From 1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Sat, 11 Jan 2020 23:36:56 +0000 Subject: Squashed 'third_party/git/' content from commit cb71568594 git-subtree-dir: third_party/git git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7 --- oidset.h | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 oidset.h (limited to 'oidset.h') diff --git a/oidset.h b/oidset.h new file mode 100644 index 000000000000..5346563b0bcc --- /dev/null +++ b/oidset.h @@ -0,0 +1,100 @@ +#ifndef OIDSET_H +#define OIDSET_H + +#include "hashmap.h" +#include "khash.h" + +/** + * This API is similar to sha1-array, in that it maintains a set of object ids + * in a memory-efficient way. The major differences are: + * + * 1. It uses a hash, so we can do online duplicate removal, rather than + * sort-and-uniq at the end. This can reduce memory footprint if you have + * a large list of oids with many duplicates. + * + * 2. The per-unique-oid memory footprint is slightly higher due to hash + * table overhead. + */ + +/** + * A single oidset; should be zero-initialized (or use OIDSET_INIT). + */ +struct oidset { + kh_oid_set_t set; +}; + +#define OIDSET_INIT { { 0 } } + + +/** + * Initialize the oidset structure `set`. + * + * If `initial_size` is bigger than 0 then preallocate to allow inserting + * the specified number of elements without further allocations. + */ +void oidset_init(struct oidset *set, size_t initial_size); + +/** + * Returns true iff `set` contains `oid`. + */ +int oidset_contains(const struct oidset *set, const struct object_id *oid); + +/** + * Insert the oid into the set; a copy is made, so "oid" does not need + * to persist after this function is called. + * + * Returns 1 if the oid was already in the set, 0 otherwise. This can be used + * to perform an efficient check-and-add. + */ +int oidset_insert(struct oidset *set, const struct object_id *oid); + +/** + * Remove the oid from the set. + * + * Returns 1 if the oid was present in the set, 0 otherwise. + */ +int oidset_remove(struct oidset *set, const struct object_id *oid); + +/** + * Remove all entries from the oidset, freeing any resources associated with + * it. + */ +void oidset_clear(struct oidset *set); + +/** + * Add the contents of the file 'path' to an initialized oidset. Each line is + * an unabbreviated object name. Comments begin with '#', and trailing comments + * are allowed. Leading whitespace and empty or white-space only lines are + * ignored. + */ +void oidset_parse_file(struct oidset *set, const char *path); + +struct oidset_iter { + kh_oid_set_t *set; + khiter_t iter; +}; + +static inline void oidset_iter_init(struct oidset *set, + struct oidset_iter *iter) +{ + iter->set = &set->set; + iter->iter = kh_begin(iter->set); +} + +static inline struct object_id *oidset_iter_next(struct oidset_iter *iter) +{ + for (; iter->iter != kh_end(iter->set); iter->iter++) { + if (kh_exist(iter->set, iter->iter)) + return &kh_key(iter->set, iter->iter++); + } + return NULL; +} + +static inline struct object_id *oidset_iter_first(struct oidset *set, + struct oidset_iter *iter) +{ + oidset_iter_init(set, iter); + return oidset_iter_next(iter); +} + +#endif /* OIDSET_H */ -- cgit 1.4.1