): <span class="title class_">Promise</span><<span class="built_in">unknown</span>>;</span><br><span class="line"> <span class="title function_">update</span>(<span class="attr">args</span>: <span class="built_in">unknown</span>): <span class="title class_">Promise</span><<span class="built_in">unknown</span>>;</span><br><span class="line"> };</span><br><span class="line">};</span><br><span class="line"></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">PrismaCompoundStore</span> <span class="keyword">implements</span> <span class="title class_">CompoundRepository</span> {</span><br><span class="line"> <span class="title function_">constructor</span>(<span class="params"><span class="keyword">private</span> <span class="keyword">readonly</span> <span class="attr">client</span>: <span class="title class_">CompoundStoreClient</span></span>) {}</span><br><span class="line"></span><br><span class="line"> <span class="keyword">async</span> <span class="title function_">findById</span>(<span class="params"><span class="attr">id</span>: <span class="built_in">string</span></span>) {</span><br><span class="line"> <span class="keyword">const</span> record = <span class="keyword">await</span> <span class="variable language_">this</span>.<span class="property">client</span>.<span class="property">compound</span>.<span class="title function_">findUnique</span>(...);</span><br><span class="line"> <span class="keyword">return</span> <span class="title class_">Compound</span>.<span class="title function_">restore</span>(record);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="keyword">async</span> <span class="title function_">save</span>(<span class="params"><span class="attr">compound</span>: <span class="title class_">Compound</span></span>) {</span><br><span class="line"> <span class="keyword">const</span> snapshot = compound.<span class="title function_">toSnapshot</span>();</span><br><span class="line"> <span class="keyword">await</span> <span class="variable language_">this</span>.<span class="property">client</span>.<span class="property">compound</span>.<span class="title function_">update</span>(...);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure> +<p>普通 repository 可以继承这个 store，传完整 Prisma client：</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">PrismaCompoundRepository</span> <span class="keyword">extends</span> <span class="title class_ inherited__">PrismaCompoundStore</span> {</span><br><span class="line"> <span class="title function_">constructor</span>(<span class="params"><span class="attr">prisma</span>: <span class="title class_">PrismaClient</span></span>) {</span><br><span class="line"> <span class="variable language_">super</span>(prisma);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure> +<p>Unit of Work 在事务里传 tx：</p> +<figure class="highlight ts"><table><tr><td class="code"><pre><span class="line"><span class="keyword">await</span> prisma.$transaction(<span class="title function_">async</span> (tx) => {</span><br><span class="line"> <span class="keyword">const</span> compoundStore = <span class="keyword">new</span> <span class="title class_">PrismaCompoundStore</span>(tx);</span><br><span class="line"> <span class="keyword">const</span> compound = <span class="keyword">await</span> compoundStore.<span class="title function_">findById</span>(input.<span class="property">compoundId</span>);</span><br><span class="line"> <span class="comment">// ...</span></span><br><span class="line"> <span class="keyword">await</span> compoundStore.<span class="title function_">save</span>(compound);</span><br><span class="line">});</span><br></pre></td></tr></table></figure> +]]></content> + <tags> + <tag>Technique</tag> + </tags> + </entry> + <entry> <title>如何管理用户界面中的危险操作</title> <url>/2024/11/26/%E5%A6%82%E4%BD%95%E7%AE%A1%E7%90%86%E7%94%A8%E6%88%B7%E7%95%8C%E9%9D%A2%E4%B8%AD%E7%9A%84%E5%8D%B1%E9%99%A9%E6%93%8D%E4%BD%9C/</url> <content><![CDATA[<blockquote> |