From 4a8851c2a5cb962eb43db0ad0eeb06e82974d6a6 Mon Sep 17 00:00:00 2001
From: kcwu <kcwu@63ad8ddf-47c3-0310-b6dd-a9e9d9715204>
Date: Fri, 25 Feb 2005 20:53:49 +0000
Subject: fix HASH_BITS checking condition. suggest to use bigger value if
 MAX_USERS is quite large.

git-svn-id: http://opensvn.csie.org/pttbbs/trunk/pttbbs@2550 63ad8ddf-47c3-0310-b6dd-a9e9d9715204
---
 include/config.h    | 4 ++++
 include/pttstruct.h | 5 +----
 mbbsd/cache.c       | 7 ++++---
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/include/config.h b/include/config.h
index 14b14d03..5b562c10 100644
--- a/include/config.h
+++ b/include/config.h
@@ -121,6 +121,10 @@
 #define ADD_EXMAILBOX     0              /* 贈送信箱 */
 #endif
 
+#ifndef HASH_BITS
+#define HASH_BITS         16             /* userid->uid hashing bits */
+#endif
+
 /* more.c 中文章頁數上限(lines/22), +4 for safe */
 #define MAX_PAGES         (MAX_EDIT_LINE / 22 + 4)
 
diff --git a/include/pttstruct.h b/include/pttstruct.h
index 26eacc51..e0259c40 100644
--- a/include/pttstruct.h
+++ b/include/pttstruct.h
@@ -280,10 +280,6 @@ typedef struct fileheader_t {
 #define STRLEN     80             /* Length of most string data */
 
 
-/* uhash is a userid->uid hash table -- jochang */
-
-#define HASH_BITS 16
-
 union xitem_t {
     struct {                    /* bbs_item */
 	char    fdate[9];       /* [mm/dd/yy] */
@@ -466,6 +462,7 @@ typedef struct keeploc_t {
 typedef struct {
     int     version;
     /* uhash */
+    /* uhash is a userid->uid hash table -- jochang */
     char    userid[MAX_USERS][IDLEN + 1];
     char    gap_1[IDLEN+1];
     int     next_in_hash[MAX_USERS];
diff --git a/mbbsd/cache.c b/mbbsd/cache.c
index 4345e282..493b9b91 100644
--- a/mbbsd/cache.c
+++ b/mbbsd/cache.c
@@ -150,9 +150,6 @@ add_to_uhash(int n, char *id)
     int            *p, h = StringHash(id)%(1<<HASH_BITS);
     int             times;
     strlcpy(SHM->userid[n], id, sizeof(SHM->userid[n]));
-#if (1<<HASH_BITS)*2 < MAX_USERS
-#error "HASH_BITS too small"
-#endif
 
     p = &(SHM->hash_head[h]);
 
@@ -186,6 +183,10 @@ remove_from_uhash(int n)
 	*p = SHM->next_in_hash[n];
 }
 
+#if (1<<HASH_BITS)*10 < MAX_USERS
+#warning "Suggest to use bigger HASH_BITS for better searchuser() performance,"
+#warning "searchuser() average chaining MAX_USERS/(1<<HASH_BITS) times."
+#endif
 int
 searchuser(char *userid)
 {
-- 
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