7 #include "object-store.h"
8 #include "sha1-lookup.h"
11 #define MIDX_SIGNATURE 0x4d494458 /* "MIDX" */
12 #define MIDX_VERSION 1
13 #define MIDX_BYTE_FILE_VERSION 4
14 #define MIDX_BYTE_HASH_VERSION 5
15 #define MIDX_BYTE_NUM_CHUNKS 6
16 #define MIDX_BYTE_NUM_PACKS 8
17 #define MIDX_HASH_VERSION 1
18 #define MIDX_HEADER_SIZE 12
19 #define MIDX_HASH_LEN 20
20 #define MIDX_MIN_SIZE (MIDX_HEADER_SIZE + MIDX_HASH_LEN)
22 #define MIDX_MAX_CHUNKS 5
23 #define MIDX_CHUNK_ALIGNMENT 4
24 #define MIDX_CHUNKID_PACKNAMES 0x504e414d /* "PNAM" */
25 #define MIDX_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
26 #define MIDX_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
27 #define MIDX_CHUNKID_OBJECTOFFSETS 0x4f4f4646 /* "OOFF" */
28 #define MIDX_CHUNKID_LARGEOFFSETS 0x4c4f4646 /* "LOFF" */
29 #define MIDX_CHUNKLOOKUP_WIDTH (sizeof(uint32_t) + sizeof(uint64_t))
30 #define MIDX_CHUNK_FANOUT_SIZE (sizeof(uint32_t) * 256)
31 #define MIDX_CHUNK_OFFSET_WIDTH (2 * sizeof(uint32_t))
32 #define MIDX_CHUNK_LARGE_OFFSET_WIDTH (sizeof(uint64_t))
33 #define MIDX_LARGE_OFFSET_NEEDED 0x80000000
35 static char *get_midx_filename(const char *object_dir
)
37 return xstrfmt("%s/pack/multi-pack-index", object_dir
);
40 struct multi_pack_index
*load_multi_pack_index(const char *object_dir
)
42 struct multi_pack_index
*m
= NULL
;
46 void *midx_map
= NULL
;
47 uint32_t hash_version
;
48 char *midx_name
= get_midx_filename(object_dir
);
50 const char *cur_pack_name
;
52 fd
= git_open(midx_name
);
57 error_errno(_("failed to read %s"), midx_name
);
61 midx_size
= xsize_t(st
.st_size
);
63 if (midx_size
< MIDX_MIN_SIZE
) {
64 error(_("multi-pack-index file %s is too small"), midx_name
);
68 FREE_AND_NULL(midx_name
);
70 midx_map
= xmmap(NULL
, midx_size
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
72 FLEX_ALLOC_MEM(m
, object_dir
, object_dir
, strlen(object_dir
));
75 m
->data_len
= midx_size
;
77 m
->signature
= get_be32(m
->data
);
78 if (m
->signature
!= MIDX_SIGNATURE
) {
79 error(_("multi-pack-index signature 0x%08x does not match signature 0x%08x"),
80 m
->signature
, MIDX_SIGNATURE
);
84 m
->version
= m
->data
[MIDX_BYTE_FILE_VERSION
];
85 if (m
->version
!= MIDX_VERSION
) {
86 error(_("multi-pack-index version %d not recognized"),
91 hash_version
= m
->data
[MIDX_BYTE_HASH_VERSION
];
92 if (hash_version
!= MIDX_HASH_VERSION
) {
93 error(_("hash version %u does not match"), hash_version
);
96 m
->hash_len
= MIDX_HASH_LEN
;
98 m
->num_chunks
= m
->data
[MIDX_BYTE_NUM_CHUNKS
];
100 m
->num_packs
= get_be32(m
->data
+ MIDX_BYTE_NUM_PACKS
);
102 for (i
= 0; i
< m
->num_chunks
; i
++) {
103 uint32_t chunk_id
= get_be32(m
->data
+ MIDX_HEADER_SIZE
+
104 MIDX_CHUNKLOOKUP_WIDTH
* i
);
105 uint64_t chunk_offset
= get_be64(m
->data
+ MIDX_HEADER_SIZE
+ 4 +
106 MIDX_CHUNKLOOKUP_WIDTH
* i
);
109 case MIDX_CHUNKID_PACKNAMES
:
110 m
->chunk_pack_names
= m
->data
+ chunk_offset
;
113 case MIDX_CHUNKID_OIDFANOUT
:
114 m
->chunk_oid_fanout
= (uint32_t *)(m
->data
+ chunk_offset
);
117 case MIDX_CHUNKID_OIDLOOKUP
:
118 m
->chunk_oid_lookup
= m
->data
+ chunk_offset
;
121 case MIDX_CHUNKID_OBJECTOFFSETS
:
122 m
->chunk_object_offsets
= m
->data
+ chunk_offset
;
125 case MIDX_CHUNKID_LARGEOFFSETS
:
126 m
->chunk_large_offsets
= m
->data
+ chunk_offset
;
130 die(_("terminating multi-pack-index chunk id appears earlier than expected"));
135 * Do nothing on unrecognized chunks, allowing future
136 * extensions to add optional chunks.
142 if (!m
->chunk_pack_names
)
143 die(_("multi-pack-index missing required pack-name chunk"));
144 if (!m
->chunk_oid_fanout
)
145 die(_("multi-pack-index missing required OID fanout chunk"));
146 if (!m
->chunk_oid_lookup
)
147 die(_("multi-pack-index missing required OID lookup chunk"));
148 if (!m
->chunk_object_offsets
)
149 die(_("multi-pack-index missing required object offsets chunk"));
151 m
->num_objects
= ntohl(m
->chunk_oid_fanout
[255]);
153 m
->pack_names
= xcalloc(m
->num_packs
, sizeof(*m
->pack_names
));
154 m
->packs
= xcalloc(m
->num_packs
, sizeof(*m
->packs
));
156 cur_pack_name
= (const char *)m
->chunk_pack_names
;
157 for (i
= 0; i
< m
->num_packs
; i
++) {
158 m
->pack_names
[i
] = cur_pack_name
;
160 cur_pack_name
+= strlen(cur_pack_name
) + 1;
162 if (i
&& strcmp(m
->pack_names
[i
], m
->pack_names
[i
- 1]) <= 0) {
163 error(_("multi-pack-index pack names out of order: '%s' before '%s'"),
164 m
->pack_names
[i
- 1],
176 munmap(midx_map
, midx_size
);
182 static void close_midx(struct multi_pack_index
*m
)
185 munmap((unsigned char *)m
->data
, m
->data_len
);
189 for (i
= 0; i
< m
->num_packs
; i
++) {
191 close_pack(m
->packs
[i
]);
195 FREE_AND_NULL(m
->packs
);
196 FREE_AND_NULL(m
->pack_names
);
199 static int prepare_midx_pack(struct multi_pack_index
*m
, uint32_t pack_int_id
)
201 struct strbuf pack_name
= STRBUF_INIT
;
203 if (pack_int_id
>= m
->num_packs
)
204 BUG("bad pack-int-id");
206 if (m
->packs
[pack_int_id
])
209 strbuf_addf(&pack_name
, "%s/pack/%s", m
->object_dir
,
210 m
->pack_names
[pack_int_id
]);
212 m
->packs
[pack_int_id
] = add_packed_git(pack_name
.buf
, pack_name
.len
, 1);
213 strbuf_release(&pack_name
);
214 return !m
->packs
[pack_int_id
];
217 int bsearch_midx(const struct object_id
*oid
, struct multi_pack_index
*m
, uint32_t *result
)
219 return bsearch_hash(oid
->hash
, m
->chunk_oid_fanout
, m
->chunk_oid_lookup
,
220 MIDX_HASH_LEN
, result
);
223 struct object_id
*nth_midxed_object_oid(struct object_id
*oid
,
224 struct multi_pack_index
*m
,
227 if (n
>= m
->num_objects
)
230 hashcpy(oid
->hash
, m
->chunk_oid_lookup
+ m
->hash_len
* n
);
234 static off_t
nth_midxed_offset(struct multi_pack_index
*m
, uint32_t pos
)
236 const unsigned char *offset_data
;
239 offset_data
= m
->chunk_object_offsets
+ pos
* MIDX_CHUNK_OFFSET_WIDTH
;
240 offset32
= get_be32(offset_data
+ sizeof(uint32_t));
242 if (m
->chunk_large_offsets
&& offset32
& MIDX_LARGE_OFFSET_NEEDED
) {
243 if (sizeof(offset32
) < sizeof(uint64_t))
244 die(_("multi-pack-index stores a 64-bit offset, but off_t is too small"));
246 offset32
^= MIDX_LARGE_OFFSET_NEEDED
;
247 return get_be64(m
->chunk_large_offsets
+ sizeof(uint64_t) * offset32
);
253 static uint32_t nth_midxed_pack_int_id(struct multi_pack_index
*m
, uint32_t pos
)
255 return get_be32(m
->chunk_object_offsets
+ pos
* MIDX_CHUNK_OFFSET_WIDTH
);
258 static int nth_midxed_pack_entry(struct multi_pack_index
*m
, struct pack_entry
*e
, uint32_t pos
)
260 uint32_t pack_int_id
;
261 struct packed_git
*p
;
263 if (pos
>= m
->num_objects
)
266 pack_int_id
= nth_midxed_pack_int_id(m
, pos
);
268 if (prepare_midx_pack(m
, pack_int_id
))
269 die(_("error preparing packfile from multi-pack-index"));
270 p
= m
->packs
[pack_int_id
];
273 * We are about to tell the caller where they can locate the
274 * requested object. We better make sure the packfile is
275 * still here and can be accessed before supplying that
276 * answer, as it may have been deleted since the MIDX was
279 if (!is_pack_valid(p
))
282 e
->offset
= nth_midxed_offset(m
, pos
);
288 int fill_midx_entry(const struct object_id
*oid
, struct pack_entry
*e
, struct multi_pack_index
*m
)
292 if (!bsearch_midx(oid
, m
, &pos
))
295 return nth_midxed_pack_entry(m
, e
, pos
);
298 int midx_contains_pack(struct multi_pack_index
*m
, const char *idx_name
)
300 uint32_t first
= 0, last
= m
->num_packs
;
302 while (first
< last
) {
303 uint32_t mid
= first
+ (last
- first
) / 2;
307 current
= m
->pack_names
[mid
];
308 cmp
= strcmp(idx_name
, current
);
321 int prepare_multi_pack_index_one(struct repository
*r
, const char *object_dir
)
323 struct multi_pack_index
*m
= r
->objects
->multi_pack_index
;
324 struct multi_pack_index
*m_search
;
327 if (repo_config_get_bool(r
, "core.multipackindex", &config_value
) ||
331 for (m_search
= m
; m_search
; m_search
= m_search
->next
)
332 if (!strcmp(object_dir
, m_search
->object_dir
))
335 r
->objects
->multi_pack_index
= load_multi_pack_index(object_dir
);
337 if (r
->objects
->multi_pack_index
) {
338 r
->objects
->multi_pack_index
->next
= m
;
345 static size_t write_midx_header(struct hashfile
*f
,
346 unsigned char num_chunks
,
349 unsigned char byte_values
[4];
351 hashwrite_be32(f
, MIDX_SIGNATURE
);
352 byte_values
[0] = MIDX_VERSION
;
353 byte_values
[1] = MIDX_HASH_VERSION
;
354 byte_values
[2] = num_chunks
;
355 byte_values
[3] = 0; /* unused */
356 hashwrite(f
, byte_values
, sizeof(byte_values
));
357 hashwrite_be32(f
, num_packs
);
359 return MIDX_HEADER_SIZE
;
363 struct packed_git
**list
;
367 uint32_t alloc_names
;
368 size_t pack_name_concat_len
;
369 struct multi_pack_index
*m
;
372 static void add_pack_to_midx(const char *full_path
, size_t full_path_len
,
373 const char *file_name
, void *data
)
375 struct pack_list
*packs
= (struct pack_list
*)data
;
377 if (ends_with(file_name
, ".idx")) {
378 if (packs
->m
&& midx_contains_pack(packs
->m
, file_name
))
381 ALLOC_GROW(packs
->list
, packs
->nr
+ 1, packs
->alloc_list
);
382 ALLOC_GROW(packs
->names
, packs
->nr
+ 1, packs
->alloc_names
);
384 packs
->list
[packs
->nr
] = add_packed_git(full_path
,
388 if (!packs
->list
[packs
->nr
]) {
389 warning(_("failed to add packfile '%s'"),
394 if (open_pack_index(packs
->list
[packs
->nr
])) {
395 warning(_("failed to open pack-index '%s'"),
397 close_pack(packs
->list
[packs
->nr
]);
398 FREE_AND_NULL(packs
->list
[packs
->nr
]);
402 packs
->names
[packs
->nr
] = xstrdup(file_name
);
403 packs
->pack_name_concat_len
+= strlen(file_name
) + 1;
409 uint32_t pack_int_id
;
413 static int pack_pair_compare(const void *_a
, const void *_b
)
415 struct pack_pair
*a
= (struct pack_pair
*)_a
;
416 struct pack_pair
*b
= (struct pack_pair
*)_b
;
417 return strcmp(a
->pack_name
, b
->pack_name
);
420 static void sort_packs_by_name(char **pack_names
, uint32_t nr_packs
, uint32_t *perm
)
423 struct pack_pair
*pairs
;
425 ALLOC_ARRAY(pairs
, nr_packs
);
427 for (i
= 0; i
< nr_packs
; i
++) {
428 pairs
[i
].pack_int_id
= i
;
429 pairs
[i
].pack_name
= pack_names
[i
];
432 QSORT(pairs
, nr_packs
, pack_pair_compare
);
434 for (i
= 0; i
< nr_packs
; i
++) {
435 pack_names
[i
] = pairs
[i
].pack_name
;
436 perm
[pairs
[i
].pack_int_id
] = i
;
442 struct pack_midx_entry
{
443 struct object_id oid
;
444 uint32_t pack_int_id
;
449 static int midx_oid_compare(const void *_a
, const void *_b
)
451 const struct pack_midx_entry
*a
= (const struct pack_midx_entry
*)_a
;
452 const struct pack_midx_entry
*b
= (const struct pack_midx_entry
*)_b
;
453 int cmp
= oidcmp(&a
->oid
, &b
->oid
);
458 if (a
->pack_mtime
> b
->pack_mtime
)
460 else if (a
->pack_mtime
< b
->pack_mtime
)
463 return a
->pack_int_id
- b
->pack_int_id
;
466 static int nth_midxed_pack_midx_entry(struct multi_pack_index
*m
,
468 struct pack_midx_entry
*e
,
471 if (pos
>= m
->num_objects
)
474 nth_midxed_object_oid(&e
->oid
, m
, pos
);
475 e
->pack_int_id
= pack_perm
[nth_midxed_pack_int_id(m
, pos
)];
476 e
->offset
= nth_midxed_offset(m
, pos
);
478 /* consider objects in midx to be from "old" packs */
483 static void fill_pack_entry(uint32_t pack_int_id
,
484 struct packed_git
*p
,
486 struct pack_midx_entry
*entry
)
488 if (!nth_packed_object_oid(&entry
->oid
, p
, cur_object
))
489 die(_("failed to locate object %d in packfile"), cur_object
);
491 entry
->pack_int_id
= pack_int_id
;
492 entry
->pack_mtime
= p
->mtime
;
494 entry
->offset
= nth_packed_object_offset(p
, cur_object
);
498 * It is possible to artificially get into a state where there are many
499 * duplicate copies of objects. That can create high memory pressure if
500 * we are to create a list of all objects before de-duplication. To reduce
501 * this memory pressure without a significant performance drop, automatically
502 * group objects by the first byte of their object id. Use the IDX fanout
503 * tables to group the data, copy to a local array, then sort.
505 * Copy only the de-duplicated entries (selected by most-recent modified time
506 * of a packfile containing the object).
508 static struct pack_midx_entry
*get_sorted_entries(struct multi_pack_index
*m
,
509 struct packed_git
**p
,
512 uint32_t *nr_objects
)
514 uint32_t cur_fanout
, cur_pack
, cur_object
;
515 uint32_t alloc_fanout
, alloc_objects
, total_objects
= 0;
516 struct pack_midx_entry
*entries_by_fanout
= NULL
;
517 struct pack_midx_entry
*deduplicated_entries
= NULL
;
518 uint32_t start_pack
= m
? m
->num_packs
: 0;
520 for (cur_pack
= start_pack
; cur_pack
< nr_packs
; cur_pack
++)
521 total_objects
+= p
[cur_pack
]->num_objects
;
524 * As we de-duplicate by fanout value, we expect the fanout
525 * slices to be evenly distributed, with some noise. Hence,
526 * allocate slightly more than one 256th.
528 alloc_objects
= alloc_fanout
= total_objects
> 3200 ? total_objects
/ 200 : 16;
530 ALLOC_ARRAY(entries_by_fanout
, alloc_fanout
);
531 ALLOC_ARRAY(deduplicated_entries
, alloc_objects
);
534 for (cur_fanout
= 0; cur_fanout
< 256; cur_fanout
++) {
535 uint32_t nr_fanout
= 0;
538 uint32_t start
= 0, end
;
541 start
= ntohl(m
->chunk_oid_fanout
[cur_fanout
- 1]);
542 end
= ntohl(m
->chunk_oid_fanout
[cur_fanout
]);
544 for (cur_object
= start
; cur_object
< end
; cur_object
++) {
545 ALLOC_GROW(entries_by_fanout
, nr_fanout
+ 1, alloc_fanout
);
546 nth_midxed_pack_midx_entry(m
, perm
,
547 &entries_by_fanout
[nr_fanout
],
553 for (cur_pack
= start_pack
; cur_pack
< nr_packs
; cur_pack
++) {
554 uint32_t start
= 0, end
;
557 start
= get_pack_fanout(p
[cur_pack
], cur_fanout
- 1);
558 end
= get_pack_fanout(p
[cur_pack
], cur_fanout
);
560 for (cur_object
= start
; cur_object
< end
; cur_object
++) {
561 ALLOC_GROW(entries_by_fanout
, nr_fanout
+ 1, alloc_fanout
);
562 fill_pack_entry(perm
[cur_pack
], p
[cur_pack
], cur_object
, &entries_by_fanout
[nr_fanout
]);
567 QSORT(entries_by_fanout
, nr_fanout
, midx_oid_compare
);
570 * The batch is now sorted by OID and then mtime (descending).
571 * Take only the first duplicate.
573 for (cur_object
= 0; cur_object
< nr_fanout
; cur_object
++) {
574 if (cur_object
&& !oidcmp(&entries_by_fanout
[cur_object
- 1].oid
,
575 &entries_by_fanout
[cur_object
].oid
))
578 ALLOC_GROW(deduplicated_entries
, *nr_objects
+ 1, alloc_objects
);
579 memcpy(&deduplicated_entries
[*nr_objects
],
580 &entries_by_fanout
[cur_object
],
581 sizeof(struct pack_midx_entry
));
586 free(entries_by_fanout
);
587 return deduplicated_entries
;
590 static size_t write_midx_pack_names(struct hashfile
*f
,
595 unsigned char padding
[MIDX_CHUNK_ALIGNMENT
];
598 for (i
= 0; i
< num_packs
; i
++) {
599 size_t writelen
= strlen(pack_names
[i
]) + 1;
601 if (i
&& strcmp(pack_names
[i
], pack_names
[i
- 1]) <= 0)
602 BUG("incorrect pack-file order: %s before %s",
606 hashwrite(f
, pack_names
[i
], writelen
);
610 /* add padding to be aligned */
611 i
= MIDX_CHUNK_ALIGNMENT
- (written
% MIDX_CHUNK_ALIGNMENT
);
612 if (i
< MIDX_CHUNK_ALIGNMENT
) {
613 memset(padding
, 0, sizeof(padding
));
614 hashwrite(f
, padding
, i
);
621 static size_t write_midx_oid_fanout(struct hashfile
*f
,
622 struct pack_midx_entry
*objects
,
625 struct pack_midx_entry
*list
= objects
;
626 struct pack_midx_entry
*last
= objects
+ nr_objects
;
631 * Write the first-level table (the list is sorted,
632 * but we use a 256-entry lookup to be able to avoid
633 * having to do eight extra binary search iterations).
635 for (i
= 0; i
< 256; i
++) {
636 struct pack_midx_entry
*next
= list
;
638 while (next
< last
&& next
->oid
.hash
[0] == i
) {
643 hashwrite_be32(f
, count
);
647 return MIDX_CHUNK_FANOUT_SIZE
;
650 static size_t write_midx_oid_lookup(struct hashfile
*f
, unsigned char hash_len
,
651 struct pack_midx_entry
*objects
,
654 struct pack_midx_entry
*list
= objects
;
658 for (i
= 0; i
< nr_objects
; i
++) {
659 struct pack_midx_entry
*obj
= list
++;
661 if (i
< nr_objects
- 1) {
662 struct pack_midx_entry
*next
= list
;
663 if (oidcmp(&obj
->oid
, &next
->oid
) >= 0)
664 BUG("OIDs not in order: %s >= %s",
665 oid_to_hex(&obj
->oid
),
666 oid_to_hex(&next
->oid
));
669 hashwrite(f
, obj
->oid
.hash
, (int)hash_len
);
676 static size_t write_midx_object_offsets(struct hashfile
*f
, int large_offset_needed
,
677 struct pack_midx_entry
*objects
, uint32_t nr_objects
)
679 struct pack_midx_entry
*list
= objects
;
680 uint32_t i
, nr_large_offset
= 0;
683 for (i
= 0; i
< nr_objects
; i
++) {
684 struct pack_midx_entry
*obj
= list
++;
686 hashwrite_be32(f
, obj
->pack_int_id
);
688 if (large_offset_needed
&& obj
->offset
>> 31)
689 hashwrite_be32(f
, MIDX_LARGE_OFFSET_NEEDED
| nr_large_offset
++);
690 else if (!large_offset_needed
&& obj
->offset
>> 32)
691 BUG("object %s requires a large offset (%"PRIx64
") but the MIDX is not writing large offsets!",
692 oid_to_hex(&obj
->oid
),
695 hashwrite_be32(f
, (uint32_t)obj
->offset
);
697 written
+= MIDX_CHUNK_OFFSET_WIDTH
;
703 static size_t write_midx_large_offsets(struct hashfile
*f
, uint32_t nr_large_offset
,
704 struct pack_midx_entry
*objects
, uint32_t nr_objects
)
706 struct pack_midx_entry
*list
= objects
;
709 while (nr_large_offset
) {
710 struct pack_midx_entry
*obj
= list
++;
711 uint64_t offset
= obj
->offset
;
716 hashwrite_be32(f
, offset
>> 32);
717 hashwrite_be32(f
, offset
& 0xffffffffUL
);
718 written
+= 2 * sizeof(uint32_t);
726 int write_midx_file(const char *object_dir
)
728 unsigned char cur_chunk
, num_chunks
= 0;
731 struct hashfile
*f
= NULL
;
733 struct pack_list packs
;
734 uint32_t *pack_perm
= NULL
;
735 uint64_t written
= 0;
736 uint32_t chunk_ids
[MIDX_MAX_CHUNKS
+ 1];
737 uint64_t chunk_offsets
[MIDX_MAX_CHUNKS
+ 1];
738 uint32_t nr_entries
, num_large_offsets
= 0;
739 struct pack_midx_entry
*entries
= NULL
;
740 int large_offsets_needed
= 0;
742 midx_name
= get_midx_filename(object_dir
);
743 if (safe_create_leading_directories(midx_name
)) {
745 die_errno(_("unable to create leading directories of %s"),
749 packs
.m
= load_multi_pack_index(object_dir
);
752 packs
.alloc_list
= packs
.m
? packs
.m
->num_packs
: 16;
753 packs
.alloc_names
= packs
.alloc_list
;
756 packs
.pack_name_concat_len
= 0;
757 ALLOC_ARRAY(packs
.list
, packs
.alloc_list
);
758 ALLOC_ARRAY(packs
.names
, packs
.alloc_names
);
761 for (i
= 0; i
< packs
.m
->num_packs
; i
++) {
762 ALLOC_GROW(packs
.list
, packs
.nr
+ 1, packs
.alloc_list
);
763 ALLOC_GROW(packs
.names
, packs
.nr
+ 1, packs
.alloc_names
);
765 packs
.list
[packs
.nr
] = NULL
;
766 packs
.names
[packs
.nr
] = xstrdup(packs
.m
->pack_names
[i
]);
767 packs
.pack_name_concat_len
+= strlen(packs
.names
[packs
.nr
]) + 1;
772 for_each_file_in_pack_dir(object_dir
, add_pack_to_midx
, &packs
);
774 if (packs
.m
&& packs
.nr
== packs
.m
->num_packs
)
777 if (packs
.pack_name_concat_len
% MIDX_CHUNK_ALIGNMENT
)
778 packs
.pack_name_concat_len
+= MIDX_CHUNK_ALIGNMENT
-
779 (packs
.pack_name_concat_len
% MIDX_CHUNK_ALIGNMENT
);
781 ALLOC_ARRAY(pack_perm
, packs
.nr
);
782 sort_packs_by_name(packs
.names
, packs
.nr
, pack_perm
);
784 entries
= get_sorted_entries(packs
.m
, packs
.list
, pack_perm
, packs
.nr
, &nr_entries
);
786 for (i
= 0; i
< nr_entries
; i
++) {
787 if (entries
[i
].offset
> 0x7fffffff)
789 if (entries
[i
].offset
> 0xffffffff)
790 large_offsets_needed
= 1;
793 hold_lock_file_for_update(&lk
, midx_name
, LOCK_DIE_ON_ERROR
);
794 f
= hashfd(lk
.tempfile
->fd
, lk
.tempfile
->filename
.buf
);
795 FREE_AND_NULL(midx_name
);
801 num_chunks
= large_offsets_needed
? 5 : 4;
803 written
= write_midx_header(f
, num_chunks
, packs
.nr
);
805 chunk_ids
[cur_chunk
] = MIDX_CHUNKID_PACKNAMES
;
806 chunk_offsets
[cur_chunk
] = written
+ (num_chunks
+ 1) * MIDX_CHUNKLOOKUP_WIDTH
;
809 chunk_ids
[cur_chunk
] = MIDX_CHUNKID_OIDFANOUT
;
810 chunk_offsets
[cur_chunk
] = chunk_offsets
[cur_chunk
- 1] + packs
.pack_name_concat_len
;
813 chunk_ids
[cur_chunk
] = MIDX_CHUNKID_OIDLOOKUP
;
814 chunk_offsets
[cur_chunk
] = chunk_offsets
[cur_chunk
- 1] + MIDX_CHUNK_FANOUT_SIZE
;
817 chunk_ids
[cur_chunk
] = MIDX_CHUNKID_OBJECTOFFSETS
;
818 chunk_offsets
[cur_chunk
] = chunk_offsets
[cur_chunk
- 1] + nr_entries
* MIDX_HASH_LEN
;
821 chunk_offsets
[cur_chunk
] = chunk_offsets
[cur_chunk
- 1] + nr_entries
* MIDX_CHUNK_OFFSET_WIDTH
;
822 if (large_offsets_needed
) {
823 chunk_ids
[cur_chunk
] = MIDX_CHUNKID_LARGEOFFSETS
;
826 chunk_offsets
[cur_chunk
] = chunk_offsets
[cur_chunk
- 1] +
827 num_large_offsets
* MIDX_CHUNK_LARGE_OFFSET_WIDTH
;
830 chunk_ids
[cur_chunk
] = 0;
832 for (i
= 0; i
<= num_chunks
; i
++) {
833 if (i
&& chunk_offsets
[i
] < chunk_offsets
[i
- 1])
834 BUG("incorrect chunk offsets: %"PRIu64
" before %"PRIu64
,
835 chunk_offsets
[i
- 1],
838 if (chunk_offsets
[i
] % MIDX_CHUNK_ALIGNMENT
)
839 BUG("chunk offset %"PRIu64
" is not properly aligned",
842 hashwrite_be32(f
, chunk_ids
[i
]);
843 hashwrite_be32(f
, chunk_offsets
[i
] >> 32);
844 hashwrite_be32(f
, chunk_offsets
[i
]);
846 written
+= MIDX_CHUNKLOOKUP_WIDTH
;
849 for (i
= 0; i
< num_chunks
; i
++) {
850 if (written
!= chunk_offsets
[i
])
851 BUG("incorrect chunk offset (%"PRIu64
" != %"PRIu64
") for chunk id %"PRIx32
,
856 switch (chunk_ids
[i
]) {
857 case MIDX_CHUNKID_PACKNAMES
:
858 written
+= write_midx_pack_names(f
, packs
.names
, packs
.nr
);
861 case MIDX_CHUNKID_OIDFANOUT
:
862 written
+= write_midx_oid_fanout(f
, entries
, nr_entries
);
865 case MIDX_CHUNKID_OIDLOOKUP
:
866 written
+= write_midx_oid_lookup(f
, MIDX_HASH_LEN
, entries
, nr_entries
);
869 case MIDX_CHUNKID_OBJECTOFFSETS
:
870 written
+= write_midx_object_offsets(f
, large_offsets_needed
, entries
, nr_entries
);
873 case MIDX_CHUNKID_LARGEOFFSETS
:
874 written
+= write_midx_large_offsets(f
, num_large_offsets
, entries
, nr_entries
);
878 BUG("trying to write unknown chunk id %"PRIx32
,
883 if (written
!= chunk_offsets
[num_chunks
])
884 BUG("incorrect final offset %"PRIu64
" != %"PRIu64
,
886 chunk_offsets
[num_chunks
]);
888 finalize_hashfile(f
, NULL
, CSUM_FSYNC
| CSUM_HASH_IN_STREAM
);
889 commit_lock_file(&lk
);
892 for (i
= 0; i
< packs
.nr
; i
++) {
894 close_pack(packs
.list
[i
]);
897 free(packs
.names
[i
]);