git/oidset.h

123 lines
3.3 KiB
C
Raw Normal View History

#ifndef OIDSET_H
#define OIDSET_H
#include "khash.h"
/**
* This API is similar to oid-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);
/**
* Insert all the oids that are in set 'src' into set 'dest'; a copy
* is made of each oid inserted into set 'dest'.
*/
void oidset_insert_from_set(struct oidset *dest, struct oidset *src);
/**
* 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);
/**
* Returns the number of oids in the set.
*/
static inline int oidset_size(const struct oidset *set)
{
return kh_size(&set->set);
}
/**
* 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);
/*
* Similar to the above, but with a callback which can (1) return non-zero to
* signal displeasure with the object and (2) replace object ID with something
* else (meant to be used to "peel").
*/
typedef int (*oidset_parse_tweak_fn)(struct object_id *, void *);
void oidset_parse_file_carefully(struct oidset *set, const char *path,
oidset_parse_tweak_fn fn, void *cbdata);
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 */