From a0b0fb83f91bb82534a0d83fdd6c0222567b098d Mon Sep 17 00:00:00 2001
From: Erkki Seppälä <erkki.seppala@vincit.fi>
Date: Mon, 20 Dec 2010 12:58:37 +0200
Subject: dix: add hashing functions to resource.h for others to use.
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The public hashing function HashResourceID uses the same hashing
hashing algorithm as resource.c uses internally, but it provides an
interface that will is usable by external modules. It provides a
parameter for the number of bits for the hash, instead of finding the
size from its internal hash table.

Signed-off-by: Erkki Seppälä <erkki.seppala@vincit.fi>
---
 dix/resource.c | 37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

(limited to 'dix/resource.c')

diff --git a/dix/resource.c b/dix/resource.c
index 5691b1608..9714061b8 100644
--- a/dix/resource.c
+++ b/dix/resource.c
@@ -636,27 +636,34 @@ InitClientResources(ClientPtr client)
     return TRUE;
 }
 
-static int
-Hash(int client, XID id)
+int
+HashResourceID(XID id, int numBits)
 {
     id &= RESOURCE_ID_MASK;
-    switch (clientTable[client].hashsize) {
-    case 6:
-        return ((int) (0x03F & (id ^ (id >> 6) ^ (id >> 12))));
-    case 7:
-        return ((int) (0x07F & (id ^ (id >> 7) ^ (id >> 13))));
-    case 8:
-        return ((int) (0x0FF & (id ^ (id >> 8) ^ (id >> 16))));
-    case 9:
-        return ((int) (0x1FF & (id ^ (id >> 9))));
-    case 10:
-        return ((int) (0x3FF & (id ^ (id >> 10))));
-    case 11:
-        return ((int) (0x7FF & (id ^ (id >> 11))));
+    switch (numBits)
+    {
+        case 6:
+            return ((int)(0x03F & (id ^ (id>>6) ^ (id>>12))));
+        case 7:
+            return ((int)(0x07F & (id ^ (id>>7) ^ (id>>13))));
+        case 8:
+            return ((int)(0x0FF & (id ^ (id>>8) ^ (id>>16))));
+        case 9:
+            return ((int)(0x1FF & (id ^ (id>>9))));
+        case 10:
+            return ((int)(0x3FF & (id ^ (id>>10))));
+        case 11:
+            return ((int)(0x7FF & (id ^ (id>>11))));
     }
     return -1;
 }
 
+static int
+Hash(int client, XID id)
+{
+    return HashResourceID(id, clientTable[client].hashsize);
+}
+
 static XID
 AvailableID(int client, XID id, XID maxid, XID goodid)
 {
-- 
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