qemu-e2k/include/qemu/range.h
Hu Tao 7f8f9ef1da Introduce signed range.
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

MST: split up patch
2014-06-19 18:44:19 +03:00

136 lines
3.5 KiB
C

#ifndef QEMU_RANGE_H
#define QEMU_RANGE_H
#include <inttypes.h>
#include <qemu/typedefs.h>
#include "qemu/queue.h"
/*
* Operations on 64 bit address ranges.
* Notes:
* - ranges must not wrap around 0, but can include the last byte ~0x0LL.
* - this can not represent a full 0 to ~0x0LL range.
*/
/* A structure representing a range of addresses. */
struct Range {
uint64_t begin; /* First byte of the range, or 0 if empty. */
uint64_t end; /* 1 + the last byte. 0 if range empty or ends at ~0x0LL. */
};
static inline void range_extend(Range *range, Range *extend_by)
{
if (!extend_by->begin && !extend_by->end) {
return;
}
if (!range->begin && !range->end) {
*range = *extend_by;
return;
}
if (range->begin > extend_by->begin) {
range->begin = extend_by->begin;
}
/* Compare last byte in case region ends at ~0x0LL */
if (range->end - 1 < extend_by->end - 1) {
range->end = extend_by->end;
}
}
/* Get last byte of a range from offset + length.
* Undefined for ranges that wrap around 0. */
static inline uint64_t range_get_last(uint64_t offset, uint64_t len)
{
return offset + len - 1;
}
/* Check whether a given range covers a given byte. */
static inline int range_covers_byte(uint64_t offset, uint64_t len,
uint64_t byte)
{
return offset <= byte && byte <= range_get_last(offset, len);
}
/* Check whether 2 given ranges overlap.
* Undefined if ranges that wrap around 0. */
static inline int ranges_overlap(uint64_t first1, uint64_t len1,
uint64_t first2, uint64_t len2)
{
uint64_t last1 = range_get_last(first1, len1);
uint64_t last2 = range_get_last(first2, len2);
return !(last2 < first1 || last1 < first2);
}
/* 0,1 can merge with 1,2 but don't overlap */
static inline bool ranges_can_merge(Range *range1, Range *range2)
{
return !(range1->end < range2->begin || range2->end < range1->begin);
}
static inline int range_merge(Range *range1, Range *range2)
{
if (ranges_can_merge(range1, range2)) {
if (range1->end < range2->end) {
range1->end = range2->end;
}
if (range1->begin > range2->begin) {
range1->begin = range2->begin;
}
return 0;
}
return -1;
}
static inline GList *g_list_insert_sorted_merged(GList *list,
gpointer data,
GCompareFunc func)
{
GList *l, *next = NULL;
Range *r, *nextr;
if (!list) {
list = g_list_insert_sorted(list, data, func);
return list;
}
nextr = data;
l = list;
while (l && l != next && nextr) {
r = l->data;
if (ranges_can_merge(r, nextr)) {
range_merge(r, nextr);
l = g_list_remove_link(l, next);
next = g_list_next(l);
if (next) {
nextr = next->data;
} else {
nextr = NULL;
}
} else {
l = g_list_next(l);
}
}
if (!l) {
list = g_list_insert_sorted(list, data, func);
}
return list;
}
static inline gint range_compare(gconstpointer a, gconstpointer b)
{
Range *ra = (Range *)a, *rb = (Range *)b;
if (ra->begin == rb->begin && ra->end == rb->end) {
return 0;
} else if (range_get_last(ra->begin, ra->end) <
range_get_last(rb->begin, rb->end)) {
return -1;
} else {
return 1;
}
}
#endif