Improve CRC performance (#412)

* Find correct parameters for crc and datarange

* Adapt output to URH values

* Added bit2int method and a length fix

* Cython implementation of crc

* cython implementation for crc (first shot)

* Fixed cython crc algorithm and renamed old crc algorithm to reference_crc.
Added tests that compare results of old and new algorithm.

* Huge performance increase for crc bruteforce test

* Performance test with cython code within python

* Cleaned up

* - Removed padding of data to %8 bits
- Some bugfixes

* performance improvement for guess_standard_parameters_and_datarange

* minor updates

* Delta Improvement

* slight performance improvement of delta algorithm

* Delta improvement implemented and used by default

* Delta improvement implemented and used by default

* Delta improvement implemented and used by default

* Bugfix for homematic encoding/decoding

.pytest_cache/v/cache/lastfailed

@@ -0,0 +1 @@
+{}

data/decodings/homematic.c

@@ -52,9 +52,9 @@ int main(int argc, char **argv)
             dec[offset+0] = enc[offset+0];
 
             dec[offset+1] = (~enc[offset+1])^0x89;
-            for(i = offset+2; i < max; i++)
+            for(i = offset + 2; i < max - 3; i++)
                 dec[i] = (enc[i-1]+0xdc) ^ enc[i];
-            dec[offset+i] = enc[offset+i] ^ dec[offset+2];
+            dec[i] = enc[i] ^ dec[offset+2];
 
             dec[max-1]=0; // Set CRC to 0x0000
             dec[max-2]=0;
@@ -85,9 +85,9 @@ int main(int argc, char **argv)
             enc[offset+0] = dec[offset+0];
 
             enc[offset+1] = ~(dec[offset+1]^0x89);
-            for(i = offset+2; i < max; i++)
+            for(i = offset + 2; i < max - 3; i++)
                 enc[i] = (enc[i-1]+0xdc) ^ dec[i];
-            enc[offset+i] = dec[offset+i] ^ dec[offset+2];
+            enc[i] = dec[i] ^ dec[offset+2];
 
             enc[max-1]=0; // Set CRC to 0x0000
             enc[max-2]=0;

data/decodings/homematic_complete.c

@@ -148,12 +148,11 @@ int main(int argc, char **argv)
              */
 
             // Decrypt
-            dec[offset+0] = enc[offset+0];
-
-            dec[offset+1] = (~enc[offset+1])^0x89;
-            for(i = offset+2; i < max; i++)
+            dec[offset+0] = enc[offset+0];            
+            dec[offset+1] = (~enc[offset+1])^0x89;            
+            for(i = offset + 2; i < max - 3; i++)
                 dec[i] = (enc[i-1]+0xdc) ^ enc[i];
-            dec[offset+i] = enc[offset+i] ^ dec[offset+2];
+            dec[i] = enc[i] ^ dec[offset+2];
 
             // Recompute CRC and overwrite with FAKE-CRC, if CRC was OK before
             if(crc_ok)
@@ -190,12 +189,11 @@ int main(int argc, char **argv)
              */
 
             // Encrypt
-            enc[offset+0] = dec[offset+0];
-
-            enc[offset+1] = ~(dec[offset+1]^0x89);
-            for(i = offset+2; i < max; i++)
+            enc[offset+0] = dec[offset+0];            
+            enc[offset+1] = ~(dec[offset+1])^0x89;            
+            for(i = offset + 2; i < max - 3; i++)
                 enc[i] = (enc[i-1]+0xdc) ^ dec[i];
-            enc[offset+i] = dec[offset+i] ^ dec[offset+2];
+            enc[i] = dec[i] ^ dec[offset+2];
 
             // Overwrite with correct CRC
             crcvalue = crc(&enc[8], max-2-8);