diff options
Diffstat (limited to 'src/common/container.c')
| -rw-r--r-- | src/common/container.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/src/common/container.c b/src/common/container.c index 979e097d99..7208d36803 100644 --- a/src/common/container.c +++ b/src/common/container.c @@ -639,15 +639,27 @@ smartlist_uniq_strings(smartlist_t *sl) * } */ -/* For a 1-indexed array, we would use LEFT_CHILD[x] = 2*x and RIGHT_CHILD[x] - * = 2*x + 1. But this is C, so we have to adjust a little. */ +/** @{ */ +/** Functions to manipulate heap indices to find a node's parent and children. + * + * For a 1-indexed array, we would use LEFT_CHILD[x] = 2*x and RIGHT_CHILD[x] + * = 2*x + 1. But this is C, so we have to adjust a little. */ //#define LEFT_CHILD(i) ( ((i)+1)*2 - 1) //#define RIGHT_CHILD(i) ( ((i)+1)*2 ) //#define PARENT(i) ( ((i)+1)/2 - 1) #define LEFT_CHILD(i) ( 2*(i) + 1 ) #define RIGHT_CHILD(i) ( 2*(i) + 2 ) #define PARENT(i) ( ((i)-1) / 2 ) - +/** }@ */ + +/** @{ */ +/** Helper macros for heaps: Given a local variable <b>idx_field_offset</b> + * set to the offset of an integer index within the heap element structure, + * IDX_OF_ITEM(p) gives you the index of p, and IDXP(p) gives you a pointer to + * where p's index is stored. Given additionally a local smartlist <b>sl</b>, + * UPDATE_IDX(i) sets the index of the element at <b>i</b> to the correct + * value (that is, to <b>i</b>). + */ #define IDXP(p) ((int*)STRUCT_VAR_P(p, idx_field_offset)) #define UPDATE_IDX(i) do { \ @@ -656,6 +668,7 @@ smartlist_uniq_strings(smartlist_t *sl) } while (0) #define IDX_OF_ITEM(p) (*IDXP(p)) +/** @} */ /** Helper. <b>sl</b> may have at most one violation of the heap property: * the item at <b>idx</b> may be greater than one or both of its children. |