* Refactoring: move sink/source buffering into separate classes.

* Buffer the HashSink.  This speeds up hashing a bit because it
  prevents lots of calls to the hash update functions (e.g. nix-hash
  went from 9.3s to 8.7s of user time on the closure of my
  /var/run/current-system).

1 files changed, 3 insertions, 6 deletions

diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 5107a93de299..525e5fc7bbe3 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -1103,16 +1103,14 @@ struct HashAndWriteSink : Sink
     HashAndWriteSink(Sink & writeSink) : writeSink(writeSink), hashSink(htSHA256)
     {
     }
-    virtual void operator ()
-        (const unsigned char * data, unsigned int len)
+    virtual void operator () (const unsigned char * data, size_t len)
     {
         writeSink(data, len);
         hashSink(data, len);
     }
     Hash currentHash()
     {
-        HashSink hashSinkClone(hashSink);
-        return hashSinkClone.finish().first;
+        return hashSink.currentHash().first;
     }
 };
 
@@ -1201,8 +1199,7 @@ struct HashAndReadSource : Source
     {
         hashing = true;
     }
-    virtual void operator ()
-        (unsigned char * data, unsigned int len)
+    virtual void operator () (unsigned char * data, size_t len)
     {
         readSource(data, len);
         if (hashing) hashSink(data, len);