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Initial implementation of GNU/pax sparse file format.

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This commit is contained in:
Sergey Poznyakoff
2003-12-01 21:18:30 +00:00
parent 475a54cc06
commit 374ce58aa0
1 changed files with 59 additions and 2 deletions
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61
src/sparse.c
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@@ -216,6 +216,7 @@ sparse_scan_file (struct tar_sparse_file *file)
static struct tar_sparse_optab oldgnu_optab;
static struct tar_sparse_optab star_optab;
static struct tar_sparse_optab pax_optab;
static bool
sparse_select_optab (struct tar_sparse_file *file)
@@ -232,8 +233,8 @@ sparse_select_optab (struct tar_sparse_file *file)
break;
case POSIX_FORMAT:
/* FIXME: Add method */
return false;
file->optab = &pax_optab;
break;
case STAR_FORMAT:
file->optab = &star_optab;
@@ -713,3 +714,59 @@ static struct tar_sparse_optab star_optab = {
NULL, /* No dump region function */
sparse_extract_region,
};
/* GNU PAX sparse file format. The sparse file map is stored in
x header:
GNU.sparse.size Real size of the stored file
GNU.sparse.numblocks Number of blocks in the sparse map
repeat numblocks time
GNU.sparse.offset Offset of the next data block
GNU.sparse.numbytes Size of the next data block
end repeat
*/
static bool
pax_dump_header (struct tar_sparse_file *file)
{
off_t block_ordinal = current_block_ordinal ();
union block *blk;
size_t i;
/* Store the real file size */
xheader_store ("GNU.sparse.size", file->stat_info, NULL);
xheader_store ("GNU.sparse.numblocks", file->stat_info, NULL);
for (i = 0; i < file->stat_info->sparse_map_avail; i++)
{
xheader_store ("GNU.sparse.offset", file->stat_info, &i);
xheader_store ("GNU.sparse.numbytes", file->stat_info, &i);
}
blk = start_header (file->stat_info);
/* Store the effective (shrunken) file size */
OFF_TO_CHARS (file->stat_info->archive_file_size, blk->header.size);
finish_header (file->stat_info, blk, block_ordinal);
return true;
}
static bool
pax_decode_header (struct tar_sparse_file *file)
{
/* Restore actual size */
size_t s = file->stat_info->archive_file_size;
file->stat_info->archive_file_size = file->stat_info->stat.st_size;
file->stat_info->stat.st_size = s;
return true;
}
static struct tar_sparse_optab pax_optab = {
NULL, /* No init function */
NULL, /* No done function */
pax_dump_header,
pax_decode_header,
NULL, /* No scan_block function */
sparse_dump_region,
sparse_extract_region,
};