X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=include%2Fwimlib%2Fdentry.h;h=05fcd2f325e762024983194376cd31ae95312020;hp=dfb5a95be76b5301f6ea31c41b235b44bc9be28b;hb=b0a6bbcba9dc23f4722827cb13fb0efff5e2799d;hpb=a20f70497fdc89f8c5cdda791f14178819ed25cb diff --git a/include/wimlib/dentry.h b/include/wimlib/dentry.h index dfb5a95b..05fcd2f3 100644 --- a/include/wimlib/dentry.h +++ b/include/wimlib/dentry.h @@ -126,7 +126,9 @@ ads_entries_have_same_name(const struct wim_ads_entry *entry_1, * dentry_tree_fix_inodes() in hardlink.c). */ struct wim_dentry { - /* The inode for this dentry */ + /* Pointer to the inode for this dentry. This will contain some + * information that was factored out of the on-disk WIM dentry as common + * to all dentries in a hard link group. */ struct wim_inode *d_inode; /* Node for the parent's red-black tree of child dentries, sorted by @@ -155,70 +157,79 @@ struct wim_dentry { * including the terminating null character. */ u32 full_path_nbytes; - /* Does this dentry need to be extracted? */ + /* For extraction operations, a subtree of dentries will have this flag + * set so we can keep track of which dentries still need to be + * extracted. Otherwise this will always be 0. */ u8 needs_extraction : 1; + /* For extraction operations, this flag will be set when a dentry in the + * tree being extracted is not being extracted for some reason (file + * type not supported by target filesystem or contains invalid + * characters). Otherwise this will always be 0. */ u8 not_extracted : 1; - /* Only used during NTFS capture */ + /* When capturing from a NTFS volume using NTFS-3g, this flag is set on + * dentries that were created from a filename in the WIN32 or WIN32+DOS + * namespaces rather than the POSIX namespace. Otherwise this will + * always be 0. */ u8 is_win32_name : 1; - /* Set to 1 if an inode has multiple DOS names. */ + /* When verifying the dentry tree after reading it into memory, this + * flag will be set on all dentries in a hard link group that have a + * nonempty DOS name except one. This is because it is supposed to be + * illegal (on NTFS, at least) for a single inode to have multiple DOS + * names. */ u8 dos_name_invalid : 1; - /* Temporary list */ + /* Temporary list field used to make lists of dentries in a few places. + * */ struct list_head tmp_list; - /* List of dentries in the inode (hard link set) */ + /* Linked list node that places this dentry in the list of aliases for + * its inode (d_inode) */ struct list_head d_alias; /* The parent of this directory entry. */ struct wim_dentry *parent; - /* - * Size of directory entry on disk, in bytes. Typical size is around - * 104 to 120 bytes. - * - * It is possible for the length field to be 0. This situation, which - * is undocumented, indicates the end of a list of sibling nodes in a - * directory. It also means the real length is 8, because the dentry - * included only the length field, but that takes up 8 bytes. - * - * The length here includes the base directory entry on disk as well as - * the long and short filenames. It does NOT include any alternate - * stream entries that may follow the directory entry, even though the - * size of those needs to be considered. The length SHOULD be 8-byte - * aligned, although we don't require it to be. We do require the - * length to be large enough to hold the file name(s) of the dentry; - * additionally, a warning is issued if this field is larger than the - * aligned size. - */ + /* 'length' and 'subdir_offset' are only used while reading and writing + * this dentry; see the corresponding field in + * `struct wim_dentry_on_disk' for explanation. */ u64 length; - - /* The offset, from the start of the uncompressed WIM metadata resource - * for this image, of this dentry's child dentries. 0 if the directory - * entry has no children, which is the case for regular files or reparse - * points. */ u64 subdir_offset; + /* These correspond to the two unused fields in the on-disk WIM dentry; + * we read them into memory so we can write them unchanged. These + * fields are set to 0 on new dentries. */ u64 d_unused_1; u64 d_unused_2; - /* Pointer to the UTF-16LE short filename (malloc()ed buffer) */ + /* Pointer to the UTF-16LE short filename (malloc()ed buffer), or NULL + * if this dentry has no short name. */ utf16lechar *short_name; - /* Pointer to the UTF-16LE filename (malloc()ed buffer). */ + /* Pointer to the UTF-16LE filename (malloc()ed buffer), or NULL if this + * dentry has no filename. */ utf16lechar *file_name; - /* Full path of this dentry in the WIM */ + /* Full path to this dentry in the WIM, in platform-dependent "tchars" + * that can be printed without convension. By default this field will + * be NULL and will only be calculated on-demand by the + * calculate_dentry_full_path() or dentry_full_path() functions. */ tchar *_full_path; - /* Actual name to extract this dentry as. */ + /* (Extraction only) Actual name to extract this dentry as, along with + * its length in tchars excluding the NULL terminator. This usually + * will be the same as file_name, with the character encoding converted + * if needed. But if file_name contains characters not accepted on the + * current platform, then this may be set slightly differently from + * file_name. This will be either NULL or a malloc()ed buffer that may + * alias file_name. */ tchar *extraction_name; size_t extraction_name_nchars; - /* List head for building a list of dentries that contain a certain - * stream. */ + /* (Extraction only) List head for building a list of dentries that + * contain a certain stream. */ struct list_head extraction_stream_list; };