| Jeff King | 29c2bd5 | 2017-02-08 20:53:07 | [diff] [blame] | 1 | #ifndef OIDSET_H |
| 2 | #define OIDSET_H |
| 3 | |
| René Scharfe | 8b2f8cb | 2018-10-04 15:13:06 | [diff] [blame] | 4 | #include "hashmap.h" |
| 5 | #include "khash.h" |
| Jonathan Tan | 9e6fabde | 2017-09-29 22:54:22 | [diff] [blame] | 6 | |
| Jeff King | 29c2bd5 | 2017-02-08 20:53:07 | [diff] [blame] | 7 | /** |
| 8 | * This API is similar to sha1-array, in that it maintains a set of object ids |
| 9 | * in a memory-efficient way. The major differences are: |
| 10 | * |
| 11 | * 1. It uses a hash, so we can do online duplicate removal, rather than |
| 12 | * sort-and-uniq at the end. This can reduce memory footprint if you have |
| 13 | * a large list of oids with many duplicates. |
| 14 | * |
| 15 | * 2. The per-unique-oid memory footprint is slightly higher due to hash |
| 16 | * table overhead. |
| 17 | */ |
| 18 | |
| René Scharfe | 8b2f8cb | 2018-10-04 15:13:06 | [diff] [blame] | 19 | static inline unsigned int oid_hash(struct object_id oid) |
| 20 | { |
| 21 | return sha1hash(oid.hash); |
| 22 | } |
| 23 | |
| 24 | static inline int oid_equal(struct object_id a, struct object_id b) |
| 25 | { |
| 26 | return oideq(&a, &b); |
| 27 | } |
| 28 | |
| 29 | KHASH_INIT(oid, struct object_id, int, 0, oid_hash, oid_equal) |
| 30 | |
| Jeff King | 29c2bd5 | 2017-02-08 20:53:07 | [diff] [blame] | 31 | /** |
| 32 | * A single oidset; should be zero-initialized (or use OIDSET_INIT). |
| 33 | */ |
| 34 | struct oidset { |
| René Scharfe | 8b2f8cb | 2018-10-04 15:13:06 | [diff] [blame] | 35 | kh_oid_t set; |
| Jeff King | 29c2bd5 | 2017-02-08 20:53:07 | [diff] [blame] | 36 | }; |
| 37 | |
| René Scharfe | 8b2f8cb | 2018-10-04 15:13:06 | [diff] [blame] | 38 | #define OIDSET_INIT { { 0 } } |
| Jeff King | 29c2bd5 | 2017-02-08 20:53:07 | [diff] [blame] | 39 | |
| Jeff Hostetler | c3a9ad3 | 2017-11-21 20:58:49 | [diff] [blame] | 40 | |
| René Scharfe | 8c84ae6 | 2018-10-04 15:14:37 | [diff] [blame] | 41 | /** |
| 42 | * Initialize the oidset structure `set`. |
| 43 | * |
| 44 | * If `initial_size` is bigger than 0 then preallocate to allow inserting |
| 45 | * the specified number of elements without further allocations. |
| 46 | */ |
| 47 | void oidset_init(struct oidset *set, size_t initial_size); |
| Jeff Hostetler | c3a9ad3 | 2017-11-21 20:58:49 | [diff] [blame] | 48 | |
| Jeff King | 29c2bd5 | 2017-02-08 20:53:07 | [diff] [blame] | 49 | /** |
| 50 | * Returns true iff `set` contains `oid`. |
| 51 | */ |
| 52 | int oidset_contains(const struct oidset *set, const struct object_id *oid); |
| 53 | |
| 54 | /** |
| 55 | * Insert the oid into the set; a copy is made, so "oid" does not need |
| 56 | * to persist after this function is called. |
| 57 | * |
| 58 | * Returns 1 if the oid was already in the set, 0 otherwise. This can be used |
| 59 | * to perform an efficient check-and-add. |
| 60 | */ |
| 61 | int oidset_insert(struct oidset *set, const struct object_id *oid); |
| 62 | |
| 63 | /** |
| Jeff Hostetler | c3a9ad3 | 2017-11-21 20:58:49 | [diff] [blame] | 64 | * Remove the oid from the set. |
| 65 | * |
| 66 | * Returns 1 if the oid was present in the set, 0 otherwise. |
| 67 | */ |
| 68 | int oidset_remove(struct oidset *set, const struct object_id *oid); |
| 69 | |
| 70 | /** |
| Jeff King | 29c2bd5 | 2017-02-08 20:53:07 | [diff] [blame] | 71 | * Remove all entries from the oidset, freeing any resources associated with |
| 72 | * it. |
| 73 | */ |
| 74 | void oidset_clear(struct oidset *set); |
| 75 | |
| Jeff Hostetler | c3a9ad3 | 2017-11-21 20:58:49 | [diff] [blame] | 76 | struct oidset_iter { |
| René Scharfe | 8b2f8cb | 2018-10-04 15:13:06 | [diff] [blame] | 77 | kh_oid_t *set; |
| 78 | khiter_t iter; |
| Jeff Hostetler | c3a9ad3 | 2017-11-21 20:58:49 | [diff] [blame] | 79 | }; |
| 80 | |
| 81 | static inline void oidset_iter_init(struct oidset *set, |
| 82 | struct oidset_iter *iter) |
| 83 | { |
| René Scharfe | 8b2f8cb | 2018-10-04 15:13:06 | [diff] [blame] | 84 | iter->set = &set->set; |
| 85 | iter->iter = kh_begin(iter->set); |
| Jeff Hostetler | c3a9ad3 | 2017-11-21 20:58:49 | [diff] [blame] | 86 | } |
| 87 | |
| 88 | static inline struct object_id *oidset_iter_next(struct oidset_iter *iter) |
| 89 | { |
| René Scharfe | 8b2f8cb | 2018-10-04 15:13:06 | [diff] [blame] | 90 | for (; iter->iter != kh_end(iter->set); iter->iter++) { |
| 91 | if (kh_exist(iter->set, iter->iter)) |
| 92 | return &kh_key(iter->set, iter->iter++); |
| 93 | } |
| 94 | return NULL; |
| Jeff Hostetler | c3a9ad3 | 2017-11-21 20:58:49 | [diff] [blame] | 95 | } |
| 96 | |
| 97 | static inline struct object_id *oidset_iter_first(struct oidset *set, |
| 98 | struct oidset_iter *iter) |
| 99 | { |
| 100 | oidset_iter_init(set, iter); |
| 101 | return oidset_iter_next(iter); |
| 102 | } |
| 103 | |
| Jeff King | 29c2bd5 | 2017-02-08 20:53:07 | [diff] [blame] | 104 | #endif /* OIDSET_H */ |
