Remove the MIMETYPE_FILE_READ_SIZE setting

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

HISTORY.rst

@@ -94,6 +94,7 @@
   management app.
 * Move the purge permission logic to the StorePermission
   manager.
+* Remove the MIMETYPE_FILE_READ_SIZE setting.
 
 3.1.11 (2019-04-XX)
 ===================

docs/releases/3.2.rst

@@ -126,6 +126,7 @@ Other changes
   management app.
 * Move the purge permission logic to the StorePermission
   manager.
+* Remove the MIMETYPE_FILE_READ_SIZE setting.
 
 Removals
 --------

mayan/apps/mimetype/api.py

@@ -1,8 +1,10 @@
 from __future__ import unicode_literals
 
+from shutil import copyfileobj
+
 import magic
 
-from .settings import setting_file_read_size
+from mayan.apps.storage.utils import NamedTemporaryFile
 
 
 def get_mimetype(file_object, mimetype_only=False):
@@ -13,22 +15,27 @@ def get_mimetype(file_object, mimetype_only=False):
     file_mimetype = None
     file_mime_encoding = None
 
-    read_size = setting_file_read_size.value
-    if read_size == 0:
-        # If the setting value is 0 that means disable read limit. To disable
-        # the read limit passing None won't work, we pass -1 instead as per
-        # the Python documentation.
-        # https://docs.python.org/2/tutorial/inputoutput.html#methods-of-file-objects
-        read_size = -1
-
-    mime = magic.Magic(mime=True)
-    file_mimetype = mime.from_buffer(file_object.read(read_size))
+    temporary_file_object = NamedTemporaryFile()
     file_object.seek(0)
+    copyfileobj(fsrc=file_object, fdst=temporary_file_object)
+    file_object.seek(0)
+    temporary_file_object.seek(0)
+
+    kwargs = {'mime': True}
 
     if not mimetype_only:
-        file_object.seek(0)
-        mime_encoding = magic.Magic(mime_encoding=True)
-        file_mime_encoding = mime_encoding.from_buffer(file_object.read(read_size))
-        file_object.seek(0)
+        kwargs['mime_encoding'] = True
+
+    try:
+        mime = magic.Magic(**kwargs)
+
+        if mimetype_only:
+            file_mimetype = mime.from_file(filename=temporary_file_object.name)
+        else:
+            file_mimetype, file_mime_encoding = mime.from_file(
+                filename=temporary_file_object.name
+            ).split('; charset=')
+    finally:
+        temporary_file_object.close()
 
     return file_mimetype, file_mime_encoding

mayan/apps/mimetype/literals.py

@@ -1,3 +0,0 @@
-from __future__ import unicode_literals
-
-DEFAULT_MIMETYPE_FILE_READ_SIZE = 1024

mayan/apps/mimetype/settings.py

@@ -1,18 +0,0 @@
-from __future__ import unicode_literals
-
-from django.utils.translation import ugettext_lazy as _
-
-from mayan.apps.smart_settings import Namespace
-
-from .literals import DEFAULT_MIMETYPE_FILE_READ_SIZE
-
-namespace = Namespace(label=_('MIME type'), name='mimetype')
-
-setting_file_read_size = namespace.add_setting(
-    default=DEFAULT_MIMETYPE_FILE_READ_SIZE,
-    global_name='MIMETYPE_FILE_READ_SIZE', help_text=_(
-        'Amount of bytes to read from a document to determine its MIME type. '
-        'Setting it to 0 disables the feature and attempts to read the entire '
-        'document file into memory.'
-    )
-)