Fix WIM_HDR_FLAG_{WRITE_IN_PROGRESS,READONLY} docs

[wimlib] / include / wimlib / header.h

diff --git a/include/wimlib/header.h b/include/wimlib/header.h
index 151d6c78b4dd1db9a08d97b4ba6423f1cfcc1495..0702b45bfa9b9c30af662ee0e074cc46033b510e 100644 (file)
--- a/include/wimlib/header.h
+++ b/include/wimlib/header.h
@@ -4,12 +4,10 @@
 #include "wimlib/resource.h"
 #include "wimlib/types.h"
 
-#define WIM_MAGIC_LEN  8
 #define WIM_GID_LEN    16
-#define WIM_UNUSED_LEN 60
 
 /* Length of the WIM header on disk. */
-#define WIM_HEADER_DISK_SIZE (148 + WIM_UNUSED_LEN)
+#define WIM_HEADER_DISK_SIZE 208
 
 /* Compressed resources in the WIM are divided into separated compressed chunks
  * of this size. */
@@ -19,29 +17,13 @@
  * yet.  The differences between the versions are undocumented. */
 #define WIM_VERSION 0x10d00
 
-/* Header at the very beginning of the WIM file. */
+/* Header at the very beginning of the WIM file.  This is the in-memory
+ * representation and does not include all fields; see `struct wim_header_disk'
+ * for the on-disk structure. */
 struct wim_header {
-       /* Identifies the file as WIM file. Must be exactly
-        * {'M', 'S', 'W', 'I', 'M', 0, 0, 0}  */
-       //u8  magic[WIM_MAGIC_LEN];
-
-       /* size of WIM header in bytes. */
-       //u32 hdr_size;
-
-       /* Version of the WIM file.  Microsoft provides no documentation about
-        * exactly what this field affects about the file format, other than the
-        * fact that more recent versions have a higher value. */
-       //u32 version;
-
        /* Bitwise OR of one or more of the WIM_HDR_FLAG_* defined below. */
        u32 flags;
 
-       /* The size of the pieces that the uncompressed files were split up into
-        * when they were compressed.  This should be the same as
-        * WIM_CHUNK_SIZE.  Microsoft incorrectly documents this as "the size of
-        * the compressed .wim file in bytes".*/
-       //u32 chunk_size;
-
        /* A unique identifier for the WIM file. */
        u8 guid[WIM_GID_LEN];
 
@@ -72,9 +54,6 @@ struct wim_header {
        /* The location of the optional integrity table used to verify the
         * integrity WIM.  Zeroed out if there is no integrity table.*/
        struct resource_entry integrity;
-
-       /* Reserved for future disuse */
-       //u8 unused[WIM_UNUSED_LEN];
 };
 
 /* Flags for the `flags' field of the struct wim_header: */
@@ -85,7 +64,8 @@ struct wim_header {
 /* Files and metadata in the WIM are compressed. */
 #define WIM_HDR_FLAG_COMPRESSION        0x00000002
 
-/* WIM is read-only (wimlib ignores this because it's pretty much pointless) */
+/* WIM is read-only, so modifications should not be allowed even if the WIM is
+ * writable at the filesystem level. */
 #define WIM_HDR_FLAG_READONLY           0x00000004
 
 /* Resource data specified by images in this WIM may be contained in a different
@@ -100,9 +80,7 @@ struct wim_header {
  * metadata resources for a split WIM should be in the first part. */
 #define WIM_HDR_FLAG_METADATA_ONLY      0x00000020
 
-/* Lock field to prevent multiple writers from writing the WIM concurrently.
- * wimlib ignores this flag as it uses flock() to acquire a real lock on the
- * file (if supported by the underlying filesystem). */
+/* The WIM is currently being written or appended to.  */
 #define WIM_HDR_FLAG_WRITE_IN_PROGRESS  0x00000040
 
 /* Reparse point fixup flag.  See docs for --rpfix and --norpfix in imagex, or