attachments: add gif resize support

- images: strip IconManager.resize_gif into its own function

litecord/blueprints/attachments.py

@@ -22,15 +22,34 @@ from pathlib import Path
 from quart import Blueprint, send_file, current_app as app, request
 from PIL import Image
 
+from litecord.images import resize_gif
+
 bp = Blueprint('attachments', __name__)
 ATTACHMENTS = Path.cwd() / 'attachments'
 
 
-async def _resize(image, attach_id: str, ext: str,
+async def _resize_gif(attach_id: int, resized_path: Path,
+                      width: int, height: int) -> str:
+    """Resize a GIF attachment."""
+
+    # get original gif bytes
+    orig_path = ATTACHMENTS / f'{attach_id}.gif'
+    orig_bytes = orig_path.read_bytes()
+
+    # give them and the target size to the
+    # image module's resize_gif
+
+    _data_fd, raw_data = await resize_gif(orig_bytes, (width, height))
+
+    # write raw_data to the destination
+    resized_path.write_bytes(raw_data)
+
+    return str(resized_path)
+
+
+async def _resize(image, attach_id: int, ext: str,
                   width: int, height: int) -> str:
     """Resize an image."""
-    # TODO: gif support
-
     # check if we have it on the folder
     resized_path = ATTACHMENTS / f'{attach_id}_{width}_{height}.{ext}'
 
@@ -44,6 +63,11 @@ async def _resize(image, attach_id: str, ext: str,
     # if we dont, we need to generate it off the
     # given image instance.
 
+    # the process is different for gif files because we need
+    # gifsicle. doing it manually is too troublesome.
+    if ext == 'gif':
+        return await _resize_gif(attach_id, resized_path, width, height)
+
     # NOTE: this is the same resize mode for icons.
     resized = image.resize((width, height), resample=Image.LANCZOS)
     resized.save(resized_path_s, format=ext)

litecord/images.py

@@ -194,6 +194,65 @@ def _try_unlink(path: str):
         pass
 
 
+async def resize_gif(raw_data: bytes, target: tuple) -> tuple:
+    """Resize a GIF image."""
+    # generate a temporary file to call gifsticle to and from.
+    input_fd, input_path = tempfile.mkstemp(suffix='.gif')
+    _, output_path = tempfile.mkstemp(suffix='.gif')
+
+    input_handler = os.fdopen(input_fd, 'wb')
+
+    # make sure its valid image data
+    data_fd = BytesIO(raw_data)
+    image = Image.open(data_fd)
+    image.close()
+
+    log.info('resizing a GIF from {} to {}',
+             image.size, target)
+
+    # insert image info on input_handler
+    # close it to make it ready for consumption by gifsicle
+    input_handler.write(raw_data)
+    input_handler.close()
+
+    # call gifsicle under subprocess
+    log.debug('input: {}', input_path)
+    log.debug('output: {}', output_path)
+
+    process = await asyncio.create_subprocess_shell(
+        f'gifsicle --resize {target[0]}x{target[1]} '
+        f'{input_path} > {output_path}',
+        stdout=asyncio.subprocess.PIPE,
+        stderr=asyncio.subprocess.PIPE,
+    )
+
+    # run it, etc.
+    out, err = await process.communicate()
+
+    log.debug('out + err from gifsicle: {}', out + err)
+
+    # write over an empty data_fd
+    data_fd = BytesIO()
+    output_handler = open(output_path, 'rb')
+    data_fd.write(output_handler.read())
+
+    # close unused handlers
+    output_handler.close()
+
+    # delete the files we created with mkstemp
+    _try_unlink(input_path)
+    _try_unlink(output_path)
+
+    # reseek, save to raw_data, reseek again.
+    # TODO: remove raw_data altogether as its inefficient
+    # to have two representations of the same bytes
+    data_fd.seek(0)
+    raw_data = data_fd.read()
+    data_fd.seek(0)
+
+    return data_fd, raw_data
+
+
 class IconManager:
     """Main icon manager."""
     def __init__(self, app):
@@ -257,65 +316,6 @@ class IconManager:
         return await self.generic_get(
             'guild', guild_id, icon_hash, **kwargs)
 
-    async def _resize_gif(self, scope: str, key,
-                          raw_data: bytes, target: tuple) -> tuple:
-        """Resize a GIF image."""
-        # generate a temporary file to call gifsticle to and from.
-        input_fd, input_path = tempfile.mkstemp(suffix='.gif')
-        _, output_path = tempfile.mkstemp(suffix='.gif')
-
-        input_handler = os.fdopen(input_fd, 'wb')
-
-        # make sure its valid image data
-        data_fd = BytesIO(raw_data)
-        image = Image.open(data_fd)
-        image.close()
-
-        log.info('resizing a GIF from {} to {}',
-                 image.size, target)
-
-        # insert image info on input_handler
-        # close it to make it ready for consumption by gifsicle
-        input_handler.write(raw_data)
-        input_handler.close()
-
-        # call gifsicle under subprocess
-        log.debug('input: {}', input_path)
-        log.debug('output: {}', output_path)
-
-        process = await asyncio.create_subprocess_shell(
-            f'gifsicle --resize {target[0]}x{target[1]} '
-            f'{input_path} > {output_path}',
-            stdout=asyncio.subprocess.PIPE,
-            stderr=asyncio.subprocess.PIPE,
-        )
-
-        # run it, etc.
-        await process.communicate()
-
-        # write over an empty data_fd
-        data_fd = BytesIO()
-        output_handler = open(output_path, 'rb')
-        data_fd.write(output_handler.read())
-
-        # close unused handlers
-        output_handler.close()
-
-        # delete the files we created with mkstemp
-        _try_unlink(input_path)
-        _try_unlink(output_path)
-
-        # reseek, save to raw_data, reseek again.
-        # TODO: remove raw_data altogether as its inefficient
-        # to have two representations of the same bytes
-        data_fd.seek(0)
-        raw_data = data_fd.read()
-        data_fd.seek(0)
-
-
-        return data_fd, raw_data
-
-
     async def put(self, scope: str, key: str,
                   b64_data: str, **kwargs) -> Icon:
         """Insert an icon."""
@@ -336,8 +336,7 @@ class IconManager:
         # size management is different for gif files
         # as they're composed of multiple frames.
         if 'size' in kwargs and mime == 'image/gif':
-            data_fd, raw_data = await self._resize_gif(
-                scope, key, raw_data, kwargs['size'])
+            data_fd, raw_data = await resize_gif(raw_data, kwargs['size'])
         elif 'size' in kwargs:
             image = Image.open(data_fd)