add extractors, rate limit, demo submit form

oedb/middleware/cache.py

@@ -0,0 +1,98 @@
+"""
+Caching middleware for the OpenEventDatabase.
+"""
+
+from oedb.utils.logging import logger
+
+class CacheMiddleware:
+    """
+    Middleware that adds caching headers to responses.
+    
+    This middleware adds appropriate Cache-Control headers to responses
+    based on the endpoint and request method. It helps reduce server load
+    by allowing clients to cache responses for a specified period.
+    """
+    
+    def __init__(self, default_max_age=60):
+        """
+        Initialize the middleware with default caching settings.
+        
+        Args:
+            default_max_age: Default max-age in seconds for cacheable responses.
+        """
+        self.default_max_age = default_max_age
+        
+        # Define caching rules for different endpoints
+        # Format: (endpoint_prefix, method, max_age)
+        self.caching_rules = [
+            # Cache GET requests to /event for 60 seconds
+            ('/event', 'GET', 60),
+            # Cache GET requests to /stats for 300 seconds (5 minutes)
+            ('/stats', 'GET', 300),
+            # Cache GET requests to /demo for 3600 seconds (1 hour)
+            ('/demo', 'GET', 3600),
+            # Don't cache search results
+            ('/event/search', 'POST', 0),
+        ]
+    
+    def process_response(self, req, resp, resource, params):
+        """
+        Add caching headers to the response.
+        
+        Args:
+            req: The request object.
+            resp: The response object.
+            resource: The resource object.
+            params: The request parameters.
+        """
+        # Don't add caching headers for error responses
+        if resp.status_code >= 400:
+            self._add_no_cache_headers(resp)
+            return
+        
+        # Check if the request matches any caching rules
+        max_age = self._get_max_age(req)
+        
+        if max_age > 0:
+            # Add caching headers
+            logger.debug(f"Adding caching headers with max-age={max_age} to {req.method} {req.path}")
+            resp.set_header('Cache-Control', f'public, max-age={max_age}')
+            resp.set_header('Vary', 'Accept-Encoding')
+        else:
+            # Add no-cache headers
+            self._add_no_cache_headers(resp)
+    
+    def _get_max_age(self, req):
+        """
+        Determine the max-age value for the current request.
+        
+        Args:
+            req: The request object.
+            
+        Returns:
+            int: The max-age value in seconds, or 0 for no caching.
+        """
+        # Check if the request matches any caching rules
+        for endpoint, method, max_age in self.caching_rules:
+            if req.path.startswith(endpoint) and req.method == method:
+                return max_age
+        
+        # Default: no caching for write operations, default max-age for read operations
+        if req.method in ('POST', 'PUT', 'DELETE', 'PATCH'):
+            return 0
+        elif req.method == 'GET':
+            return self.default_max_age
+        else:
+            return 0
+    
+    def _add_no_cache_headers(self, resp):
+        """
+        Add headers to prevent caching.
+        
+        Args:
+            resp: The response object.
+        """
+        logger.debug("Adding no-cache headers to response")
+        resp.set_header('Cache-Control', 'no-store, no-cache, must-revalidate, max-age=0')
+        resp.set_header('Pragma', 'no-cache')
+        resp.set_header('Expires', '0')