Athena's Parthenon - Rust Athena's Parthenon Zola 2026-05-15T00:00:00+00:00 https://parthen.online/topics/rust/atom.xml Rust Language Model Usage Policy (Suggested) 2026-05-15T00:00:00+00:00 2026-05-15T00:00:00+00:00 Athena https://parthen.online/notes/rust-llm-rfc/ <p>The following is a draft I wrote with what I would like to see in favor of the policy laid out in <a rel="external" href="https://github.com/rust-lang/rust-forge/pull/1040">github/rust-lang/rust-forge#1040</a>.</p> <hr /> <h2 id="overview">Overview</h2> <p>This RFC proposes a policy regarding the contribution of content generated by language models (a.k.a. LLMs, chatbots, or agents, including but not limited to Claude, ChatGPT, DeepSeek and others) to rust-lang/rust. This policy was written with the aim of being concise and clearly understandable, so that there is a minimum of confusion as to how the policy applies to a given situation. First, we will state the policy, consider enforcement, and give a brief overview of the reasoning behind it.</p> <h2 id="the-policy">The Policy</h2> <ul> <li>Content generated by a language model may not be contributed to rust-lang/rust.</li> </ul> <p>"Lenguage model" here means any program or service which outputs text in response to a generic natural language directive or completes substantial portions of an incomplete document or code unit. Note that dedicated translation and grammar assistance tools are not covered by this description, though in this case we ask that you disclose usage of these tools.</p> <p>"Contributed" here means submitted as code or documentation as part of commits, commit messages, PR descriptions, issue descriptions, or comments on PRs or issues.</p> <h2 id="enforcement">Enforcement</h2> <p>Verification of "LLM generated content" is up to moderation. Do not make public accusations of language-model contributed content; if you have concerns report it to the mods and move on. Each contributor is resonsible for ensuring the content they contribute follows this policy, in the same way that they must be sure that they do not submit content from, e.g. proprietary code from an employer, and in a similar way good faith should generally be assumed.</p> <h2 id="reasoning">Reasoning</h2> <p>This policy was written to be clear and concise while rectifying issues present in other policies, notably overreach. There is no way in which this policy could dicatate private usage of language models by contributors; it would be unenforceable if nothing else.</p> <p>Language model generated content is disallowed because current implementations of such technology carry:</p> <ol> <li>Severe and well-documented ethical concerns around their production and operation, especially with regards to their environmental impact, use of copyrighted material, abusive work practices, psychological effect on users, and bias. In order to maintain a welcoming community for all in accordance with the Rust Code of Conduct, particularly those who have been directly harmed by the production or operation of these technologies, we disallow language model generated content.</li> <li>Deep uncertainty with regard to copyright status of output. In order to protect the Rust project as a whole, we disallow language model generated content.</li> </ol> Java's Functional Interfaces for Rust/UniFFI 2026-04-26T00:00:00+00:00 2026-04-26T00:00:00+00:00 Athena https://parthen.online/notes/rust-uniffi-functional-interface/ <h2 id="functional-interfaces">Functional Interfaces</h2> <p>UniFFI has good support for callback interfaces, allowing calling code to supply its own logic to be called from Rust. How to make this work on the other-language side was relatively obvious to me: you just implement the interface. However, how to make this smooth in Rust took a moment to figure out, so I figured I'd make a note.</p> <p>A UniFFI callback interface looks (using the proc macros) like this:</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);">#</span><span style="color: light-dark(#24292E, #A89984);">[</span><span>uniffi</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span>export</span><span style="color: light-dark(#24292E, #A89984);">(</span><span>callback_interface</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">]</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FB4934);">pub</span><span style="color: light-dark(#D73A49, #FE8019);"> trait</span><span style="color: light-dark(#6F42C1, #FABD2F);"> MyCallback</span><span style="color: light-dark(#D73A49, #8EC07C);">:</span><span style="color: light-dark(#6F42C1, #FABD2F);"> Send</span><span style="color: light-dark(#D73A49, #8EC07C);"> +</span><span style="color: light-dark(#6F42C1, #FABD2F);"> Sync</span><span style="color: light-dark(#24292E, #A89984);"> {</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FB4934);"> fn</span><span style="color: light-dark(#6F42C1, #FABD2F);"> consume</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#D73A49, #8EC07C);">&amp;</span><span style="color: light-dark(#005CC5, #83A598);">self</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#24292E, #83A598);"> value</span><span style="color: light-dark(#D73A49, #8EC07C);">:</span><span style="color: light-dark(#6F42C1, #FABD2F);"> MyValue</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);">}</span></span></code></pre> <p>(where <code>MyValue</code> has <code>#[uniffi::export]</code> as well)</p> <p>and some function which takes it (boxed, because we can't know the implementing type at compile time, so it's gotta be a <code>dyn</code> rather than being able to use a generic/<code>impl Trait</code>) like so:</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);">#</span><span style="color: light-dark(#24292E, #A89984);">[</span><span>uniffi</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span>export</span><span style="color: light-dark(#24292E, #A89984);">]</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FB4934);">pub</span><span style="color: light-dark(#D73A49, #FB4934);"> fn</span><span style="color: light-dark(#6F42C1, #FABD2F);"> do_it</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">doer</span><span style="color: light-dark(#D73A49, #8EC07C);">:</span><span style="color: light-dark(#6F42C1, #FABD2F);"> Box</span><span style="color: light-dark(#24292E, #A89984);">&lt;</span><span style="color: light-dark(#D73A49, #FB4934);">dyn</span><span style="color: light-dark(#6F42C1, #FABD2F);"> MyCallback</span><span style="color: light-dark(#24292E, #A89984);">&gt;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);"> {</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #83A598);"> doer</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">consume</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">some_value</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);">}</span></span></code></pre> <p>Which is all well and good. But using this from Rust is a bit of a pain - there's just one method, so it should be possible to just yunk in a closure. But if you wanna do that you gotta tell Rust that's okay, it doesn't infer it like Java's functional interfaces. Here's how you do that:</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#D73A49, #FB4934);">impl</span><span style="color: light-dark(#24292E, #A89984);">&lt;</span><span style="color: light-dark(#6F42C1, #FABD2F);">T</span><span style="color: light-dark(#24292E, #A89984);">&gt;</span><span style="color: light-dark(#6F42C1, #FABD2F);"> MyCallback</span><span style="color: light-dark(#D73A49, #FB4934);"> for</span><span style="color: light-dark(#6F42C1, #FABD2F);"> T</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FB4934);">where</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> T</span><span style="color: light-dark(#D73A49, #8EC07C);">:</span><span style="color: light-dark(#6F42C1, #FABD2F);"> Fn</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#6F42C1, #FABD2F);">MyValue</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#D73A49, #8EC07C);"> -&gt;</span><span style="color: light-dark(#24292E, #A89984);"> (</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#D73A49, #8EC07C);"> +</span><span style="color: light-dark(#6F42C1, #FABD2F);"> Send</span><span style="color: light-dark(#D73A49, #8EC07C);"> +</span><span style="color: light-dark(#6F42C1, #FABD2F);"> Sync</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);">{</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FB4934);"> fn</span><span style="color: light-dark(#6F42C1, #FABD2F);"> consume</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#D73A49, #8EC07C);">&amp;</span><span style="color: light-dark(#005CC5, #83A598);">self</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#24292E, #83A598);"> value</span><span style="color: light-dark(#D73A49, #8EC07C);">:</span><span style="color: light-dark(#6F42C1, #FABD2F);"> MyValue</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);"> {</span></span> <span class="giallo-l"><span style="color: light-dark(#005CC5, #83A598);"> self</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">value</span><span style="color: light-dark(#24292E, #A89984);">)</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);"> }</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);">}</span></span></code></pre> <p>Getting the syntax right on this took a sec but it's fairly self-explanatory if you're used to Rust. I also went down a road of trying to use <code>impl From</code>, which doesn't really work out (try it yourself if you want to know why). Anyway, now you can call <code>do_it</code> from Rust and give it a boxed, but otherwise plain, closure:</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);">do_it</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#6F42C1, #FABD2F);">Box</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">new</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#D73A49, #FB4934);">|</span><span style="color: light-dark(#24292E, #83A598);">_it</span><span style="color: light-dark(#D73A49, #FB4934);">|</span><span style="color: light-dark(#24292E, #A89984);"> {</span><span style="color: light-dark(#24292E, #A89984);">}</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">)</span></span></code></pre> Veilid DHT Usage 2026-03-27T00:00:00+00:00 2026-05-11T00:00:00+00:00 Athena https://parthen.online/notes/veilid-dht-example/ <p><em>Written for <code>veilid_core</code> version 0.5.3.</em></p> <p>This page walks through a unit test I wrote to check my own understanding of how to use the Veilid DHT. This is just about the simplest possible usage in demonstrating a put and a get, none of the fancy watch stuff. Walking through section by section:</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);">#</span><span style="color: light-dark(#24292E, #A89984);">[</span><span>tokio</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span>test</span><span style="color: light-dark(#24292E, #A89984);">]</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FB4934);">async</span><span style="color: light-dark(#D73A49, #FB4934);"> fn</span><span style="color: light-dark(#6F42C1, #FABD2F);"> basic_dht_write_and_get</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);"> {</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> done</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#6F42C1, #FABD2F);"> CancellationToken</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">new</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> alice_done</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> done</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">child_token</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #A89984);"> (</span><span style="color: light-dark(#24292E, #83A598);">dht_key_in</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#24292E, #83A598);"> dht_key_out</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#6F42C1, #FABD2F);"> tokio</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">sync</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">oneshot</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">channel</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> alice_task</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#6F42C1, #FABD2F);"> tokio</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">spawn</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#D73A49, #FB4934);">async</span><span style="color: light-dark(#D73A49, #FB4934);"> move</span><span style="color: light-dark(#24292E, #A89984);"> {</span></span></code></pre> <p>The <code>CancellationToken</code> and associated <code>child_token</code> are from <code>tokio_util</code> and is coincidental; it could be replaced with another oneshot channel if so desired. The <code>oneshot</code> channel is used to communicate the DHT record key from Alice to Bob. Each Alice and Bob are assigned individual Tokio tasks to ensure that they are otherwise isolated and allow them to connect to the Veilid network concurrently.</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> alice</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#6F42C1, #FABD2F);"> create_and_attach_veilid_node</span><span style="color: light-dark(#24292E, #A89984);">(</span></span> <span class="giallo-l"><span style="color: light-dark(#032F62, #A89984);"> &quot;</span><span style="color: light-dark(#032F62, #B8BB26);">alice</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">to_string</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">,</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> Arc</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">new</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#D73A49, #FB4934);">|</span><span style="color: light-dark(#24292E, #83A598);">_update</span><span style="color: light-dark(#D73A49, #FB4934);">|</span><span style="color: light-dark(#24292E, #A89984);"> (</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">)</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);"> )</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#D73A49, #FB4934);">await</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">expect</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">failed to start alice node</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> println!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">alice ready</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span></code></pre> <p>Each Alice and Bob get their own Veilid node in their own namespace. This is a fairly easy way to do integration tests as far as I can tell, without having to actually spin up separate processes to create multiple nodes. It <em>is</em> fairly expensive though, so if you wanna do this in tests for an actual application you should probably share those nodes among tests.</p> <p>I've omitted the definition of <code>create_and_attach_node</code> for brevity; it calls <code>veilid_core::api_startup</code> and spin-waits until <code>veilid_api.get_state().attachment.public_internet_ready</code> is <code>true</code>. A real applicaton would definitely want to be more sophisticated here, but it works for tests.</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> crypto_step</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> alice</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">crypto</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">expect</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">failed to get alice&#39;s cryptosystem</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> cryptosystem</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> crypto_step</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">get</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#005CC5, #D3869B);">CRYPTO_KIND_VLD0</span><span style="color: light-dark(#24292E, #A89984);">)</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">expect</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">failed to get alice&#39;s vld0 cryptosystem</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> alice_record_keypair</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> cryptosystem</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">generate_keypair</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> alice_rc</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> alice</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">routing_context</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">expect</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">failed to get alice&#39;s routing context</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> dht_record</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> alice_rc</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">create_dht_record</span><span style="color: light-dark(#24292E, #A89984);">(</span></span> <span class="giallo-l"><span style="color: light-dark(#005CC5, #D3869B);"> CRYPTO_KIND_VLD0</span><span style="color: light-dark(#24292E, #A89984);">,</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> veilid_core</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">DHTSchema</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#005CC5, #D3869B);">DFLT</span><span style="color: light-dark(#24292E, #A89984);">(</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> DHTSchemaDFLT</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">new</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#005CC5, #D3869B);">6</span><span style="color: light-dark(#24292E, #A89984);">)</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">expect</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">failed to make alice&#39;s schema</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">,</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);"> )</span><span style="color: light-dark(#24292E, #A89984);">,</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> Some</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">alice_record_keypair</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">,</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);"> )</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#D73A49, #FB4934);">await</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> assert!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">dht_record</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">is_ok</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> println!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">dht record created</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span></code></pre> <p>Here I create the owning <code>KeyPair</code> manually because I wanted to make sure I knew how that pathway works. It's a huge pain in the butt to get a <code>CryptoSystem</code> reference (and even then it's some weird guard type) and the compiler complains for reasons I haven't taken the time to grok without <code>crypto_step</code> being an intermediate variable. Anyway, once we get ahold of the cryptosystem it's quite straightforward to make a keypair and turn it into a DHT record.</p> <p>This gets you a <code>RecordKey</code> which includes a <code>SharedSecret</code>, which is transparently used to encrypt &amp; decrypt the value data. You can get a <code>RecordKey</code> without one of those, if you like, by using <code>VeilidAPI.get_dht_record_key</code>, which deterministically generates a <code>RecordKey</code> from the public key of the owner <code>KeyPair</code>, the schema, and (optionally) a <code>SharedSecret</code>, but does <em>not</em> open or create an actual DHT record, just the key used to identify the record. In order to do this, you will need to create the record, then close it, and re-open it using a <code>RecordKey</code> created via <code>get_dht_record_key</code> using the key (or not) of your choice.</p> <p>I used a DFLT schema (meaning only the owner can write to it, as opposed to SMPL which means subkeys can be delegated to other writer keypairs) with an arbitrarily chosen 6 subkeys. As far as I can tell, with a DFLT schema, subkeys are just a way to organize the data stored in the DHT record, though each has a maximum size considerably smaller than the overall DHT record size limit, so multiple subkeys <em>must</em> be used in order to store the maximum amount of data in each DHT record.</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> record_key</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> dht_record</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">unwrap</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">key</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> println!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">record enc key</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> value_set_result</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> alice_rc</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">set_dht_value</span><span style="color: light-dark(#24292E, #A89984);">(</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #83A598);"> record_key</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">clone</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">,</span></span> <span class="giallo-l"><span style="color: light-dark(#005CC5, #D3869B);"> 0</span><span style="color: light-dark(#24292E, #A89984);">,</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> vec!</span><span style="color: light-dark(#24292E, #A89984);">[</span><span style="color: light-dark(#005CC5, #D3869B);">42</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#005CC5, #D3869B);"> 42</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#005CC5, #D3869B);"> 42</span><span style="color: light-dark(#24292E, #A89984);">]</span><span style="color: light-dark(#24292E, #A89984);">,</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> None</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);"> )</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#D73A49, #FB4934);">await</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> assert!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">value_set_result</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">is_ok</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> println!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">dht value set</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span></code></pre> <p>And once we have the record, we can set a DHT value, in this case an array of <code>42</code> three times in a row to subkey <code>0</code>. Easy enough.</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> send_result</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> dht_key_in</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">send</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">record_key</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> assert!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">send_result</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">is_ok</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> tokio</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">select!</span><span style="color: light-dark(#24292E, #A89984);"> {</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #83A598);"> _</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> alice_done</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">cancelled</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#D73A49, #8EC07C);"> =&gt;</span><span style="color: light-dark(#24292E, #A89984);"> {</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #83A598);"> alice</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">shutdown</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#D73A49, #FB4934);">await</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);"> }</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);"> }</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);"> }</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span></code></pre> <p>Here we send the record key to bob and commence waiting for notice that we've concluded our business and should terminate Alice's node. I don't know how long the DHT record would be available if Alice's node just went offline immediately after publishing the value; possibly some amount of time but I have heard the devs say the DHT isn't intended for storage even though some caching may happen.</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> bob_task</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#6F42C1, #FABD2F);"> tokio</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">spawn</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#D73A49, #FB4934);">async</span><span style="color: light-dark(#D73A49, #FB4934);"> move</span><span style="color: light-dark(#24292E, #A89984);"> {</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> bob</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#6F42C1, #FABD2F);"> create_and_attach_veilid_node</span><span style="color: light-dark(#24292E, #A89984);">(</span></span> <span class="giallo-l"><span style="color: light-dark(#032F62, #A89984);"> &quot;</span><span style="color: light-dark(#032F62, #B8BB26);">bob</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">to_string</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">,</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> Arc</span><span style="color: light-dark(#D73A49, #8EC07C);">::</span><span style="color: light-dark(#6F42C1, #FABD2F);">new</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#D73A49, #FB4934);">|</span><span style="color: light-dark(#24292E, #83A598);">_update</span><span style="color: light-dark(#D73A49, #FB4934);">|</span><span style="color: light-dark(#24292E, #A89984);"> (</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">)</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);"> )</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#D73A49, #FB4934);">await</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">expect</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">failed to start bob node</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> bob_rc</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> bob</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">routing_context</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">expect</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">failed to get bob&#39;s routing context</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> println!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">awaiting from record key from alice</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> record_key</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> dht_key_out</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#D73A49, #FB4934);">await</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">expect</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">failed to get record from from alice</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span></code></pre> <p>Over in Bob's task, start up Bob's node and wait for the DHT record key, just like it says.</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> opened_dht_rec</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> bob_rc</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">open_dht_record</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">record_key</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">clone</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#6F42C1, #FABD2F);"> None</span><span style="color: light-dark(#24292E, #A89984);">)</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#D73A49, #FB4934);">await</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> println!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">opened dht value</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> assert!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">opened_dht_rec</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">is_ok</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #83A598);"> value_result</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#24292E, #83A598);"> bob_rc</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#6F42C1, #FABD2F);">get_dht_value</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">record_key</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#005CC5, #D3869B);"> 0</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#005CC5, #D3869B);"> true</span><span style="color: light-dark(#24292E, #A89984);">)</span></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #8EC07C);"> .</span><span style="color: light-dark(#D73A49, #FB4934);">await</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> println!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#032F62, #B8BB26);">got dht value</span><span style="color: light-dark(#032F62, #A89984);">&quot;</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> assert!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">value_result</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">is_ok</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> assert_eq!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">value_result</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">unwrap</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">unwrap</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">data</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#6F42C1, #FABD2F);"> vec!</span><span style="color: light-dark(#24292E, #A89984);">[</span><span style="color: light-dark(#005CC5, #D3869B);">42</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#005CC5, #D3869B);"> 42</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#005CC5, #D3869B);"> 42</span><span style="color: light-dark(#24292E, #A89984);">]</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span></code></pre> <p>Note that we must open the value before we try to get any of its subkeys. Trying to get the value before opening it will result in an error.</p> <p>The boolean (<code>true</code>, in this case) passed to <code>get_dht_value</code> is used to indicate whether the value must be refreshed from the network - it <em>may</em> be fetched from the network even if <code>false</code> is given here, but the network <em>will</em> be checked if <code>true</code> is given.</p> <pre class="giallo" style="color-scheme: light dark; color: light-dark(#24292E, #EBDBB2); background-color: light-dark(#FFFFFF, #1D2021);"><code data-lang="rust"><span class="giallo-l"><span style="color: light-dark(#24292E, #83A598);"> done</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">cancel</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #83A598);"> bob</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">shutdown</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#D73A49, #FB4934);">await</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);"> }</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"></span> <span class="giallo-l"><span style="color: light-dark(#D73A49, #FE8019);"> let</span><span style="color: light-dark(#24292E, #A89984);"> (</span><span style="color: light-dark(#24292E, #83A598);">alice_result</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#24292E, #83A598);"> bob_result</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#D73A49, #8EC07C);"> =</span><span style="color: light-dark(#6F42C1, #FABD2F);"> join!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">bob_task</span><span style="color: light-dark(#24292E, #A89984);">,</span><span style="color: light-dark(#24292E, #83A598);"> alice_task</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> assert!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">alice_result</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">is_ok</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#6F42C1, #FABD2F);"> assert!</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #83A598);">bob_result</span><span style="color: light-dark(#D73A49, #8EC07C);">.</span><span style="color: light-dark(#6F42C1, #FABD2F);">is_ok</span><span style="color: light-dark(#24292E, #A89984);">(</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">)</span><span style="color: light-dark(#24292E, #A89984);">;</span></span> <span class="giallo-l"><span style="color: light-dark(#24292E, #A89984);">}</span></span></code></pre> <p>And then send the signal that everything is done, shut down bob's node, and (back in the main task) wait for both Alice and Bob's task to finish (using <code>join!</code> from the <code>futures</code> crate) before finishing out the test.</p>