semweb and http compile now (but they don't work properly yet).

packages/semweb/murmur.c

@@ -0,0 +1,171 @@
+/*  $Id$
+
+    Part of SWI-Prolog
+
+    Author:	Austin Appleby
+    License:	Public domain
+    See:	http://murmurhash.googlepages.com/
+*/
+
+#include <SWI-Prolog.h>			/* het uintptr_t */
+
+/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+The first one is actually  MurmurHashNeutral2().   It  produces the same
+hash  as  MurmurHashAligned2()  on  little    endian  machines,  but  is
+significantly  slower.  MurmurHashAligned2()  however    is   broken  on
+big-endian machines, as it produces different   hashes, depending on the
+alignment. 
+
+NOTE: This file is a copy of src/pl-hash.c from SWI-Prolog.
+- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
+
+#if WORDS_BIGENDIAN
+
+unsigned int
+rdf_murmer_hash(const void * key, int len, unsigned int seed)
+{ const unsigned int m = 0x5bd1e995;
+  const int r = 24;
+  unsigned int h = seed ^ len;
+  const unsigned char * data = (const unsigned char *)key;
+
+  while( len >= 4 )
+  { unsigned int k;
+
+    k  = data[0];
+    k |= data[1] << 8;
+    k |= data[2] << 16;
+    k |= data[3] << 24;
+
+    k *= m;
+    k ^= k >> r;
+    k *= m;
+    
+    h *= m;
+    h ^= k;
+    
+    data += 4;
+    len -= 4;
+  }
+
+  switch( len )
+  { case 3: h ^= data[2] << 16;
+    case 2: h ^= data[1] << 8;
+    case 1: h ^= data[0];
+      h *= m;
+  };
+
+  h ^= h >> 13;
+  h *= m;
+  h ^= h >> 15;
+
+  return h;
+}
+
+#else /*WORDS_BIGENDIAN*/
+
+#define MIX(h,k,m) { k *= m; k ^= k >> r; k *= m; h *= m; h ^= k; }
+
+unsigned int
+rdf_murmer_hash(const void *key, int len, unsigned int seed)
+{ const unsigned int m = 0x5bd1e995;
+  const int r = 24;
+  const unsigned char * data = (const unsigned char *)key;
+  unsigned int h = seed ^ len;
+  int align = (int)(uintptr_t)data & 3;
+
+  if ( align && (len >= 4) )
+  { unsigned int t = 0, d = 0;
+    int sl, sr;
+
+    switch( align )
+    { case 1: t |= data[2] << 16;
+      case 2: t |= data[1] << 8;
+      case 3: t |= data[0];
+    }
+
+    t <<= (8 * align);
+
+    data += 4-align;
+    len -= 4-align;
+
+    sl = 8 * (4-align);
+    sr = 8 * align;
+
+    while ( len >= 4 )
+    { unsigned int k;
+
+      d = *(unsigned int *)data;
+      t = (t >> sr) | (d << sl);
+      
+      k = t;
+      MIX(h,k,m);
+      t = d;
+      
+      data += 4;
+      len -= 4;
+    }
+
+    d = 0;
+
+    if ( len >= align )
+    { unsigned int k;
+
+      switch( align )
+      { case 3: d |= data[2] << 16;
+	case 2: d |= data[1] << 8;
+	case 1: d |= data[0];
+      }
+
+      k = (t >> sr) | (d << sl);
+      MIX(h,k,m);
+
+      data += align;
+      len -= align;
+
+      switch(len)
+      { case 3: h ^= data[2] << 16;
+	case 2: h ^= data[1] << 8;
+	case 1: h ^= data[0];
+	h *= m;
+      };
+    } else
+    { switch(len)
+      { case 3: d |= data[2] << 16;
+	case 2: d |= data[1] << 8;
+	case 1: d |= data[0];
+	case 0: h ^= (t >> sr) | (d << sl);
+	h *= m;
+      }
+    }
+
+    h ^= h >> 13;
+    h *= m;
+    h ^= h >> 15;
+
+    return h;
+  } else
+  { while( len >= 4 )
+    { unsigned int k = *(unsigned int *)data;
+
+      MIX(h,k,m);
+
+      data += 4;
+      len -= 4;
+    }
+
+    switch(len)
+    { case 3: h ^= data[2] << 16;
+      case 2: h ^= data[1] << 8;
+      case 1: h ^= data[0];
+      h *= m;
+    };
+    
+    h ^= h >> 13;
+    h *= m;
+    h ^= h >> 15;
+    
+    return h;
+  }
+}
+
+#endif /*WORDS_BIGENDIAN*/