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1 #ifndef RANGESORT_H
2 #define RANGESORT_H
3 
4 /* This implements a simple sorted list of non-overlapping ranges. */
5 
6 #include <debug.h>
7 #include <common.h>
8 #include <gelf.h>
9 
10 typedef enum range_error_t {
11     ERROR_CONTAINS,
12     ERROR_OVERLAPS
13 } range_error_t;
14 
15 typedef struct range_t range_t;
16 struct range_t {
17     GElf_Off start;
18     GElf_Off length;
19     void *user;
20     void (*err_fn)(range_error_t, range_t *, range_t *);
21     void (*user_dtor)(void *);
22 };
23 
24 typedef struct range_list_t range_list_t;
25 
26 range_list_t* init_range_list();
27 void destroy_range_list(range_list_t *);
28 
29 /* Just adds a range to the list. We won't detect whether the range overlaps
30    other ranges or contains them, or is contained by them, till we call
31    sort_ranges(). */
32 void add_unique_range_nosort(range_list_t *ranges,
33                              GElf_Off start, GElf_Off length,
34                              void *user,
35                              void (*err_fn)(range_error_t, range_t *, range_t *),
36                              void (*user_dtor)(void * ));
37 
38 /* Sorts the ranges.  If there are overlapping ranges or ranges that contain
39    other ranges, it will cause the program to exit with a FAIL. */
40 range_list_t* sort_ranges(range_list_t *ranges);
41 /* Find which range value falls in.  Return that range or NULL if value does
42    not fall within any range. */
43 range_t *find_range(range_list_t *ranges, GElf_Off value);
44 int get_num_ranges(const range_list_t *ranges);
45 range_t *get_sorted_ranges(const range_list_t *ranges, int *num_ranges);
46 GElf_Off get_last_address(const range_list_t *ranges);
47 
48 /* This returns a range_list_t handle that contains ranges composed of the
49    adjacent ranges of the input range list.  The user data of each range in
50    the range list is a structure of the type contiguous_range_info_t.
51    This structure contains an array of pointers to copies of the original
52    range_t structures comprising each new contiguous range, as well as the
53    length of that array.
54 
55    NOTE: The input range must be sorted!
56 
57    NOTE: destroy_range_list() will take care of releasing the data that it
58    allocates as a result of calling get_contiguous_ranges().  Do not free that
59    data yourself.
60 
61    NOTE: the user data of the original range_t structures is simply copied, so
62    be careful handling it. You can destroy the range_list_t with
63    destroy_range_list() as usual.  On error, the function does not return--the
64    program terminates.
65 
66    NOTE: The returned range is not sorted.  You must call sort_ranges() if you
67    need to.
68 */
69 
70 typedef struct {
71     int num_ranges;
72     range_t *ranges;
73 } contiguous_range_info_t;
74 
75 range_list_t* get_contiguous_ranges(const range_list_t *);
76 
77 /* The function below takes in two range lists: r and s, and subtracts the
78    ranges in s from those in r.  For example, if r and s are as follows:
79 
80    r = { [0, 10) }
81    s = { [3, 5), [7, 9) }
82 
83    Then r - s is { [0, 3), [5, 7), [9, 10) }
84 
85    NOTE: Both range lists must be sorted on input.  This is guarded by an
86          assertion.
87 
88    NOTE: Range s must contain ranges, which are fully contained by the span of
89          range r (the span being the interval between the start of the lowest
90          range in r, inclusive, and the end of the highest range in r,
91          exclusive).
92 
93    NOTE: In addition to the requirement above, range s must contain ranges,
94          each of which is a subrange of one of the ranges of r.
95 
96    NOTE: There is no user info associated with the resulting range.
97 
98    NOTE: The resulting range is not sorted.
99 
100    Ther returned list must be destroyed with destroy_range_list().
101 */
102 
103 range_list_t* subtract_ranges(const range_list_t *r, const range_list_t *s);
104 
105 #endif/*RANGESORT_H*/
106