Improved image cache filename creation

apps/converter/api.py

@@ -36,36 +36,36 @@ def execute_convert(input_filepath, arguments, output_filepath):
 
     proc = subprocess.Popen(command, stderr=subprocess.PIPE)
     return (proc.wait(), proc.stderr.read())
-    
+
-#TODO: merge w/ convert
+
-def in_cache(input_filepath, size, page=0, format='jpg'):
+def create_image_cache_filename(input_filepath, size, page=0, format='jpg'):
     temp_filename, separator = os.path.splitext(os.path.basename(input_filepath))
     temp_path = os.path.join(TEMPORARY_DIRECTORY, temp_filename)
-    output_arg = '%s_%s%s%s' % (temp_path, size, os.extsep, format)
+    return '%s_%s%s%s' % (temp_path, size, os.extsep, format)
-    input_arg = '%s[%s]' % (input_filepath, page)
+
-    if os.path.exists(output_arg):
+   
-        return output_arg
+def in_image_cache(input_filepath, size, page=0, format='jpg'):
+    output_filepath = create_image_cache_filename(input_filepath, size, page, format)
+    if os.path.exists(output_filepath):
+        return output_filepath
     else:
         return None
     
     
 def convert(input_filepath, size, cache=True, page=0, format='jpg'):
-    #TODO: generate output file using lightweight hash function on
+    output_filepath = create_image_cache_filename(input_filepath, size, page, format)
-    #file name or file content
+    if os.path.exists(output_filepath):
-    temp_filename, separator = os.path.splitext(os.path.basename(input_filepath))
+        return output_filepath
-    temp_path = os.path.join(TEMPORARY_DIRECTORY, temp_filename)
+        
-    output_arg = '%s_%s%s%s' % (temp_path, size, os.extsep, format)
-    input_arg = '%s[%s]' % (input_filepath, page)
-    if os.path.exists(output_arg):
-        return output_arg
     #TODO: Check mimetype and use corresponding utility
     try:
-        status, error_string = execute_convert(input_arg, '-resize %s' % size, output_arg)
+        input_arg = '%s[%s]' % (input_filepath, page)
+        status, error_string = execute_convert(input_arg, '-resize %s' % size, output_filepath)
         if status:
             errors = get_errors(error_string)
             raise ConvertError(status, errors)
     finally:
-        return output_arg
+        return output_filepath
     
 
 #TODO: slugify OCR_OPTIONS and add to file name to cache

apps/documents/views.py

@@ -15,7 +15,7 @@ from django.utils.http import urlencode
 
 
 from filetransfers.api import serve_file
-from converter.api import convert, in_cache
+from converter.api import convert, in_image_cache
 from common.utils import pretty_size
 
 from utils import from_descriptor_to_tempfile
@@ -360,12 +360,13 @@ def document_edit_metadata(request, document_id):
 def get_document_image(request, document_id, size=PREVIEW_SIZE):
     document = get_object_or_404(Document, pk=document_id)
     
-    filepath = in_cache(document.checksum, size)
+    filepath = in_image_cache(document.checksum, size)
    
     if filepath:
         return serve_file(request, File(file=open(filepath, 'r')))
     else:
         try:
+            #Save to a temporary location
             document.file.open()
             desc = document.file.storage.open(document.file.path)
             filepath = from_descriptor_to_tempfile(desc, document.checksum)