X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=include%2Fwimlib%2Fblob_table.h;h=c5295820a744b12b19cfe3943d254adad10fd89e;hb=0ce21c13081441f53d88ef58fbeba957abb74574;hp=dcf6af7ffaa2c2a44870b1e3d8eb6bb55e8caf6b;hpb=fef476297d762fec1f4c1517895add6b4c342915;p=wimlib

diff --git a/include/wimlib/blob_table.h b/include/wimlib/blob_table.h
index dcf6af7f..c5295820 100644
--- a/include/wimlib/blob_table.h
+++ b/include/wimlib/blob_table.h
@@ -74,7 +74,20 @@ struct blob_descriptor {
 	/* List node for a hash bucket of the blob table  */
 	struct hlist_node hash_list;
 
-	/* Uncompressed size of this blob  */
+	/*
+	 * Uncompressed size of this blob.
+	 *
+	 * In most cases we are now enforcing that this is nonzero; i.e. an
+	 * empty stream will have "no blob" rather than "an empty blob".  The
+	 * exceptions are:
+	 *
+	 *	- blob descriptors with 'blob_location == BLOB_NONEXISTENT',
+	 *	  e.g. placeholder entries for new metadata resources or for
+	 *	  blobs required for pipable WIM extraction.  In these cases the
+	 *	  size is not meaningful information anyway.
+	 *	- blob descriptors with 'blob_location == BLOB_IN_STAGING_FILE'
+	 *	  can vary their size over time, including to 0.
+	 */
 	u64 size;
 
 	union {
@@ -95,7 +108,7 @@ struct blob_descriptor {
 			struct wim_inode *back_inode;
 			u32 back_stream_id;
 		};
-	};
+	} _packed_attribute; /* union is SHA1_HASH_SIZE bytes */
 
 	/* Number of times this blob is referenced by file streams in WIM
 	 * images.  See blob_decrement_refcnt() for information about the
@@ -328,8 +341,7 @@ blob_to_wimlib_resource_entry(const struct blob_descriptor *blob,
 			      struct wimlib_resource_entry *wentry);
 
 extern int
-sort_blob_list(struct list_head *blob_list,
-	       size_t list_head_offset,
+sort_blob_list(struct list_head *blob_list, size_t list_head_offset,
 	       int (*compar)(const void *, const void*));
 
 extern int
@@ -340,7 +352,7 @@ extern int
 cmp_blobs_by_sequential_order(const void *p1, const void *p2);
 
 static inline const struct blob_extraction_target *
-blob_extraction_targets(struct blob_descriptor *blob)
+blob_extraction_targets(const struct blob_descriptor *blob)
 {
 	if (blob->out_refcnt <= ARRAY_LEN(blob->inline_blob_extraction_targets))
 		return blob->inline_blob_extraction_targets;
@@ -363,18 +375,6 @@ blob_set_is_located_in_wim_resource(struct blob_descriptor *blob,
 	blob->offset_in_res = offset_in_res;
 }
 
-/*
- * Declare that the specified blob is located in the specified non-solid WIM
- * resource.  In this case, the blob data is the entire uncompressed resource.
- */
-static inline void
-blob_set_is_located_in_nonsolid_wim_resource(struct blob_descriptor *blob,
-					     struct wim_resource_descriptor *rdesc)
-{
-	blob_set_is_located_in_wim_resource(blob, rdesc, 0);
-	blob->size = rdesc->uncompressed_size;
-}
-
 static inline void
 blob_unset_is_located_in_wim_resource(struct blob_descriptor *blob)
 {
@@ -401,8 +401,7 @@ after_blob_hashed(struct blob_descriptor *blob,
 		  struct blob_table *blob_table);
 
 extern int
-hash_unhashed_blob(struct blob_descriptor *blob,
-		   struct blob_table *blob_table,
+hash_unhashed_blob(struct blob_descriptor *blob, struct blob_table *blob_table,
 		   struct blob_descriptor **blob_ret);
 
 extern struct blob_descriptor **