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<span id="96"> 96</span> <span id="97"> 97</span> <span id="98"> 98</span> <span id="99"> 99</span> <span id="100">100</span> <span id="101">101</span> </pre><pre class="rust"><code><span class="doccomment">//! Some helpers for working with fast_paths.</span> <span class="kw">use</span> <span class="ident">std::collections::BTreeMap</span>; <span class="kw">use</span> <span class="ident">std::fmt::Debug</span>; <span class="kw">use</span> <span class="ident">fast_paths</span>::{<span class="ident">InputGraph</span>, <span class="ident">NodeId</span>}; <span class="kw">use</span> <span class="ident">serde</span>::{<span class="ident">Deserialize</span>, <span class="ident">Deserializer</span>, <span class="ident">Serialize</span>}; <span class="doccomment">/// A bidirectional mapping between fast_paths NodeId and some custom ID type.</span> <span class="comment">// TODO Upstream this in fast_paths when this is more solid.</span> <span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>, <span class="ident">Serialize</span>)]</span> <span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">NodeMap</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">Copy</span> <span class="op">+</span> <span class="ident">Ord</span> <span class="op">+</span> <span class="ident">Debug</span> <span class="op">+</span> <span class="ident">Serialize</span><span class="op">></span> { <span class="comment">// These two fields are redundant and large, so don't serialize the bigger one, to cut down</span> <span class="comment">// file size.</span> <span class="attribute">#[<span class="ident">serde</span>(<span class="ident">skip_serializing</span>)]</span> <span class="ident">node_to_id</span>: <span class="ident">BTreeMap</span><span class="op"><</span><span class="ident">T</span>, <span class="ident">NodeId</span><span class="op">></span>, <span class="ident">id_to_node</span>: <span class="ident">Vec</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>, } <span class="kw">impl</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">Copy</span> <span class="op">+</span> <span class="ident">Ord</span> <span class="op">+</span> <span class="ident">Debug</span> <span class="op">+</span> <span class="ident">Serialize</span><span class="op">></span> <span class="ident">NodeMap</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> { <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>() -> <span class="ident">NodeMap</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> { <span class="ident">NodeMap</span> { <span class="ident">node_to_id</span>: <span class="ident">BTreeMap::new</span>(), <span class="ident">id_to_node</span>: <span class="ident">Vec::new</span>(), } } <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">get_or_insert</span>(<span class="kw-2">&mut</span> <span class="self">self</span>, <span class="ident">node</span>: <span class="ident">T</span>) -> <span class="ident">NodeId</span> { <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">id</span>) <span class="op">=</span> <span class="self">self</span>.<span class="ident">node_to_id</span>.<span class="ident">get</span>(<span class="kw-2">&</span><span class="ident">node</span>) { <span class="kw">return</span> <span class="kw-2">*</span><span class="ident">id</span>; } <span class="kw">let</span> <span class="ident">id</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">id_to_node</span>.<span class="ident">len</span>(); <span class="self">self</span>.<span class="ident">node_to_id</span>.<span class="ident">insert</span>(<span class="ident">node</span>, <span class="ident">id</span>); <span class="self">self</span>.<span class="ident">id_to_node</span>.<span class="ident">push</span>(<span class="ident">node</span>); <span class="ident">id</span> } <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">get</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">node</span>: <span class="ident">T</span>) -> <span class="ident">NodeId</span> { <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">id</span>) <span class="op">=</span> <span class="self">self</span>.<span class="ident">node_to_id</span>.<span class="ident">get</span>(<span class="kw-2">&</span><span class="ident">node</span>) { <span class="kw-2">*</span><span class="ident">id</span> } <span class="kw">else</span> { <span class="macro">panic!</span>(<span class="string">"{:?} not in NodeMap"</span>, <span class="ident">node</span>); } } <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">translate_id</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">id</span>: <span class="ident">usize</span>) -> <span class="ident">T</span> { <span class="self">self</span>.<span class="ident">id_to_node</span>[<span class="ident">id</span>] } <span class="doccomment">/// Call this after filling out the input graph, right before preparation.</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">guarantee_node_ordering</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">input_graph</span>: <span class="kw-2">&mut</span> <span class="ident">InputGraph</span>) { <span class="comment">// The fast_paths implementation will trim out the last nodes in the input graph if there</span> <span class="comment">// are no edges involving them:</span> <span class="comment">// https://github.com/easbar/fast_paths/blob/fdb65f25c5485c9c74c1b3cbe66d829eea81b14b/src/input_graph.rs#L151</span> <span class="comment">//</span> <span class="comment">// We sometimes add nodes that aren't used yet, so that we can reuse the same node ordering</span> <span class="comment">// later. Detect if the last node isn't used.</span> <span class="kw">let</span> <span class="ident">last_node</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">id_to_node</span>.<span class="ident">len</span>() <span class="op">-</span> <span class="number">1</span>; <span class="ident">input_graph</span>.<span class="ident">freeze</span>(); <span class="kw">for</span> <span class="ident">edge</span> <span class="kw">in</span> <span class="ident">input_graph</span>.<span class="ident">get_edges</span>() { <span class="kw">if</span> <span class="ident">edge</span>.<span class="ident">from</span> <span class="op">==</span> <span class="ident">last_node</span> <span class="op">|</span><span class="op">|</span> <span class="ident">edge</span>.<span class="ident">to</span> <span class="op">==</span> <span class="ident">last_node</span> { <span class="comment">// The last node is used, so we're fine</span> <span class="ident">input_graph</span>.<span class="ident">thaw</span>(); <span class="kw">return</span>; } } <span class="ident">input_graph</span>.<span class="ident">thaw</span>(); <span class="comment">// Add a dummy edge from this unused node to any arbitrary node (namely the first), to</span> <span class="comment">// prevent it from getting trimmed out. Since no path will start or end from this unused</span> <span class="comment">// node, this won't affect resulting paths.</span> <span class="kw">let</span> <span class="ident">first_node</span> <span class="op">=</span> <span class="number">0</span>; <span class="ident">input_graph</span>.<span class="ident">add_edge</span>(<span class="ident">last_node</span>, <span class="ident">first_node</span>, <span class="number">1</span>); } } <span class="comment">// A serialized NodeMap has this form in JSON. Use this to deserialize.</span> <span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Deserialize</span>)]</span> <span class="kw">struct</span> <span class="ident">InnerNodeMap</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">Copy</span> <span class="op">+</span> <span class="ident">Ord</span> <span class="op">+</span> <span class="ident">Debug</span><span class="op">></span> { <span class="ident">id_to_node</span>: <span class="ident">Vec</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>, } <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">deserialize_nodemap</span><span class="op"><</span> <span class="lifetime">'de</span>, <span class="ident">D</span>: <span class="ident">Deserializer</span><span class="op"><</span><span class="lifetime">'de</span><span class="op">></span>, <span class="ident">T</span>: <span class="ident">Deserialize</span><span class="op"><</span><span class="lifetime">'de</span><span class="op">></span> <span class="op">+</span> <span class="ident">Copy</span> <span class="op">+</span> <span class="ident">Ord</span> <span class="op">+</span> <span class="ident">Debug</span> <span class="op">+</span> <span class="ident">Serialize</span>, <span class="op">></span>( <span class="ident">d</span>: <span class="ident">D</span>, ) -> <span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">NodeMap</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>, <span class="ident">D::Error</span><span class="op">></span> { <span class="kw">let</span> <span class="ident">inner</span> <span class="op">=</span> <span class="op"><</span><span class="ident">InnerNodeMap</span><span class="op"><</span><span class="ident">T</span><span class="op">></span><span class="op">></span><span class="ident">::deserialize</span>(<span class="ident">d</span>)<span class="question-mark">?</span>; <span class="kw">let</span> <span class="ident">id_to_node</span> <span class="op">=</span> <span class="ident">inner</span>.<span class="ident">id_to_node</span>; <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">node_to_id</span> <span class="op">=</span> <span class="ident">BTreeMap::new</span>(); <span class="kw">for</span> (<span class="ident">id</span>, <span class="ident">node</span>) <span class="kw">in</span> <span class="ident">id_to_node</span>.<span class="ident">iter</span>().<span class="ident">enumerate</span>() { <span class="ident">node_to_id</span>.<span class="ident">insert</span>(<span class="kw-2">*</span><span class="ident">node</span>, <span class="ident">id</span>); } <span class="prelude-val">Ok</span>(<span class="ident">NodeMap</span> { <span class="ident">node_to_id</span>, <span class="ident">id_to_node</span>, }) } </code></pre></div> </section><section id="search" class="content hidden"></section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="map_model" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.60.0 (7737e0b5c 2022-04-04)" ></div> </body></html>