X-Git-Url: https://git.dogcows.com/gitweb?a=blobdiff_plain;ds=sidebyside;f=src%2Fsparse.c;h=a661ab18d3a47b3ed6cf5446130fc1dc957d2a76;hb=d46025b23c5bbe31902ba4e902312ce8fe05ed63;hp=39be72db56f964ad5046553859c2fe3934b5664c;hpb=8d6e47cc7fcfb6781b82ba60b8eb823c7fdc7013;p=chaz%2Ftar

diff --git a/src/sparse.c b/src/sparse.c
index 39be72d..a661ab1 100644
--- a/src/sparse.c
+++ b/src/sparse.c
@@ -205,10 +205,8 @@ sparse_scan_file (struct tar_sparse_file *file)
     }
       
   if (sp.numbytes == 0)
-    {
-      sp.offset = offset - 1;
-      sp.numbytes = 1;
-    }
+    sp.offset = offset;
+
   sparse_add_map (file, &sp);
   file->stat_info->archive_file_size += count;
   return tar_sparse_scan (file, scan_end, NULL);
@@ -216,6 +214,7 @@ 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 +231,8 @@ 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;
@@ -255,7 +254,7 @@ sparse_dump_region (struct tar_sparse_file *file, size_t index)
 		       SEEK_SET))
     return false;
 
-  do
+  while (bytes_left > 0)
     {
       size_t bufsize = (bytes_left > BLOCKSIZE) ? BLOCKSIZE : bytes_left;
       off_t bytes_read;
@@ -277,7 +276,7 @@ sparse_dump_region (struct tar_sparse_file *file, size_t index)
       file->dumped_size += bytes_read;
       set_next_block_after (blk);
     }
-  while (bytes_left > 0);
+
   return true;
 }
 
@@ -289,8 +288,16 @@ sparse_extract_region (struct tar_sparse_file *file, size_t index)
   if (!lseek_or_error (file, file->stat_info->sparse_map[index].offset,
 		       SEEK_SET))
     return false;
+
   write_size = file->stat_info->sparse_map[index].numbytes;
-  while (write_size > 0)
+
+  if (write_size == 0)
+    {
+      /* Last block of the file is a hole */
+      if (sys_truncate (file->fd))
+	truncate_warn (file->stat_info->orig_file_name);
+    }
+  else while (write_size > 0)
     {
       size_t count;
       size_t wrbytes = (write_size > BLOCKSIZE) ? BLOCKSIZE : write_size;
@@ -482,7 +489,7 @@ sparse_diff_file (int fd, struct tar_stat_info *stat)
 	        + file.stat_info->sparse_map[i].numbytes;
     }
 
-  if (rc)
+  if (!rc)
     skip_file (file.stat_info->archive_file_size - file.dumped_size);
 
   tar_sparse_done (&file);
@@ -713,3 +720,59 @@ 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,
+};
+