implement caching

2 files changed, 32 insertions, 1 deletions

diff --git a/lib/array.fnl b/lib/array.fnl
index 8b81c5c..8af6244 100644
--- a/lib/array.fnl
+++ b/lib/array.fnl
@@ -53,6 +53,16 @@
       (lua "return true")))
   false)
 
+(fn list [obj]
+  (local result [])
+  (var cursor 1)
+  (each [_ v (pairs obj)]
+    (tset result cursor v)
+    (set cursor (+ 1 cursor)))
+  ;; sort so we always return the same list for the same object
+  (table.sort result)
+  result)
+
 (local join table.concat)
 
-{: sort : concat : diff : unique : flatten : join : contains}
+{: sort : concat : diff : unique : flatten : join : contains : list}
diff --git a/lib/cache.fnl b/lib/cache.fnl
new file mode 100644
index 0000000..b21a05e
--- /dev/null
+++ b/lib/cache.fnl
@@ -0,0 +1,21 @@
+(local {: must} (require :lib.utils))
+
+(fn get [db key else]
+  (local result
+    (must (luna.db.query db "SELECT value FROM cache WHERE key = ?"
+                         [key])))
+  (or (if (and result (< 0 (# result)))
+        (. (. result 1) 1)
+        nil)
+      else))
+
+(fn _set [db key value]
+  value
+  (must (luna.db.exec db "INSERT OR REPLACE INTO cache VALUES (?, ?)"
+                      [key value]))
+  value)
+
+(fn clear-tx [tx]
+  (must (luna.db.exec-tx tx "DELETE FROM cache" [])))
+
+{: get :set _set : clear-tx}