initial work on redis scripts

storage/redis/scripts.go

@@ -0,0 +1,67 @@
+package storage
+
+import (
+	"github.com/garyburd/redigo/redis"
+)
+
+var incSlotsScript = redis.NewScript(1, incSlotsScriptSrc)
+
+const incSlotsScriptSrc = `
+if redis.call("exists", keys[1]) == 1 then
+  local json = redis.call("get", keys[1])
+  local user = cjson.decode(json)
+  user["slots_used"] = user["slots_used"] + 1
+  json = cjson.encode(user)
+  redis.call("set", key, json)
+  return user["slots_used"]
+else
+  return nil
+end
+`
+
+var decSlotsScript = redis.NewScript(1, incSlotsScriptSrc)
+
+const decSlotsScriptSrc = `
+if redis.call("exists", keys[1]) == 1 then
+  local json = redis.call("get", keys[1])
+  local user = cjson.decode(json)
+  if user["slots_used"] > 0
+    user["slots_used"] = user["slots_used"] - 1
+  end
+  json = cjson.encode(user)
+  redis.call("set", key, json)
+  return user["slots_used"]
+else
+  return nil
+end
+`
+
+var activeScript = redis.NewScript(1, decSlotsScriptSrc)
+
+const activeScriptSrc = `
+if redis.call("exists", keys[1]) == 1 then
+  local json = redis.call("get", keys[1])
+  local torrent = cjson.decode(json)
+  torrent["active"] = true
+  json = cjson.encode(torrent)
+  redis.call("set", key, json)
+  return user["slots_used"]
+else
+  return nil
+end
+`
+
+var rmSeederScript = redis.NewScript(2, rmSeederScriptSrc)
+
+const rmSeederScriptSrc = `
+if redis.call("EXISTS", keys[1]) == 1 then
+  local json = redis.call("GET", keys[1])
+  local torrent = cjson.decode(json)
+  table.remove(torrent["seeders"], keys[2])
+  json = cjson.encode(torrent)
+  redis.call("SET", key, json)
+  return 0
+else
+  return nil
+end
+`