Feature: Built django-images into Pinry

django_images/models.py

@@ -0,0 +1,132 @@
+import hashlib
+import os.path
+from io import BytesIO
+
+from django.db import models
+from django.core.files.uploadedfile import InMemoryUploadedFile
+from django.core.urlresolvers import reverse
+from django.dispatch import receiver
+import PIL
+
+try:
+    from importlib import import_module
+except ImportError:
+    from django.utils.importlib import import_module
+
+from . import utils
+from .settings import IMAGE_SIZES, IMAGE_PATH, IMAGE_AUTO_DELETE
+
+
+def hashed_upload_to(instance, filename, **kwargs):
+    image_type = 'original' if isinstance(instance, Image) else 'thumbnail'
+    prefix = 'image/%s/by-md5/' % (image_type,)
+    hasher = hashlib.md5()
+    for chunk in instance.image.chunks():
+        hasher.update(chunk)
+    hash_ = hasher.hexdigest()
+    base, ext = os.path.splitext(filename)
+    return '%(prefix)s%(first)s/%(second)s/%(hash)s/%(base)s%(ext)s' % {
+        'prefix': prefix,
+        'first': hash_[0],
+        'second': hash_[1],
+        'hash': hash_,
+        'base': base,
+        'ext': ext,
+    }
+
+
+if IMAGE_PATH is None:
+    upload_to = hashed_upload_to
+else:
+    if callable(IMAGE_PATH):
+        upload_to = IMAGE_PATH
+    else:
+        parts = IMAGE_PATH.split('.')
+        module_name = '.'.join(parts[:-1])
+        module = import_module(module_name)
+        upload_to = getattr(module, parts[-1])
+
+
+class Image(models.Model):
+    image = models.ImageField(upload_to=upload_to,
+                              height_field='height', width_field='width',
+                              max_length=255)
+    height = models.PositiveIntegerField(default=0, editable=False)
+    width = models.PositiveIntegerField(default=0, editable=False)
+
+    def get_by_size(self, size):
+        return self.thumbnail_set.get(size=size)
+
+    def get_absolute_url(self, size=None):
+        if not size:
+            return self.image.url
+        try:
+            return self.get_by_size(size).image.url
+        except Thumbnail.DoesNotExist:
+            return reverse('image-thumbnail', args=(self.id, size))
+
+
+class ThumbnailManager(models.Manager):
+    def get_or_create_at_size(self, image_id, size):
+        image = Image.objects.get(id=image_id)
+        if size not in IMAGE_SIZES:
+            raise ValueError("Received unknown size: %s" % size)
+        try:
+            thumbnail = image.get_by_size(size)
+        except Thumbnail.DoesNotExist:
+            img = utils.scale_and_crop(image.image, **IMAGE_SIZES[size])
+            # save to memory
+            buf = BytesIO()
+            try:
+                img.save(buf, img.format, **img.info)
+            except IOError:
+                if img.info.get('progression'):
+                    orig_MAXBLOCK = PIL.ImageFile.MAXBLOCK
+                    temp_MAXBLOCK = 1048576
+                    if orig_MAXBLOCK >= temp_MAXBLOCK:
+                        raise
+                    PIL.ImageFile.MAXBLOCK = temp_MAXBLOCK
+                    try:
+                        img.save(buf, img.format, **img.info)
+                    finally:
+                        PIL.ImageFile.MAXBLOCK = orig_MAXBLOCK
+                else:
+                    raise
+            # and save to storage
+            original_dir, original_file = os.path.split(image.image.name)
+            thumb_file = InMemoryUploadedFile(buf, "image", original_file,
+                                              None, buf.tell(), None)
+            thumbnail, created = image.thumbnail_set.get_or_create(
+                size=size, defaults={'image': thumb_file})
+        return thumbnail
+
+
+class Thumbnail(models.Model):
+    original = models.ForeignKey(Image)
+    image = models.ImageField(upload_to=upload_to,
+                              height_field='height', width_field='width',
+                              max_length=255)
+    size = models.CharField(max_length=100)
+    height = models.PositiveIntegerField(default=0, editable=False)
+    width = models.PositiveIntegerField(default=0, editable=False)
+
+    objects = ThumbnailManager()
+
+    class Meta:
+        unique_together = ('original', 'size')
+
+    def get_absolute_url(self):
+        return self.image.url
+
+
+@receiver(models.signals.post_save)
+def original_changed(sender, instance, created, **kwargs):
+    if isinstance(instance, Image):
+        instance.thumbnail_set.all().delete()
+
+
+@receiver(models.signals.post_delete)
+def delete_image_files(sender, instance, **kwargs):
+    if isinstance(instance, (Image, Thumbnail)) and IMAGE_AUTO_DELETE:
+        if instance.image.storage.exists(instance.image.name):
+            instance.image.delete(save=False)