/* Functions for dealing with sparse files
- Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
- 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
-#include "system.h"
+#include <system.h>
+#include <inttostr.h>
#include <quotearg.h>
#include "common.h"
struct tar_sparse_file
{
int fd; /* File descriptor */
- size_t dumped_size; /* Number of bytes actually written
+ bool seekable; /* Is fd seekable? */
+ off_t offset; /* Current offset in fd if seekable==false.
+ Otherwise unused */
+ off_t dumped_size; /* Number of bytes actually written
to the archive */
struct tar_stat_info *stat_info; /* Information about the file */
- struct tar_sparse_optab *optab;
+ struct tar_sparse_optab const *optab;
void *closure; /* Any additional data optab calls might
- reqiure */
+ require */
};
+/* Dump zeros to file->fd until offset is reached. It is used instead of
+ lseek if the output file is not seekable */
+static bool
+dump_zeros (struct tar_sparse_file *file, off_t offset)
+{
+ static char const zero_buf[BLOCKSIZE];
+
+ if (offset < file->offset)
+ {
+ errno = EINVAL;
+ return false;
+ }
+
+ while (file->offset < offset)
+ {
+ size_t size = (BLOCKSIZE < offset - file->offset
+ ? BLOCKSIZE
+ : offset - file->offset);
+ ssize_t wrbytes;
+
+ wrbytes = write (file->fd, zero_buf, size);
+ if (wrbytes <= 0)
+ {
+ if (wrbytes == 0)
+ errno = EINVAL;
+ return false;
+ }
+ file->offset += wrbytes;
+ }
+
+ return true;
+}
+
static bool
tar_sparse_member_p (struct tar_sparse_file *file)
{
\f
static bool
-lseek_or_error (struct tar_sparse_file *file, off_t offset, int whence)
+lseek_or_error (struct tar_sparse_file *file, off_t offset)
{
- if (lseek (file->fd, offset, whence) < 0)
+ if (file->seekable
+ ? lseek (file->fd, offset, SEEK_SET) < 0
+ : ! dump_zeros (file, offset))
{
seek_diag_details (file->stat_info->orig_file_name, offset);
return false;
it's made *entirely* of zeros, returning a 0 the instant it finds
something that is a nonzero, i.e., useful data. */
static bool
-zero_block_p (char *buffer, size_t size)
+zero_block_p (char const *buffer, size_t size)
{
while (size--)
if (*buffer++)
return true;
}
-#define clear_block(p) memset (p, 0, BLOCKSIZE);
-
-#define SPARSES_INIT_COUNT SPARSES_IN_SPARSE_HEADER
-
static void
-sparse_add_map (struct tar_sparse_file *file, struct sp_array *sp)
+sparse_add_map (struct tar_stat_info *st, struct sp_array const *sp)
{
- if (file->stat_info->sparse_map == NULL)
- {
- file->stat_info->sparse_map =
- xmalloc (SPARSES_INIT_COUNT * sizeof file->stat_info->sparse_map[0]);
- file->stat_info->sparse_map_size = SPARSES_INIT_COUNT;
- }
- else if (file->stat_info->sparse_map_avail == file->stat_info->sparse_map_size)
- {
- file->stat_info->sparse_map_size *= 2;
- file->stat_info->sparse_map =
- xrealloc (file->stat_info->sparse_map,
- file->stat_info->sparse_map_size
- * sizeof file->stat_info->sparse_map[0]);
- }
- file->stat_info->sparse_map[file->stat_info->sparse_map_avail++] = *sp;
+ struct sp_array *sparse_map = st->sparse_map;
+ size_t avail = st->sparse_map_avail;
+ if (avail == st->sparse_map_size)
+ st->sparse_map = sparse_map =
+ x2nrealloc (sparse_map, &st->sparse_map_size, sizeof *sparse_map);
+ sparse_map[avail] = *sp;
+ st->sparse_map_avail = avail + 1;
}
/* Scan the sparse file and create its map */
static bool
sparse_scan_file (struct tar_sparse_file *file)
{
- static char buffer[BLOCKSIZE];
+ struct tar_stat_info *st = file->stat_info;
+ int fd = file->fd;
+ char buffer[BLOCKSIZE];
size_t count;
- size_t offset = 0;
+ off_t offset = 0;
struct sp_array sp = {0, 0};
- if (!lseek_or_error (file, 0, SEEK_SET))
+ if (!lseek_or_error (file, 0))
return false;
- clear_block (buffer);
-
- file->stat_info->sparse_map_avail = 0;
- file->stat_info->archive_file_size = 0;
+ st->archive_file_size = 0;
+
if (!tar_sparse_scan (file, scan_begin, NULL))
return false;
- while ((count = safe_read (file->fd, buffer, sizeof buffer)) != 0
+ while ((count = safe_read (fd, buffer, sizeof buffer)) != 0
&& count != SAFE_READ_ERROR)
{
- /* Analize the block */
+ /* Analyze the block. */
if (zero_block_p (buffer, count))
{
if (sp.numbytes)
{
- sparse_add_map (file, &sp);
+ sparse_add_map (st, &sp);
sp.numbytes = 0;
if (!tar_sparse_scan (file, scan_block, NULL))
return false;
if (sp.numbytes == 0)
sp.offset = offset;
sp.numbytes += count;
- file->stat_info->archive_file_size += count;
+ st->archive_file_size += count;
if (!tar_sparse_scan (file, scan_block, buffer))
return false;
}
offset += count;
- clear_block (buffer);
}
if (sp.numbytes == 0)
sp.offset = offset;
- sparse_add_map (file, &sp);
- file->stat_info->archive_file_size += count;
+ sparse_add_map (st, &sp);
+ st->archive_file_size += count;
return tar_sparse_scan (file, scan_end, NULL);
}
-static struct tar_sparse_optab oldgnu_optab;
-static struct tar_sparse_optab star_optab;
-static struct tar_sparse_optab pax_optab;
+static struct tar_sparse_optab const oldgnu_optab;
+static struct tar_sparse_optab const star_optab;
+static struct tar_sparse_optab const pax_optab;
static bool
sparse_select_optab (struct tar_sparse_file *file)
union block *blk;
off_t bytes_left = file->stat_info->sparse_map[i].numbytes;
- if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset,
- SEEK_SET))
+ if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset))
return false;
while (bytes_left > 0)
size_t bytes_read;
blk = find_next_block ();
- memset (blk->buffer, 0, BLOCKSIZE);
bytes_read = safe_read (file->fd, blk->buffer, bufsize);
if (bytes_read == SAFE_READ_ERROR)
{
read_diag_details (file->stat_info->orig_file_name,
- file->stat_info->sparse_map[i].offset
- + file->stat_info->sparse_map[i].numbytes
- - bytes_left,
- bufsize);
+ (file->stat_info->sparse_map[i].offset
+ + file->stat_info->sparse_map[i].numbytes
+ - bytes_left),
+ bufsize);
return false;
}
+ memset (blk->buffer + bytes_read, 0, BLOCKSIZE - bytes_read);
bytes_left -= bytes_read;
file->dumped_size += bytes_read;
set_next_block_after (blk);
{
size_t write_size;
- if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset,
- SEEK_SET))
+ if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset))
return false;
write_size = file->stat_info->sparse_map[i].numbytes;
if (write_size == 0)
{
/* Last block of the file is a hole */
- if (sys_truncate (file->fd))
+ if (file->seekable && sys_truncate (file->fd))
truncate_warn (file->stat_info->orig_file_name);
}
else while (write_size > 0)
count = full_write (file->fd, blk->buffer, wrbytes);
write_size -= count;
file->dumped_size += count;
+ file->offset += count;
if (count != wrbytes)
{
write_error_details (file->stat_info->orig_file_name,
sparse_dump_file (int fd, struct tar_stat_info *st)
{
bool rc;
- struct tar_sparse_file file;
+ struct tar_sparse_file file = { 0, };
file.stat_info = st;
file.fd = fd;
+ file.seekable = true; /* File *must* be seekable for dump to work */
if (!sparse_select_optab (&file)
|| !tar_sparse_init (&file))
}
}
- pad_archive(file.stat_info->archive_file_size - file.dumped_size);
+ pad_archive (file.stat_info->archive_file_size - file.dumped_size);
return (tar_sparse_done (&file) && rc) ? dump_status_ok : dump_status_short;
}
file.stat_info = st;
file.fd = fd;
+ file.seekable = lseek (fd, 0, SEEK_SET) == 0;
+ file.offset = 0;
if (!sparse_select_optab (&file)
|| !tar_sparse_init (&file))
}
\f
-static char diff_buffer[BLOCKSIZE];
-
static bool
check_sparse_region (struct tar_sparse_file *file, off_t beg, off_t end)
{
- if (!lseek_or_error (file, beg, SEEK_SET))
+ if (!lseek_or_error (file, beg))
return false;
while (beg < end)
{
size_t bytes_read;
- size_t rdsize = end - beg;
+ size_t rdsize = BLOCKSIZE < end - beg ? BLOCKSIZE : end - beg;
+ char diff_buffer[BLOCKSIZE];
- if (rdsize > BLOCKSIZE)
- rdsize = BLOCKSIZE;
- clear_block (diff_buffer);
bytes_read = safe_read (file->fd, diff_buffer, rdsize);
if (bytes_read == SAFE_READ_ERROR)
{
}
if (!zero_block_p (diff_buffer, bytes_read))
{
+ char begbuf[INT_BUFSIZE_BOUND (off_t)];
report_difference (file->stat_info,
- _("File fragment at %lu is not a hole"), beg);
+ _("File fragment at %s is not a hole"),
+ offtostr (beg, begbuf));
return false;
}
{
size_t size_left;
- if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset,
- SEEK_SET))
+ if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset))
return false;
size_left = file->stat_info->sparse_map[i].numbytes;
while (size_left > 0)
{
size_t bytes_read;
size_t rdsize = (size_left > BLOCKSIZE) ? BLOCKSIZE : size_left;
+ char diff_buffer[BLOCKSIZE];
union block *blk = find_next_block ();
if (!blk)
if (bytes_read == SAFE_READ_ERROR)
{
read_diag_details (file->stat_info->orig_file_name,
- file->stat_info->sparse_map[i].offset
- + file->stat_info->sparse_map[i].numbytes
- - size_left,
+ (file->stat_info->sparse_map[i].offset
+ + file->stat_info->sparse_map[i].numbytes
+ - size_left),
rdsize);
return false;
}
|| file->stat_info->archive_file_size < 0)
return add_fail;
- sparse_add_map (file, &sp);
+ sparse_add_map (file->stat_info, &sp);
return add_ok;
}
which actually contains archived size. The following fixes it */
file->stat_info->archive_file_size = file->stat_info->stat.st_size;
file->stat_info->stat.st_size =
- OFF_FROM_HEADER (current_header->oldgnu_header.realsize);
+ OFF_FROM_HEADER (current_header->oldgnu_header.realsize);
return true;
}
size_t i;
union block *h = current_header;
int ext_p;
- static enum oldgnu_add_status rc;
+ enum oldgnu_add_status rc;
file->stat_info->sparse_map_avail = 0;
for (i = 0; i < SPARSES_IN_OLDGNU_HEADER; i++)
return true;
}
-static struct tar_sparse_optab oldgnu_optab = {
+static struct tar_sparse_optab const oldgnu_optab = {
NULL, /* No init function */
NULL, /* No done function */
oldgnu_sparse_member_p,
size_t i;
union block *h = current_header;
int ext_p;
- static enum oldgnu_add_status rc;
+ enum oldgnu_add_status rc = add_ok;
file->stat_info->sparse_map_avail = 0;
}
-static struct tar_sparse_optab star_optab = {
+static struct tar_sparse_optab const star_optab = {
NULL, /* No init function */
NULL, /* No done function */
star_sparse_member_p,
static bool
pax_sparse_member_p (struct tar_sparse_file *file)
{
- return file->stat_info->archive_file_size != file->stat_info->stat.st_size;
+ return file->stat_info->sparse_map_avail > 0;
}
static bool
return true;
}
-static struct tar_sparse_optab pax_optab = {
+static struct tar_sparse_optab const pax_optab = {
NULL, /* No init function */
NULL, /* No done function */
pax_sparse_member_p,
sparse_dump_region,
sparse_extract_region,
};
-
projects / chaz / tar / blobdiff