Cancel HFS+ compression if the compressed size is not enouph small.

diff --git a/libarchive/archive_write_disk_posix.c b/libarchive/archive_write_disk_posix.c
index a522d9c8a59cc28944684166aaa8ab4c6a9523a2..90c82c51af51b68d386a08685eb609663507d790 100644 (file)
--- a/libarchive/archive_write_disk_posix.c
+++ b/libarchive/archive_write_disk_posix.c
@@ -322,6 +322,7 @@ struct archive_write_disk {
 #define DECMPFS_UNCOMPRESSED_SIZE      8
 #define DECMPFS_HEADER_SIZE            16
 
+#define HFS_BLOCKS(s)  ((s) >> 12)
 
 static int     check_symlinks(struct archive_write_disk *);
 static int     create_filesystem_object(struct archive_write_disk *);
@@ -1033,6 +1034,67 @@ hfs_reset_compressor(struct archive_write_disk *a)
        return (ARCHIVE_OK);
 }
 
+static int
+hfs_decompress(struct archive_write_disk *a)
+{
+       uint32_t *block_info;
+       unsigned int block_count;
+       uint32_t data_pos, data_size;
+       ssize_t r;
+       ssize_t bytes_written, bytes_to_write;
+       unsigned char *b;
+
+       block_info = (uint32_t *)(a->resource_fork + RSRC_H_SIZE);
+       block_count = archive_le32dec(block_info++);
+       while (block_count--) {
+               data_pos = RSRC_H_SIZE + archive_le32dec(block_info++);
+               data_size = archive_le32dec(block_info++);
+               r = fgetxattr(a->fd, XATTR_RESOURCEFORK_NAME,
+                   a->compressed_buffer, data_size, data_pos, 0);
+               if (r != data_size)  {
+                       archive_set_error(&a->archive,
+                           (r < 0)?errno:ARCHIVE_ERRNO_MISC,
+                           "Failed to read resource fork");
+                       return (ARCHIVE_WARN);
+               }
+               if (a->compressed_buffer[0] == 0xff) {
+                       bytes_to_write = data_size -1;
+                       b = a->compressed_buffer + 1;
+               } else {
+                       uLong dest_len = MAX_DECMPFS_BLOCK_SIZE;
+                       int zr;
+
+                       zr = uncompress((Bytef *)a->uncompressed_buffer,
+                           &dest_len, a->compressed_buffer, data_size);
+                       if (zr != Z_OK) {
+                               archive_set_error(&a->archive,
+                                   ARCHIVE_ERRNO_MISC,
+                                   "Failed to decompress resource fork");
+                               return (ARCHIVE_WARN);
+                       }
+                       bytes_to_write = dest_len;
+                       b = (unsigned char *)a->uncompressed_buffer;
+               }
+               do {
+                       bytes_written = write(a->fd, b, bytes_to_write);
+                       if (bytes_written < 0) {
+                               archive_set_error(&a->archive, errno,
+                                   "Write failed");
+                               return (ARCHIVE_WARN);
+                       }
+                       bytes_to_write -= bytes_written;
+                       b += bytes_written;
+               } while (bytes_to_write > 0);
+       }
+       r = fremovexattr(a->fd, XATTR_RESOURCEFORK_NAME, 0);
+       if (r == -1)  {
+               archive_set_error(&a->archive, errno,
+                   "Failed to remove resource fork");
+               return (ARCHIVE_WARN);
+       }
+       return (ARCHIVE_OK);
+}
+
 static int
 hfs_drive_compressor(struct archive_write_disk *a, const char *buff,
     size_t size)
@@ -1155,6 +1217,7 @@ fprintf(stderr, "block %u bytes --> %u bytes in resource fork\n", (unsigned)size
         */
        if (a->file_remaining_bytes == 0) {
                size_t rsrc_size;
+               int64_t bk;
 
                /* Append the resource footer. */
                rsrc_size = hfs_set_resource_fork_footer(
@@ -1162,6 +1225,15 @@ fprintf(stderr, "block %u bytes --> %u bytes in resource fork\n", (unsigned)size
                    a->compressed_buffer_remaining);
                ret = hfs_write_compressed_data(a, bytes_used + rsrc_size);
                a->compressed_buffer_remaining = a->compressed_buffer_size;
+
+               /* If the compressed size is not enouph smaller than
+                * the uncompressed size. cancel HFS+ compression.
+                * TODO: study a behavior of ditto utility and improve
+                * the condition to fall back into no HFS+ compression. */
+               bk = HFS_BLOCKS(a->compressed_rsrc_position);
+               bk += bk >> 7;
+               if (bk > HFS_BLOCKS(a->filesize))
+                       return hfs_decompress(a);
                /*
                 * Write the resourcefork header.
                 */