def crop_image(image: Image.Image, x: int, y: int, w: int, h: int) -> Image.Image:
logger.debug(
'图片裁剪：裁剪图片 {image}，'
'裁剪区域 x:{x}+{w} y:{y}+{h}'.format(image=image, x=x, y=y, w=w, h=h))
image = image.crop((x, y, x + w, y + h))
logger.debug('图片裁剪：完成√')
return image
def resize_image(image: Image.Image, max_width: int, max_height: int) -> Image.Image:
logger.debug('图片缩放：缩放图片 {image}，'
'目标尺寸 {width} * {height}'.format(image=image, width=max_width,
height=max_height))
w, h = image.size
if w > max_width or h > max_height:
ratio = min(max_width / w, max_height / h)
image = image.resize((int(w * ratio), int(h * ratio)), Image.ANTIALIAS)
logger.debug('图片缩放：完成√')
return image
def generate_thumbnails(image: Image, sizes: dict, target_format: str = 'PNG',
target_mode: str = 'RGBA', optimize: bool = False) -> dict:
thumbs = {}
for size, limits in sizes.items():
logger.debug('缩略图生成：生成缩略图 {size} {limits}'.format(size=size, limits=limits))
resized_image = resize_image(image, limits['WIDTH'], limits['HEIGHT'])
compressed_io = compress_image(resized_image, limits['SIZE'], target_format, target_mode,
optimize)
thumbs[size] = compressed_io
logger.debug('缩略图生成：完成√')
return thumbs
def url(self, name, virtual_name: str = None, sign: bool = True):
name = self._get_target_name(name)
logger.debug('OSS存储后端：生成url {path}，签名：{sign}'.format(path=name,
sign=sign))
params = dict()
if not virtual_name:
virtual_name = name
params.update(_make_content_headers(virtual_name))
if sign:
return self.bucket.sign_url(
'GET', name, OSS_SIGNED_URL_EXPIRE,
params=params) # default access link expire time: 5min
else:
return self.bucket._make_url(self.bucket_name, name)
def listdir(self, name):
name = self._get_target_name(name)
logger.debug('OSS存储后端：列目录 {path}'.format(path=name))
if name and name.endswith('/'):
name = name[:-1]
files = []
dirs = set()
for obj in ObjectIterator(self.bucket, prefix=name, delimiter='/'):
if obj.is_prefix():
dirs.add(obj.key)
else:
files.append(obj.key)
return list(dirs), files
def get_preferred_language(cls, request):
try:
lang_codes = request.headers['Accept-Language'].split(';')
lang_codes = [x.split(',') for x in lang_codes]
accept_langs = set()
accept_langs.add(cls.LANGUAGE_CODE_MAPPING[lang_codes[0][0]])
for lang in lang_codes[1:]:
try:
accept_langs.add(cls.LANGUAGE_CODE_MAPPING[lang[1]])
except KeyError:
pass
for lang in accept_langs:
if lang in settings.LANGUAGES:
return lang
except Exception:
pass # 忽略处理过程中的所有错误，并返回网站默认语言
logger.debug('语言中间件：读取Accept-Language发生错误，返回系统默认语言')
return settings.LANGUAGE_CODE
def compress_image(image: Image.Image, target_size: int, target_format: str = 'PNG',
target_mode: str = 'RGBA', optimize: bool = False) -> BytesIO:
image = image.convert(mode=target_mode)
temp_io = BytesIO()
image.save(temp_io, target_format, optimize=optimize)
w, h = image.size
ratio = 1
logger.debug(
'图片压缩：压缩图片 {image}({size})，目标大小 {target_size}，'
'目标格式 {target_format}'.format(image=image,
size=temp_io.tell(),
target_size=target_size,
target_format=target_format))
while temp_io.tell() > target_size:
ratio -= 0.1
if ratio <= 0:
raise Exception(_('图片压缩失败！'))
resized_image = image.resize(w * ratio, h * ratio)
temp_io = BytesIO()
resized_image.save(temp_io, target_format, optimize=optimize)
logger.debug('图片压缩：完成√')
return temp_io
def __call__(self, request):
logger.debug('语言中间件：收到请求，开始处理。')
user = request.user
if user.is_authenticated:
profile = user.profile
lang = profile.language
logger.debug('语言中间件：成功获取到UserProfile')
translation.activate(lang)
response = self.get_response(request)
response.set_cookie(settings.LANGUAGE_COOKIE_NAME, lang)
elif settings.LANGUAGE_COOKIE_NAME in request.COOKIES:
logger.debug('语言中间件：用户未登录，读取COOKIE')
lang = request.COOKIES[settings.LANGUAGE_COOKIE_NAME]
if lang in settings.LANGUAGES:
translation.activate(lang)
response = self.get_response(request)
else:
logger.debug('语言中间件：用户未登录，读取Accept-Language请求头')
lang = self.get_preferred_language(request)
translation.activate(lang)
response = self.get_response(request)
response.set_cookie(settings.LANGUAGE_COOKIE_NAME, lang)
logger.debug('语言中间件：语言已设定为 %s' % lang)
return response
def _save(self, name, content: File):
# 为保证django行为的一致性，保存文件时，应该返回相对于`media path`的相对路径。
target_name = self._get_target_name(name)
logger.debug('OSS存储后端：保存文件 %s' % target_name)
content.open()
# 默认分片大小 1MB
DEFAULT_CHUNK_SIZE = 1 * 1024 * 1024
logger.debug('OSS存储后端：读取完成，文件大小 %d' % content.size)
if not content.multiple_chunks(chunk_size=DEFAULT_CHUNK_SIZE):
logger.debug('OSS存储后端：不分片，开始上传')
# 不分片
content_str = content.file.read()
self.bucket.put_object(target_name, content_str)
else:
logger.debug('OSS存储后端：分片，开始上传')
# 改用分片上传方式
upload_id = self.bucket.init_multipart_upload(
target_name).upload_id
parts = []
part_id = 1
for chunk in content.chunks(chunk_size=DEFAULT_CHUNK_SIZE):
# TODO Create an API endpoint for getting uploading process
result = self.bucket.upload_part(target_name, upload_id,
part_id, chunk)
parts.append(PartInfo(part_id, result.etag))
part_id += 1
logger.debug('OSS存储后端：上传分片 #%d' % part_id)
result = self.bucket.complete_multipart_upload(
target_name, upload_id, parts)
logger.debug('OSS存储后端：上传完毕，关闭文件')
content.close()
return self._clean_name(name)
def _open(self, name, mode='rb'):
name = self._get_target_name(name)
logger.debug('OSS存储后端：打开文件 {name}，模式 {mode}'.format(name=name,
mode=mode))
file = AliyunFile(name, self, mode)
return file
