1 #ifndef _WIMLIB_LOOKUP_TABLE_H
2 #define _WIMLIB_LOOKUP_TABLE_H
3 #include "wimlib_internal.h"
7 /* Size of each lookup table entry in the WIM file. */
8 #define WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE 50
10 #define LOOKUP_FLAG_ADS_OK 0x00000001
11 #define LOOKUP_FLAG_DIRECTORY_OK 0x00000002
12 #define LOOKUP_FLAG_FOLLOW_SYMLINKS 0x00000004
15 /* A lookup table that is used to translate the hash codes of dentries into the
16 * offsets and sizes of uncompressed or compressed file resources. It is
17 * implemented as a hash table. */
19 struct lookup_table_entry **array;
28 * An entry in the lookup table in the WIM file.
30 * It is used to find data streams for files in the WIM.
32 * The lookup_table_entry for a given dentry in the WIM is found using the SHA1
33 * message digest field.
35 struct lookup_table_entry {
37 /* The next struct lookup_table_entry in the hash bucket. NULL if this is the
39 struct lookup_table_entry *next;
41 /* @resource_entry is read from the lookup table in the WIM
42 * file; it says where to find the file resource in the WIM
43 * file, and whether it is compressed or not. */
44 struct resource_entry resource_entry;
46 /* Currently ignored; set to 1 in new lookup table entries. */
49 /* If %true, this lookup table entry corresponds to a symbolic link
50 * reparse buffer. @symlink_reparse_data_buf will give the target of
51 * the symbolic link. */
54 /* Number of times this lookup table entry is referenced by dentries. */
58 /* SHA1 hash of the file resource pointed to by this lookup
60 u8 hash[WIM_HASH_SIZE];
62 /* First 4 or 8 bytes of the SHA1 hash, used for inserting the
63 * entry into the hash table. Since the SHA1 hashes can be
64 * considered random, we don't really need the full 20 byte hash
65 * just to insert the entry in a hash table. */
69 /* If @file_on_disk != NULL, the file resource indicated by this lookup
70 * table entry is not in the WIM file, but rather a file on disk; this
71 * occurs for files that are added to the WIM. In that case,
72 * file_on_disk is the name of the file in the outside filesystem.
73 * It will not be compressed, and its size will be given by
74 * resource_entry.size and resource_entry.original_size. */
77 char *staging_file_name;
79 struct lookup_table_entry *next_lte_in_swm;
83 struct { /* Used for wimlib_export. */
85 /* If (other_wim_fp != NULL), the file resource indicated
86 * by this lookup table entry is in a different WIM
87 * file, and other_wim_fp is the FILE* for it. */
90 /* Compression type used in other WIM. */
94 struct { /* Used for wimlib_mount */
96 /* File descriptors table for this data stream */
97 struct wimlib_fd **fds;
98 u16 num_allocated_fds;
103 /* When a WIM file is written, out_refcnt starts at 0 and is incremented
104 * whenever the file resource pointed to by this lookup table entry
105 * needs to be written. Naturally, the file resource only need to be
106 * written when out_refcnt is 0. Incrementing it further is needed to
107 * find the correct reference count to write to the lookup table in the
108 * output file, which may be less than the regular refcnt if not all
109 * images in the WIM file are written.
111 * output_resource_entry is the struct resource_entry for the position of the
112 * file resource when written to the output file. */
114 struct resource_entry output_resource_entry;
116 /* Circular linked list of streams that share the same lookup table
119 * This list of streams may include streams from different hard link
120 * sets that happen to be the same. */
121 struct list_head lte_group_list;
123 /* List of lookup table entries that correspond to streams that have
124 * been extracted to the staging directory when modifying a read-write
126 struct list_head staging_list;
129 extern struct lookup_table *new_lookup_table(size_t capacity);
131 extern void lookup_table_insert(struct lookup_table *table,
132 struct lookup_table_entry *lte);
134 extern void lookup_table_unlink(struct lookup_table *table,
135 struct lookup_table_entry *lte);
137 extern struct lookup_table_entry *
138 lookup_table_decrement_refcnt(struct lookup_table* table, const u8 hash[]);
140 extern struct lookup_table_entry *
141 lte_decrement_refcnt(struct lookup_table_entry *lte,
142 struct lookup_table *table);
145 extern struct lookup_table_entry *new_lookup_table_entry();
147 extern int for_lookup_table_entry(struct lookup_table *table,
148 int (*visitor)(struct lookup_table_entry *, void *),
151 extern struct lookup_table_entry *
152 __lookup_resource(const struct lookup_table *lookup_table, const u8 hash[]);
154 extern int lookup_resource(WIMStruct *w, const char *path,
155 int lookup_flags, struct dentry **dentry_ret,
156 struct lookup_table_entry **lte_ret,
157 unsigned *stream_idx_ret);
159 extern int zero_out_refcnts(struct lookup_table_entry *entry, void *ignore);
161 extern int print_lookup_table_entry(struct lookup_table_entry *entry, void *ignore);
163 extern int read_lookup_table(FILE *fp, u64 offset, u64 size,
164 struct lookup_table **table_ret);
166 extern void free_lookup_table(struct lookup_table *table);
168 extern int write_lookup_table_entry(struct lookup_table_entry *lte, void *__out);
170 extern void free_lookup_table_entry(struct lookup_table_entry *lte);
172 extern int dentry_resolve_ltes(struct dentry *dentry, void *__table);
174 /* Writes the lookup table to the output file. */
175 static inline int write_lookup_table(struct lookup_table *table, FILE *out)
177 return for_lookup_table_entry(table, write_lookup_table_entry, out);
180 /* Unlinks and frees an entry from a lookup table. */
181 static inline void lookup_table_remove(struct lookup_table *table,
182 struct lookup_table_entry *lte)
184 lookup_table_unlink(table, lte);
185 free_lookup_table_entry(lte);
188 static inline struct resource_entry* wim_metadata_resource_entry(WIMStruct *w)
190 return &w->image_metadata[
191 w->current_image - 1].metadata_lte->resource_entry;