Merge pull request #215 from ToMe25/optimize_libs

Optimize devices lua and python lib

src/main/scripts/lib/lua/devices.lua

@@ -107,7 +107,6 @@ local function fillBuffer(bus)
     return nil, "timeout"
   else
     bus.buffer = unistd.read(bus.fd, 1024)
-    bus.bufferLen = string.len(bus.buffer)
     bus.bufferPos = 1
     return true
   end
@@ -126,7 +125,7 @@ local function readOne(bus)
   end
 
   local result = bus.buffer:byte(bus.bufferPos)
-  if bus.bufferPos >= bus.bufferLen then
+  if bus.bufferPos >= #bus.buffer then
     bus.buffer = nil
   else
     bus.bufferPos = bus.bufferPos + 1
@@ -139,23 +138,39 @@ local function readMessage(bus)
   local value
   local message = ""
   while true do
-    value, reason = readOne(bus)
-    if value == nil then -- error
-      return value, reason
+    if not bus.buffer then
+      local result, status = fillBuffer(bus)
+      if not result then
+        return result, status
+      end
+    end
+
+    value = bus.buffer:sub(bus.bufferPos, -1)
+
+    if #message == 0 and value:byte(1) == 0 then
+      bus.bufferPos = bus.bufferPos + 1
+      value = value:sub(2, -1)
+    end
+
+    if value:find(message_delimiter) then
+      value = value:sub(1, value:find(message_delimiter))
+      bus.bufferPos = bus.bufferPos + #value
+      if bus.bufferPos > #bus.buffer then
+        clearBuffer(bus)
+      end
     else
-      if value == 0 then
-        if message:match("%S") ~= nil then
-          local ok, result = pcall(cjson.decode, message)
-          if ok then
-            return result
-          else
-            return nil, result
-          end
-        else
-          message = ""
-        end
+        clearBuffer(bus)
+    end
+
+    message = message .. value
+
+    if message:byte(-1) == 0 then
+      message = message:sub(1, -2)
+      local ok, result = pcall(cjson.decode, message)
+      if ok then
+        return result
       else
-        message = message .. string.char(value)
+        return nil, result
       end
     end
   end

src/main/scripts/lib/micropython/devices.py

@@ -109,20 +109,36 @@ class DeviceBus:
     def _read_message(self, expected_type):
         message = ""
         while True:
-            value = chr(self._read_one())
-            if value == self.MESSAGE_DELIMITER:
-                if message:
-                    data = json.loads(message)
-                    if data["type"] != expected_type:
-                        raise Exception("unexpected message type: %s" % data["type"])
+            if self.buffer is None:
+                self._fill_buffer()
+
+            value = self.buffer.decode()[self.buffer_pos:]
+
+            if len(message) == 0 and value[0] == self.MESSAGE_DELIMITER:
+                self.buffer_pos += 1
+                value = value[1:]
+
+            if value.find(self.MESSAGE_DELIMITER) != -1:
+                value = value[:value.find(self.MESSAGE_DELIMITER) + 1]
+                self.buffer_pos += len(value)
+                if self.buffer_pos >= len(self.buffer):
+                    self._clear_buffer()
+            else:
+                self._clear_buffer()
+
+            message += value
+ 
+            if message[-1] == self.MESSAGE_DELIMITER:
+                data = json.loads(message)
+                if data["type"] == expected_type:
                     if "data" in data:
                         return data["data"]
                     else:
                         return
+                elif data["type"] == "error":
+                    raise Exception(data["data"])
                 else:
-                    message = ""
-            else:
-                message += value
+                    raise Exception("unexpected message type: %s" % data["type"])
 
     def _read_one(self):
         if self.buffer is None:
@@ -146,8 +162,10 @@ class DeviceBus:
         # This is horrible, but don't know how to know how many bytes are available,
         # so reading one by one is necessary to avoid blocking.
         data = bytearray()
-        while len(data) < limit and len(self.poll.poll(0)) > 0:
+        bytesRead = 0
+        while bytesRead < limit and len(self.poll.poll(0)) > 0:
             data.extend(self.file.read(1))
+            bytesRead += 1
         return data
 
     def _skip_input(self):