7c47959d0c
Calling our function g_list_insert_sorted_merged is a misnomer, since we are NOT writing a glib function. Furthermore, we are making every caller pass the same comparator function of range_merge(): any caller that would try otherwise would break in weird ways since our internal call to ranges_can_merge() is hard-coded to operate only on ranges, rather than paying attention to the caller's comparator. Better is to fix things so that callers don't have to care about our internal comparator, by picking a function name and updating the parameter type away from a gratuitous use of void*, to make it obvious that we are operating specifically on a list of ranges and not a generic list. Plus, refactoring the code here will make it easier to plug a memory leak in the next patch. range_compare() is now internal only, and moves to the .c file. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1464712890-14262-3-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
85 lines
2.5 KiB
C
85 lines
2.5 KiB
C
/*
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* QEMU 64-bit address ranges
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*
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* Copyright (c) 2015-2016 Red Hat, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#ifndef QEMU_RANGE_H
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#define QEMU_RANGE_H
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#include "qemu/queue.h"
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/*
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* Operations on 64 bit address ranges.
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* Notes:
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* - ranges must not wrap around 0, but can include the last byte ~0x0LL.
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* - this can not represent a full 0 to ~0x0LL range.
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*/
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/* A structure representing a range of addresses. */
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struct Range {
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uint64_t begin; /* First byte of the range, or 0 if empty. */
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uint64_t end; /* 1 + the last byte. 0 if range empty or ends at ~0x0LL. */
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};
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static inline void range_extend(Range *range, Range *extend_by)
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{
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if (!extend_by->begin && !extend_by->end) {
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return;
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}
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if (!range->begin && !range->end) {
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*range = *extend_by;
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return;
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}
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if (range->begin > extend_by->begin) {
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range->begin = extend_by->begin;
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}
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/* Compare last byte in case region ends at ~0x0LL */
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if (range->end - 1 < extend_by->end - 1) {
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range->end = extend_by->end;
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}
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}
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/* Get last byte of a range from offset + length.
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* Undefined for ranges that wrap around 0. */
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static inline uint64_t range_get_last(uint64_t offset, uint64_t len)
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{
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return offset + len - 1;
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}
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/* Check whether a given range covers a given byte. */
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static inline int range_covers_byte(uint64_t offset, uint64_t len,
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uint64_t byte)
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{
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return offset <= byte && byte <= range_get_last(offset, len);
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}
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/* Check whether 2 given ranges overlap.
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* Undefined if ranges that wrap around 0. */
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static inline int ranges_overlap(uint64_t first1, uint64_t len1,
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uint64_t first2, uint64_t len2)
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{
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uint64_t last1 = range_get_last(first1, len1);
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uint64_t last2 = range_get_last(first2, len2);
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return !(last2 < first1 || last1 < first2);
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}
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GList *range_list_insert(GList *list, Range *data);
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#endif
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