pack-objects: clean up write_object() a bit

... for improved readability.  No functional changes.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
maint
Nicolas Pitre 2008-05-02 15:11:48 -04:00 committed by Junio C Hamano
parent bcd7954e21
commit 2c5ef82463
1 changed files with 33 additions and 31 deletions

View File

@ -226,41 +226,43 @@ static unsigned long write_object(struct sha1file *f,
struct object_entry *entry, struct object_entry *entry,
off_t write_offset) off_t write_offset)
{ {
unsigned long size; unsigned long size, limit;
void *buf; void *buf;
unsigned char header[10]; unsigned char header[10], dheader[10];
unsigned char dheader[10];
unsigned hdrlen; unsigned hdrlen;
off_t datalen; off_t datalen;
enum object_type obj_type; enum object_type type;
int to_reuse = 0; int usable_delta, to_reuse;
/* write limit if limited packsize and not first object */
unsigned long limit = pack_size_limit && nr_written ?
pack_size_limit - write_offset : 0;
/* no if no delta */
int usable_delta = !entry->delta ? 0 :
/* yes if unlimited packfile */
!pack_size_limit ? 1 :
/* no if base written to previous pack */
entry->delta->idx.offset == (off_t)-1 ? 0 :
/* otherwise double-check written to this
* pack, like we do below
*/
entry->delta->idx.offset ? 1 : 0;


if (!pack_to_stdout) if (!pack_to_stdout)
crc32_begin(f); crc32_begin(f);


obj_type = entry->type; type = entry->type;

/* write limit if limited packsize and not first object */
limit = pack_size_limit && nr_written ?
pack_size_limit - write_offset : 0;

if (!entry->delta)
usable_delta = 0; /* no delta */
else if (!pack_size_limit)
usable_delta = 1; /* unlimited packfile */
else if (entry->delta->idx.offset == (off_t)-1)
usable_delta = 0; /* base was written to another pack */
else if (entry->delta->idx.offset)
usable_delta = 1; /* base already exists in this pack */
else
usable_delta = 0; /* base could end up in another pack */

if (!reuse_object) if (!reuse_object)
to_reuse = 0; /* explicit */ to_reuse = 0; /* explicit */
else if (!entry->in_pack) else if (!entry->in_pack)
to_reuse = 0; /* can't reuse what we don't have */ to_reuse = 0; /* can't reuse what we don't have */
else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA) else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
/* check_object() decided it for us ... */ /* check_object() decided it for us ... */
to_reuse = usable_delta; to_reuse = usable_delta;
/* ... but pack split may override that */ /* ... but pack split may override that */
else if (obj_type != entry->in_pack_type) else if (type != entry->in_pack_type)
to_reuse = 0; /* pack has delta which is unusable */ to_reuse = 0; /* pack has delta which is unusable */
else if (entry->delta) else if (entry->delta)
to_reuse = 0; /* we want to pack afresh */ to_reuse = 0; /* we want to pack afresh */
@ -274,19 +276,19 @@ static unsigned long write_object(struct sha1file *f,
unsigned long maxsize; unsigned long maxsize;
void *out; void *out;
if (!usable_delta) { if (!usable_delta) {
buf = read_sha1_file(entry->idx.sha1, &obj_type, &size); buf = read_sha1_file(entry->idx.sha1, &type, &size);
if (!buf) if (!buf)
die("unable to read %s", sha1_to_hex(entry->idx.sha1)); die("unable to read %s", sha1_to_hex(entry->idx.sha1));
} else if (entry->delta_data) { } else if (entry->delta_data) {
size = entry->delta_size; size = entry->delta_size;
buf = entry->delta_data; buf = entry->delta_data;
entry->delta_data = NULL; entry->delta_data = NULL;
obj_type = (allow_ofs_delta && entry->delta->idx.offset) ? type = (allow_ofs_delta && entry->delta->idx.offset) ?
OBJ_OFS_DELTA : OBJ_REF_DELTA; OBJ_OFS_DELTA : OBJ_REF_DELTA;
} else { } else {
buf = get_delta(entry); buf = get_delta(entry);
size = entry->delta_size; size = entry->delta_size;
obj_type = (allow_ofs_delta && entry->delta->idx.offset) ? type = (allow_ofs_delta && entry->delta->idx.offset) ?
OBJ_OFS_DELTA : OBJ_REF_DELTA; OBJ_OFS_DELTA : OBJ_REF_DELTA;
} }
/* compress the data to store and put compressed length in datalen */ /* compress the data to store and put compressed length in datalen */
@ -308,9 +310,9 @@ static unsigned long write_object(struct sha1file *f,
* The object header is a byte of 'type' followed by zero or * The object header is a byte of 'type' followed by zero or
* more bytes of length. * more bytes of length.
*/ */
hdrlen = encode_header(obj_type, size, header); hdrlen = encode_header(type, size, header);


if (obj_type == OBJ_OFS_DELTA) { if (type == OBJ_OFS_DELTA) {
/* /*
* Deltas with relative base contain an additional * Deltas with relative base contain an additional
* encoding of the relative offset for the delta * encoding of the relative offset for the delta
@ -329,7 +331,7 @@ static unsigned long write_object(struct sha1file *f,
sha1write(f, header, hdrlen); sha1write(f, header, hdrlen);
sha1write(f, dheader + pos, sizeof(dheader) - pos); sha1write(f, dheader + pos, sizeof(dheader) - pos);
hdrlen += sizeof(dheader) - pos; hdrlen += sizeof(dheader) - pos;
} else if (obj_type == OBJ_REF_DELTA) { } else if (type == OBJ_REF_DELTA) {
/* /*
* Deltas with a base reference contain * Deltas with a base reference contain
* an additional 20 bytes for the base sha1. * an additional 20 bytes for the base sha1.
@ -361,11 +363,11 @@ static unsigned long write_object(struct sha1file *f,
off_t offset; off_t offset;


if (entry->delta) { if (entry->delta) {
obj_type = (allow_ofs_delta && entry->delta->idx.offset) ? type = (allow_ofs_delta && entry->delta->idx.offset) ?
OBJ_OFS_DELTA : OBJ_REF_DELTA; OBJ_OFS_DELTA : OBJ_REF_DELTA;
reused_delta++; reused_delta++;
} }
hdrlen = encode_header(obj_type, entry->size, header); hdrlen = encode_header(type, entry->size, header);
offset = entry->in_pack_offset; offset = entry->in_pack_offset;
revidx = find_pack_revindex(p, offset); revidx = find_pack_revindex(p, offset);
datalen = revidx[1].offset - offset; datalen = revidx[1].offset - offset;
@ -374,7 +376,7 @@ static unsigned long write_object(struct sha1file *f,
die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1)); die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
offset += entry->in_pack_header_size; offset += entry->in_pack_header_size;
datalen -= entry->in_pack_header_size; datalen -= entry->in_pack_header_size;
if (obj_type == OBJ_OFS_DELTA) { if (type == OBJ_OFS_DELTA) {
off_t ofs = entry->idx.offset - entry->delta->idx.offset; off_t ofs = entry->idx.offset - entry->delta->idx.offset;
unsigned pos = sizeof(dheader) - 1; unsigned pos = sizeof(dheader) - 1;
dheader[pos] = ofs & 127; dheader[pos] = ofs & 127;
@ -385,7 +387,7 @@ static unsigned long write_object(struct sha1file *f,
sha1write(f, header, hdrlen); sha1write(f, header, hdrlen);
sha1write(f, dheader + pos, sizeof(dheader) - pos); sha1write(f, dheader + pos, sizeof(dheader) - pos);
hdrlen += sizeof(dheader) - pos; hdrlen += sizeof(dheader) - pos;
} else if (obj_type == OBJ_REF_DELTA) { } else if (type == OBJ_REF_DELTA) {
if (limit && hdrlen + 20 + datalen + 20 >= limit) if (limit && hdrlen + 20 + datalen + 20 >= limit)
return 0; return 0;
sha1write(f, header, hdrlen); sha1write(f, header, hdrlen);