core: remove reset() from SharedQueue API

4 files changed, 34 insertions, 30 deletions

diff --git a/core/isolate.rs b/core/isolate.rs
index 33b52da75..ef2da2a68 100644
--- a/core/isolate.rs
+++ b/core/isolate.rs
@@ -375,7 +375,6 @@ impl<B: Behavior> Future for Isolate<B> {
         self.respond()?;
         // The other side should have shifted off all the messages.
         assert_eq!(self.shared.size(), 0);
-        self.shared.reset();
       }
     }
 
diff --git a/core/shared_queue.js b/core/shared_queue.js
index 36f5dc91b..756f86e72 100644
--- a/core/shared_queue.js
+++ b/core/shared_queue.js
@@ -22,7 +22,8 @@
   }
 
   function reset() {
-    shared32.fill(0, 0, INDEX_RECORDS);
+    shared32[INDEX_NUM_RECORDS] = 0;
+    shared32[INDEX_NUM_SHIFTED_OFF] = 0;
     shared32[INDEX_HEAD] = HEAD_INIT;
   }
 
@@ -34,6 +35,10 @@
     return shared32[INDEX_NUM_RECORDS];
   }
 
+  function size() {
+    return shared32[INDEX_NUM_RECORDS] - shared32[INDEX_NUM_SHIFTED_OFF];
+  }
+
   function setEnd(index, end) {
     shared32[INDEX_OFFSETS + index] = end;
   }
@@ -77,17 +82,21 @@
   /// Returns null if empty.
   function shift() {
     let i = shared32[INDEX_NUM_SHIFTED_OFF];
-    if (i >= numRecords()) {
+    if (size() == 0) {
+      assert(i == 0);
       return null;
     }
+
     let off = getOffset(i);
     let end = getEnd(i);
-    shared32[INDEX_NUM_SHIFTED_OFF] += 1;
-    return sharedBytes.subarray(off, end);
-  }
 
-  function size() {
-    return shared32[INDEX_NUM_RECORDS] - shared32[INDEX_NUM_SHIFTED_OFF];
+    if (size() > 1) {
+      shared32[INDEX_NUM_SHIFTED_OFF] += 1;
+    } else {
+      reset();
+    }
+
+    return sharedBytes.subarray(off, end);
   }
 
   let asyncHandler = null;
@@ -119,7 +128,6 @@
     numRecords,
     size,
     push,
-    reset,
     shift
   };
 
diff --git a/core/shared_queue.rs b/core/shared_queue.rs
index 8e3199504..1a8692b5f 100644
--- a/core/shared_queue.rs
+++ b/core/shared_queue.rs
@@ -36,12 +36,10 @@ impl SharedQueue {
     unsafe { deno_buf::from_raw_parts(ptr, len) }
   }
 
-  /// Clears the shared buffer.
-  pub fn reset(&mut self) {
+  fn reset(&mut self) {
     let s: &mut [u32] = self.as_u32_slice_mut();
-    for i in 0..INDEX_RECORDS {
-      s[i] = 0;
-    }
+    s[INDEX_NUM_RECORDS] = 0;
+    s[INDEX_NUM_SHIFTED_OFF] = 0;
     s[INDEX_HEAD] = HEAD_INIT as u32;
   }
 
@@ -101,15 +99,20 @@ impl SharedQueue {
   pub fn shift<'a>(&'a mut self) -> Option<&'a [u8]> {
     let u32_slice = self.as_u32_slice();
     let i = u32_slice[INDEX_NUM_SHIFTED_OFF] as usize;
-    if i >= self.num_records() {
-      assert_eq!(self.size(), 0);
+    if self.size() == 0 {
+      assert_eq!(i, 0);
       return None;
     }
+
     let off = self.get_offset(i).unwrap();
     let end = self.get_end(i).unwrap();
 
-    let u32_slice = self.as_u32_slice_mut();
-    u32_slice[INDEX_NUM_SHIFTED_OFF] += 1;
+    if self.size() > 1 {
+      let u32_slice = self.as_u32_slice_mut();
+      u32_slice[INDEX_NUM_SHIFTED_OFF] += 1;
+    } else {
+      self.reset();
+    }
 
     Some(&self.bytes[off..end])
   }
@@ -173,16 +176,12 @@ mod tests {
 
     let r = q.shift().unwrap();
     assert_eq!(r.as_ref(), vec![8, 9, 10, 11].as_slice());
-    assert_eq!(q.num_records(), 3);
+    assert_eq!(q.num_records(), 0);
     assert_eq!(q.size(), 0);
 
     assert!(q.shift().is_none());
     assert!(q.shift().is_none());
 
-    assert_eq!(q.num_records(), 3);
-    assert_eq!(q.size(), 0);
-
-    q.reset();
     assert_eq!(q.num_records(), 0);
     assert_eq!(q.size(), 0);
   }
@@ -205,10 +204,11 @@ mod tests {
 
     assert_eq!(q.shift().unwrap().len(), RECOMMENDED_SIZE - 1);
     assert_eq!(q.size(), 1);
-    assert_eq!(q.shift().unwrap().len(), 1);
-    assert_eq!(q.size(), 0);
 
     assert!(!q.push(alloc_buf(1)));
+
+    assert_eq!(q.shift().unwrap().len(), 1);
+    assert_eq!(q.size(), 0);
   }
 
   #[test]
diff --git a/core/shared_queue_test.js b/core/shared_queue_test.js
index 33000fd45..e1e4c9987 100644
--- a/core/shared_queue_test.js
+++ b/core/shared_queue_test.js
@@ -48,17 +48,14 @@ function main() {
   assert(r[1] == 9);
   assert(r[2] == 10);
   assert(r[3] == 11);
-  assert(q.numRecords() == 3);
+  assert(q.numRecords() == 0);
   assert(q.size() == 0);
 
   assert(q.shift() == null);
   assert(q.shift() == null);
-  assert(q.numRecords() == 3);
-  assert(q.size() == 0);
-
-  q.reset();
   assert(q.numRecords() == 0);
   assert(q.size() == 0);
+
   libdeno.print("shared_queue_test.js ok\n");
 }