Refactor mapping buffer parser

handel/parser.py

@@ -65,31 +65,39 @@ def dword(array, index, bitsize=16):
 
 def parse_mapping_buffer(raw):
     spectrums, statistics = {}, {}
+
     # Header advance
     header = raw[0:256]
     current = 256
+
     # Header parsing
     assert header[0] == 0x55aa
     assert header[1] == 0xaa55
     assert header[2] == 0x100
     mapping_mode = header[3]
     buffer_index = dword(header, 4)
-    buffer_id = ['a', 'b'][header[7]]
+    buffer_id = header[7]
     pixel_number = header[8]
     starting_pixel = dword(header, 9)
     module_serial_number = header[11]
-    dc1, de1 = header[12:14]
-    dc2, de2 = header[14:16]
-    dc3, de3 = header[16:18]
-    dc4, de4 = header[18:20]
-    sizes = header[20:24]
-    # Check
+    channel_ids = header[12:20:2]
+    channel_detector_ids = header[13:20:2]
+
+    # Checks
     assert mapping_mode == 1  # MCA mapping mode
+    assert starting_pixel == dword(raw, 256+4)
+    assert buffer_id in (0, 1)
+
+    # Unused information, should we do something with it?
+    buffer_index, module_serial_number, channel_detector_ids
+
     # Iterate over pixels
     for _ in range(pixel_number):
+
         # Pixel header advance
         pixel_header = raw[current:current+256]
         current += 256
+
         # Pixel header parsing
         assert pixel_header[0] == 0x33cc
         assert pixel_header[1] == 0xcc33
@@ -98,27 +106,34 @@ def parse_mapping_buffer(raw):
         pixel = dword(pixel_header, 4)
         total_size = dword(pixel_header, 6)
         sizes = pixel_header[8:12]
+
+        # Statistics block
+        stats_block = [
+            [dword(pixel_header, 32 + 8 * i + 2 * j) for j in range(4)]
+            for i in range(4)]
+
         # Iterate over channels
-        for i in range(4):
-            # Get statistics
-            stats = [dword(header, 32 + 8 * i + 2 * j) for j in range(4)]
-            # Set data
-            lst = statistics.setdefault(pixel, [])
-            lst.append(tuple(stats))
-        # Iterate over channels
+        spectrums[pixel] = {}
+        statistics[pixel] = {}
         remaining = total_size - 256
-        for size in sizes:
+        for index, channel_id, size in zip(range(4), channel_ids, sizes):
+
             # Update remaining size
             assert remaining >= 0
             if remaining == 0:
                 break
             remaining -= size
+
             # Sectrum Advance
             spectrum = raw[current:current+size]
             current += size
+
             # Set data
-            lst = spectrums.setdefault(pixel, [])
-            lst.append(spectrum)
+            spectrums[pixel][channel_id] = spectrum
+            statistics[pixel][channel_id] = tuple(stats_block[index])
+
+        # Checks
         assert remaining == 0
-    # Return result
+
+    # Return results
     return spectrums, statistics