From 84e7dee81bad02078876827132b60d3633469aa9 Mon Sep 17 00:00:00 2001
From: Hannes Mehnert <hannes@mehnert.org>
Date: Sun, 27 Jan 2019 13:10:09 +0100
Subject: [PATCH] vmmd_console: further refactoring

---
 src/vmm_ring.ml | 37 ++++++++++++-------------------------
 1 file changed, 12 insertions(+), 25 deletions(-)

diff --git a/src/vmm_ring.ml b/src/vmm_ring.ml
index ac7efa9..54980a8 100644
--- a/src/vmm_ring.ml
+++ b/src/vmm_ring.ml
@@ -19,38 +19,25 @@ let write t entry =
 
 let dec t n = (pred n + t.size) mod t.size
 
-let written (ts, _) = not (Ptime.equal ts Ptime.min)
+let not_written ts = Ptime.equal ts Ptime.min
 
-let read t =
+let entry_not_written (ts, _) = not_written ts
+
+let earlier than (ts, v) =
+  if not_written ts then true else Ptime.is_earlier ts ~than
+
+let read_some tst t =
   let rec go s acc idx =
     if idx = s then (* don't read it twice *)
       acc
     else
       let entry = Array.get t.data idx in
-      if written entry then go s (entry :: acc) (dec t idx)
-      else acc
+      if tst entry then acc else go s (entry :: acc) (dec t idx)
   in
   let idx = dec t t.write in
-  let s =
-    let entry = Array.get t.data idx in
-    if written entry then [entry] else []
-  in
-  go idx s (dec t idx)
+  let entry = Array.get t.data idx in
+  if tst entry then [] else go idx [entry] (dec t idx)
 
-let earlier ts than =
-  if ts = Ptime.min then true
-  else Ptime.is_earlier ts ~than
+let read t = read_some entry_not_written t
 
-let read_history t than =
-  let rec go s acc idx =
-    if idx = s then (* don't read it twice *)
-      acc
-    else
-      let ts, v = Array.get t.data idx in
-      if earlier ts than then acc
-      else go s ((ts, v) :: acc) (dec t idx)
-  in
-  let idx = dec t t.write in
-  let ts, v = Array.get t.data idx in
-  if earlier ts than then []
-  else go idx [(ts,v)] (dec t idx)
+let read_history t than = read_some (earlier than) t