Remove some bugs and add some functionalities

This commit was SVN r1020.

src/lfc/lam_bitmap.c

@@ -5,7 +5,6 @@
 #include "lfc/lam_bitmap.h"
 
 #define SIZE_OF_CHAR (sizeof(char) * 8)
-#define LAM_INVALID_BIT -1
 
 static void lam_bitmap_construct(lam_bitmap_t *bm);
 static void lam_bitmap_destruct(lam_bitmap_t *bm);
@@ -21,7 +20,7 @@ lam_class_t lam_bitmap_t_class = {
 static void 
 lam_bitmap_construct(lam_bitmap_t *bm) 
 {
-    bm->size = 0;
+    bm->legal_numbits = 0;
     bm->array_size = 0;
     bm->bitmap = NULL;
 }
@@ -36,11 +35,17 @@ lam_bitmap_destruct(lam_bitmap_t *bm)
 int
 lam_bitmap_init(lam_bitmap_t *bm, size_t size)
 {
-    size_t actual_size = size / SIZE_OF_CHAR;
+    
+    size_t actual_size;
+
+    if (((int)size <= 0) || (NULL == bm))
+	return LAM_ERR_ARG;
+
+    bm->legal_numbits = size;
+    actual_size = size / SIZE_OF_CHAR;
   
     actual_size += (size % SIZE_OF_CHAR == 0) ? 0 : 1;
-    bm->size = actual_size * SIZE_OF_CHAR;
+    bm->bitmap = (unsigned char *) malloc(actual_size);
-    bm->bitmap = (char *) realloc(bm->bitmap, actual_size);
     if (NULL == bm->bitmap)
 	return LAM_ERR_SYSRESOURCE;
 
@@ -56,19 +61,22 @@ lam_bitmap_set_bit(lam_bitmap_t *bm, int bit)
     size_t index, offset, new_size;
     int i;
 
-    index = bit / SIZE_OF_CHAR - 1; 
+    if ((bit < 0) || (NULL == bm))
-    offset = bit % SIZE_OF_CHAR -1;
+	return LAM_ERR_ARG;
+
+    index = bit / SIZE_OF_CHAR; 
+    offset = bit % SIZE_OF_CHAR;
 
     if (index >= bm->array_size) {
 	/* We need to allocate more space for the bitmap, since we are
 	   out of range. We dont throw any error here, because this is
 	   valid and we simply expand the bitmap */
 
-	new_size = index / bm->array_size * bm->array_size;
+	new_size = (index / bm->array_size + 1 ) * bm->array_size;
 	/* New size is just a multiple of the original size to fit in
 	   the index */
 
-	bm->bitmap = (char *) realloc(bm->bitmap, new_size);
+	bm->bitmap = (unsigned char *) realloc(bm->bitmap, new_size);
 	if (NULL == bm->bitmap) {
 	    return LAM_ERR_SYSRESOURCE;
 	}
@@ -77,8 +85,15 @@ lam_bitmap_set_bit(lam_bitmap_t *bm, int bit)
 	for (i = bm->array_size; i < new_size; ++i) {
 	    bm->bitmap[i] = 0;
 	}
+
+	/* Update the array_size */
+	bm->array_size = new_size;
+	bm->legal_numbits = bit + 1;
     }
+    
+    /* Now set the bit */
     bm->bitmap[index] |= (1 << offset);
+
     return 0;
 }
 
@@ -88,7 +103,10 @@ lam_bitmap_clear_bit(lam_bitmap_t *bm, int bit)
 {
     size_t index, offset;
 
-    index = bit / SIZE_OF_CHAR - 1; 
+    if ((bit < 0) || (bit > bm->legal_numbits - 1) || (NULL == bm))
+	return LAM_ERR_ARG;
+
+    index = bit / SIZE_OF_CHAR; 
     offset = bit % SIZE_OF_CHAR;
   
     if (index >= bm->array_size) {
@@ -105,65 +123,94 @@ lam_bitmap_is_set_bit(lam_bitmap_t *bm, int bit)
 {
     size_t index, offset;
   
-    index = bit / SIZE_OF_CHAR - 1; 
+    if ((bit < 0) || (bit > bm->legal_numbits - 1) || (NULL == bm))
-    offset = bit % SIZE_OF_CHAR -1;
+	return LAM_ERR_ARG;
+
+
+    index = bit / SIZE_OF_CHAR; 
+    offset = bit % SIZE_OF_CHAR;
   
     if (index >= bm->array_size) {
 	return LAM_INVALID_BIT;
     }
   
-    if ((0 != bm->bitmap[index]) & (1 << offset))
+    if (0 != (bm->bitmap[index] & (1 << offset)))
 	return 1;
 
     return 0;
 }
 
 
-void
+int
 lam_bitmap_clear_all_bits(lam_bitmap_t *bm)
 {
+    if (NULL == bm)
+	return LAM_ERR_ARG;
+
     memset(bm->bitmap, 0, bm->array_size);
-}
+    return 0;
-
-
-void
-lam_bitmap_set_all_bits(lam_bitmap_t *bm)
-{
-    int i;
-    for (i = 0; i < bm->array_size; ++i) {
-	bm->bitmap[i] = ~((char) 0);
-    }
 }
 
 
 int
-lam_bitmap_find_and_set_first_unset_bit(lam_bitmap_t *bm)
+lam_bitmap_set_all_bits(lam_bitmap_t *bm)
 {
-    size_t i;
+    int i;
-    int position = 0;
+    
-    char temp;
+    if (NULL == bm)
+	return LAM_ERR_ARG;
+     
     for (i = 0; i < bm->array_size; ++i) {
-    
+	bm->bitmap[i] = ~((char) 0);
-	/* Neglect all which dont have an unset bit */
-	while (bm->bitmap[i] == (char)~0)
-	    continue;
-    
-	/* This one has an unset bit, find its bit number */
-	temp = bm->bitmap[i];
-	while (temp & 0x1) {
-	    ++position;
-	    temp >>= 1;
-	}
-      
-	/* Now set the bit number */
-	bm->bitmap[i] |= (bm->bitmap[i] + 1);
     }
     return 0;
 }
 
+#include <stdio.h>
+int
+lam_bitmap_find_and_set_first_unset_bit(lam_bitmap_t *bm)
+{
+    size_t i = 0;
+    int position = 0;
+    unsigned char temp;
+    unsigned char all_ones = 0xff;
+
+    if (NULL == bm)
+	return LAM_ERR_ARG;
+
+    /* Neglect all which dont have an unset bit */
+    while((i < bm->array_size) && (bm->bitmap[i] == all_ones)) {
+	++i;
+    }
+
+    if (i == bm->array_size) {
+	/* increase the bitmap size then */
+	position = bm->array_size * SIZE_OF_CHAR;
+	lam_bitmap_set_bit(bm, position);
+	return position;
+    }
+
+    /* This one has an unset bit, find its bit number */
+
+    temp = bm->bitmap[i];
+    while (temp & 0x1) {
+	++position;
+	temp >>= 1;
+    }
+      
+    /* Now set the bit number */
+    bm->bitmap[i] |= (bm->bitmap[i] + 1);
+
+    position += i * SIZE_OF_CHAR;
+    return position;
+}
+
 
 size_t
 lam_bitmap_size(lam_bitmap_t *bm)
 {
-    return bm->size;
+    if (NULL == bm)
+	return LAM_ERR_ARG;
+    
+    return bm->legal_numbits;
 }

src/lfc/lam_bitmap.h

@@ -5,8 +5,14 @@
 
 /** @file
  *
- *  A bitmap implementation. The bits start off with 0, so this
+ *  A bitmap implementation. The bits start off with 0, so this bitmap
- *  bitmap has bits numbered as bit 0, bit 1, bit 2 and so on
+ *  has bits numbered as bit 0, bit 1, bit 2 and so on. This bitmap
+ *  has auto-expansion capabilities, that is once the size is set
+ *  during init, it can be automatically expanded by setting the bit
+ *  beyond the current size. But note, this is allowed just when the
+ *  bit is set -- so the valid functions are set_bit and
+ *  find_and_set_bit. Other functions like clear, if passed a bit
+ *  outside the initialized range will result in an error.
  */
 
 #ifndef LAM_BITMAP_H
@@ -19,15 +25,21 @@
 #include "lfc/lam_object.h"
 
 /* VPS: Just to compile right now, has to move later on */
+
 #define LAM_ERR_SYSRESOURCE -1
+#define LAM_INVALID_BIT -1
+#define LAM_ERR_ARG -2
 
 extern lam_class_t lam_bitmap_t_class;
 
 struct lam_bitmap_t {
     lam_object_t super; /**< Subclass of lam_object_t */
-    char *bitmap;       /**< The actual bitmap array of characters */
+    unsigned char *bitmap; /**< The actual bitmap array of characters */
-    size_t size;        /**< The number of bits in the bitmap */
     size_t array_size;  /**< The actual array size that maintains the bitmap */
+    size_t legal_numbits; /**< The number of bits which are legal (the
+			    actual bitmap may contain more bits, since
+			    it needs to be rounded to the nearest
+			    char  */
 };
 
 typedef struct lam_bitmap_t lam_bitmap_t;
@@ -100,23 +112,27 @@ int lam_bitmap_find_and_set_first_unset_bit(lam_bitmap_t *bm);
  * Clear all bits in the bitmap
  *
  * @param bitmap The input bitmap (IN)
+ * @return LAM error code if bm is NULL
  * 
  */
-void lam_bitmap_clear_all_bits(lam_bitmap_t *bm);
+int lam_bitmap_clear_all_bits(lam_bitmap_t *bm);
 
 
 /**
  * Set all bits in the bitmap
  * @param bitmap The input bitmap (IN)
+ * @return LAM error code if bm is NULL
  *
  */
-void lam_bitmap_set_all_bits(lam_bitmap_t *bm);
+int lam_bitmap_set_all_bits(lam_bitmap_t *bm);
 
 
 /**
- * Gives the current size (number of bits) in the bitmap
+ * Gives the current size (number of bits) in the bitmap. This is the
+ * legal (accessible) number of bits
  *
  * @param bitmap The input bitmap (IN)
+ * @return LAM error code if bm is NULL
  *
  */
 size_t lam_bitmap_size (lam_bitmap_t *bm);