Better handling of boundary conditions

Trying with serialport.readpartial

app/helpers/ConfirmingSyncPatternState.rb

@@ -5,7 +5,7 @@ class ConfirmingSyncPatternState < StatePattern::State
    sync_length = Synchronizer::SYNC_PATTERN.length
    
    # confirm rest of sync pattern 
-   while ((idx < sync_length) && bytes[idx] == Synchronizer::SYNC_PATTERN[idx]) do idx = idx+1 end
+   while (idx < bytes.length && idx < sync_length && bytes[idx] == Synchronizer::SYNC_PATTERN[idx]) do idx = idx+1 end
    
    if (idx == sync_length)
      #p "Sync pattern confirmed"

app/helpers/InSyncState.rb

@@ -1,18 +1,35 @@
 class InSyncState < StatePattern::State
   
-  END_OF_FRAME = "!\n"
+ # END_OF_FRAME = "!\n"
 
   def handle_byte_stream(bytes)
     idx = 0
+    sync_pattern_length = Synchronizer::SYNC_PATTERN.length
+    #p "Sync length: #{sync_length}"
+      
     frame = ""
-    while (idx < bytes.length && bytes[idx] != END_OF_FRAME[0]) do
+
+    while (idx+sync_pattern_length < bytes.length && !new_frame_starts(bytes,idx,sync_pattern_length)) do
       frame = frame + bytes[idx]
       idx = idx +1
+      
     end
-    p "------ FRAME -----"
+        
-    frame_lines = frame.split("\n")
+    # did we reach the end of the frame?
-    p frame_lines # should call to higher level
+    if new_frame_starts(bytes,idx,sync_pattern_length)
-    p "##################"
+      p "------ FRAME -----"
-    return ""
+      frame_lines = frame.split("\n")
+      p frame_lines # should call to higher level
+      p "##################"
+      return bytes[idx+sync_pattern_length..-1]
+    else
+      return nil      
+    end
+
   end
+  
+  private
+     def new_frame_starts(bytes,idx,sync_pattern_length)
+       return bytes[idx..idx+sync_pattern_length-1].eql?(Synchronizer::SYNC_PATTERN)
+     end
 end

app/helpers/SearchingForSyncState.rb

@@ -2,7 +2,7 @@ class SearchingForSyncState < StatePattern::State
   def handle_byte_stream(bytes)
    idx = 0;
    # spool unwanted bytes
-   while (bytes[idx] != Synchronizer::SYNC_PATTERN[0]) do idx = idx+1 end
+   while (idx < bytes.length && bytes[idx] != Synchronizer::SYNC_PATTERN[0]) do idx = idx+1 end
    
    #p "Found pattern at idx = #{idx}"
    transition_to(ConfirmingSyncPatternState)

example_blurp.txt

@@ -117,5 +117,5 @@
 0-1:96.1.0(3238303131303031323439333134383132)
 0-1:24.3.0(130626090000)(00)(60)(1)(0-1:24.2.1)(m3)
 (00309.466)
-0-1:24.4.0(1)
+0-1:24.4.0(3)
 !

smartmeter.rb

@@ -12,7 +12,7 @@ connection_details = YAML::load(File.open('config/database.yml'))
 ActiveRecord::Base.establish_connection(connection_details)
 
 # # Open connection to serial port
-# ser = SerialPort.new("/dev/ttyUSB1", 9600, 7, 1, SerialPort::EVEN)
+ser = SerialPort.new("/dev/ttyUSB1", 9600, 7, 1, SerialPort::EVEN)
 # 
 # # read until newline
 # response = ser.readline("\r")
@@ -20,9 +20,12 @@ ActiveRecord::Base.establish_connection(connection_details)
 # print "#{response}\n"
 
 sync = Synchronizer.new
-lines = File.read("example_blurp.txt")[rand(500)..-1]
+#lines = File.read("example_blurp.txt")[rand(1500)..-1]
-while (lines.length > 0)
+lines = ser.readpartial(4096) # read max 4k of data
+p "There are #{lines.length} characters"
+while (!lines.nil? && lines.length > 0)
   lines = sync.handle_byte_stream(lines)
+  #p lines
 end
 
-p sync
+#p sync