Add "capacity" accessor (#125)

Author: jamesmunns

bbqueue/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bbqueue"
-version = "0.6.0"
+version = "0.6.1"
 description = "A SPSC, lockless, no_std, thread safe, queue, based on BipBuffers"
 repository = "https://github.com/jamesmunns/bbqueue"
 authors = ["James Munns <james@onevariable.com>"]

bbqueue/src/prod_cons/framed.rs

@@ -147,6 +147,11 @@ where
             hdr: sz,
         })
     }
+
+    /// Get the total capacity of the buffer, e.g. how much space is present in [`Storage`]
+    pub fn capacity(&self) -> usize {
+        self.bbq.capacity()
+    }
 }
 
 impl<Q, H> FramedProducer<Q, H>
@@ -222,6 +227,11 @@ where
             hdr,
         })
     }
+
+    /// Get the total capacity of the buffer, e.g. how much space is present in [`Storage`]
+    pub fn capacity(&self) -> usize {
+        self.bbq.capacity()
+    }
 }
 
 impl<Q, H> FramedConsumer<Q, H>

bbqueue/src/prod_cons/stream.rs

@@ -120,6 +120,11 @@ where
             to_commit: 0,
         })
     }
+
+    /// Get the total capacity of the buffer, e.g. how much space is present in [`Storage`]
+    pub fn capacity(&self) -> usize {
+        self.bbq.capacity()
+    }
 }
 
 impl<Q> StreamProducer<Q>
@@ -174,6 +179,11 @@ where
             to_release: 0,
         })
     }
+
+    /// Get the total capacity of the buffer, e.g. how much space is present in [`Storage`]
+    pub fn capacity(&self) -> usize {
+        self.bbq.capacity()
+    }
 }
 
 impl<Q> StreamConsumer<Q>

bbqueue/src/queue.rs

@@ -95,6 +95,14 @@ impl<S: Storage, C: Coord, N: Notifier> BBQueue<S, C, N> {
     pub const fn stream_consumer(&self) -> StreamConsumer<&'_ Self> {
         StreamConsumer { bbq: self }
     }
+
+    /// Get the total capacity of the buffer, e.g. how much space is present in [`Storage`]
+    pub fn capacity(&self) -> usize {
+        // SAFETY: capacity never changes, therefore reading the len is safe
+        unsafe {
+            self.sto.ptr_len().1
+        }
+    }
 }
 
 #[cfg(feature = "alloc")]