messagesoverlay - Replace low memory limit with better automatic predictions

apps/messagesoverlay/README.md

@@ -8,18 +8,20 @@ Messages are ephemeral and not stored on the Bangle.
 
 ## Usage
 
-Close app by tapping the X and scroll by swiping. The border of the pop up changes color if the Bangle is locked. The color depends on your currently active theme.
+Close app by tapping the X and scroll by swiping. The title background of the pop up changes color if the Bangle is locked. The color depends on your currently active theme.
 
 ## Theme support
 
 Using the system theme needs more RAM since it uses a 16 bit color buffer for normal message display. Selecting the "low RAM" theme reduces that to a 4 bit buffer.
+16 bit buffer with a small message takes ~4K RAM blocks while 4 bit buffer only needs about 1.5K.
 
 ## Low memory mode
 
-If free memory is below a configured number of blocks (default is 4000), the overlay automatically only uses 1 bit depth. Default mode uses roundabout 1300 blocks, while low memory mode uses about 600.
+If the overlay estimates that showing the next message would get under the configured minimum free memory limit it automatically only tries to use 1 bit depth. Low memory mode uses about 0.8K blocks plus memory needed for messages. If dropping to 1 bit depth is not enough the oldest messages are discarded to keep the overlay working.
 
 ## Creator
 
 [halemmerich](https://github.com/halemmerich)
+
 Forked from messages_light by Rarder44
 

apps/messagesoverlay/default.json

@@ -2,6 +2,5 @@
     "autoclear": 30,
     "border": 10,
     "minfreemem": 2,
-    "lowmem": 4,
     "systemTheme": true
 }

apps/messagesoverlay/lib.js

@@ -669,11 +669,37 @@ exports.message = function(type, event) {
   if(event.handled) return;
   if(event.messagesoverlayignore) return;
 
+  let free = process.memory().free;
   bpp = settings.systemTheme ? 16 : 4;
-  if (process.memory().free < settings.lowmem)
-    bpp = 1;
 
-  while (process.memory().free < settings.minfreemem && eventQueue.length > 0){
+  let estimatedMemUse = bpp == 16 ? 4096 : (bpp == 4 ? 1536 : 768);
+  // reduce estimation if ovr already exists and uses memory;
+  if (ovr)
+    estimatedMemUse -= ovr.getBPP() == 16 ? 4096 : (ovr.getBPP() == 4 ? 1536 : 768);
+
+  if (process.memory().free - estimatedMemUse < settings.minfreemem * 1024) {
+    // we are going to be under our minfreemem setting if we proceed
+    bpp = 1;
+    if (ovr && ovr.getBPP() > 1){
+      // can reduce memory by going 1 bit
+      let saves = ovr.getBPP() == 16 ? 4096 - 768 : 768;
+      estimatedMemUse -= saves;
+      LOG("Go to 1 bit, saving", saves);
+    } else {
+      estimatedMemUse = 768;
+    }
+  }
+
+
+  if (E.getSizeOf){
+    let e = E.getSizeOf(eventQueue);
+    estimatedMemUse += e;
+    LOG("EventQueue has", e, "blocks");
+  }
+
+  LOG("Free ", free, "estimated use", estimatedMemUse, "for", bpp, "BPP");
+
+  while (process.memory().free - estimatedMemUse < settings.minfreemem * 1024 && eventQueue.length > 0){
     const dropped = eventQueue.pop();
     print("Dropped message because of memory constraints", dropped);
   }
@@ -682,6 +708,8 @@ exports.message = function(type, event) {
     ovr = Graphics.createArrayBuffer(ovrw, ovrh, bpp, {
       msb: true
     });
+    if(E.getSizeOf)
+       LOG("New overlay uses", E.getSizeOf(ovr), "blocks");
   }
 
   ovr.reset();
@@ -713,4 +741,5 @@ exports.message = function(type, event) {
 
   if (!isQuiet()) Bangle.setLCDPower(1);
   event.handled = true;
+  g.flip();
 };

apps/messagesoverlay/settings.js

@@ -57,16 +57,6 @@
         onchange: v => {
           writeSettings("minfreemem",v);
         }
-      },
-      'Low RAM mode': {
-        value: settings.lowmem,
-        min: 0,
-        max: process.memory().total/1000,
-        step: 1,
-        format: v=>v + "k free",
-        onchange: v => {
-          writeSettings("lowmem",v);
-        }
       }
     };
     return mainmenu;