Implemented the hash checking of generate_headers.py to avoid rebuilding unnecessarily (https://github.com/CoolProp/CoolProp/issues/34)

Signed-off-by: Ian bell <ian.h.bell@gmail.com>

dev/JSON_to_CPP.py

@@ -6,6 +6,7 @@ import struct
 import os
 import argparse, textwrap
 import sys
+import generate_headers
 
 # 0: Input file path relative to dev folder
 # 1: Output file path relative to include folder
@@ -16,7 +17,7 @@ values = [
     ('mixtures/mixture_reducing_parameters.json', 'mixture_reducing_parameters_JSON.h', 'mixture_reducing_parameters_JSON')
 ]
 
-def TO_CPP(root_dir):
+def TO_CPP(root_dir, hashes):
     def to_chunks(l, n):
         if n<1:
             n=1
@@ -48,17 +49,26 @@ def TO_CPP(root_dir):
         # Put the lines back together again
         # The chunks are joined together with commas, and then EOL are used to join the rest
         hex_string = ',\n'.join([', '.join(chunk) for chunk in chunks])
+            
+        # Check if hash is up to date based on using variable as key
+        if variable not in hashes or (variable in hashes and hashes[variable] != generate_headers.get_hash(hex_string)):
         
-        # Generate the output string
-        output  = '// File generated by the script dev/JSON_to_CPP.py on '+ str(datetime.now()) + '\n\n'
-        output += '// JSON file encoded in binary form\n'
-        output += 'const unsigned char '+variable+'_binary[] = {\n' + hex_string + '\n};'+'\n\n'
-        output += '// Combined into a single std::string \n'
-        output += 'std::string {v:s}({v:s}_binary, {v:s}_binary + sizeof({v:s}_binary)/sizeof({v:s}_binary[0]));'.format(v = variable)
-        
-        f = open(os.path.join(root_dir,'include',outfile), 'w')
-        f.write(output)
-        f.close()
+            # Generate the output string
+            output  = '// File generated by the script dev/JSON_to_CPP.py on '+ str(datetime.now()) + '\n\n'
+            output += '// JSON file encoded in binary form\n'
+            output += 'const unsigned char '+variable+'_binary[] = {\n' + hex_string + '\n};'+'\n\n'
+            output += '// Combined into a single std::string \n'
+            output += 'std::string {v:s}({v:s}_binary, {v:s}_binary + sizeof({v:s}_binary)/sizeof({v:s}_binary[0]));'.format(v = variable)
+            
+            # Write it to file
+            f = open(os.path.join(root_dir,'include',outfile), 'w')
+            f.write(output)
+            f.close()
+            
+            # Store the hash of the data that was written to file (not including the header)
+            hashes[variable] = generate_headers.get_hash(hex_string)
+        else:
+            print(outfile + 'is up to date')
 
 if __name__=='__main__':
     parser = argparse.ArgumentParser(

dev/generate_headers.py

@@ -8,33 +8,50 @@ from datetime import datetime
 import subprocess
 import os
 import sys
+import json
+import hashlib
+
+def get_hash(data):
+    return hashlib.sha224("Nobody inspects the spammish repetition").hexdigest()
+
+# Load up the hashes of the data that will be written to each file
+if os.path.exists('hashes.json'):
+    hashes = json.load(open('hashes.json','r'))
+else:
+    hashes = dict()
 
 def version_to_file(root_dir):
-    print('*** Generating cpversion.h ***')
+    
     # Get the version from the version.txt file
     version = open(os.path.join(root_dir,'version.txt'),'r').read().strip()
     
-    # Format the string to be written
-    string_for_file = '//Generated by the generate_headers.py script on {t:s}\n\nstatic char version [] ="{v:s}";'.format(t = str(datetime.now()),v = version)
-    
-    # Include path relative to the root
-    include_dir = os.path.join(root_dir,'include')
-    
-    # The name of the file to be written into
-    file_name = os.path.join(include_dir,'cpversion.h')
-    
-    # Write to file
-    f = open(file_name,'w')
-    f.write(string_for_file)
-    f.close()
+    # Get the hash of the version
+    if 'version' not in hashes or ('version' in hashes and hashes['version'] != get_hash(version)):
+        print('*** Generating cpversion.h ***')
+        hashes['version'] = get_hash(version)
+        
+        # Format the string to be written
+        string_for_file = '//Generated by the generate_headers.py script on {t:s}\n\nstatic char version [] ="{v:s}";'.format(t = str(datetime.now()),v = version)
+        
+        # Include path relative to the root
+        include_dir = os.path.join(root_dir,'include')
+        
+        # The name of the file to be written into
+        file_name = os.path.join(include_dir,'cpversion.h')
+        
+        # Write to file
+        f = open(file_name,'w')
+        f.write(string_for_file)
+        f.close()
+    else:
+        print('cpversion.h is up to date')
     
 def gitrev_to_file(root_dir):
     """
     If a git repo, use git to update the gitrevision.  If not a git repo, read 
     the gitrevision from the gitrevision.txt file.  Otherwise, fail.
     """
-    print('*** Generating gitrevision.h ***')
-        
+    
     try:
         try:
             subprocess.check_call('git --version', shell=True)
@@ -53,28 +70,31 @@ def gitrev_to_file(root_dir):
         
         if p.returncode != 0:
             print('tried to update git revision, but it failed for some reason (building from zip file?)')
-            gitstring = '//Generated by the generate_headers.py script on {t:s}\n\n std::string gitrevision = \"???????\";'
-            f = open(os.path.join(include_dir,'gitrevision.h'),'w')
-            f.write(gitstring)
-            f.close()
-            return
+            gitrev = '???'
         else:
-            rev = stdout.strip()
-            print('git revision is', rev)
-            
-            gitstring = '//Generated by the generate_headers.py script on {t:s}\n\nstd::string gitrevision = \"{rev:s}\";'.format(t = str(datetime.now()), rev = rev)
+            gitrev = stdout.strip()
+            print('git revision is', gitrev)
             
             try:
-                is_hash = rev.find(' ') == -1 # python 2.x
+                is_hash = gitrev.find(' ') == -1 # python 2.x
             except TypeError:
-                is_hash = ' ' not in str(rev) # python 3.x
+                is_hash = ' ' not in str(gitrev) # python 3.x
                                 
             if not is_hash:
                 raise ValueError('No hash returned from call to git, got '+rev+' instead')
             
+        if 'gitrevision' not in hashes or ('gitrevision' in hashes and hashes['gitrevision'] != get_hash(gitrev)):
+            print('*** Generating gitrevision.h ***')
+            gitstring = '//Generated by the generate_headers.py script on {t:s}\n\nstd::string gitrevision = \"{rev:s}\";'.format(t = str(datetime.now()), rev = gitrev)
+        
             f = open(os.path.join(include_dir,'gitrevision.h'),'w')
             f.write(gitstring)
             f.close()
+            
+            hashes['gitrevision'] = get_hash(gitrev)
+        else:
+            print('gitrevision.h is up to date')
+            
                 
     except (subprocess.CalledProcessError,OSError):
         pass
@@ -83,14 +103,15 @@ if __name__=='__main__':
     path = os.path.abspath(__file__)
     path = os.path.dirname(path)
     path = os.path.dirname(path)
-   
-#     if os.path.exists(os.path.join(path, ".JSON_done")):
-#       sys.exit()
 
     version_to_file(root_dir = path)
     gitrev_to_file(root_dir = path)
     import JSON_to_CPP
-    JSON_to_CPP.TO_CPP(root_dir = path)
+    JSON_to_CPP.TO_CPP(root_dir = path, hashes = hashes)
 
-    open(os.path.join(path, ".JSON_done"), "w").close()
+    # Write the hashes to a hashes JSON file
+    if hashes:
+        fp = open('hashes.json','w')
+        fp.write(json.dumps(hashes))
+        fp.close()