NDOJ/judge/utils/texoid.py

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2020-01-21 06:35:58 +00:00
import hashlib
import json
import logging
from base64 import b64decode
import requests
from django.conf import settings
from django.core.cache import caches
from judge.utils.file_cache import HashFileCache
from judge.utils.unicode import utf8bytes
logger = logging.getLogger('judge.texoid')
TEXOID_ENABLED = hasattr(settings, 'TEXOID_URL')
class TexoidRenderer(object):
def __init__(self):
self.cache = HashFileCache(settings.TEXOID_CACHE_ROOT,
settings.TEXOID_CACHE_URL,
settings.TEXOID_GZIP)
self.meta_cache = caches[settings.TEXOID_META_CACHE]
self.meta_cache_ttl = settings.TEXOID_META_CACHE_TTL
def query_texoid(self, document, hash):
self.cache.create(hash)
try:
response = requests.post(settings.TEXOID_URL, data=utf8bytes(document), headers={
'Content-Type': 'application/x-tex',
})
response.raise_for_status()
except requests.HTTPError as e:
if e.response.status == 400:
logger.error('Texoid failed to render: %s\n%s', document, e.response.text)
else:
logger.exception('Failed to connect to texoid for: %s', document)
return
except Exception:
logger.exception('Failed to connect to texoid for: %s', document)
return
try:
data = response.json()
except ValueError:
logger.exception('Invalid texoid response for: %s\n%s', document, response.text)
return
if not data['success']:
logger.error('Texoid failure for: %s\n%s', document, data)
return {'error': data['error']}
meta = data['meta']
self.cache.cache_data(hash, 'meta', utf8bytes(json.dumps(meta)), url=False, gzip=False)
result = {
'png': self.cache.cache_data(hash, 'png', b64decode(data['png'])),
'svg': self.cache.cache_data(hash, 'svg', data['svg'].encode('utf-8')),
'meta': meta,
}
return result
def query_cache(self, hash):
result = {
'svg': self.cache.get_url(hash, 'svg'),
'png': self.cache.get_url(hash, 'png'),
}
key = 'texoid:meta:' + hash
cached_meta = self.meta_cache.get(key)
if cached_meta is None:
cached_meta = json.loads(self.cache.read_data(hash, 'meta').decode('utf-8'))
self.meta_cache.set(key, cached_meta, self.meta_cache_ttl)
result['meta'] = cached_meta
return result
def get_result(self, formula):
hash = hashlib.sha1(utf8bytes(formula)).hexdigest()
if self.cache.has_file(hash, 'svg'):
return self.query_cache(hash)
else:
return self.query_texoid(formula, hash)