Merge branch 'po-id' of github.com:bagasme/git-po
[alt-git.git] / oidset.h
blobba4a5a2cd3a7a233bc9ca2cb7cf4a58a1e5a122c
1 #ifndef OIDSET_H
2 #define OIDSET_H
4 #include "khash.h"
6 /**
7 * This API is similar to oid-array, in that it maintains a set of object ids
8 * in a memory-efficient way. The major differences are:
10 * 1. It uses a hash, so we can do online duplicate removal, rather than
11 * sort-and-uniq at the end. This can reduce memory footprint if you have
12 * a large list of oids with many duplicates.
14 * 2. The per-unique-oid memory footprint is slightly higher due to hash
15 * table overhead.
18 /**
19 * A single oidset; should be zero-initialized (or use OIDSET_INIT).
21 struct oidset {
22 kh_oid_set_t set;
25 #define OIDSET_INIT { { 0 } }
28 /**
29 * Initialize the oidset structure `set`.
31 * If `initial_size` is bigger than 0 then preallocate to allow inserting
32 * the specified number of elements without further allocations.
34 void oidset_init(struct oidset *set, size_t initial_size);
36 /**
37 * Returns true iff `set` contains `oid`.
39 int oidset_contains(const struct oidset *set, const struct object_id *oid);
41 /**
42 * Insert the oid into the set; a copy is made, so "oid" does not need
43 * to persist after this function is called.
45 * Returns 1 if the oid was already in the set, 0 otherwise. This can be used
46 * to perform an efficient check-and-add.
48 int oidset_insert(struct oidset *set, const struct object_id *oid);
50 /**
51 * Remove the oid from the set.
53 * Returns 1 if the oid was present in the set, 0 otherwise.
55 int oidset_remove(struct oidset *set, const struct object_id *oid);
57 /**
58 * Returns the number of oids in the set.
60 static inline int oidset_size(const struct oidset *set)
62 return kh_size(&set->set);
65 /**
66 * Remove all entries from the oidset, freeing any resources associated with
67 * it.
69 void oidset_clear(struct oidset *set);
71 /**
72 * Add the contents of the file 'path' to an initialized oidset. Each line is
73 * an unabbreviated object name. Comments begin with '#', and trailing comments
74 * are allowed. Leading whitespace and empty or white-space only lines are
75 * ignored.
77 void oidset_parse_file(struct oidset *set, const char *path);
80 * Similar to the above, but with a callback which can (1) return non-zero to
81 * signal displeasure with the object and (2) replace object ID with something
82 * else (meant to be used to "peel").
84 typedef int (*oidset_parse_tweak_fn)(struct object_id *, void *);
85 void oidset_parse_file_carefully(struct oidset *set, const char *path,
86 oidset_parse_tweak_fn fn, void *cbdata);
88 struct oidset_iter {
89 kh_oid_set_t *set;
90 khiter_t iter;
93 static inline void oidset_iter_init(struct oidset *set,
94 struct oidset_iter *iter)
96 iter->set = &set->set;
97 iter->iter = kh_begin(iter->set);
100 static inline struct object_id *oidset_iter_next(struct oidset_iter *iter)
102 for (; iter->iter != kh_end(iter->set); iter->iter++) {
103 if (kh_exist(iter->set, iter->iter))
104 return &kh_key(iter->set, iter->iter++);
106 return NULL;
109 static inline struct object_id *oidset_iter_first(struct oidset *set,
110 struct oidset_iter *iter)
112 oidset_iter_init(set, iter);
113 return oidset_iter_next(iter);
116 #endif /* OIDSET_H */