diff options
| -rw-r--r-- | src/libcollections/ring_buf.rs | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/src/libcollections/ring_buf.rs b/src/libcollections/ring_buf.rs index 1024a2828b3..359dffa0853 100644 --- a/src/libcollections/ring_buf.rs +++ b/src/libcollections/ring_buf.rs @@ -98,6 +98,10 @@ impl<T> RingBuf<T> { /// Returns true iff the buffer is at capacity #[inline] fn is_full(&self) -> bool { self.cap - self.len() == 1 } + + /// Returns the index in the underlying buffer for a given logical element index. + #[inline] + fn wrap_index(&self, idx: uint) -> uint { wrap_index(idx, self.cap) } } impl<T> RingBuf<T> { @@ -149,7 +153,7 @@ impl<T> RingBuf<T> { #[unstable = "matches collection reform specification, waiting for dust to settle"] pub fn get(&self, i: uint) -> Option<&T> { if i < self.len() { - let idx = wrap_index(self.tail + i, self.cap); + let idx = self.wrap_index(self.tail + i); unsafe { Some(&*self.ptr.offset(idx as int)) } } else { None @@ -179,7 +183,7 @@ impl<T> RingBuf<T> { #[unstable = "matches collection reform specification, waiting for dust to settle"] pub fn get_mut(&mut self, i: uint) -> Option<&mut T> { if i < self.len() { - let idx = wrap_index(self.tail + i, self.cap); + let idx = self.wrap_index(self.tail + i); unsafe { Some(&mut *self.ptr.offset(idx as int)) } } else { None @@ -208,8 +212,8 @@ impl<T> RingBuf<T> { pub fn swap(&mut self, i: uint, j: uint) { assert!(i < self.len()); assert!(j < self.len()); - let ri = wrap_index(self.tail + i, self.cap); - let rj = wrap_index(self.tail + j, self.cap); + let ri = self.wrap_index(self.tail + i); + let rj = self.wrap_index(self.tail + j); unsafe { ptr::swap(self.ptr.offset(ri as int), self.ptr.offset(rj as int)) } @@ -334,6 +338,7 @@ impl<T> RingBuf<T> { } debug_assert!(self.head < self.cap); debug_assert!(self.tail < self.cap); + debug_assert!(self.cap.count_ones() == 1); } } @@ -549,7 +554,7 @@ impl<T> RingBuf<T> { None } else { let tail = self.tail; - self.tail = wrap_index(self.tail + 1, self.cap); + self.tail = self.wrap_index(self.tail + 1); unsafe { Some(self.buffer_read(tail)) } } } @@ -573,7 +578,7 @@ impl<T> RingBuf<T> { debug_assert!(!self.is_full()); } - self.tail = wrap_index(self.tail - 1, self.cap); + self.tail = self.wrap_index(self.tail - 1); let tail = self.tail; unsafe { self.buffer_write(tail, t); } } @@ -604,7 +609,7 @@ impl<T> RingBuf<T> { } let head = self.head; - self.head = wrap_index(self.head + 1, self.cap); + self.head = self.wrap_index(self.head + 1); unsafe { self.buffer_write(head, t) } } @@ -633,7 +638,7 @@ impl<T> RingBuf<T> { if self.is_empty() { None } else { - self.head = wrap_index(self.head - 1, self.cap); + self.head = self.wrap_index(self.head - 1); let head = self.head; unsafe { Some(self.buffer_read(head)) } } @@ -644,9 +649,7 @@ impl<T> RingBuf<T> { #[inline] fn wrap_index(index: uint, size: uint) -> uint { // size is always a power of 2 - let idx = index & (size - 1); - debug_assert!(idx < size); - idx + index & (size - 1) } /// Calculate the number of elements left to be read in the buffer |