lib/fit4ruby/FitFile.rb in fit4ruby-3.0.0 vs lib/fit4ruby/FitFile.rb in fit4ruby-3.1.0

@@ -1,18 +1,20 @@
 #!/usr/bin/env ruby -w
 # encoding: UTF-8
 #
 # = FitFile.rb -- Fit4Ruby - FIT file processing library for Ruby
 #
-# Copyright (c) 2014, 2015 by Chris Schlaeger <[e-mail]>
+# Copyright (c) 2014, 2015, 2016, 2017, 2018
+#   by Chris Schlaeger <[e-mail]>
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of version 2 of the GNU General Public License as
 # published by the Free Software Foundation.
 #
 
 require 'fit4ruby/Log'
+require 'fit4ruby/CRC16'
 require 'fit4ruby/FileNameCoder'
 require 'fit4ruby/FitHeader'
 require 'fit4ruby/FitFileEntity'
 require 'fit4ruby/FitRecord'
 require 'fit4ruby/FitFilter'
@@ -22,10 +24,12 @@
 
 module Fit4Ruby
 
   class FitFile
 
+    include CRC16
+
     def initialize()
       @header = nil
     end
 
     def read(file_name, filter = nil)
@@ -41,14 +45,19 @@
       begin
         while !io.eof?
           offset = io.pos
 
           header = FitHeader.read(io)
-          header.check
 
-          check_crc(io, io.pos, offset + header.end_pos)
+          # If the header has a CRC the header is not included in the
+          # checksumed bytes. Otherwise it is included.
+          check_crc(io, header.has_crc? ? header.header_size : 0,
+                    offset + header.end_pos)
 
+          # Rewind back to the beginning of the data right after the header.
+          io.seek(header.header_size)
+
           entity = FitFileEntity.new
           # This Array holds the raw data of the records that may be needed to
           # dump a human readable form of the FIT file.
           records = []
           # This hash will hold a counter for each record type. The counter is
@@ -84,10 +93,11 @@
 
       begin
         # Create a header object, but don't yet write it into the file.
         header = FitHeader.new
         start_pos = header.header_size
+
         # Move the pointer behind the header section.
         io.seek(start_pos)
         id_mapper = FitMessageIdMapper.new
         top_level_record.write(io, id_mapper)
         end_pos = io.pos
@@ -95,11 +105,10 @@
         crc = write_crc(io, start_pos, end_pos)
 
         # Complete the data of the header section and write it at the start of
         # the file.
         header.data_size = end_pos - start_pos
-        header.crc = crc
         io.seek(0)
         header.write(io)
       ensure
         io.close
       end
@@ -111,48 +120,15 @@
       crc = compute_crc(io, start_pos, end_pos)
 
       # Read the 2 CRC bytes from the end of the file
       io.seek(end_pos)
       crc_ref = io.readbyte.to_i | (io.readbyte.to_i << 8)
-      io.seek(start_pos)
 
       unless crc == crc_ref
-        Log.fatal "Checksum error in file '#{@file_name}'. " +
+        Log.error "Checksum error of segment #{start_pos} to #{end_pos} " +
+                  "in file '#{@file_name}'. " +
                   "Computed 0x#{"%04X" % crc} instead of 0x#{"%04X" % crc_ref}."
       end
-    end
-
-    def write_crc(io, start_pos, end_pos)
-      # Compute the checksum over the data section of the file and append it
-      # to the file. Ideally, we should compute the CRC from data in memory
-      # instead of the file data.
-      crc = compute_crc(io, start_pos, end_pos)
-      io.seek(end_pos)
-      BinData::Uint16le.new(crc).write(io)
-
-      crc
-    end
-
-    def compute_crc(io, start_pos, end_pos)
-      crc_table = [
-        0x0000, 0xCC01, 0xD801, 0x1400, 0xF001, 0x3C00, 0x2800, 0xE401,
-        0xA001, 0x6C00, 0x7800, 0xB401, 0x5000, 0x9C01, 0x8801, 0x4400
-      ]
-
-      io.seek(start_pos)
-
-      crc = 0
-      while io.pos < end_pos
-        byte = io.readbyte
-
-        0.upto(1) do |i|
-          tmp = crc_table[crc & 0xF]
-          crc = (crc >> 4) & 0x0FFF
-          crc = crc ^ tmp ^ crc_table[(byte >> (4 * i)) & 0xF]
-        end
-      end
-
-      crc
     end
 
     def dump_records(records)
       # For each message number we keep a count for how often we already had
       # this kind of message.