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derrickstoleegitster
derrickstolee
authored and
gitster
committed
midx: use chunk-format read API
Instead of parsing the table of contents directly, use the chunk-format API methods read_table_of_contents() and pair_chunk(). In particular, we can use the return value of pair_chunk() to generate an error when a required chunk is missing. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
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+29
-50
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2 files changed

+29
-50
lines changed

‎midx.c‎

Lines changed: 26 additions & 47 deletions
Original file line numberDiff line numberDiff line change
@@ -28,7 +28,6 @@
2828
#define MIDX_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
2929
#define MIDX_CHUNKID_OBJECTOFFSETS 0x4f4f4646 /* "OOFF" */
3030
#define MIDX_CHUNKID_LARGEOFFSETS 0x4c4f4646 /* "LOFF" */
31-
#define MIDX_CHUNKLOOKUP_WIDTH (sizeof(uint32_t) + sizeof(uint64_t))
3231
#define MIDX_CHUNK_FANOUT_SIZE (sizeof(uint32_t) * 256)
3332
#define MIDX_CHUNK_OFFSET_WIDTH (2 * sizeof(uint32_t))
3433
#define MIDX_CHUNK_LARGE_OFFSET_WIDTH (sizeof(uint64_t))
@@ -53,6 +52,19 @@ static char *get_midx_filename(const char *object_dir)
5352
return xstrfmt("%s/pack/multi-pack-index", object_dir);
5453
}
5554

55+
static int midx_read_oid_fanout(const unsigned char *chunk_start,
56+
size_t chunk_size, void *data)
57+
{
58+
struct multi_pack_index *m = data;
59+
m->chunk_oid_fanout = (uint32_t *)chunk_start;
60+
61+
if (chunk_size != 4 * 256) {
62+
error(_("multi-pack-index OID fanout is of the wrong size"));
63+
return 1;
64+
}
65+
return 0;
66+
}
67+
5668
struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local)
5769
{
5870
struct multi_pack_index *m = NULL;
@@ -64,6 +76,7 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local
6476
char *midx_name = get_midx_filename(object_dir);
6577
uint32_t i;
6678
const char *cur_pack_name;
79+
struct chunkfile *cf = NULL;
6780

6881
fd = git_open(midx_name);
6982

@@ -113,58 +126,23 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local
113126

114127
m->num_packs = get_be32(m->data + MIDX_BYTE_NUM_PACKS);
115128

116-
for (i = 0; i < m->num_chunks; i++) {
117-
uint32_t chunk_id = get_be32(m->data + MIDX_HEADER_SIZE +
118-
MIDX_CHUNKLOOKUP_WIDTH * i);
119-
uint64_t chunk_offset = get_be64(m->data + MIDX_HEADER_SIZE + 4 +
120-
MIDX_CHUNKLOOKUP_WIDTH * i);
121-
122-
if (chunk_offset >= m->data_len)
123-
die(_("invalid chunk offset (too large)"));
124-
125-
switch (chunk_id) {
126-
case MIDX_CHUNKID_PACKNAMES:
127-
m->chunk_pack_names = m->data + chunk_offset;
128-
break;
129-
130-
case MIDX_CHUNKID_OIDFANOUT:
131-
m->chunk_oid_fanout = (uint32_t *)(m->data + chunk_offset);
132-
break;
133-
134-
case MIDX_CHUNKID_OIDLOOKUP:
135-
m->chunk_oid_lookup = m->data + chunk_offset;
136-
break;
137-
138-
case MIDX_CHUNKID_OBJECTOFFSETS:
139-
m->chunk_object_offsets = m->data + chunk_offset;
140-
break;
141-
142-
case MIDX_CHUNKID_LARGEOFFSETS:
143-
m->chunk_large_offsets = m->data + chunk_offset;
144-
break;
145-
146-
case 0:
147-
die(_("terminating multi-pack-index chunk id appears earlier than expected"));
148-
break;
149-
150-
default:
151-
/*
152-
* Do nothing on unrecognized chunks, allowing future
153-
* extensions to add optional chunks.
154-
*/
155-
break;
156-
}
157-
}
129+
cf = init_chunkfile(NULL);
158130

159-
if (!m->chunk_pack_names)
131+
if (read_table_of_contents(cf, m->data, midx_size,
132+
MIDX_HEADER_SIZE, m->num_chunks))
133+
goto cleanup_fail;
134+
135+
if (pair_chunk(cf, MIDX_CHUNKID_PACKNAMES, &m->chunk_pack_names) == CHUNK_NOT_FOUND)
160136
die(_("multi-pack-index missing required pack-name chunk"));
161-
if (!m->chunk_oid_fanout)
137+
if (read_chunk(cf, MIDX_CHUNKID_OIDFANOUT, midx_read_oid_fanout, m) == CHUNK_NOT_FOUND)
162138
die(_("multi-pack-index missing required OID fanout chunk"));
163-
if (!m->chunk_oid_lookup)
139+
if (pair_chunk(cf, MIDX_CHUNKID_OIDLOOKUP, &m->chunk_oid_lookup) == CHUNK_NOT_FOUND)
164140
die(_("multi-pack-index missing required OID lookup chunk"));
165-
if (!m->chunk_object_offsets)
141+
if (pair_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, &m->chunk_object_offsets) == CHUNK_NOT_FOUND)
166142
die(_("multi-pack-index missing required object offsets chunk"));
167143

144+
pair_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS, &m->chunk_large_offsets);
145+
168146
m->num_objects = ntohl(m->chunk_oid_fanout[255]);
169147

170148
m->pack_names = xcalloc(m->num_packs, sizeof(*m->pack_names));
@@ -190,6 +168,7 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local
190168
cleanup_fail:
191169
free(m);
192170
free(midx_name);
171+
free(cf);
193172
if (midx_map)
194173
munmap(midx_map, midx_size);
195174
if (0 <= fd)

‎t/t5319-multi-pack-index.sh‎

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -314,12 +314,12 @@ test_expect_success 'verify bad OID version' '
314314

315315
test_expect_success 'verify truncated chunk count' '
316316
corrupt_midx_and_verify $MIDX_BYTE_CHUNK_COUNT "\01" $objdir \
317-
"missing required"
317+
"final chunk has non-zero id"
318318
'
319319

320320
test_expect_success 'verify extended chunk count' '
321321
corrupt_midx_and_verify $MIDX_BYTE_CHUNK_COUNT "\07" $objdir \
322-
"terminating multi-pack-index chunk id appears earlier than expected"
322+
"terminating chunk id appears earlier than expected"
323323
'
324324

325325
test_expect_success 'verify missing required chunk' '
@@ -329,7 +329,7 @@ test_expect_success 'verify missing required chunk' '
329329

330330
test_expect_success 'verify invalid chunk offset' '
331331
corrupt_midx_and_verify $MIDX_BYTE_CHUNK_OFFSET "\01" $objdir \
332-
"invalid chunk offset (too large)"
332+
"improper chunk offset(s)"
333333
'
334334

335335
test_expect_success 'verify packnames out of order' '

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