app.py: Add route to page through all item statistics

This route exposes all item statistics and uses the limit and offset
parameters to control paging throug the result set. The logic here
is extremely easy thanks to the brilliant LIMIT and OFFSET features
of SQLite (of course the SQL query sorts the results by some unique
field to ensure the order is already the same).

app.py

@@ -9,6 +9,41 @@ from solr import solr_connection
 db = database_connection_ro()
 solr = solr_connection()
 
+class AllItemsResource:
+    def on_get(self, req, resp):
+        """Handles GET requests"""
+        # Return HTTPBadRequest if id parameter is not present and valid
+        limit = req.get_param_as_int("limit", min=0, max=100) or 100
+        page = req.get_param_as_int("page", min=0) or 0
+        offset = limit * page
+
+        cursor = db.cursor()
+
+        # get total number of items so we can estimate the pages
+        cursor.execute('SELECT COUNT(id) FROM items')
+        pages = round(cursor.fetchone()[0] / limit)
+
+        # get statistics, ordered by id, and use limit and offset to page through results
+        cursor.execute('SELECT id, views, downloads FROM items ORDER BY id ASC LIMIT {0} OFFSET {1}'.format(limit, offset))
+        results = cursor.fetchmany(limit)
+        cursor.close()
+
+        # create a list to hold dicts of item stats
+        statistics = list()
+
+        # iterate over results and build statistics object
+        for item in results:
+            statistics.append({ 'id': item['id'], 'views': item['views'], 'downloads': item['downloads'] })
+
+        message = {
+                'currentPage': page,
+                'totalPages': pages,
+                'limit': limit,
+                'statistics': statistics
+        }
+
+        resp.media = message
+
 class ItemResource:
     def on_get(self, req, resp, item_id):
         """Handles GET requests"""
@@ -27,6 +62,7 @@ class ItemResource:
         resp.media = statistics
 
 api = falcon.API()
+api.add_route('/', AllItemsResource())
 api.add_route('/item/{item_id:int}', ItemResource())
 
 # vim: set sw=4 ts=4 expandtab: