[libvirt] [PATCH 1/3] Add simple bitmap operations to utils

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(a)novell.com&gt; + */ + +#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(a)novell.com&gt; + */ + +#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