Cloned DMOJ

judge/utils/texoid.py

@@ -0,0 +1,85 @@
+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)