1 files changed, 60 insertions, 0 deletions
diff --git a/mysys/my_bitmap.c b/mysys/my_bitmap.c
new file mode 100644
index 00000000000..1434f472f98
--- /dev/null
+++ b/mysys/my_bitmap.c
@@ -0,0 +1,60 @@
+/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
+   
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License as published by the Free Software Foundation; either
+   version 2 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
+   Library General Public License for more details.
+   
+   You should have received a copy of the GNU Library 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 */
+
+/*
+  Handling of uchar arrays as large bitmaps.
+*/
+
+#include "mysys_priv.h"
+#include <my_bitmap.h>
+
+pthread_mutex_t LOCK_bitmap;
+
+void bitmap_set_bit(uchar *bitmap, uint bitmap_size, uint bitmap_bit) {
+  if((bitmap_bit != MY_BIT_NONE) && (bitmap_bit < bitmap_size*8)) {
+    pthread_mutex_lock(&LOCK_bitmap);
+    bitmap[bitmap_bit / 8] |= (1 << bitmap_bit % 8);
+    pthread_mutex_unlock(&LOCK_bitmap);
+  };
+};
+
+uint bitmap_set_next(uchar *bitmap, uint bitmap_size) {
+  uint bit_found = MY_BIT_NONE;
+  int i, b;
+
+  pthread_mutex_lock(&LOCK_bitmap);
+  for(i=0; (i<bitmap_size) && (bit_found==MY_BIT_NONE); i++) {
+    if(bitmap[i] == 0xff) continue;
+    for(b=0; (b<8) && (bit_found==MY_BIT_NONE); b++)
+      if((bitmap[i] & 1<<b) == 0) {
+        bit_found = (i*8)+b;
+        bitmap[i] |= 1<<b;
+      };
+  };
+  pthread_mutex_unlock(&LOCK_bitmap);
+
+  return bit_found;
+};
+
+void bitmap_clear_bit(uchar *bitmap, uint bitmap_size, uint bitmap_bit) {
+  if((bitmap_bit != MY_BIT_NONE) && (bitmap_bit < bitmap_size*8)) {
+    pthread_mutex_lock(&LOCK_bitmap);
+    bitmap[bitmap_bit / 8] &= ~(1 << bitmap_bit % 8);
+    pthread_mutex_unlock(&LOCK_bitmap);
+  };
+};
+