Files
deb-python-django-compressor/compressor/base.py
2011-03-30 12:10:39 +02:00

200 lines
7.1 KiB
Python

import os
import re
import socket
from itertools import chain
import tempfile
from subprocess import Popen, PIPE
from django.template.loader import render_to_string
from django.core.files.base import ContentFile
from compressor.cache import get_hexdigest, get_mtime
from compressor.conf import settings
from compressor.exceptions import UncompressableFileError, PrecompilerError
from compressor.storage import default_storage
from compressor.utils import get_class, cached_property, cmd_split
class Compressor(object):
def __init__(self, content=None, output_prefix="compressed"):
self.content = content or ""
self.extra_context = {}
self.type = None
self.output_prefix = output_prefix
self.split_content = []
self.charset = settings.DEFAULT_CHARSET
self.precompilers = settings.COMPRESS_PRECOMPILERS
def split_contents(self):
"""
To be implemented in a subclass, should return an
iterable with three values: kind, value, element
"""
raise NotImplementedError
def get_filename(self, url):
try:
base_url = self.storage.base_url
except AttributeError:
base_url = settings.COMPRESS_URL
if not url.startswith(base_url):
raise UncompressableFileError(
"'%s' isn't accesible via COMPRESS_URL ('%s') and can't be"
" compressed" % (url, base_url))
basename = url.replace(base_url, "", 1)
filename = os.path.join(settings.COMPRESS_ROOT, basename)
if not os.path.exists(filename):
raise UncompressableFileError("'%s' does not exist" % filename)
return filename
@cached_property
def parser(self):
return get_class(settings.COMPRESS_PARSER)(self.content)
@cached_property
def cached_filters(self):
return [get_class(filter_cls) for filter_cls in self.filters]
@cached_property
def mtimes(self):
for kind, value, elem in self.split_contents():
if kind == 'file':
yield str(get_mtime(value))
@cached_property
def cachekey(self):
cachestr = "".join(
chain([self.content], self.mtimes)).encode(self.charset)
return "django_compressor.%s.%s" % (socket.gethostname(),
get_hexdigest(cachestr)[:12])
@cached_property
def storage(self):
return default_storage
@cached_property
def hunks(self):
for kind, value, elem in self.split_contents():
attribs = self.parser.elem_attribs(elem)
if kind == "hunk":
# Let's cast BeautifulSoup element to unicode here since
# it will try to encode using ascii internally later
yield unicode(
self.filter(value, method="input", elem=elem, kind=kind))
elif kind == "file":
content = ""
try:
fd = open(value, 'rb')
try:
content = fd.read()
finally:
fd.close()
except IOError, e:
raise UncompressableFileError(
"IOError while processing '%s': %s" % (value, e))
content = self.filter(content, "input", filename=value, elem=elem, kind=kind)
yield unicode(content, attribs.get("charset", self.charset))
def concat(self):
return "\n".join((hunk.encode(self.charset) for hunk in self.hunks))
def precompile(self, content, **kwargs):
type = None
compiler = None
elem = kwargs['elem']
kind = kwargs['kind']
if kind == "file":
type = os.path.splitext(kwargs['filename'])[1][1:]
for pc in self.precompilers:
if pc.get('extension', None) == type:
compiler = pc
break
elif kind == "hunk":
type = self.parser.elem_attribs(elem).get('type', None)
slash = type.rindex('/')
if slash >= 0:
type = type[slash + 1:]
for pc in self.precompilers:
if pc.get('type', None) == type:
compiler = pc
break
if not compiler:
return content
source_file = tempfile.NamedTemporaryFile(mode='w+b', suffix='.' + compiler['extension'])
dest_file_name = source_file.name[:-len(compiler['extension'])] + compiler['dest_extension']
dest_dir_name = os.path.split(dest_file_name)[0]
command = compiler['command'].format(source=source_file.name, dest=dest_file_name, dest_dir=dest_dir_name)
source_file.write(content)
source_file.flush()
try:
p = Popen(cmd_split(command), stdout=PIPE, stdin=PIPE, stderr=PIPE)
output, err = p.communicate(self.content)
except IOError, e:
raise PrecompilerError(e)
if p.wait() != 0:
if not err:
err = 'Error running pre-compiler with command "{0}"'.format(command)
raise PrecompilerError(err)
if compiler.get('stdout', False):
content = output
else:
output_file = open(dest_file_name)
content = output_file.read()
output_file.close()
os.remove(dest_file_name)
source_file.close()
return content
def filter(self, content, method, **kwargs):
# run compiler
if method == "input":
content = self.precompile(content, **kwargs)
for filter_cls in self.cached_filters:
filter_func = getattr(
filter_cls(content, filter_type=self.type), method)
try:
if callable(filter_func):
content = filter_func(**kwargs)
except NotImplementedError:
pass
return content
@cached_property
def combined(self):
return self.filter(self.concat(), method="output")
@cached_property
def hash(self):
return get_hexdigest(self.combined)[:12]
@cached_property
def new_filepath(self):
return os.path.join(settings.COMPRESS_OUTPUT_DIR.strip(os.sep),
self.output_prefix, "%s.%s" % (self.hash, self.type))
def save_file(self):
if self.storage.exists(self.new_filepath):
return False
self.storage.save(self.new_filepath, ContentFile(self.combined))
return True
def output(self, forced=False):
if not settings.COMPRESS_ENABLED and not forced:
return self.content
context = {
"saved": self.save_file(),
"url": self.storage.url(self.new_filepath),
}
context.update(self.extra_context)
return render_to_string(self.template_name, context)
def output_inline(self):
if settings.COMPRESS_ENABLED:
content = self.combined
else:
content = self.concat()
context = dict(content=content, **self.extra_context)
return render_to_string(self.template_name_inline, context)