Cache compression format in 'struct wim_resource_spec'

[wimlib] / src / resource.c

diff --git a/src/resource.c b/src/resource.c
index 6e47dff71da9c932f73d1cc89c14412d314f530c..116873ffc16b68d9be4c590631a4f2167964722a 100644 (file)
--- a/src/resource.c
+++ b/src/resource.c
@@ -175,37 +175,21 @@ read_compressed_wim_resource(const struct wim_resource_spec * const rspec,
 
        /* Get the maximum size of uncompressed chunks in this resource, which
         * we require be a power of 2.  */
-       u32 chunk_size = 0;
        u64 cur_read_offset = rspec->offset_in_wim;
-       int ctype = WIMLIB_COMPRESSION_TYPE_NONE;
+       int ctype = rspec->compression_type;
+       u32 chunk_size = rspec->chunk_size;
        if (alt_chunk_table) {
                /* Alternate chunk table format.  Its header specifies the chunk
-                * size and compression format.  */
-               struct alt_chunk_table_header_disk hdr;
-
-               ret = full_pread(in_fd, &hdr, sizeof(hdr), cur_read_offset);
-               if (ret)
-                       goto read_error;
-               cur_read_offset += sizeof(hdr);
-
-               chunk_size = le32_to_cpu(hdr.chunk_size);
-               ctype = le32_to_cpu(hdr.compression_format);
-
-               /* Format numbers must be the same as in WIMGAPI to be
-                * compatible.  */
-               BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_NONE != 0);
-               BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_LZX != 1);
-               BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_XPRESS != 2);
-               BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_LZMS != 3);
-       } else {
-               /* "Normal" format: the maximum uncompressed chunk size and the
-                * compression format default to those of the WIM itself.  */
-               chunk_size = rspec->wim->chunk_size;
-               ctype = rspec->wim->compression_type;
+                * size and compression format.  Note: it could be read here;
+                * however, the relevant data was already loaded into @rspec by
+                * read_wim_lookup_table().  */
+               cur_read_offset += sizeof(struct alt_chunk_table_header_disk);
        }
+
        if (!is_power_of_2(chunk_size)) {
                ERROR("Invalid compressed resource: "
-                     "expected power-of-2 chunk size (got %u)", chunk_size);
+                     "expected power-of-2 chunk size (got %"PRIu32")",
+                     chunk_size);
                ret = WIMLIB_ERR_INVALID_CHUNK_SIZE;
                goto out_free_memory;
        }
@@ -1377,7 +1361,10 @@ sha1_stream(struct wim_lookup_table_entry *lte)
 }
 
 /* Convert a short WIM resource header to a stand-alone WIM resource
- * specification.  */
+ * specification.
+ *
+ * Note: for packed resources some fields still need to be overridden.
+ */
 void
 wim_res_hdr_to_spec(const struct wim_reshdr *reshdr, WIMStruct *wim,
                    struct wim_resource_spec *rspec)
@@ -1389,6 +1376,13 @@ wim_res_hdr_to_spec(const struct wim_reshdr *reshdr, WIMStruct *wim,
        INIT_LIST_HEAD(&rspec->stream_list);
        rspec->flags = reshdr->flags;
        rspec->is_pipable = wim_is_pipable(wim);
+       if (rspec->flags & WIM_RESHDR_FLAG_COMPRESSED) {
+               rspec->compression_type = wim->compression_type;
+               rspec->chunk_size = wim->chunk_size;
+       } else {
+               rspec->compression_type = WIMLIB_COMPRESSION_TYPE_NONE;
+               rspec->chunk_size = 0;
+       }
 }
 
 /* Convert a stand-alone resource specification to a WIM resource header.  */