resource: Move opening of the transformed resources after cache check

The old version should be functionally the same, but opening up these readers (potentially files) every time is wasteful if we don't read from them.

diff --git a/resource/transform.go b/resource/transform.go
index 005ede7679a63713108b5d6f438a7f9a4bbce0cd..93ace2ba05298c16ef198797cbf051dd35e9aa1d 100644 (file)
--- a/resource/transform.go
+++ b/resource/transform.go
@@ -303,12 +303,6 @@ func (r *transformedResource) transform(setContent bool) (err error) {
 
        first := chain[0]
 
-       contentrc, err := contentReadSeekerCloser(first)
-       if err != nil {
-               return err
-       }
-       defer contentrc.Close()
-
        // Files with a suffix will be stored in cache (both on disk and in memory)
        // partitioned by their suffix. There will be other files below /other.
        // This partition is also how we determine what to delete on server reloads.
@@ -347,6 +341,7 @@ func (r *transformedResource) transform(setContent bool) (err error) {
                r.cache.nlocker.Unlock(key)
                return
        }
+
        defer r.cache.nlocker.Unlock(key)
        defer r.cache.set(key, r)
 
@@ -362,6 +357,13 @@ func (r *transformedResource) transform(setContent bool) (err error) {
 
        tctx.InMediaType = first.MediaType()
        tctx.OutMediaType = first.MediaType()
+
+       contentrc, err := contentReadSeekerCloser(first)
+       if err != nil {
+               return err
+       }
+       defer contentrc.Close()
+
        tctx.From = contentrc
        tctx.To = b1