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
11 /* A lookup table that is used to translate the hash codes of dentries into the
12 * offsets and sizes of uncompressed or compressed file resources. It is
13 * implemented as a hash table. */
15 struct lookup_table_entry **array;
20 /* An entry in the lookup table in the WIM file. */
21 struct lookup_table_entry {
23 /* The next struct lookup_table_entry in the hash bucket. NULL if this is the
25 struct lookup_table_entry *next;
27 /* @resource_entry is read from the lookup table in the WIM
28 * file; it says where to find the file resource in the WIM
29 * file, and whether it is compressed or not. */
30 struct resource_entry resource_entry;
32 /* Currently ignored; set to 1 in new lookup table entries. */
35 /* Number of times this lookup table entry is referenced by dentries. */
39 /* SHA1 hash of the file resource pointed to by this lookup
41 u8 hash[WIM_HASH_SIZE];
43 /* First 4 or 8 bytes of the SHA1 hash, used for inserting the
44 * entry into the hash table. Since the SHA1 hashes can be
45 * considered random, we don't really need the full 20 byte hash
46 * just to insert the entry in a hash table. */
50 /* If @file_on_disk != NULL, the file resource indicated by this lookup
51 * table entry is not in the WIM file, but rather a file on disk; this
52 * occurs for files that are added to the WIM. In that case,
53 * file_on_disk is the name of the file in the outside filesystem.
54 * It will not be compressed, and its size will be given by
55 * resource_entry.size and resource_entry.original_size. */
58 char *staging_file_name;
59 struct lookup_table_entry *next_lte_in_swm;
63 struct { /* Used for wimlib_export. */
65 /* If (other_wim_fp != NULL), the file resource indicated
66 * by this lookup table entry is in a different WIM
67 * file, and other_wim_fp is the FILE* for it. */
70 /* Compression type used in other WIM. */
74 struct { /* Used for read-write mounts. */
77 /* Offset of the stream file_on_disk_fd. */
81 /* If file_on_disk_fd, if it is not -1, is the file
82 * descriptor, opened for reading, for file_on_disk. */
85 /* Number of times the file has been opened.
86 * file_on_disk_fd can be closed when num_times_opened
87 * is decremented to 0. */
88 int staging_num_times_opened;
92 /* When a WIM file is written, out_refcnt starts at 0 and is incremented
93 * whenever the file resource pointed to by this lookup table entry
94 * needs to be written. Naturally, the file resource only need to be
95 * written when out_refcnt is 0. Incrementing it further is needed to
96 * find the correct reference count to write to the lookup table in the
97 * output file, which may be less than the regular refcnt if not all
98 * images in the WIM file are written.
100 * output_resource_entry is the struct resource_entry for the position of the
101 * file resource when written to the output file. */
104 bool refcnt_is_incremented;
106 struct resource_entry output_resource_entry;
109 extern struct lookup_table *new_lookup_table(size_t capacity);
111 extern void lookup_table_insert(struct lookup_table *table,
112 struct lookup_table_entry *lte);
114 extern void lookup_table_unlink(struct lookup_table *table,
115 struct lookup_table_entry *lte);
117 extern void lookup_table_decrement_refcnt(struct lookup_table* table,
121 extern struct lookup_table_entry *new_lookup_table_entry();
123 extern int for_lookup_table_entry(struct lookup_table *table,
124 int (*visitor)(struct lookup_table_entry *, void *),
127 extern struct lookup_table_entry *lookup_resource(const struct lookup_table *table,
130 static inline struct lookup_table_entry *
131 wim_lookup_resource(const WIMStruct *w, const struct dentry *dentry)
133 return lookup_resource(w->lookup_table, dentry->hash);
136 extern int zero_out_refcnts(struct lookup_table_entry *entry, void *ignore);
138 extern int print_lookup_table_entry(struct lookup_table_entry *entry, void *ignore);
140 extern int read_lookup_table(FILE *fp, u64 offset, u64 size,
141 struct lookup_table **table_ret);
143 extern void free_lookup_table(struct lookup_table *table);
145 extern int write_lookup_table_entry(struct lookup_table_entry *lte, void *__out);
147 static inline void free_lookup_table_entry(struct lookup_table_entry *lte)
150 FREE(lte->file_on_disk);
155 /* Writes the lookup table to the output file. */
156 static inline int write_lookup_table(struct lookup_table *table, FILE *out)
158 return for_lookup_table_entry(table, write_lookup_table_entry, out);
161 /* Unlinks and frees an entry from a lookup table. */
162 static inline void lookup_table_remove(struct lookup_table *table,
163 struct lookup_table_entry *lte)
165 lookup_table_unlink(table, lte);
166 free_lookup_table_entry(lte);
169 static inline struct resource_entry* wim_metadata_resource_entry(WIMStruct *w)
171 return &w->image_metadata[
172 w->current_image - 1].metadata_lte->resource_entry;