From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Fri, 27 Nov 2020 23:53:18 +0000 (+0000)
Subject: shapelib: Use parking_lot, not rental
X-Git-Tag: otter-0.2.0~321
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=94d03bbd74a2fb2a447df471a53cd4600c2ac48f;p=otter.git

shapelib: Use parking_lot, not rental

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/src/global.rs b/src/global.rs
index 76f452bd..727ca872 100644
--- a/src/global.rs
+++ b/src/global.rs
@@ -192,8 +192,6 @@ pub struct Global {
 
   // per-game lock:
   // <- InstanceContainer ->
-  pub shapelibs : RwLock<shapelib::Registry>,
-
   // inner locks which the game needs:
   dirty   : Mutex<VecDeque<InstanceRef>>,
   pub config: RwLock<Arc<ServerConfig>>,
diff --git a/src/shapelib.rs b/src/shapelib.rs
index 3cd0e66e..76cc8014 100644
--- a/src/shapelib.rs
+++ b/src/shapelib.rs
@@ -4,6 +4,8 @@
 
 pub use crate::imports::*;
 
+use parking_lot::{RwLock, const_rwlock, RwLockReadGuard, MappedRwLockReadGuard};
+
 // Naming convention:
 //  *Data, *List   from toml etc. (processed if need be)
 //  *Defn          raw read from library toml file (where different from Info)
@@ -191,14 +193,19 @@ impl Piece for Item {
   
 }
 
+static SHAPELIBS : RwLock<Option<Registry>> = const_rwlock(None);
+
 #[throws(SpecError)]
 pub fn libs_lookup(libname: &str)
-                   -> RentRef<RwLockReadGuard<'static, Registry>,
-                              Contents> {
-  let libs = GLOBAL.shapelibs.read().unwrap();
-  RentRef::try_new(libs,|libs| Ok::<_,SpecError>({
-    libs.get(libname).ok_or(SE::LibraryNotFound)?
-  })).map_err(|e|e.0)?
+                   -> MappedRwLockReadGuard<'static, Contents> {
+  let libs = SHAPELIBS.read();
+  RwLockReadGuard::try_map( libs, |libs: &Option<Registry>| -> Option<_> {
+    (|| Some({
+      libs.as_ref()?.get(libname)?
+    }))()
+  })
+    .map_err(|_| SE::LibraryNotFound)
+    ?
 }
 
 impl ItemSpec {
@@ -398,7 +405,9 @@ pub struct Explicit1 {
 pub fn load1(l: &Explicit1) {
   let data = load_catalogue(&l.name, &l.dirname, &l.catalogue)?;
   let count = data.items.len();
-  GLOBAL.shapelibs.write().unwrap().insert(l.name.clone(), data);
+  SHAPELIBS.write()
+    .get_or_insert_with(default)
+    .insert(l.name.clone(), data);
   info!("loaded {} shapes in library {:?} from {:?} and {:?}",
         count, &l.name, &l.catalogue, &l.dirname);
 }