Got the cache channels setup.

src/morethantext/mod.rs

@@ -1,9 +1,9 @@
 use async_std::{
-    channel::{unbounded, Sender},
+    channel::{unbounded, Receiver, Sender},
     path::PathBuf,
     task::spawn,
 };
-use std::{error::Error, fmt};
+use std::{collections::HashMap, error::Error, fmt};
 
 const ENTRY: &str = "EntryPoint";
 
@@ -180,17 +180,33 @@ mod datatypes {
     }
 }
 
+#[derive(Debug)]
+enum FromCache {
+    Data(HashMap<String, DataType>),
+    Error(MTTError),
+}
+
+struct CacheQuery {
+    ids: Vec<String>,
+    reply: Sender<FromCache>,
+}
+
+enum ToCache {
+    Query(CacheQuery),
+}
+
 #[derive(Clone)]
 pub struct MoreThanText {
     session: Vec<String>,
-    channel: Sender<String>,
+    cache: Sender<Vec<String>>,
 }
 
 impl MoreThanText {
-    async fn new() {}
-
-    async fn get_entry(&self, id: String) {
-        self.channel.send(id).await.unwrap();
+    async fn new(cache: Sender<Vec<String>>) -> Result<Self, MTTError> {
+        Ok(Self {
+            session: [ENTRY.to_string()].to_vec(),
+            cache: cache,
+        })
     }
 }
 
@@ -200,25 +216,116 @@ mod mtt {
 
     #[async_std::test]
     async fn create() {
-        MoreThanText::new().await;
+        let (s, _) = unbounded();
+        let mtt = MoreThanText::new(s).await.unwrap();
+        assert_eq!(mtt.session, [ENTRY]);
     }
 }
 
-pub async fn start_db<P>(dir: P) -> Result<MoreThanText, MTTError>
+struct Cache {
+    channel: Receiver<ToCache>,
+}
+
+impl Cache {
+    async fn new<P>(_dir: P, channel: Receiver<ToCache>) -> Result<Self, MTTError>
+    where
+        P: Into<PathBuf>,
+    {
+        Ok(Self { channel: channel })
+    }
+
+    async fn start(&self) {
+        loop {
+            match self.channel.recv().await.unwrap() {
+                ToCache::Query(data) => {
+                    for id in data.ids {
+                        if id == ENTRY {
+                            let mut holder = HashMap::new();
+                            holder.insert(ENTRY.to_string(), DataType::new("store").unwrap());
+                            data.reply.send(FromCache::Data(holder)).await.unwrap();
+                        } else {
+                            data.reply
+                                .send(FromCache::Error(MTTError::new("fred")))
+                                .await
+                                .unwrap();
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod caches {
+    use super::*;
+    use tempfile::tempdir;
+
+    async fn start_cache<P>(dir: P) -> Sender<ToCache>
+    where
+        P: Into<PathBuf>,
+    {
+        let (s, r) = unbounded();
+        let datadir = dir.into();
+        spawn(async move {
+            let cache = Cache::new(datadir, r).await.unwrap();
+            cache.start().await;
+        });
+        s
+    }
+
+    #[async_std::test]
+    async fn create() {
+        let dir = tempdir().unwrap();
+        let s_cache = start_cache(dir.path()).await;
+        let (s_rep, r_rep) = unbounded();
+        let request = ToCache::Query(CacheQuery {
+            ids: [ENTRY.to_string()].to_vec(),
+            reply: s_rep,
+        });
+        s_cache.send(request).await.unwrap();
+        let result = r_rep.recv().await.unwrap();
+        match result {
+            FromCache::Data(data) => match data.get(ENTRY) {
+                Some(output) => match output {
+                    DataType::DBMap(_) => (),
+                    _ => assert!(false, "{:?} is not a database store.", output),
+                },
+                None => assert!(false, "Should contain entry point."),
+            },
+            _ => assert!(false, "{:?} should have been a store.", result),
+        }
+    }
+
+    #[async_std::test]
+    async fn bad_entry() {
+        let dir = tempdir().unwrap();
+        let s_cache = start_cache(dir.path()).await;
+        let (s_rep, r_rep) = unbounded();
+        let request = ToCache::Query(CacheQuery {
+            ids: ["bad_id".to_string()].to_vec(),
+            reply: s_rep,
+        });
+        s_cache.send(request).await.unwrap();
+        let result = r_rep.recv().await.unwrap();
+        match result {
+            FromCache::Error(_) => (),
+            _ => assert!(false, "{:?} should have been an error.", result),
+        }
+    }
+}
+
+pub async fn start_db<P>(_dir: P) -> Result<MoreThanText, MTTError>
 where
     P: Into<PathBuf>,
 {
-    let data_dir = dir.into();
     let (s, r) = unbounded();
     spawn(async move {
         loop {
             r.recv().await.unwrap();
         }
     });
-    Ok(MoreThanText {
-        session: [ENTRY.to_string()].to_vec(),
-        channel: s,
-    })
+    Ok(MoreThanText::new(s).await.unwrap())
 }
 
 #[cfg(test)]