extract.c: simplify extract_from_tmpfile()

[wimlib] / include / wimlib / blob_table.h

diff --git a/include/wimlib/blob_table.h b/include/wimlib/blob_table.h
index e273de2531b8fd16280b5737c6421526e32afb75..6dbbe55a7e9c9b489e39c9eeb6ebb28bb8c8650b 100644 (file)
--- a/include/wimlib/blob_table.h
+++ b/include/wimlib/blob_table.h
@@ -12,7 +12,7 @@ enum blob_location {
        /* The blob's data does not exist.  This is a temporary state only.  */
        BLOB_NONEXISTENT = 0,
 
-       /* The blob's data is located in a WIM resource identified by the
+       /* The blob's data is available in the WIM resource identified by the
         * `struct wim_resource_descriptor' pointed to by @rdesc.
         * @offset_in_res identifies the offset at which this particular blob
         * begins in the uncompressed data of the resource.  */
@@ -35,9 +35,8 @@ enum blob_location {
 
 #ifdef WITH_NTFS_3G
        /* The blob's data is available as the contents of an NTFS attribute
-        * accessible through libntfs-3g.  The attribute is identified by
-        * volume, path to an inode, attribute name, and attribute type.
-        * @ntfs_loc points to a structure containing this information.  */
+        * accessible through libntfs-3g.  @ntfs_loc points to a structure which
+        * identifies the attribute.  */
        BLOB_IN_NTFS_VOLUME,
 #endif
 
@@ -55,16 +54,17 @@ enum blob_location {
 #endif
 };
 
-/* A "blob target" is a stream, and the inode to which that stream belongs, to
- * which a blob needs to be extracted as part of an extraction operation.  Since
- * blobs are single-instanced, a blob may have multiple targets.  */
+/* A "blob extraction target" is a stream, and the inode to which that stream
+ * belongs, to which a blob needs to be extracted as part of an extraction
+ * operation.  Since blobs are single-instanced, a blob may have multiple
+ * extraction targets.  */
 struct blob_extraction_target {
        struct wim_inode *inode;
        struct wim_inode_stream *stream;
 };
 
 /*
- * Descriptor for a blob, which is a known length sequence of binary data.
+ * Descriptor for a "blob", which is a known length sequence of binary data.
  *
  * Within a WIM file, blobs are single instanced and are identified by SHA-1
  * message digest.
@@ -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 {
@@ -121,7 +134,7 @@ struct blob_descriptor {
 
 #ifdef WITH_FUSE
        /* Number of open file descriptors to this blob during a FUSE mount of
-        * the containing image.  */
+        * a WIM image.  */
        u16 num_opened_fds;
 #endif
 
@@ -174,6 +187,9 @@ struct blob_descriptor {
                                struct {
                                        tchar *file_on_disk;
                                        struct wim_inode *file_inode;
+                               #ifdef __WIN32__
+                                       u64 sort_key;
+                               #endif
                                };
 
                                /* BLOB_IN_ATTACHED_BUFFER */
@@ -337,7 +353,7 @@ 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;
@@ -345,13 +361,19 @@ blob_extraction_targets(struct blob_descriptor *blob)
                return blob->blob_extraction_targets;
 }
 
+/*
+ * Declare that the specified blob is located in the specified WIM resource at
+ * the specified offset.  The caller is expected to set blob->size if required.
+ */
 static inline void
 blob_set_is_located_in_wim_resource(struct blob_descriptor *blob,
-                                   struct wim_resource_descriptor *rdesc)
+                                   struct wim_resource_descriptor *rdesc,
+                                   u64 offset_in_res)
 {
        blob->blob_location = BLOB_IN_WIM;
        blob->rdesc = rdesc;
        list_add_tail(&blob->rdesc_node, &rdesc->blob_list);
+       blob->offset_in_res = offset_in_res;
 }
 
 static inline void
@@ -361,6 +383,15 @@ blob_unset_is_located_in_wim_resource(struct blob_descriptor *blob)
        blob->blob_location = BLOB_NONEXISTENT;
 }
 
+static inline void
+blob_set_is_located_in_attached_buffer(struct blob_descriptor *blob,
+                                      void *buffer, size_t size)
+{
+       blob->blob_location = BLOB_IN_ATTACHED_BUFFER;
+       blob->attached_buffer = buffer;
+       blob->size = size;
+}
+
 extern struct blob_descriptor *
 new_blob_from_data_buffer(const void *buffer, size_t size,
                          struct blob_table *blob_table);