[PATCH] new functions libxl_bitmap_{or,and}

[Linda Jacobson <lindaj@jma3.com>]

provide logical and and or of two bitmaps

---

v.1  updated comments and format
v.2  rewrote bitmap functions to manipulate bytes not bits

Signed-off-by: Linda Jacobson <lindaj@jma3.com>
---
 tools/libxl/libxl_utils.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++
 tools/libxl/libxl_utils.h |  5 ++++
 2 files changed, 79 insertions(+)

diff --git a/tools/libxl/libxl_utils.c b/tools/libxl/libxl_utils.c
index 9053b27..5c7178f 100644
--- a/tools/libxl/libxl_utils.c
+++ b/tools/libxl/libxl_utils.c
@@ -691,6 +691,80 @@ void libxl_bitmap_reset(libxl_bitmap *bitmap, int bit)
     bitmap->map[bit / 8] &= ~(1 << (bit & 7));
 }
 
+/* provide logical or and logical and of two bitmaps */
+int libxl_bitmap_or(libxl_ctx *ctx, libxl_bitmap *or_map,
+                    libxl_bitmap *map1, libxl_bitmap *map2)
+{
+    GC_INIT(ctx);
+    int rc;
+    uint32_t i;
+    libxl_bitmap *lgmap;
+    libxl_bitmap *smap;
+
+    if (map1->size > map2->size) {
+        lgmap = map1;
+        smap = map2;
+    }
+    else {
+        lgmap = map2;
+        smap = map1;
+    }
+
+    rc = libxl_bitmap_alloc(ctx, or_map, lgmap->size * 8);
+    if (rc)
+        goto out;
+
+    /*
+     *  if bitmaps aren't the same size, their union (logical or) will
+     *  be size of larger bit map.  Any bit past the end of the
+     *  smaller bit map, will match the larger one.
+     */
+    for (i = 0; i < smap->size; i++)
+        or_map->map[i] = (smap->map[i] | lgmap->map[i]);
+
+    for (i = smap->size; i < lgmap->size; i++)
+        or_map->map[i] = lgmap->map[i];
+
+out:
+    GC_FREE;
+    return rc;
+}
+
+int libxl_bitmap_and(libxl_ctx *ctx, libxl_bitmap *and_map,
+                     libxl_bitmap *map1, libxl_bitmap *map2)
+{
+    GC_INIT(ctx);    
+    int rc;
+    uint32_t i;
+    libxl_bitmap *lgmap, *smap;
+
+    if (map1->size >  map2->size) {
+        lgmap = map1;
+        smap = map2;
+    }
+    else {
+        lgmap = map2;
+        smap = map1;
+    }
+
+
+    rc = libxl_bitmap_alloc(ctx, and_map, smap->size * 8);
+    if (rc)
+        goto out;
+
+    /* 
+     *  if bitmaps aren't same size, their 'and' will be size of
+     *  smaller bit map
+     */
+    for (i = 0; i < and_map->size; i++)
+        and_map->map[i] = (lgmap->map[i] & smap->map[i]);
+
+out: 
+    GC_FREE;
+    return rc;
+
+}
+
 int libxl_bitmap_count_set(const libxl_bitmap *bitmap)
 {
     int i, nr_set_bits = 0;
diff --git a/tools/libxl/libxl_utils.h b/tools/libxl/libxl_utils.h
index acacdd9..1c0086b 100644
--- a/tools/libxl/libxl_utils.h
+++ b/tools/libxl/libxl_utils.h
@@ -90,6 +90,11 @@ int libxl_bitmap_test(const libxl_bitmap *bitmap, int bit);
 void libxl_bitmap_set(libxl_bitmap *bitmap, int bit);
 void libxl_bitmap_reset(libxl_bitmap *bitmap, int bit);
 int libxl_bitmap_count_set(const libxl_bitmap *cpumap);
+/* or and and functions for two bitmaps */
+int libxl_bitmap_or(libxl_ctx *ctx, libxl_bitmap *or_map,
+                    libxl_bitmap *map1, libxl_bitmap *map2); 
+int libxl_bitmap_and(libxl_ctx *ctx, libxl_bitmap *and_map,
+                     libxl_bitmap *map1, libxl_bitmap *map2);
 char *libxl_bitmap_to_hex_string(libxl_ctx *ctx, const libxl_bitmap *cpumap);
 static inline void libxl_bitmap_set_any(libxl_bitmap *bitmap)
 {
-- 
1.9.1