Add VBM, a resizing bitmap implementation we previously had in kqueue.

git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@2769 d4fa192b-c00b-0410-8231-f00ffab90ce4

diff --git a/varnish-cache/include/vbm.h b/varnish-cache/include/vbm.h
new file mode 100644 (file)
index 0000000..7015a1d
--- /dev/null
+++ b/varnish-cache/include/vbm.h
@@ -0,0 +1,103 @@
+/*-
+ * Copyright (c) 2006 Verdens Gang AS
+ * Copyright (c) 2006-2008 Linpro AS
+ * All rights reserved.
+ *
+ * Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $Id: cache_acceptor_kqueue.c 2513 2008-02-18 17:04:30Z des $
+ *
+ * Self-sizeing bitmap operations
+ */
+
+#include "config.h"
+
+/**********************************************************************
+ * Generic bitmap functions, may be generalized at some point.
+ */
+
+#define VBITMAP_TYPE   unsigned        /* Our preferred wordsize */
+#define VBITMAP_LUMP   (32*1024)       /* How many bits we alloc at a time */
+#define VBITMAP_WORD   (sizeof(VBITMAP_TYPE) * 8)
+#define VBITMAP_IDX(n) (n / VBITMAP_WORD)
+#define VBITMAP_BIT(n) (1U << (n % VBITMAP_WORD))
+
+struct vbitmap {
+       VBITMAP_TYPE    *bits;
+       unsigned        nbits;
+};
+
+static inline void
+vbit_expand(struct vbitmap *vb, unsigned bit)
+{
+       unsigned char *p;
+
+       bit += VBITMAP_LUMP - 1;
+       bit -= (bit % VBITMAP_LUMP);
+       p = realloc(vb->bits, bit / 8);
+       AN(p);
+       memset(p + vb->nbits / 8, 0, (bit - vb->nbits) / 8);
+       vb->bits = (void*)p;
+       vb->nbits = bit;
+}
+
+static inline struct vbitmap *
+vbit_init(unsigned initial)
+{
+       struct vbitmap *vb;
+
+       vb = calloc(sizeof *vb, 1);
+       AN(vb);
+       if (initial == 0)
+               initial = VBITMAP_LUMP;
+       vbit_expand(vb, initial);
+       return (vb);
+}
+
+static inline void
+vbit_set(struct vbitmap *vb, unsigned bit)
+{
+
+       if (bit >= vb->nbits)
+               vbit_expand(vb, bit);
+       vb->bits[VBITMAP_IDX(bit)] |= VBITMAP_BIT(bit);
+}
+
+static inline void
+vbit_clr(struct vbitmap *vb, unsigned bit)
+{
+
+       if (bit >= vb->nbits)
+               vbit_expand(vb, bit);
+       vb->bits[VBITMAP_IDX(bit)] &= ~VBITMAP_BIT(bit);
+}
+
+static inline int
+vbit_test(struct vbitmap *vb, unsigned bit)
+{
+
+       if (bit >= vb->nbits)
+               vbit_expand(vb, bit);
+       return (vb->bits[VBITMAP_IDX(bit)] & VBITMAP_BIT(bit));
+}