Index: /trunk/src/kmk/w32/imagecache.c
===================================================================
--- /trunk/src/kmk/w32/imagecache.c	(revision 2635)
+++ /trunk/src/kmk/w32/imagecache.c	(revision 2635)
@@ -0,0 +1,136 @@
+/* $Id$ */
+/** @file
+ * kBuild specific executable image cache for Windows.
+ */
+
+/*
+ * Copyright (c) 2012 knut st. osmundsen <bird-kBuild-spamx@anduin.net>
+ *
+ * This file is part of kBuild.
+ *
+ * kBuild is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * kBuild is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with kBuild.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+/* No GNU coding style here! */
+
+/*******************************************************************************
+*   Header Files                                                               *
+*******************************************************************************/
+#include "make.h"
+
+#include <Windows.h>
+
+
+/*******************************************************************************
+*   Structures and Typedefs                                                    *
+*******************************************************************************/
+typedef struct EXECCACHEENTRY
+{
+    /** The name hash value. */
+    unsigned                uHash;
+    /** The name length. */
+    unsigned                cchName;
+    /** Pointer to the next name with the same hash. */
+    struct EXECCACHEENTRY  *pNext;
+    /** When it was last referenced. */
+    unsigned                uLastRef;
+    /** The module handle. */
+    HMODULE                 hmod1;
+    /** The module handle. */
+    HMODULE                 hmod2;
+    /** The executable path. */
+    char                    szName[1];
+} EXECCACHEENTRY;
+typedef EXECCACHEENTRY *PEXECCACHEENTRY;
+
+/*******************************************************************************
+*   Global Variables                                                           *
+*******************************************************************************/
+/** The number of cached images. */
+static unsigned         g_cCached;
+/** Used noting when entries was last used.
+ * Increased on each kmk_cache_exec_image call.  */
+static unsigned         g_uNow;
+
+/** The size of the hash table. */
+#define EXECCACHE_HASHTAB_SIZE  128
+/** The hash table. */
+static PEXECCACHEENTRY  g_apHashTab[EXECCACHE_HASHTAB_SIZE];
+
+
+/* sdbm:
+   This algorithm was created for sdbm (a public-domain reimplementation of
+   ndbm) database library. it was found to do well in scrambling bits,
+   causing better distribution of the keys and fewer splits. it also happens
+   to be a good general hashing function with good distribution. the actual
+   function is hash(i) = hash(i - 1) * 65599 + str[i]; what is included below
+   is the faster version used in gawk. [there is even a faster, duff-device
+   version] the magic constant 65599 was picked out of thin air while
+   experimenting with different constants, and turns out to be a prime.
+   this is one of the algorithms used in berkeley db (see sleepycat) and
+   elsewhere. */
+
+static unsigned execcache_calc_hash(const char *psz, unsigned *pcch)
+{
+    unsigned char  *puch = (unsigned char *)psz;
+    unsigned        hash = 0;
+    int             ch;
+
+    while ((ch = *puch++))
+        hash = ch + (hash << 6) + (hash << 16) - hash;
+
+    *pcch = (unsigned)(puch - psz - 1);
+    return hash;
+}
+
+
+extern void kmk_cache_exec_image(const char *pszExec)
+{
+    /*
+     * Lookup the name.
+     */
+    unsigned            cchName;
+    const unsigned      uHash = execcache_calc_hash(pszExec, &cchName);
+    PEXECCACHEENTRY    *ppCur = &g_apHashTab[uHash % EXECCACHE_HASHTAB_SIZE];
+    PEXECCACHEENTRY     pCur  = *ppCur;
+    while (pCur)
+    {
+        if (   pCur->uHash   == uHash
+            && pCur->cchName == cchName
+            && !memcmp(pCur->szName, pszExec, cchName))
+        {
+            pCur->uLastRef = ++g_uNow;
+            return;
+        }
+        ppCur = &pCur->pNext;
+        pCur = pCur->pNext;
+    }
+
+    /*
+     * Not found, create a new entry.
+     */
+    pCur = xmalloc(sizeof(*pCur) + cchName);
+    pCur->uHash    = uHash;
+    pCur->cchName  = cchName;
+    pCur->pNext    = NULL;
+    pCur->uLastRef = ++g_uNow;
+    memcpy(pCur->szName, pszExec, cchName + 1);
+    pCur->hmod1 = LoadLibraryEx(pszExec, NULL, LOAD_LIBRARY_AS_DATAFILE);
+    pCur->hmod2 = LoadLibraryEx(pszExec, NULL, DONT_RESOLVE_DLL_REFERENCES);
+
+    *ppCur = pCur;
+    g_cCached++;
+}
+