[Guile-commits] 03/04: Add weak-table fast path for update

[Andy Wingo]

wingo pushed a commit to branch master
in repository guile.

commit 668153dbb61040dc0f2d44e6653d4f7ed6e7c407
Author: Andy Wingo <address@hidden>
Date:   Sat Nov 26 16:30:57 2016 +0100

    Add weak-table fast path for update
    
    * libguile/weak-table.c (weak_table_put_x): If the key is the same and
      the table is weak-key, avoid re-setting disappearing links.
---
 libguile/weak-table.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/libguile/weak-table.c b/libguile/weak-table.c
index f6f8dd6..1bb513b 100644
--- a/libguile/weak-table.c
+++ b/libguile/weak-table.c
@@ -686,6 +686,16 @@ weak_table_put_x (scm_t_weak_table *table, unsigned long 
hash,
         }
     }
           
+  /* Fast path for updated values for existing entries of weak-key
+     tables.  */
+  if (table->kind == SCM_WEAK_TABLE_KIND_KEY &&
+      entries[k].hash == hash &&
+      entries[k].key == SCM_UNPACK (key))
+    {
+      entries[k].value = SCM_UNPACK (value);
+      return;
+    }
+
   if (entries[k].hash)
     unregister_disappearing_links (&entries[k], table->kind);
   else