Create two open and create index functions

meilidb-core/examples/from_file.rs

@@ -12,7 +12,7 @@ use serde::{Serialize, Deserialize};
 use structopt::StructOpt;
 use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};
 
-use meilidb_core::{Highlight, Database, UpdateResult, BoxUpdateFn};
+use meilidb_core::{Highlight, Database, UpdateResult};
 use meilidb_schema::SchemaAttr;
 
 const INDEX_NAME: &str = "default";
@@ -86,7 +86,14 @@ fn index_command(command: IndexCommand, database: Database) -> Result<(), Box<dy
 
     let (sender, receiver) = mpsc::sync_channel(100);
     let update_fn = move |update: UpdateResult| sender.send(update.update_id).unwrap();
-    let index = database.open_index(INDEX_NAME, Some(Box::new(update_fn)))?;
+    let index = match database.open_index(INDEX_NAME) {
+        Some(index) => index,
+        None => database.create_index(INDEX_NAME).unwrap()
+    };
+
+    let done = database.set_update_callback(INDEX_NAME, Box::new(update_fn));
+    assert!(done, "could not set the index update function");
+
     let rkv = database.rkv.read().unwrap();
 
     let schema = {
@@ -256,8 +263,7 @@ fn crop_text(
 
 fn search_command(command: SearchCommand, database: Database) -> Result<(), Box<dyn Error>> {
     let rkv = database.rkv.read().unwrap();
-    let update_fn = None as Option::<BoxUpdateFn>;
-    let index = database.open_index(INDEX_NAME, update_fn)?;
+    let index = database.open_index(INDEX_NAME).expect("Could not find index");
     let reader = rkv.read().unwrap();
 
     let schema = index.main.schema(&reader)?;

meilidb-core/src/database.rs

@@ -1,4 +1,4 @@
-use std::collections::HashMap;
+use std::collections::hash_map::{HashMap, Entry};
 use std::path::Path;
 use std::sync::{Arc, RwLock};
 use std::{fs, thread};
@@ -116,53 +116,64 @@ impl Database {
         Ok(Database { rkv, main_store, indexes_store, indexes: RwLock::new(indexes) })
     }
 
-    pub fn open_index(
-        &self,
-        name: impl Into<String>,
-        update_fn: Option<BoxUpdateFn>,
-    ) -> MResult<Index>
-    {
+    pub fn open_index(&self, name: impl AsRef<str>) -> Option<Index> {
         let indexes_lock = self.indexes.read().unwrap();
-        let name = name.into();
+        match indexes_lock.get(name.as_ref()) {
+            Some((index, ..)) => Some(index.clone()),
+            None => None,
+        }
+    }
 
-        match indexes_lock.get(&name) {
-            Some((index, old_update_fn, _)) => {
-                old_update_fn.swap(update_fn.map(Arc::new));
-                Ok(index.clone())
-            },
-            None => {
-                drop(indexes_lock);
+    pub fn create_index(&self, name: impl AsRef<str>) -> MResult<Index> {
+        let name = name.as_ref();
+        let mut indexes_lock = self.indexes.write().unwrap();
 
+        match indexes_lock.entry(name.to_owned()) {
+            Entry::Occupied(_) => Err(crate::Error::IndexAlreadyExists),
+            Entry::Vacant(entry) => {
                 let rkv_lock = self.rkv.read().unwrap();
                 let (sender, receiver) = crossbeam_channel::bounded(100);
-                let index = store::create(&rkv_lock, &name, sender)?;
+                let index = store::create(&rkv_lock, name, sender)?;
 
                 let mut writer = rkv_lock.write()?;
                 let value = rkv::Value::Blob(&[]);
-                self.indexes_store.put(&mut writer, &name, &value)?;
+                self.indexes_store.put(&mut writer, name, &value)?;
 
-                {
-                    let mut indexes_write = self.indexes.write().unwrap();
-                    indexes_write.entry(name).or_insert_with(|| {
                 let rkv_clone = self.rkv.clone();
                 let index_clone = index.clone();
 
-                        let update_fn = update_fn.map(Arc::new);
-                        let update_fn = Arc::new(ArcSwapFn::new(update_fn));
-                        let update_fn_clone = update_fn.clone();
+                let no_update_fn = Arc::new(ArcSwapFn::empty());
+                let no_update_fn_clone = no_update_fn.clone();
 
                 let handle = thread::spawn(move || {
-                            update_awaiter(receiver, rkv_clone, update_fn_clone, index_clone)
+                    update_awaiter(receiver, rkv_clone, no_update_fn_clone, index_clone)
                 });
 
-                        (index.clone(), update_fn, handle)
-                    });
-                }
-
                 writer.commit()?;
+                entry.insert((index.clone(), no_update_fn, handle));
 
                 Ok(index)
+            }
+        }
+    }
+
+    pub fn set_update_callback(&self, name: impl AsRef<str>, update_fn: BoxUpdateFn) -> bool {
+        let indexes_lock = self.indexes.read().unwrap();
+        match indexes_lock.get(name.as_ref()) {
+            Some((_, current_update_fn, _)) => {
+                let update_fn = Some(Arc::new(update_fn));
+                current_update_fn.swap(update_fn);
+                true
             },
+            None => false,
+        }
+    }
+
+    pub fn unset_update_callback(&self, name: impl AsRef<str>) -> bool {
+        let indexes_lock = self.indexes.read().unwrap();
+        match indexes_lock.get(name.as_ref()) {
+            Some((_, current_update_fn, _)) => { current_update_fn.swap(None); true },
+            None => false,
         }
     }
 

meilidb-core/src/error.rs

@@ -6,6 +6,7 @@ pub type MResult<T> = Result<T, Error>;
 #[derive(Debug)]
 pub enum Error {
     Io(io::Error),
+    IndexAlreadyExists,
     SchemaDiffer,
     SchemaMissing,
     WordIndexMissing,
@@ -79,6 +80,7 @@ impl fmt::Display for Error {
         use self::Error::*;
         match self {
             Io(e) => write!(f, "{}", e),
+            IndexAlreadyExists => write!(f, "index already exists"),
             SchemaDiffer => write!(f, "schemas differ"),
             SchemaMissing => write!(f, "this index does not have a schema"),
             WordIndexMissing => write!(f, "this index does not have a word index"),

meilidb-core/src/query_builder.rs

@@ -551,7 +551,7 @@ mod tests {
     use tempfile::TempDir;
 
     use crate::automaton::normalize_str;
-    use crate::database::{Database, BoxUpdateFn};
+    use crate::database::Database;
     use crate::DocIndex;
     use crate::store::Index;
 
@@ -646,8 +646,7 @@ mod tests {
         fn from_iter<I: IntoIterator<Item=(&'a str, &'a [DocIndex])>>(iter: I) -> Self {
             let tempdir = TempDir::new().unwrap();
             let database = Database::open_or_create(&tempdir).unwrap();
-            let update_fn = None as Option::<BoxUpdateFn>;
-            let index = database.open_index("default", update_fn).unwrap();
+            let index = database.create_index("default").unwrap();
 
             let rkv = database.rkv.read().unwrap();
             let mut writer = rkv.write().unwrap();