[thirdparty/git.git] / split-index.c

#include "cache.h"
#include "split-index.h"
#include "ewah/ewok.h"

struct split_index *init_split_index(struct index_state *istate)
{
	if (!istate->split_index) {
		istate->split_index = xcalloc(1, sizeof(*istate->split_index));
		istate->split_index->refcount = 1;
	}
	return istate->split_index;
}

int read_link_extension(struct index_state *istate,
			 const void *data_, unsigned long sz)
{
	const unsigned char *data = data_;
	struct split_index *si;
	int ret;

	if (sz < 20)
		return error("corrupt link extension (too short)");
	si = init_split_index(istate);
	hashcpy(si->base_sha1, data);
	data += 20;
	sz -= 20;
	if (!sz)
		return 0;
	si->delete_bitmap = ewah_new();
	ret = ewah_read_mmap(si->delete_bitmap, data, sz);
	if (ret < 0)
		return error("corrupt delete bitmap in link extension");
	data += ret;
	sz -= ret;
	si->replace_bitmap = ewah_new();
	ret = ewah_read_mmap(si->replace_bitmap, data, sz);
	if (ret < 0)
		return error("corrupt replace bitmap in link extension");
	if (ret != sz)
		return error("garbage at the end of link extension");
	return 0;
}

int write_link_extension(struct strbuf *sb,
			 struct index_state *istate)
{
	struct split_index *si = istate->split_index;
	strbuf_add(sb, si->base_sha1, 20);
	if (!si->delete_bitmap && !si->replace_bitmap)
		return 0;
	ewah_serialize_strbuf(si->delete_bitmap, sb);
	ewah_serialize_strbuf(si->replace_bitmap, sb);
	return 0;
}

static void mark_base_index_entries(struct index_state *base)
{
	int i;
	/*
	 * To keep track of the shared entries between
	 * istate->base->cache[] and istate->cache[], base entry
	 * position is stored in each base entry. All positions start
	 * from 1 instead of 0, which is reserved to say "this is a new
	 * entry".
	 */
	for (i = 0; i < base->cache_nr; i++)
		base->cache[i]->index = i + 1;
}

void move_cache_to_base_index(struct index_state *istate)
{
	struct split_index *si = istate->split_index;
	int i;

	/*
	 * If "si" is shared with another index_state (e.g. by
	 * unpack-trees code), we will need to duplicate split_index
	 * struct. It's not happening now though, luckily.
	 */
	assert(si->refcount <= 1);

	unshare_split_index(istate, 0);
	if (si->base) {
		discard_index(si->base);
		free(si->base);
	}
	si->base = xcalloc(1, sizeof(*si->base));
	si->base->version = istate->version;
	/* zero timestamp disables racy test in ce_write_index() */
	si->base->timestamp = istate->timestamp;
	ALLOC_GROW(si->base->cache, istate->cache_nr, si->base->cache_alloc);
	si->base->cache_nr = istate->cache_nr;
	COPY_ARRAY(si->base->cache, istate->cache, istate->cache_nr);
	mark_base_index_entries(si->base);
	for (i = 0; i < si->base->cache_nr; i++)
		si->base->cache[i]->ce_flags &= ~CE_UPDATE_IN_BASE;
}

static void mark_entry_for_delete(size_t pos, void *data)
{
	struct index_state *istate = data;
	if (pos >= istate->cache_nr)
		die("position for delete %d exceeds base index size %d",
		    (int)pos, istate->cache_nr);
	istate->cache[pos]->ce_flags |= CE_REMOVE;
	istate->split_index->nr_deletions = 1;
}

static void replace_entry(size_t pos, void *data)
{
	struct index_state *istate = data;
	struct split_index *si = istate->split_index;
	struct cache_entry *dst, *src;

	if (pos >= istate->cache_nr)
		die("position for replacement %d exceeds base index size %d",
		    (int)pos, istate->cache_nr);
	if (si->nr_replacements >= si->saved_cache_nr)
		die("too many replacements (%d vs %d)",
		    si->nr_replacements, si->saved_cache_nr);
	dst = istate->cache[pos];
	if (dst->ce_flags & CE_REMOVE)
		die("entry %d is marked as both replaced and deleted",
		    (int)pos);
	src = si->saved_cache[si->nr_replacements];
	if (ce_namelen(src))
		die("corrupt link extension, entry %d should have "
		    "zero length name", (int)pos);
	src->index = pos + 1;
	src->ce_flags |= CE_UPDATE_IN_BASE;
	src->ce_namelen = dst->ce_namelen;
	copy_cache_entry(dst, src);
	free(src);
	si->nr_replacements++;
}

void merge_base_index(struct index_state *istate)
{
	struct split_index *si = istate->split_index;
	unsigned int i;

	mark_base_index_entries(si->base);

	si->saved_cache	    = istate->cache;
	si->saved_cache_nr  = istate->cache_nr;
	istate->cache_nr    = si->base->cache_nr;
	istate->cache	    = NULL;
	istate->cache_alloc = 0;
	ALLOC_GROW(istate->cache, istate->cache_nr, istate->cache_alloc);
	COPY_ARRAY(istate->cache, si->base->cache, istate->cache_nr);

	si->nr_deletions = 0;
	si->nr_replacements = 0;
	ewah_each_bit(si->replace_bitmap, replace_entry, istate);
	ewah_each_bit(si->delete_bitmap, mark_entry_for_delete, istate);
	if (si->nr_deletions)
		remove_marked_cache_entries(istate);

	for (i = si->nr_replacements; i < si->saved_cache_nr; i++) {
		if (!ce_namelen(si->saved_cache[i]))
			die("corrupt link extension, entry %d should "
			    "have non-zero length name", i);
		add_index_entry(istate, si->saved_cache[i],
				ADD_CACHE_OK_TO_ADD |
				ADD_CACHE_KEEP_CACHE_TREE |
				/*
				 * we may have to replay what
				 * merge-recursive.c:update_stages()
				 * does, which has this flag on
				 */
				ADD_CACHE_SKIP_DFCHECK);
		si->saved_cache[i] = NULL;
	}

	ewah_free(si->delete_bitmap);
	ewah_free(si->replace_bitmap);
	free(si->saved_cache);
	si->delete_bitmap  = NULL;
	si->replace_bitmap = NULL;
	si->saved_cache	   = NULL;
	si->saved_cache_nr = 0;
}

void prepare_to_write_split_index(struct index_state *istate)
{
	struct split_index *si = init_split_index(istate);
	struct cache_entry **entries = NULL, *ce;
	int i, nr_entries = 0, nr_alloc = 0;

	si->delete_bitmap = ewah_new();
	si->replace_bitmap = ewah_new();

	if (si->base) {
		/* Go through istate->cache[] and mark CE_MATCHED to
		 * entry with positive index. We'll go through
		 * base->cache[] later to delete all entries in base
		 * that are not marked with either CE_MATCHED or
		 * CE_UPDATE_IN_BASE. If istate->cache[i] is a
		 * duplicate, deduplicate it.
		 */
		for (i = 0; i < istate->cache_nr; i++) {
			struct cache_entry *base;
			/* namelen is checked separately */
			const unsigned int ondisk_flags =
				CE_STAGEMASK | CE_VALID | CE_EXTENDED_FLAGS;
			unsigned int ce_flags, base_flags, ret;
			ce = istate->cache[i];
			if (!ce->index)
				continue;
			if (ce->index > si->base->cache_nr) {
				ce->index = 0;
				continue;
			}
			ce->ce_flags |= CE_MATCHED; /* or "shared" */
			base = si->base->cache[ce->index - 1];
			if (ce == base)
				continue;
			if (ce->ce_namelen != base->ce_namelen ||
			    strcmp(ce->name, base->name)) {
				ce->index = 0;
				continue;
			}
			ce_flags = ce->ce_flags;
			base_flags = base->ce_flags;
			/* only on-disk flags matter */
			ce->ce_flags   &= ondisk_flags;
			base->ce_flags &= ondisk_flags;
			ret = memcmp(&ce->ce_stat_data, &base->ce_stat_data,
				     offsetof(struct cache_entry, name) -
				     offsetof(struct cache_entry, ce_stat_data));
			ce->ce_flags = ce_flags;
			base->ce_flags = base_flags;
			if (ret)
				ce->ce_flags |= CE_UPDATE_IN_BASE;
			free(base);
			si->base->cache[ce->index - 1] = ce;
		}
		for (i = 0; i < si->base->cache_nr; i++) {
			ce = si->base->cache[i];
			if ((ce->ce_flags & CE_REMOVE) ||
			    !(ce->ce_flags & CE_MATCHED))
				ewah_set(si->delete_bitmap, i);
			else if (ce->ce_flags & CE_UPDATE_IN_BASE) {
				ewah_set(si->replace_bitmap, i);
				ce->ce_flags |= CE_STRIP_NAME;
				ALLOC_GROW(entries, nr_entries+1, nr_alloc);
				entries[nr_entries++] = ce;
			}
		}
	}

	for (i = 0; i < istate->cache_nr; i++) {
		ce = istate->cache[i];
		if ((!si->base || !ce->index) && !(ce->ce_flags & CE_REMOVE)) {
			assert(!(ce->ce_flags & CE_STRIP_NAME));
			ALLOC_GROW(entries, nr_entries+1, nr_alloc);
			entries[nr_entries++] = ce;
		}
		ce->ce_flags &= ~CE_MATCHED;
	}

	/*
	 * take cache[] out temporarily, put entries[] in its place
	 * for writing
	 */
	si->saved_cache = istate->cache;
	si->saved_cache_nr = istate->cache_nr;
	istate->cache = entries;
	istate->cache_nr = nr_entries;
}

void finish_writing_split_index(struct index_state *istate)
{
	struct split_index *si = init_split_index(istate);

	ewah_free(si->delete_bitmap);
	ewah_free(si->replace_bitmap);
	si->delete_bitmap = NULL;
	si->replace_bitmap = NULL;
	free(istate->cache);
	istate->cache = si->saved_cache;
	istate->cache_nr = si->saved_cache_nr;
}

void unshare_split_index(struct index_state *istate, int discard)
{
	struct split_index *si = istate->split_index;
	int i;

	if (!si || !si->base)
		return;

	for (i = 0; i < istate->cache_nr; i++) {
		struct cache_entry *ce = istate->cache[i];
		struct cache_entry *new = NULL;

		if (!ce->index ||
		    ce->index > si->base->cache_nr ||
		    ce != si->base->cache[ce->index - 1])
			continue;

		if (!discard) {
			int len = ce_namelen(ce);
			new = xcalloc(1, cache_entry_size(len));
			copy_cache_entry(new, ce);
			memcpy(new->name, ce->name, len);
			new->index = 0;
		}
		istate->cache[i] = new;
	}
}


void discard_split_index(struct index_state *istate)
{
	struct split_index *si = istate->split_index;
	if (!si)
		return;
	unshare_split_index(istate, 0);
	istate->split_index = NULL;
	si->refcount--;
	if (si->refcount)
		return;
	if (si->base) {
		discard_index(si->base);
		free(si->base);
	}
	free(si);
}

void save_or_free_index_entry(struct index_state *istate, struct cache_entry *ce)
{
	if (ce->index &&
	    istate->split_index &&
	    istate->split_index->base &&
	    ce->index <= istate->split_index->base->cache_nr &&
	    ce == istate->split_index->base->cache[ce->index - 1])
		ce->ce_flags |= CE_REMOVE;
	else
		free(ce);
}

void replace_index_entry_in_base(struct index_state *istate,
				 struct cache_entry *old,
				 struct cache_entry *new)
{
	if (old->index &&
	    istate->split_index &&
	    istate->split_index->base &&
	    old->index <= istate->split_index->base->cache_nr) {
		new->index = old->index;
		if (old != istate->split_index->base->cache[new->index - 1])
			free(istate->split_index->base->cache[new->index - 1]);
		istate->split_index->base->cache[new->index - 1] = new;
	}
}

void add_split_index(struct index_state *istate)
{
	if (!istate->split_index) {
		init_split_index(istate);
		istate->cache_changed |= SPLIT_INDEX_ORDERED;
	}
}

void remove_split_index(struct index_state *istate)
{
	if (!istate->split_index)
		return;
	discard_split_index(istate);
	istate->cache_changed |= SOMETHING_CHANGED;
}
Commit	Line	Data
5fc2fc8f NTND	1	#include "cache.h"
5fc2fc8f NTND	2	#include "split-index.h"
96a1d8d3	3	#include "ewah/ewok.h"
5fc2fc8f NTND	4
	5	struct split_index init_split_index(struct index_state istate)
	6	{
	7	if (!istate->split_index) {
	8	istate->split_index = xcalloc(1, sizeof(*istate->split_index));
	9	istate->split_index->refcount = 1;
	10	}
	11	return istate->split_index;
	12	}
	13
	14	int read_link_extension(struct index_state *istate,
	15	const void *data_, unsigned long sz)
	16	{
	17	const unsigned char *data = data_;
	18	struct split_index *si;
76b07b37 NTND	19	int ret;
76b07b37 NTND	20
5fc2fc8f NTND	21	if (sz < 20)
	22	return error("corrupt link extension (too short)");
	23	si = init_split_index(istate);
	24	hashcpy(si->base_sha1, data);
	25	data += 20;
	26	sz -= 20;
76b07b37 NTND	27	if (!sz)
	28	return 0;
	29	si->delete_bitmap = ewah_new();
	30	ret = ewah_read_mmap(si->delete_bitmap, data, sz);
	31	if (ret < 0)
	32	return error("corrupt delete bitmap in link extension");
	33	data += ret;
	34	sz -= ret;
	35	si->replace_bitmap = ewah_new();
	36	ret = ewah_read_mmap(si->replace_bitmap, data, sz);
	37	if (ret < 0)
	38	return error("corrupt replace bitmap in link extension");
	39	if (ret != sz)
5fc2fc8f NTND	40	return error("garbage at the end of link extension");
	41	return 0;
	42	}
	43
	44	int write_link_extension(struct strbuf *sb,
	45	struct index_state *istate)
	46	{
	47	struct split_index *si = istate->split_index;
	48	strbuf_add(sb, si->base_sha1, 20);
96a1d8d3 NTND	49	if (!si->delete_bitmap && !si->replace_bitmap)
96a1d8d3 NTND	50	return 0;
be0d9d53 NTND	51	ewah_serialize_strbuf(si->delete_bitmap, sb);
be0d9d53 NTND	52	ewah_serialize_strbuf(si->replace_bitmap, sb);
5fc2fc8f NTND	53	return 0;
	54	}
	55
	56	static void mark_base_index_entries(struct index_state *base)
	57	{
	58	int i;
	59	/*
	60	* To keep track of the shared entries between
	61	* istate->base->cache[] and istate->cache[], base entry
	62	* position is stored in each base entry. All positions start
832c0e5e	63	* from 1 instead of 0, which is reserved to say "this is a new
5fc2fc8f NTND	64	* entry".
	65	*/
	66	for (i = 0; i < base->cache_nr; i++)
	67	base->cache[i]->index = i + 1;
	68	}
	69
c18b80a0 NTND	70	void move_cache_to_base_index(struct index_state *istate)
	71	{
	72	struct split_index *si = istate->split_index;
	73	int i;
	74
	75	/*
f9d7abec NTND	76	* If "si" is shared with another index_state (e.g. by
	77	* unpack-trees code), we will need to duplicate split_index
	78	* struct. It's not happening now though, luckily.
c18b80a0	79	*/
f9d7abec NTND	80	assert(si->refcount <= 1);
	81
	82	unshare_split_index(istate, 0);
	83	if (si->base) {
	84	discard_index(si->base);
	85	free(si->base);
	86	}
c18b80a0 NTND	87	si->base = xcalloc(1, sizeof(*si->base));
	88	si->base->version = istate->version;
	89	/* zero timestamp disables racy test in ce_write_index() */
	90	si->base->timestamp = istate->timestamp;
	91	ALLOC_GROW(si->base->cache, istate->cache_nr, si->base->cache_alloc);
	92	si->base->cache_nr = istate->cache_nr;
45ccef87	93	COPY_ARRAY(si->base->cache, istate->cache, istate->cache_nr);
c18b80a0 NTND	94	mark_base_index_entries(si->base);
	95	for (i = 0; i < si->base->cache_nr; i++)
	96	si->base->cache[i]->ce_flags &= ~CE_UPDATE_IN_BASE;
	97	}
	98
76b07b37 NTND	99	static void mark_entry_for_delete(size_t pos, void *data)
	100	{
	101	struct index_state *istate = data;
	102	if (pos >= istate->cache_nr)
	103	die("position for delete %d exceeds base index size %d",
	104	(int)pos, istate->cache_nr);
	105	istate->cache[pos]->ce_flags \|= CE_REMOVE;
	106	istate->split_index->nr_deletions = 1;
	107	}
	108
	109	static void replace_entry(size_t pos, void *data)
	110	{
	111	struct index_state *istate = data;
	112	struct split_index *si = istate->split_index;
	113	struct cache_entry dst, src;
b3c96fb1	114
76b07b37 NTND	115	if (pos >= istate->cache_nr)
	116	die("position for replacement %d exceeds base index size %d",
	117	(int)pos, istate->cache_nr);
	118	if (si->nr_replacements >= si->saved_cache_nr)
	119	die("too many replacements (%d vs %d)",
	120	si->nr_replacements, si->saved_cache_nr);
	121	dst = istate->cache[pos];
	122	if (dst->ce_flags & CE_REMOVE)
	123	die("entry %d is marked as both replaced and deleted",
	124	(int)pos);
	125	src = si->saved_cache[si->nr_replacements];
b3c96fb1 NTND	126	if (ce_namelen(src))
	127	die("corrupt link extension, entry %d should have "
	128	"zero length name", (int)pos);
76b07b37 NTND	129	src->index = pos + 1;
76b07b37 NTND	130	src->ce_flags \|= CE_UPDATE_IN_BASE;
b3c96fb1 NTND	131	src->ce_namelen = dst->ce_namelen;
	132	copy_cache_entry(dst, src);
	133	free(src);
76b07b37 NTND	134	si->nr_replacements++;
	135	}
	136
5fc2fc8f NTND	137	void merge_base_index(struct index_state *istate)
	138	{
	139	struct split_index *si = istate->split_index;
76b07b37	140	unsigned int i;
5fc2fc8f NTND	141
5fc2fc8f NTND	142	mark_base_index_entries(si->base);
76b07b37 NTND	143
	144	si->saved_cache = istate->cache;
	145	si->saved_cache_nr = istate->cache_nr;
	146	istate->cache_nr = si->base->cache_nr;
	147	istate->cache = NULL;
	148	istate->cache_alloc = 0;
5fc2fc8f	149	ALLOC_GROW(istate->cache, istate->cache_nr, istate->cache_alloc);
45ccef87	150	COPY_ARRAY(istate->cache, si->base->cache, istate->cache_nr);
76b07b37 NTND	151
	152	si->nr_deletions = 0;
	153	si->nr_replacements = 0;
	154	ewah_each_bit(si->replace_bitmap, replace_entry, istate);
	155	ewah_each_bit(si->delete_bitmap, mark_entry_for_delete, istate);
	156	if (si->nr_deletions)
	157	remove_marked_cache_entries(istate);
	158
	159	for (i = si->nr_replacements; i < si->saved_cache_nr; i++) {
b3c96fb1 NTND	160	if (!ce_namelen(si->saved_cache[i]))
	161	die("corrupt link extension, entry %d should "
	162	"have non-zero length name", i);
76b07b37 NTND	163	add_index_entry(istate, si->saved_cache[i],
76b07b37 NTND	164	ADD_CACHE_OK_TO_ADD \|
ce7c614b	165	ADD_CACHE_KEEP_CACHE_TREE \|
76b07b37 NTND	166	/*
	167	* we may have to replay what
	168	* merge-recursive.c:update_stages()
	169	* does, which has this flag on
	170	*/
	171	ADD_CACHE_SKIP_DFCHECK);
	172	si->saved_cache[i] = NULL;
	173	}
	174
	175	ewah_free(si->delete_bitmap);
	176	ewah_free(si->replace_bitmap);
	177	free(si->saved_cache);
	178	si->delete_bitmap = NULL;
	179	si->replace_bitmap = NULL;
	180	si->saved_cache = NULL;
	181	si->saved_cache_nr = 0;
5fc2fc8f NTND	182	}
	183
	184	void prepare_to_write_split_index(struct index_state *istate)
	185	{
	186	struct split_index *si = init_split_index(istate);
96a1d8d3 NTND	187	struct cache_entry *entries = NULL, ce;
	188	int i, nr_entries = 0, nr_alloc = 0;
	189
	190	si->delete_bitmap = ewah_new();
	191	si->replace_bitmap = ewah_new();
	192
	193	if (si->base) {
	194	/* Go through istate->cache[] and mark CE_MATCHED to
	195	* entry with positive index. We'll go through
	196	* base->cache[] later to delete all entries in base
753c4515	197	* that are not marked with either CE_MATCHED or
96a1d8d3 NTND	198	* CE_UPDATE_IN_BASE. If istate->cache[i] is a
	199	* duplicate, deduplicate it.
	200	*/
	201	for (i = 0; i < istate->cache_nr; i++) {
	202	struct cache_entry *base;
	203	/* namelen is checked separately */
	204	const unsigned int ondisk_flags =
	205	CE_STAGEMASK \| CE_VALID \| CE_EXTENDED_FLAGS;
	206	unsigned int ce_flags, base_flags, ret;
	207	ce = istate->cache[i];
	208	if (!ce->index)
	209	continue;
	210	if (ce->index > si->base->cache_nr) {
	211	ce->index = 0;
	212	continue;
	213	}
	214	ce->ce_flags \|= CE_MATCHED; /* or "shared" */
	215	base = si->base->cache[ce->index - 1];
	216	if (ce == base)
	217	continue;
	218	if (ce->ce_namelen != base->ce_namelen \|\|
	219	strcmp(ce->name, base->name)) {
	220	ce->index = 0;
	221	continue;
	222	}
	223	ce_flags = ce->ce_flags;
	224	base_flags = base->ce_flags;
	225	/* only on-disk flags matter */
	226	ce->ce_flags &= ondisk_flags;
	227	base->ce_flags &= ondisk_flags;
	228	ret = memcmp(&ce->ce_stat_data, &base->ce_stat_data,
	229	offsetof(struct cache_entry, name) -
	230	offsetof(struct cache_entry, ce_stat_data));
	231	ce->ce_flags = ce_flags;
	232	base->ce_flags = base_flags;
	233	if (ret)
	234	ce->ce_flags \|= CE_UPDATE_IN_BASE;
	235	free(base);
	236	si->base->cache[ce->index - 1] = ce;
	237	}
	238	for (i = 0; i < si->base->cache_nr; i++) {
	239	ce = si->base->cache[i];
	240	if ((ce->ce_flags & CE_REMOVE) \|\|
	241	!(ce->ce_flags & CE_MATCHED))
	242	ewah_set(si->delete_bitmap, i);
	243	else if (ce->ce_flags & CE_UPDATE_IN_BASE) {
	244	ewah_set(si->replace_bitmap, i);
b3c96fb1	245	ce->ce_flags \|= CE_STRIP_NAME;
96a1d8d3 NTND	246	ALLOC_GROW(entries, nr_entries+1, nr_alloc);
	247	entries[nr_entries++] = ce;
	248	}
	249	}
	250	}
	251
	252	for (i = 0; i < istate->cache_nr; i++) {
	253	ce = istate->cache[i];
	254	if ((!si->base \|\| !ce->index) && !(ce->ce_flags & CE_REMOVE)) {
b3c96fb1	255	assert(!(ce->ce_flags & CE_STRIP_NAME));
96a1d8d3 NTND	256	ALLOC_GROW(entries, nr_entries+1, nr_alloc);
	257	entries[nr_entries++] = ce;
	258	}
	259	ce->ce_flags &= ~CE_MATCHED;
	260	}
	261
	262	/*
	263	* take cache[] out temporarily, put entries[] in its place
	264	* for writing
	265	*/
	266	si->saved_cache = istate->cache;
5fc2fc8f	267	si->saved_cache_nr = istate->cache_nr;
96a1d8d3 NTND	268	istate->cache = entries;
96a1d8d3 NTND	269	istate->cache_nr = nr_entries;
5fc2fc8f NTND	270	}
	271
	272	void finish_writing_split_index(struct index_state *istate)
	273	{
	274	struct split_index *si = init_split_index(istate);
96a1d8d3 NTND	275
	276	ewah_free(si->delete_bitmap);
	277	ewah_free(si->replace_bitmap);
	278	si->delete_bitmap = NULL;
	279	si->replace_bitmap = NULL;
	280	free(istate->cache);
	281	istate->cache = si->saved_cache;
5fc2fc8f NTND	282	istate->cache_nr = si->saved_cache_nr;
	283	}
	284
f9d7abec NTND	285	void unshare_split_index(struct index_state *istate, int discard)
	286	{
	287	struct split_index *si = istate->split_index;
	288	int i;
	289
	290	if (!si \|\| !si->base)
	291	return;
	292
	293	for (i = 0; i < istate->cache_nr; i++) {
	294	struct cache_entry *ce = istate->cache[i];
	295	struct cache_entry *new = NULL;
	296
	297	if (!ce->index \|\|
	298	ce->index > si->base->cache_nr \|\|
	299	ce != si->base->cache[ce->index - 1])
	300	continue;
	301
	302	if (!discard) {
	303	int len = ce_namelen(ce);
	304	new = xcalloc(1, cache_entry_size(len));
	305	copy_cache_entry(new, ce);
	306	memcpy(new->name, ce->name, len);
	307	new->index = 0;
	308	}
	309	istate->cache[i] = new;
	310	}
	311	}
	312
	313
5fc2fc8f NTND	314	void discard_split_index(struct index_state *istate)
	315	{
	316	struct split_index *si = istate->split_index;
	317	if (!si)
	318	return;
f9d7abec	319	unshare_split_index(istate, 0);
5fc2fc8f NTND	320	istate->split_index = NULL;
	321	si->refcount--;
	322	if (si->refcount)
	323	return;
	324	if (si->base) {
	325	discard_index(si->base);
	326	free(si->base);
	327	}
	328	free(si);
	329	}
045113a5 NTND	330
	331	void save_or_free_index_entry(struct index_state istate, struct cache_entry ce)
	332	{
	333	if (ce->index &&
	334	istate->split_index &&
	335	istate->split_index->base &&
	336	ce->index <= istate->split_index->base->cache_nr &&
	337	ce == istate->split_index->base->cache[ce->index - 1])
	338	ce->ce_flags \|= CE_REMOVE;
	339	else
	340	free(ce);
	341	}
078a58e8 NTND	342
	343	void replace_index_entry_in_base(struct index_state *istate,
	344	struct cache_entry *old,
	345	struct cache_entry *new)
	346	{
	347	if (old->index &&
	348	istate->split_index &&
	349	istate->split_index->base &&
	350	old->index <= istate->split_index->base->cache_nr) {
	351	new->index = old->index;
	352	if (old != istate->split_index->base->cache[new->index - 1])
	353	free(istate->split_index->base->cache[new->index - 1]);
	354	istate->split_index->base->cache[new->index - 1] = new;
	355	}
	356	}
cef4fc7e CC	357
	358	void add_split_index(struct index_state *istate)
	359	{
	360	if (!istate->split_index) {
	361	init_split_index(istate);
	362	istate->cache_changed \|= SPLIT_INDEX_ORDERED;
	363	}
	364	}
	365
	366	void remove_split_index(struct index_state *istate)
	367	{
f9d7abec NTND	368	if (!istate->split_index)
	369	return;
	370	discard_split_index(istate);
	371	istate->cache_changed \|= SOMETHING_CHANGED;
cef4fc7e	372	}