git/split-index.h
Nguyễn Thái Ngọc Duy f9d7abec2a split-index: add and use unshare_split_index()
When split-index is being used, we have two cache_entry arrays in
index_state->cache[] and index_state->split_index->base->cache[].

index_state->cache[] may share the same entries with base->cache[] so
we can quickly determine what entries are shared. This makes memory
management tricky, we can't free base->cache[] until we know
index_state->cache[] does not point to any of those entries.

unshare_split_index() is added for this purpose, to find shared
entries and either duplicate them in index_state->cache[], or discard
them. Either way it should be safe to free base->cache[] after
unshare_split_index().

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 10:50:20 +09:00

38 lines
1.3 KiB
C

#ifndef SPLIT_INDEX_H
#define SPLIT_INDEX_H
struct index_state;
struct strbuf;
struct ewah_bitmap;
struct split_index {
unsigned char base_sha1[20];
struct index_state *base;
struct ewah_bitmap *delete_bitmap;
struct ewah_bitmap *replace_bitmap;
struct cache_entry **saved_cache;
unsigned int saved_cache_nr;
unsigned int nr_deletions;
unsigned int nr_replacements;
int refcount;
};
struct split_index *init_split_index(struct index_state *istate);
void save_or_free_index_entry(struct index_state *istate, struct cache_entry *ce);
void replace_index_entry_in_base(struct index_state *istate,
struct cache_entry *old,
struct cache_entry *new);
int read_link_extension(struct index_state *istate,
const void *data, unsigned long sz);
int write_link_extension(struct strbuf *sb,
struct index_state *istate);
void move_cache_to_base_index(struct index_state *istate);
void merge_base_index(struct index_state *istate);
void prepare_to_write_split_index(struct index_state *istate);
void finish_writing_split_index(struct index_state *istate);
void discard_split_index(struct index_state *istate);
void add_split_index(struct index_state *istate);
void remove_split_index(struct index_state *istate);
void unshare_split_index(struct index_state *istate, int discard);
#endif