map: Allow using the Levenshtein algorithm to search

Cargo.lock

@@ -99,6 +99,15 @@ dependencies = [
  "memmap 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "fst-levenshtein"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "fst 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "utf8-ranges 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "fuchsia-zircon"
 version = "0.3.3"
@@ -306,6 +315,7 @@ dependencies = [
  "bincode 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "fst 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fst-levenshtein 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.42 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.42 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -598,6 +608,11 @@ dependencies = [
  "percent-encoding 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "utf8-ranges"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "winapi"
 version = "0.2.8"
@@ -650,6 +665,7 @@ dependencies = [
 "checksum dtoa 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "09c3753c3db574d215cba4ea76018483895d7bff25a31b49ba45db21c48e50ab"
 "checksum env_logger 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "15abd780e45b3ea4f76b4e9a26ff4843258dd8a3eed2775a0e7368c2e7936c2f"
 "checksum fst 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d94485a00b1827b861dd9d1a2cc9764f9044d4c535514c0760a5a2012ef3399f"
+"checksum fst-levenshtein 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "64f12af1569dd78afbefe476034bbdce0372d18e9dc75b634bde0e7b8bf994c8"
 "checksum fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2e9763c69ebaae630ba35f74888db465e49e259ba1bc0eda7d06f4a067615d82"
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 "checksum futures 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)" = "1a70b146671de62ec8c8ed572219ca5d594d9b06c0b364d5e67b722fc559b48c"
@@ -706,6 +722,7 @@ dependencies = [
 "checksum unicode-normalization 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "51ccda9ef9efa3f7ef5d91e8f9b83bbe6955f9bf86aec89d5cce2c874625920f"
 "checksum unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
 "checksum url 1.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f808aadd8cfec6ef90e4a14eb46f24511824d1ac596b9682703c87056c8678b7"
+"checksum utf8-ranges 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "a1ca13c08c41c9c3e04224ed9ff80461d97e121589ff27c753a16cb10830ae0f"
 "checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 "checksum winapi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "04e3bd221fcbe8a271359c04f21a76db7d0c6028862d1bb5512d85e1e2eb5bb3"
 "checksum winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2d315eee3b34aca4797b2da6b13ed88266e6d612562a0c46390af8299fc699bc"

Cargo.toml

@@ -7,12 +7,13 @@ authors = ["Kerollmops <renault.cle@gmail.com>"]
 bincode = "1.0"
 env_logger = { version = "0.3", default-features = false }
 fst = "0.3"
+fst-levenshtein = "0.2"
 futures = "0.1"
+serde = "1.0"
+serde_derive = "1.0"
+serde_json = "1.0"
+smallvec = { version = "0.6", features = ["serde"] }
 tokio-minihttp = { git = "https://github.com/tokio-rs/tokio-minihttp.git" }
 tokio-proto = "0.1"
 tokio-service = "0.1"
-serde = "1.0"
-serde_json = "1.0"
-serde_derive = "1.0"
-smallvec = { version = "0.6", features = ["serde"] }
 url = "1.7"

src/bin/raptor.rs

@@ -1,4 +1,6 @@
 extern crate env_logger;
+extern crate fst;
+extern crate fst_levenshtein;
 extern crate futures;
 extern crate raptor;
 extern crate tokio_minihttp;
@@ -8,6 +10,8 @@ extern crate url;
 
 use std::io;
 
+use fst_levenshtein::Levenshtein;
+use fst::{IntoStreamer, Streamer};
 use futures::future;
 use tokio_minihttp::{Request, Response, Http};
 use tokio_proto::TcpServer;
@@ -34,8 +38,18 @@ impl Service for MainService {
 
         if let Some((_, key)) = url.query_pairs().find(|&(ref k, _)| k == "q") {
             let key = key.to_lowercase();
-            let values = self.map.get(&key).map(|a| &a[..10]);
+
-            resp.body(&format!("{:?}", values));
+            let lev = Levenshtein::new(&key, 2).unwrap();
+
+            let mut body = String::new();
+
+            let mut stream = self.map.search(lev).into_stream();
+            while let Some((key, values)) = stream.next() {
+                let values = &values[..values.len().min(10)];
+                body.push_str(&format!("{:?} {:?}\n", key, values));
+            }
+
+            resp.body(&body);
         }
 
         future::ok(resp)

src/lib.rs

@@ -5,6 +5,7 @@ extern crate serde_json;
 #[macro_use] extern crate serde_derive;
 extern crate smallvec;
 
+use std::ops::{Deref, DerefMut};
 use std::io::Write;
 use std::fs::File;
 use std::path::Path;
@@ -50,6 +51,45 @@ impl MultiMap {
     pub fn get<K: AsRef<[u8]>>(&self, key: K) -> Option<&[u64]> {
         self.map.get(key).map(|i| &*self.values[i as usize])
     }
+
+    pub fn search<A: fst::Automaton>(&self, aut: A) -> StreamBuilder<A> {
+        StreamBuilder {
+            inner: self.map.search(aut),
+            values: &self.values,
+        }
+    }
+}
+
+pub struct StreamBuilder<'a, A: fst::Automaton> {
+    inner: fst::map::StreamBuilder<'a, A>,
+    values: &'a [SmallVec32<u64>],
+}
+
+impl<'a, A: fst::Automaton> Deref for StreamBuilder<'a, A> {
+    type Target = fst::map::StreamBuilder<'a, A>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.inner
+    }
+}
+
+impl<'a, A: fst::Automaton> DerefMut for StreamBuilder<'a, A> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.inner
+    }
+}
+
+impl<'a, A: fst::Automaton> fst::IntoStreamer<'a> for StreamBuilder<'a, A> {
+    type Item = (&'a str, &'a [u64]);
+
+    type Into = Stream<'a, A>;
+
+    fn into_stream(self) -> Self::Into {
+        Stream {
+            inner: self.inner.into_stream(),
+            values: self.values,
+        }
+    }
 }
 
 pub struct Stream<'a, A: fst::Automaton = fst::automaton::AlwaysMatch> {