sigrok-fwextract-kingst-la2016: rephrase resource file writer

Rearrange the res_writer class of the KingstVis firmware extractor.

Separate the bytes/hexfile handling from file writing. Get the CRC
in that data handing part. Which leaves data processing to internal
helpers, while the calling public routine has all details available,
to provide a more helpful log message to users.

Separate the resource enumeration from the output file creation. Which
prettifies the output (sorted order), and allows future implementations
to easier filter the output if desired.

diff --git a/firmware/kingst-la/sigrok-fwextract-kingst-la2016 b/firmware/kingst-la/sigrok-fwextract-kingst-la2016
index 712bb01f9399c5479a96b2249318a746293bb291..3575b04928a7989523ac69da288aa8e543cae7a2 100755 (executable)
--- a/firmware/kingst-la/sigrok-fwextract-kingst-la2016
+++ b/firmware/kingst-la/sigrok-fwextract-kingst-la2016
@@ -129,25 +129,28 @@ class res_writer(object):
     def __init__(self, res):
         self.res = res
 
-    def _write_file(self, fn, data, decoder=None, zero_pad_to=None):
+    def _decode_crc(self, data, decoder=None):
         if decoder is not None:
             data = decoder(data)
-        if zero_pad_to is not None:
-            if len(data) > zero_pad_to:
-                raise Exception("can not zero_pad_to %d bytes -- data is already %d bytes" % (zero_pad_to, len(data)))
-            data += b"\0" * (zero_pad_to - len(data))
+        data = bytearray(data)
+        crc = zlib.crc32(data) & 0xffffffff
+        return data, crc
+
+    def _write_file(self, fn, data):
         with open(fn, "wb") as fp:
             fp.write(data)
-        data_crc32 = zlib.crc32(data) & 0xffffffff
-        print("saved %d bytes to %s (crc32=%08x)" % (len(data), fn, data_crc32))
-
-    def extract(self, res_fn, out_fn, decoder=None, zero_pad_to=None):
-        self._write_file(out_fn, self.res.get_resource(res_fn), decoder=decoder, zero_pad_to=zero_pad_to)
 
-    def extract_re(self, res_fn_re, out_fn, decoder=None):
-        for res_fn in res.find_resource_names(res_fn_re):
-            fn = re.sub(res_fn_re, out_fn, res_fn).lower()
-            self._write_file(fn, self.res.get_resource(res_fn), decoder=decoder)
+    def extract_re(self, resource_pattern, fname_pattern, decoder=None):
+        resources = sorted(res.find_resource_names(resource_pattern))
+        for resource in resources:
+            fname = re.sub(resource_pattern, fname_pattern, resource)
+            fname = fname.lower()
+            data = self.res.get_resource(resource)
+            data, crc = self._decode_crc(data, decoder=decoder)
+            self._write_file(fname, data)
+            print("resource {rsc}, file {fname}, size {size}, checksum {crc:08x}".format(
+                rsc = resource, fname = fname, size = len(data), crc = crc,
+            ))
 
 def decode_intel_hex(hexdata):
     """ return list of (address, data)