From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 29 May 2013 21:29:58 +0000 (-0700)
Subject: Merge branch 'jk/lookup-object-prefer-latest'
X-Git-Tag: v1.8.4-rc0~247
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/4818cfcdcc8011e5eef353d0f64cd9d2374ea381?ds=inline;hp=-c

Merge branch 'jk/lookup-object-prefer-latest'

Optimizes object lookup when the object hashtable starts to become
crowded.

* jk/lookup-object-prefer-latest:
lookup_object: prioritize recently found objects
---

4818cfcdcc8011e5eef353d0f64cd9d2374ea381
diff --combined object.c
index 20703f52ed,3fb1caa29f..88d0bece81
--- a/object.c
+++ b/object.c
@@@ -71,13 -71,13 +71,13 @@@ static unsigned int hashtable_index(con
  
  struct object *lookup_object(const unsigned char *sha1)
  {
- 	unsigned int i;
+ 	unsigned int i, first;
  	struct object *obj;
  
  	if (!obj_hash)
  		return NULL;
  
- 	i = hashtable_index(sha1);
+ 	first = i = hashtable_index(sha1);
  	while ((obj = obj_hash[i]) != NULL) {
  		if (!hashcmp(sha1, obj->sha1))
  			break;
@@@ -85,6 -85,16 +85,16 @@@
  		if (i == obj_hash_size)
  			i = 0;
  	}
+ 	if (obj && i != first) {
+ 		/*
+ 		 * Move object to where we started to look for it so
+ 		 * that we do not need to walk the hash table the next
+ 		 * time we look for it.
+ 		 */
+ 		struct object *tmp = obj_hash[i];
+ 		obj_hash[i] = obj_hash[first];
+ 		obj_hash[first] = tmp;
+ 	}
  	return obj;
  }
  
@@@ -185,16 -195,6 +195,16 @@@ struct object *parse_object_buffer(cons
  	return obj;
  }
  
 +struct object *parse_object_or_die(const unsigned char *sha1,
 +				   const char *name)
 +{
 +	struct object *o = parse_object(sha1);
 +	if (o)
 +		return o;
 +
 +	die(_("unable to parse object: %s"), name ? name : sha1_to_hex(sha1));
 +}
 +
  struct object *parse_object(const unsigned char *sha1)
  {
  	unsigned long size;