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git/oidset.h
René Scharfe 325006f2db oidset: make oidset_size() an inline function
oidset_size() just reads a single word from memory and returns it.
Avoid the function call overhead for this trivial operation by turning
it into an inline function.

While we're at it, declare its parameter const to allow it to be used
on read-only oidsets.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-12 16:14:32 -07:00

117 lines
3.1 KiB
C

#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);
/**
* 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 */