| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/tantivy-fst-0.4.0/src/raw/build.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>build.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../normalize.css"><link rel="stylesheet" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../ayu.css" disabled><link rel="stylesheet" href="../../../dark.css" disabled><link rel="stylesheet" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script defer src="../../../source-script.js"></script><script defer src="../../../source-files.js"></script><script defer src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../../tantivy_fst/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../tantivy_fst/index.html"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="kw">use </span>std::io::{<span class="self">self</span>, Write}; |
| |
| <span class="kw">use </span>byteorder::{LittleEndian, WriteBytesExt}; |
| |
| <span class="kw">use </span><span class="kw">crate</span>::error::Result; |
| <span class="kw">use </span><span class="kw">crate</span>::raw::counting_writer::CountingWriter; |
| <span class="kw">use </span><span class="kw">crate</span>::raw::error::Error; |
| <span class="kw">use </span><span class="kw">crate</span>::raw::registry::{Registry, RegistryEntry}; |
| <span class="kw">use </span><span class="kw">crate</span>::raw::{CompiledAddr, FstType, Output, Transition, EMPTY_ADDRESS, NONE_ADDRESS, VERSION}; |
| <span class="comment">// use raw::registry_minimal::{Registry, RegistryEntry}; |
| </span><span class="kw">use </span><span class="kw">crate</span>::stream::{IntoStreamer, Streamer}; |
| |
| <span class="doccomment">/// A builder for creating a finite state transducer. |
| /// |
| /// This is not your average everyday builder. It has two important qualities |
| /// that make it a bit unique from what you might expect: |
| /// |
| /// 1. All keys must be added in lexicographic order. Adding a key out of order |
| /// will result in an error. Additionally, adding a duplicate key with an |
| /// output value will also result in an error. That is, once a key is |
| /// associated with a value, that association can never be modified or |
| /// deleted. |
| /// 2. The representation of an fst is streamed to *any* `io::Write` as it is |
| /// built. For an in memory representation, this can be a `Vec<u8>`. |
| /// |
| /// Point (2) is especially important because it means that an fst can be |
| /// constructed *without storing the entire fst in memory*. Namely, since it |
| /// works with any `io::Write`, it can be streamed directly to a file. |
| /// |
| /// With that said, the builder does use memory, but **memory usage is bounded |
| /// to a constant size**. The amount of memory used trades off with the |
| /// compression ratio. Currently, the implementation hard codes this trade off |
| /// which can result in about 5-20MB of heap usage during construction. (N.B. |
| /// Guaranteeing a maximal compression ratio requires memory proportional to |
| /// the size of the fst, which defeats some of the benefit of streaming |
| /// it to disk. In practice, a small bounded amount of memory achieves |
| /// close-to-minimal compression ratios.) |
| /// |
| /// The algorithmic complexity of fst construction is `O(n)` where `n` is the |
| /// number of elements added to the fst. |
| </span><span class="kw">pub struct </span>Builder<W> { |
| <span class="doccomment">/// The FST raw data is written directly to `wtr`. |
| /// |
| /// No internal buffering is done. |
| </span>wtr: CountingWriter<W>, |
| <span class="doccomment">/// The stack of unfinished nodes. |
| /// |
| /// An unfinished node is a node that could potentially have a new |
| /// transition added to it when a new word is added to the dictionary. |
| </span>unfinished: UnfinishedNodes, |
| <span class="doccomment">/// A map of finished nodes. |
| /// |
| /// A finished node is one that has been compiled and written to `wtr`. |
| /// After this point, the node is considered immutable and will never |
| /// Achange. |
| </span>registry: Registry, |
| <span class="doccomment">/// The last word added. |
| /// |
| /// This is used to enforce the invariant that words are added in sorted |
| /// order. |
| </span>last: <span class="prelude-ty">Option</span><Vec<u8>>, |
| <span class="doccomment">/// The address of the last compiled node. |
| /// |
| /// This is used to optimize states with one transition that point |
| /// to the previously compiled node. (The previously compiled node in |
| /// this case actually corresponds to the next state for the transition, |
| /// since states are compiled in reverse.) |
| </span>last_addr: CompiledAddr, |
| <span class="doccomment">/// The number of keys added. |
| </span>len: usize, |
| } |
| |
| <span class="attribute">#[derive(Debug)] |
| </span><span class="kw">struct </span>UnfinishedNodes { |
| stack: Vec<BuilderNodeUnfinished>, |
| } |
| |
| <span class="attribute">#[derive(Debug)] |
| </span><span class="kw">struct </span>BuilderNodeUnfinished { |
| node: BuilderNode, |
| last: <span class="prelude-ty">Option</span><LastTransition>, |
| } |
| |
| <span class="attribute">#[derive(Debug, Hash, Eq, PartialEq)] |
| </span><span class="kw">pub struct </span>BuilderNode { |
| <span class="kw">pub </span>is_final: bool, |
| <span class="kw">pub </span>final_output: Output, |
| <span class="kw">pub </span>trans: Vec<Transition>, |
| } |
| |
| <span class="attribute">#[derive(Debug)] |
| </span><span class="kw">struct </span>LastTransition { |
| inp: u8, |
| out: Output, |
| } |
| |
| <span class="kw">impl </span>Builder<Vec<u8>> { |
| <span class="doccomment">/// Create a builder that builds an fst in memory. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>memory() -> <span class="self">Self </span>{ |
| Builder::new(Vec::with_capacity(<span class="number">10 </span>* (<span class="number">1 </span><< <span class="number">10</span>))).unwrap() |
| } |
| } |
| |
| <span class="kw">impl</span><W: io::Write> Builder<W> { |
| <span class="doccomment">/// Create a builder that builds an fst by writing it to `wtr` in a |
| /// streaming fashion. |
| </span><span class="kw">pub fn </span>new(wtr: W) -> <span class="prelude-ty">Result</span><Builder<W>> { |
| Builder::new_type(wtr, <span class="number">0</span>) |
| } |
| |
| <span class="doccomment">/// The same as `new`, except it sets the type of the fst to the type |
| /// given. |
| </span><span class="kw">pub fn </span>new_type(wtr: W, ty: FstType) -> <span class="prelude-ty">Result</span><Builder<W>> { |
| <span class="kw">let </span><span class="kw-2">mut </span>wtr = CountingWriter::new(wtr); |
| <span class="comment">// Don't allow any nodes to have address 0-7. We use these to encode |
| // the API version. We also use addresses `0` and `1` as special |
| // sentinel values, so they should never correspond to a real node. |
| </span>wtr.write_u64::<LittleEndian>(VERSION)<span class="question-mark">?</span>; |
| <span class="comment">// Similarly for 8-15 for the fst type. |
| </span>wtr.write_u64::<LittleEndian>(ty)<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(Builder { |
| wtr, |
| unfinished: UnfinishedNodes::new(), |
| registry: Registry::new(<span class="number">10_000</span>, <span class="number">2</span>), |
| last: <span class="prelude-val">None</span>, |
| last_addr: NONE_ADDRESS, |
| len: <span class="number">0</span>, |
| }) |
| } |
| |
| <span class="doccomment">/// Adds a byte string to this FST with a zero output value. |
| </span><span class="kw">pub fn </span>add<B>(<span class="kw-2">&mut </span><span class="self">self</span>, bs: B) -> <span class="prelude-ty">Result</span><()> |
| <span class="kw">where |
| </span>B: AsRef<[u8]>, |
| { |
| <span class="self">self</span>.check_last_key(bs.as_ref(), <span class="bool-val">false</span>)<span class="question-mark">?</span>; |
| <span class="self">self</span>.insert_output(bs, <span class="prelude-val">None</span>) |
| } |
| |
| <span class="doccomment">/// Insert a new key-value pair into the fst. |
| /// |
| /// Keys must be convertible to byte strings. Values must be a `u64`, which |
| /// is a restriction of the current implementation of finite state |
| /// transducers. (Values may one day be expanded to other types.) |
| /// |
| /// If a key is inserted that is less than or equal to any previous key |
| /// added, then an error is returned. Similarly, if there was a problem |
| /// writing to the underlying writer, an error is returned. |
| </span><span class="kw">pub fn </span>insert<B>(<span class="kw-2">&mut </span><span class="self">self</span>, bs: B, val: u64) -> <span class="prelude-ty">Result</span><()> |
| <span class="kw">where |
| </span>B: AsRef<[u8]>, |
| { |
| <span class="self">self</span>.check_last_key(bs.as_ref(), <span class="bool-val">true</span>)<span class="question-mark">?</span>; |
| <span class="self">self</span>.insert_output(bs, <span class="prelude-val">Some</span>(Output::new(val))) |
| } |
| |
| <span class="doccomment">/// Calls insert on each item in the iterator. |
| /// |
| /// If an error occurred while adding an element, processing is stopped |
| /// and the error is returned. |
| /// |
| /// If a key is inserted that is less than or equal to any previous key |
| /// added, then an error is returned. Similarly, if there was a problem |
| /// writing to the underlying writer, an error is returned. |
| </span><span class="kw">pub fn </span>extend_iter<T, I>(<span class="kw-2">&mut </span><span class="self">self</span>, iter: I) -> <span class="prelude-ty">Result</span><()> |
| <span class="kw">where |
| </span>T: AsRef<[u8]>, |
| I: IntoIterator<Item = (T, Output)>, |
| { |
| <span class="kw">for </span>(key, out) <span class="kw">in </span>iter { |
| <span class="self">self</span>.insert(key, out.value())<span class="question-mark">?</span>; |
| } |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="doccomment">/// Calls insert on each item in the stream. |
| /// |
| /// Note that unlike `extend_iter`, this is not generic on the items in |
| /// the stream. |
| /// |
| /// If a key is inserted that is less than or equal to any previous key |
| /// added, then an error is returned. Similarly, if there was a problem |
| /// writing to the underlying writer, an error is returned. |
| </span><span class="kw">pub fn </span>extend_stream<<span class="lifetime">'f</span>, I, S>(<span class="kw-2">&mut </span><span class="self">self</span>, stream: I) -> <span class="prelude-ty">Result</span><()> |
| <span class="kw">where |
| </span>I: <span class="kw">for</span><<span class="lifetime">'a</span>> IntoStreamer<<span class="lifetime">'a</span>, Into = S, Item = (<span class="kw-2">&</span><span class="lifetime">'a </span>[u8], Output)>, |
| S: <span class="lifetime">'f </span>+ <span class="kw">for</span><<span class="lifetime">'a</span>> Streamer<<span class="lifetime">'a</span>, Item = (<span class="kw-2">&</span><span class="lifetime">'a </span>[u8], Output)>, |
| { |
| <span class="kw">let </span><span class="kw-2">mut </span>stream = stream.into_stream(); |
| <span class="kw">while let </span><span class="prelude-val">Some</span>((key, out)) = stream.next() { |
| <span class="self">self</span>.insert(key, out.value())<span class="question-mark">?</span>; |
| } |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="doccomment">/// Finishes the construction of the fst and flushes the underlying |
| /// writer. After completion, the data written to `W` may be read using |
| /// one of `Fst`'s constructor methods. |
| </span><span class="kw">pub fn </span>finish(<span class="self">self</span>) -> <span class="prelude-ty">Result</span><()> { |
| <span class="self">self</span>.into_inner()<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="doccomment">/// Just like `finish`, except it returns the underlying writer after |
| /// flushing it. |
| </span><span class="kw">pub fn </span>into_inner(<span class="kw-2">mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><W> { |
| <span class="self">self</span>.compile_from(<span class="number">0</span>)<span class="question-mark">?</span>; |
| <span class="kw">let </span>root_node = <span class="self">self</span>.unfinished.pop_root(); |
| <span class="kw">let </span>root_addr = <span class="self">self</span>.compile(<span class="kw-2">&</span>root_node)<span class="question-mark">?</span>; |
| <span class="self">self</span>.wtr.write_u64::<LittleEndian>(<span class="self">self</span>.len <span class="kw">as </span>u64)<span class="question-mark">?</span>; |
| <span class="self">self</span>.wtr.write_u64::<LittleEndian>(root_addr <span class="kw">as </span>u64)<span class="question-mark">?</span>; |
| <span class="self">self</span>.wtr.flush()<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(<span class="self">self</span>.wtr.into_inner()) |
| } |
| |
| <span class="kw">fn </span>insert_output<B>(<span class="kw-2">&mut </span><span class="self">self</span>, bs: B, out: <span class="prelude-ty">Option</span><Output>) -> <span class="prelude-ty">Result</span><()> |
| <span class="kw">where |
| </span>B: AsRef<[u8]>, |
| { |
| <span class="kw">let </span>bs = bs.as_ref(); |
| <span class="kw">if </span>bs.is_empty() { |
| <span class="self">self</span>.len = <span class="number">1</span>; <span class="comment">// must be first key, so length is always 1 |
| </span><span class="self">self</span>.unfinished |
| .set_root_output(out.unwrap_or_else(Output::zero)); |
| <span class="kw">return </span><span class="prelude-val">Ok</span>(()); |
| } |
| <span class="kw">let </span>(prefix_len, out) = <span class="kw">if let </span><span class="prelude-val">Some</span>(out) = out { |
| <span class="self">self</span>.unfinished.find_common_prefix_and_set_output(bs, out) |
| } <span class="kw">else </span>{ |
| (<span class="self">self</span>.unfinished.find_common_prefix(bs), Output::zero()) |
| }; |
| <span class="kw">if </span>prefix_len == bs.len() { |
| <span class="comment">// If the prefix found consumes the entire set of bytes, then |
| // the prefix *equals* the bytes given. This means it is a |
| // duplicate value with no output. So we can give up here. |
| // |
| // If the below assert fails, then that means we let a duplicate |
| // value through even when inserting outputs. |
| </span><span class="macro">assert!</span>(out.is_zero()); |
| <span class="kw">return </span><span class="prelude-val">Ok</span>(()); |
| } |
| <span class="self">self</span>.len += <span class="number">1</span>; |
| <span class="self">self</span>.compile_from(prefix_len)<span class="question-mark">?</span>; |
| <span class="self">self</span>.unfinished.add_suffix(<span class="kw-2">&</span>bs[prefix_len..], out); |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="kw">fn </span>compile_from(<span class="kw-2">&mut </span><span class="self">self</span>, istate: usize) -> <span class="prelude-ty">Result</span><()> { |
| <span class="kw">let </span><span class="kw-2">mut </span>addr = NONE_ADDRESS; |
| <span class="kw">while </span>istate + <span class="number">1 </span>< <span class="self">self</span>.unfinished.len() { |
| <span class="kw">let </span>node = <span class="kw">if </span>addr == NONE_ADDRESS { |
| <span class="self">self</span>.unfinished.pop_empty() |
| } <span class="kw">else </span>{ |
| <span class="self">self</span>.unfinished.pop_freeze(addr) |
| }; |
| addr = <span class="self">self</span>.compile(<span class="kw-2">&</span>node)<span class="question-mark">?</span>; |
| <span class="macro">assert_ne!</span>(addr, NONE_ADDRESS); |
| } |
| <span class="self">self</span>.unfinished.top_last_freeze(addr); |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>compile(<span class="kw-2">&mut </span><span class="self">self</span>, node: <span class="kw-2">&</span>BuilderNode) -> <span class="prelude-ty">Result</span><CompiledAddr> { |
| <span class="kw">if </span>node.is_final && node.trans.is_empty() && node.final_output.is_zero() { |
| <span class="kw">return </span><span class="prelude-val">Ok</span>(EMPTY_ADDRESS); |
| } |
| <span class="kw">let </span>entry = <span class="self">self</span>.registry.entry(<span class="kw-2">&</span>node); |
| <span class="kw">if let </span>RegistryEntry::Found(<span class="kw-2">ref </span>addr) = entry { |
| <span class="kw">return </span><span class="prelude-val">Ok</span>(<span class="kw-2">*</span>addr); |
| } |
| <span class="kw">let </span>start_addr = <span class="self">self</span>.wtr.count() <span class="kw">as </span>CompiledAddr; |
| node.compile_to(<span class="kw-2">&mut </span><span class="self">self</span>.wtr, <span class="self">self</span>.last_addr, start_addr)<span class="question-mark">?</span>; |
| <span class="self">self</span>.last_addr = <span class="self">self</span>.wtr.count() <span class="kw">as </span>CompiledAddr - <span class="number">1</span>; |
| <span class="kw">if let </span>RegistryEntry::NotFound(cell) = entry { |
| cell.insert(<span class="self">self</span>.last_addr); |
| } |
| <span class="prelude-val">Ok</span>(<span class="self">self</span>.last_addr) |
| } |
| |
| <span class="kw">fn </span>check_last_key(<span class="kw-2">&mut </span><span class="self">self</span>, bs: <span class="kw-2">&</span>[u8], check_dupe: bool) -> <span class="prelude-ty">Result</span><()> { |
| <span class="kw">if let </span><span class="prelude-val">Some</span>(<span class="kw-2">ref mut </span>last) = <span class="self">self</span>.last { |
| <span class="kw">if </span>check_dupe && bs == <span class="kw-2">&**</span>last { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::DuplicateKey { got: bs.to_vec() }.into()); |
| } |
| <span class="kw">if </span>bs < <span class="kw-2">&**</span>last { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::OutOfOrder { |
| previous: last.to_vec(), |
| got: bs.to_vec(), |
| } |
| .into()); |
| } |
| last.clear(); |
| <span class="kw">for </span><span class="kw-2">&</span>b <span class="kw">in </span>bs { |
| last.push(b); |
| } |
| } <span class="kw">else </span>{ |
| <span class="self">self</span>.last = <span class="prelude-val">Some</span>(bs.to_vec()); |
| } |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="doccomment">/// Gets a reference to the underlying writer. |
| </span><span class="kw">pub fn </span>get_ref(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>W { |
| <span class="self">self</span>.wtr.get_ref() |
| } |
| |
| <span class="doccomment">/// Returns the number of bytes written to the underlying writer |
| </span><span class="kw">pub fn </span>bytes_written(<span class="kw-2">&</span><span class="self">self</span>) -> u64 { |
| <span class="self">self</span>.wtr.count() |
| } |
| } |
| |
| <span class="kw">impl </span>UnfinishedNodes { |
| <span class="kw">fn </span>new() -> UnfinishedNodes { |
| <span class="kw">let </span><span class="kw-2">mut </span>unfinished = UnfinishedNodes { |
| stack: Vec::with_capacity(<span class="number">64</span>), |
| }; |
| unfinished.push_empty(<span class="bool-val">false</span>); |
| unfinished |
| } |
| |
| <span class="kw">fn </span>len(<span class="kw-2">&</span><span class="self">self</span>) -> usize { |
| <span class="self">self</span>.stack.len() |
| } |
| |
| <span class="kw">fn </span>push_empty(<span class="kw-2">&mut </span><span class="self">self</span>, is_final: bool) { |
| <span class="self">self</span>.stack.push(BuilderNodeUnfinished { |
| node: BuilderNode { |
| is_final, |
| ..BuilderNode::default() |
| }, |
| last: <span class="prelude-val">None</span>, |
| }); |
| } |
| |
| <span class="kw">fn </span>pop_root(<span class="kw-2">&mut </span><span class="self">self</span>) -> BuilderNode { |
| <span class="macro">assert_eq!</span>(<span class="self">self</span>.stack.len(), <span class="number">1</span>); |
| <span class="macro">assert!</span>(<span class="self">self</span>.stack[<span class="number">0</span>].last.is_none()); |
| <span class="self">self</span>.stack.pop().unwrap().node |
| } |
| |
| <span class="kw">fn </span>pop_freeze(<span class="kw-2">&mut </span><span class="self">self</span>, addr: CompiledAddr) -> BuilderNode { |
| <span class="kw">let </span><span class="kw-2">mut </span>unfinished = <span class="self">self</span>.stack.pop().unwrap(); |
| unfinished.last_compiled(addr); |
| unfinished.node |
| } |
| |
| <span class="kw">fn </span>pop_empty(<span class="kw-2">&mut </span><span class="self">self</span>) -> BuilderNode { |
| <span class="kw">let </span>unfinished = <span class="self">self</span>.stack.pop().unwrap(); |
| <span class="macro">assert!</span>(unfinished.last.is_none()); |
| unfinished.node |
| } |
| |
| <span class="kw">fn </span>set_root_output(<span class="kw-2">&mut </span><span class="self">self</span>, out: Output) { |
| <span class="self">self</span>.stack[<span class="number">0</span>].node.is_final = <span class="bool-val">true</span>; |
| <span class="self">self</span>.stack[<span class="number">0</span>].node.final_output = out; |
| } |
| |
| <span class="kw">fn </span>top_last_freeze(<span class="kw-2">&mut </span><span class="self">self</span>, addr: CompiledAddr) { |
| <span class="kw">let </span>last = <span class="self">self</span>.stack.len().checked_sub(<span class="number">1</span>).unwrap(); |
| <span class="self">self</span>.stack[last].last_compiled(addr); |
| } |
| |
| <span class="kw">fn </span>add_suffix(<span class="kw-2">&mut </span><span class="self">self</span>, bs: <span class="kw-2">&</span>[u8], out: Output) { |
| <span class="kw">if </span>bs.is_empty() { |
| <span class="kw">return</span>; |
| } |
| <span class="kw">let </span>last = <span class="self">self</span>.stack.len().checked_sub(<span class="number">1</span>).unwrap(); |
| <span class="macro">assert!</span>(<span class="self">self</span>.stack[last].last.is_none()); |
| <span class="self">self</span>.stack[last].last = <span class="prelude-val">Some</span>(LastTransition { inp: bs[<span class="number">0</span>], out }); |
| <span class="kw">for </span><span class="kw-2">&</span>b <span class="kw">in </span><span class="kw-2">&</span>bs[<span class="number">1</span>..] { |
| <span class="self">self</span>.stack.push(BuilderNodeUnfinished { |
| node: BuilderNode::default(), |
| last: <span class="prelude-val">Some</span>(LastTransition { |
| inp: b, |
| out: Output::zero(), |
| }), |
| }); |
| } |
| <span class="self">self</span>.push_empty(<span class="bool-val">true</span>); |
| } |
| |
| <span class="kw">fn </span>find_common_prefix(<span class="kw-2">&mut </span><span class="self">self</span>, bs: <span class="kw-2">&</span>[u8]) -> usize { |
| bs.iter() |
| .zip(<span class="kw-2">&</span><span class="self">self</span>.stack) |
| .take_while(|<span class="kw-2">&</span>(<span class="kw-2">&</span>b, <span class="kw-2">ref </span>node)| node.last.as_ref().map(|t| t.inp == b).unwrap_or(<span class="bool-val">false</span>)) |
| .count() |
| } |
| |
| <span class="kw">fn </span>find_common_prefix_and_set_output(<span class="kw-2">&mut </span><span class="self">self</span>, bs: <span class="kw-2">&</span>[u8], <span class="kw-2">mut </span>out: Output) -> (usize, Output) { |
| <span class="kw">let </span><span class="kw-2">mut </span>i = <span class="number">0</span>; |
| <span class="kw">while </span>i < bs.len() { |
| <span class="kw">let </span>add_prefix = <span class="kw">match </span><span class="self">self</span>.stack[i].last.as_mut() { |
| <span class="prelude-val">Some</span>(<span class="kw-2">ref mut </span>t) <span class="kw">if </span>t.inp == bs[i] => { |
| i += <span class="number">1</span>; |
| <span class="kw">let </span>common_pre = t.out.prefix(out); |
| <span class="kw">let </span>add_prefix = t.out.sub(common_pre); |
| out = out.sub(common_pre); |
| t.out = common_pre; |
| add_prefix |
| } |
| <span class="kw">_ </span>=> <span class="kw">break</span>, |
| }; |
| <span class="kw">if </span>!add_prefix.is_zero() { |
| <span class="self">self</span>.stack[i].add_output_prefix(add_prefix); |
| } |
| } |
| (i, out) |
| } |
| } |
| |
| <span class="kw">impl </span>BuilderNodeUnfinished { |
| <span class="kw">fn </span>last_compiled(<span class="kw-2">&mut </span><span class="self">self</span>, addr: CompiledAddr) { |
| <span class="kw">if let </span><span class="prelude-val">Some</span>(trans) = <span class="self">self</span>.last.take() { |
| <span class="self">self</span>.node.trans.push(Transition { |
| inp: trans.inp, |
| out: trans.out, |
| addr, |
| }); |
| } |
| } |
| |
| <span class="kw">fn </span>add_output_prefix(<span class="kw-2">&mut </span><span class="self">self</span>, prefix: Output) { |
| <span class="kw">if </span><span class="self">self</span>.node.is_final { |
| <span class="self">self</span>.node.final_output = prefix.cat(<span class="self">self</span>.node.final_output); |
| } |
| <span class="kw">for </span>t <span class="kw">in </span><span class="kw-2">&mut </span><span class="self">self</span>.node.trans { |
| t.out = prefix.cat(t.out); |
| } |
| <span class="kw">if let </span><span class="prelude-val">Some</span>(<span class="kw-2">ref mut </span>t) = <span class="self">self</span>.last { |
| t.out = prefix.cat(t.out); |
| } |
| } |
| } |
| |
| <span class="kw">impl </span>Clone <span class="kw">for </span>BuilderNode { |
| <span class="kw">fn </span>clone(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="self">Self </span>{ |
| BuilderNode { |
| is_final: <span class="self">self</span>.is_final, |
| final_output: <span class="self">self</span>.final_output, |
| trans: <span class="self">self</span>.trans.clone(), |
| } |
| } |
| |
| <span class="kw">fn </span>clone_from(<span class="kw-2">&mut </span><span class="self">self</span>, source: <span class="kw-2">&</span><span class="self">Self</span>) { |
| <span class="self">self</span>.is_final = source.is_final; |
| <span class="self">self</span>.final_output = source.final_output; |
| <span class="self">self</span>.trans.clear(); |
| <span class="self">self</span>.trans.extend(source.trans.iter()); |
| } |
| } |
| |
| <span class="kw">impl </span>Default <span class="kw">for </span>BuilderNode { |
| <span class="kw">fn </span>default() -> <span class="self">Self </span>{ |
| BuilderNode { |
| is_final: <span class="bool-val">false</span>, |
| final_output: Output::zero(), |
| trans: <span class="macro">vec!</span>[], |
| } |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="tantivy_fst" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
