[libvirt] [PATCH 1/3] Add simple bitmap operations to utils
Jim Fehlig
jfehlig at novell.com
Thu May 20 20:45:03 UTC 2010
V2:
- Move bitmap impl to src/util/bitmap.[ch]
- Use CHAR_BIT instead of explicit '8'
- Use size_t instead of unsigned int
- Fix calculation of bitmap size in virBitmapAlloc
- Ensure bit is within range of map in the set, clear, and get
operations
- Use bool in virBitmapGetBit
- Add virBitmapFree to free-like funcs in cfg.mk
---
cfg.mk | 1 +
src/Makefile.am | 1 +
src/libvirt_private.syms | 8 +++
src/util/bitmap.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++
src/util/bitmap.h | 60 ++++++++++++++++++
5 files changed, 225 insertions(+), 0 deletions(-)
create mode 100644 src/util/bitmap.c
create mode 100644 src/util/bitmap.h
diff --git a/cfg.mk b/cfg.mk
index 04719d4..18a83df 100644
--- a/cfg.mk
+++ b/cfg.mk
@@ -67,6 +67,7 @@ local-checks-to-skip = \
useless_free_options = \
--name=VIR_FREE \
--name=sexpr_free \
+ --name=virBitmapFree \
--name=virCPUDefFree \
--name=virCapabilitiesFree \
--name=virCapabilitiesFreeGuest \
diff --git a/src/Makefile.am b/src/Makefile.am
index 889de8e..fad1bc4 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -50,6 +50,7 @@ augeastest_DATA =
# helper APIs for various purposes
UTIL_SOURCES = \
util/authhelper.c util/authhelper.h \
+ util/bitmap.c util/bitmap.h \
util/bridge.c util/bridge.h \
util/buf.c util/buf.h \
util/conf.c util/conf.h \
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index bdeab0f..8149719 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -4,6 +4,14 @@
#
+# bitmap.h
+virBitmapAlloc;
+virBitmapFree;
+virBitmapSetBit;
+virBitmapClearBit;
+virBitmapGetBit;
+
+
# buf.h
virBufferVSprintf;
virBufferEscapeString;
diff --git a/src/util/bitmap.c b/src/util/bitmap.c
new file mode 100644
index 0000000..d733373
--- /dev/null
+++ b/src/util/bitmap.c
@@ -0,0 +1,155 @@
+/*
+ * bitmap.h: Simple bitmap operations
+ *
+ * Copyright (C) 2010 Novell, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Jim Fehlig <jfehlig at novell.com>
+ */
+
+#include <config.h>
+
+#include <limits.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+
+#include "bitmap.h"
+#include "memory.h"
+
+
+struct _virBitmap {
+ size_t size;
+ uint32_t *map;
+};
+
+
+#define VIR_BITMAP_BITS_PER_UNIT (sizeof(uint32_t) * CHAR_BIT)
+#define VIR_BITMAP_UNIT_OFFSET(b) ((b) / VIR_BITMAP_BITS_PER_UNIT)
+#define VIR_BITMAP_BIT_OFFSET(b) ((b) % VIR_BITMAP_BITS_PER_UNIT)
+
+
+/**
+ * virBitmapAlloc:
+ * @size: number of bits
+ *
+ * Allocate a bitmap capable of containing @size bits.
+ *
+ * Returns a pointer to the allocated bitmap or NULL if
+ * memory cannot be allocated.
+ */
+virBitmapPtr virBitmapAlloc(size_t size)
+{
+ virBitmapPtr bitmap;
+ size_t sz = (size + VIR_BITMAP_BITS_PER_UNIT - 1) /
+ VIR_BITMAP_BITS_PER_UNIT;
+
+ if (VIR_ALLOC_N(bitmap, sizeof(virBitmap)) < 0)
+ return NULL;
+
+ if (VIR_ALLOC_N(bitmap->map, sz) < 0) {
+ VIR_FREE(bitmap);
+ return NULL;
+ }
+
+ return bitmap;
+}
+
+/**
+ * virBitmapFree:
+ * @bitmap: previously allocated bitmap
+ *
+ * Free @bitmap previously allocated by virBitmapAlloc.
+ */
+void virBitmapFree(virBitmapPtr bitmap)
+{
+ if (bitmap) {
+ VIR_FREE(bitmap->map);
+ VIR_FREE(bitmap);
+ }
+}
+
+/**
+ * virBitmapSetBit:
+ * @bitmap: Pointer to bitmap
+ * @b: bit position to set
+ *
+ * Set bit position @b in @bitmap
+ *
+ * Returns 0 on if bit is successfully set, -1 on error.
+ */
+int virBitmapSetBit(virBitmapPtr bitmap, unsigned int b)
+{
+ if (bitmap == NULL)
+ return -1;
+
+ if (b > bitmap->size - 1)
+ return -1;
+
+ bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] |= (1 << VIR_BITMAP_BIT_OFFSET(b));
+ return 0;
+}
+
+/**
+ * virBitmapClearBit:
+ * @bitmap: Pointer to bitmap
+ * @b: bit position to clear
+ *
+ * Clear bit position @b in @bitmap
+ *
+ * Returns 0 on if bit is successfully clear, -1 on error.
+ */
+int virBitmapClearBit(virBitmapPtr bitmap, unsigned int b)
+{
+ if (bitmap == NULL)
+ return -1;
+
+ if (b > bitmap->size - 1)
+ return -1;
+
+ bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] &= ~(1 << VIR_BITMAP_BIT_OFFSET(b));
+ return 0;
+}
+
+/**
+ * virBitmapGetBit:
+ * @bitmap: Pointer to bitmap
+ * @b: bit position to get
+ * @result: bool pointer to receive bit setting
+ *
+ * Get setting of bit position @b in @bitmap and store in @result
+ *
+ * On success, @result will contain the setting of @b and 0 is
+ * returned. On failure, -1 is returned and @result is unchanged.
+ */
+int virBitmapGetBit(virBitmapPtr bitmap, unsigned int b, bool *result)
+{
+ uint32_t bit;
+
+ if (bitmap == NULL)
+ return -1;
+
+ if (b > bitmap->size - 1)
+ return -1;
+
+ bit = bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] &
+ (1 << VIR_BITMAP_BIT_OFFSET(b));
+
+ *result = bit != 0;
+ return 0;
+}
diff --git a/src/util/bitmap.h b/src/util/bitmap.h
new file mode 100644
index 0000000..0143b0e
--- /dev/null
+++ b/src/util/bitmap.h
@@ -0,0 +1,60 @@
+/*
+ * bitmap.h: Simple bitmap operations
+ *
+ * Copyright (C) 2010 Novell, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Jim Fehlig <jfehlig at novell.com>
+ */
+
+#ifndef __BITMAP_H__
+# define __BITMAP_H__
+
+#include "internal.h"
+
+#include <stdbool.h>
+#include <sys/types.h>
+
+
+typedef struct _virBitmap virBitmap;
+typedef virBitmap *virBitmapPtr;
+
+/*
+ * Allocate a bitmap capable of containing @size bits.
+ */
+virBitmapPtr virBitmapAlloc(size_t size);
+
+/*
+ * Free previously allocated bitmap
+ */
+void virBitmapFree(virBitmapPtr bitmap);
+
+/*
+ * Set bit position @b in @bitmap
+ */
+int virBitmapSetBit(virBitmapPtr bitmap, unsigned int b);
+
+/*
+ * Clear bit position @b in @bitmap
+ */
+int virBitmapClearBit(virBitmapPtr bitmap, unsigned int b);
+
+/*
+ * Get setting of bit position @b in @bitmap and store in @result
+ */
+int virBitmapGetBit(virBitmapPtr bitmap, unsigned int b, bool *result);
+
+#endif
--
1.6.0.2
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