4 * Lookup table, implemented as a hash table, that maps dentries to file
9 * Copyright (C) 2012 Eric Biggers
11 * This file is part of wimlib, a library for working with WIM files.
13 * wimlib is free software; you can redistribute it and/or modify it under the
14 * terms of the GNU Lesser General Public License as published by the Free
15 * Software Foundation; either version 2.1 of the License, or (at your option)
18 * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
19 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
20 * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
23 * You should have received a copy of the GNU Lesser General Public License
24 * along with wimlib; if not, see http://www.gnu.org/licenses/.
27 #include "wimlib_internal.h"
28 #include "lookup_table.h"
32 struct lookup_table *new_lookup_table(size_t capacity)
34 struct lookup_table *table;
35 struct hlist_head *array;
37 table = MALLOC(sizeof(struct lookup_table));
40 array = CALLOC(capacity, sizeof(array[0]));
45 table->num_entries = 0;
46 table->capacity = capacity;
50 ERROR("Failed to allocate memory for lookup table with capacity %zu",
55 struct lookup_table_entry *new_lookup_table_entry()
57 struct lookup_table_entry *lte;
59 lte = CALLOC(1, sizeof(struct lookup_table_entry));
61 ERROR("Out of memory (tried to allocate %zu bytes for "
62 "lookup table entry)",
63 sizeof(struct lookup_table_entry));
69 INIT_LIST_HEAD(<e->lte_group_list);
73 void free_lookup_table_entry(struct lookup_table_entry *lte)
77 if (lte->staging_list.next)
78 list_del(<e->staging_list);
80 switch (lte->resource_location) {
81 case RESOURCE_IN_STAGING_FILE:
82 case RESOURCE_IN_ATTACHED_BUFFER:
83 case RESOURCE_IN_FILE_ON_DISK:
84 wimlib_assert(<e->file_on_disk ==
85 <e->staging_file_name ==
86 <e->attached_buffer);
87 FREE(lte->file_on_disk);
90 case RESOURCE_IN_NTFS_VOLUME:
92 FREE(lte->ntfs_loc->path_utf8);
93 FREE(lte->ntfs_loc->stream_name_utf16);
105 static int do_free_lookup_table_entry(struct lookup_table_entry *entry,
108 free_lookup_table_entry(entry);
113 void free_lookup_table(struct lookup_table *table)
115 DEBUG("Freeing lookup table");
118 for_lookup_table_entry(table,
119 do_free_lookup_table_entry,
128 * Inserts an entry into the lookup table.
130 * @table: A pointer to the lookup table.
131 * @entry: A pointer to the entry to insert.
133 void lookup_table_insert(struct lookup_table *table,
134 struct lookup_table_entry *lte)
136 size_t i = lte->hash_short % table->capacity;
137 hlist_add_head(<e->hash_list, &table->array[i]);
139 /* XXX Make the table grow when too many entries have been inserted. */
140 table->num_entries++;
145 /* Decrements the reference count for the lookup table entry @lte. If its
146 * reference count reaches 0, it is unlinked from the lookup table. If,
147 * furthermore, the entry has no opened file descriptors associated with it, the
149 struct lookup_table_entry *
150 lte_decrement_refcnt(struct lookup_table_entry *lte, struct lookup_table *table)
153 wimlib_assert(lte->refcnt);
154 if (--lte->refcnt == 0) {
155 lookup_table_unlink(table, lte);
157 if (lte->num_opened_fds == 0)
160 free_lookup_table_entry(lte);
169 * Calls a function on all the entries in the lookup table. Stop early and
170 * return nonzero if any call to the function returns nonzero.
172 int for_lookup_table_entry(struct lookup_table *table,
173 int (*visitor)(struct lookup_table_entry *, void *),
176 struct lookup_table_entry *lte;
177 struct hlist_node *pos, *tmp;
180 for (size_t i = 0; i < table->capacity; i++) {
181 hlist_for_each_entry_safe(lte, pos, tmp, &table->array[i],
184 ret = visitor(lte, arg);
194 * Reads the lookup table from a WIM file.
196 int read_lookup_table(WIMStruct *w)
199 u8 buf[WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE];
201 struct lookup_table *table;
203 DEBUG("Reading lookup table: offset %"PRIu64", size %"PRIu64"",
204 w->hdr.lookup_table_res_entry.offset,
205 w->hdr.lookup_table_res_entry.original_size);
207 if (fseeko(w->fp, w->hdr.lookup_table_res_entry.offset, SEEK_SET) != 0) {
208 ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" to read "
210 w->hdr.lookup_table_res_entry.offset);
211 return WIMLIB_ERR_READ;
214 num_entries = w->hdr.lookup_table_res_entry.original_size /
215 WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE;
216 table = new_lookup_table(num_entries * 2 + 1);
218 return WIMLIB_ERR_NOMEM;
220 while (num_entries--) {
222 struct lookup_table_entry *cur_entry, *duplicate_entry;
224 if (fread(buf, 1, sizeof(buf), w->fp) != sizeof(buf)) {
226 ERROR("Unexpected EOF in WIM lookup table!");
228 ERROR_WITH_ERRNO("Error reading WIM lookup "
231 ret = WIMLIB_ERR_READ;
234 cur_entry = new_lookup_table_entry();
236 ret = WIMLIB_ERR_NOMEM;
240 cur_entry->resource_location = RESOURCE_IN_WIM;
242 p = get_resource_entry(buf, &cur_entry->resource_entry);
243 p = get_u16(p, &cur_entry->part_number);
244 p = get_u32(p, &cur_entry->refcnt);
245 p = get_bytes(p, SHA1_HASH_SIZE, cur_entry->hash);
247 if (is_zero_hash(cur_entry->hash)) {
248 ERROR("The WIM lookup table contains an entry with a "
249 "SHA1 message digest of all 0's");
250 ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
255 duplicate_entry = __lookup_resource(table, cur_entry->hash);
256 if (duplicate_entry) {
257 ERROR("The WIM lookup table contains two entries with the "
258 "same SHA1 message digest!");
259 ERROR("The first entry is:");
260 print_lookup_table_entry(duplicate_entry);
261 ERROR("The second entry is:");
262 print_lookup_table_entry(cur_entry);
263 ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
267 lookup_table_insert(table, cur_entry);
269 if (!(cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED)
270 && (cur_entry->resource_entry.size !=
271 cur_entry->resource_entry.original_size))
273 ERROR("Found uncompressed resource with original size "
274 "not the same as compressed size");
275 ERROR("The lookup table entry for the resource is as follows:");
276 print_lookup_table_entry(cur_entry);
277 ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
281 DEBUG("Done reading lookup table.");
282 w->lookup_table = table;
285 free_lookup_table(table);
291 * Writes a lookup table entry to the output file.
293 int write_lookup_table_entry(struct lookup_table_entry *lte, void *__out)
296 u8 buf[WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE];
301 /* Don't write entries that have not had file resources or metadata
302 * resources written for them. */
303 if (lte->out_refcnt == 0)
306 if (lte->output_resource_entry.flags & WIM_RESHDR_FLAG_METADATA)
307 DEBUG("Writing metadata entry at %lu (orig size = %zu)",
308 ftello(out), lte->output_resource_entry.original_size);
310 p = put_resource_entry(buf, <e->output_resource_entry);
311 p = put_u16(p, lte->part_number);
312 p = put_u32(p, lte->out_refcnt);
313 p = put_bytes(p, SHA1_HASH_SIZE, lte->hash);
314 if (fwrite(buf, 1, sizeof(buf), out) != sizeof(buf)) {
315 ERROR_WITH_ERRNO("Failed to write lookup table entry");
316 return WIMLIB_ERR_WRITE;
323 int zero_out_refcnts(struct lookup_table_entry *entry, void *ignore)
325 entry->out_refcnt = 0;
329 void print_lookup_table_entry(const struct lookup_table_entry *lte)
335 printf("Offset = %"PRIu64" bytes\n",
336 lte->resource_entry.offset);
337 printf("Size = %"PRIu64" bytes\n",
338 (u64)lte->resource_entry.size);
339 printf("Original size = %"PRIu64" bytes\n",
340 lte->resource_entry.original_size);
341 printf("Part Number = %hu\n", lte->part_number);
342 printf("Reference Count = %u\n", lte->refcnt);
344 print_hash(lte->hash);
347 u8 flags = lte->resource_entry.flags;
348 if (flags & WIM_RESHDR_FLAG_COMPRESSED)
349 fputs("WIM_RESHDR_FLAG_COMPRESSED, ", stdout);
350 if (flags & WIM_RESHDR_FLAG_FREE)
351 fputs("WIM_RESHDR_FLAG_FREE, ", stdout);
352 if (flags & WIM_RESHDR_FLAG_METADATA)
353 fputs("WIM_RESHDR_FLAG_METADATA, ", stdout);
354 if (flags & WIM_RESHDR_FLAG_SPANNED)
355 fputs("WIM_RESHDR_FLAG_SPANNED, ", stdout);
357 switch (lte->resource_location) {
358 case RESOURCE_IN_WIM:
359 if (lte->wim->filename) {
360 printf("WIM file = `%s'\n",
364 case RESOURCE_IN_FILE_ON_DISK:
365 printf("File on Disk = `%s'\n", lte->file_on_disk);
367 case RESOURCE_IN_STAGING_FILE:
368 printf("Staging File = `%s'\n", lte->staging_file_name);
376 static int do_print_lookup_table_entry(struct lookup_table_entry *lte,
379 print_lookup_table_entry(lte);
384 * Prints the lookup table of a WIM file.
386 WIMLIBAPI void wimlib_print_lookup_table(WIMStruct *w)
388 for_lookup_table_entry(w->lookup_table,
389 do_print_lookup_table_entry,
394 * Looks up an entry in the lookup table.
396 struct lookup_table_entry *
397 __lookup_resource(const struct lookup_table *table, const u8 hash[])
400 struct lookup_table_entry *lte;
401 struct hlist_node *pos;
403 i = *(size_t*)hash % table->capacity;
404 hlist_for_each_entry(lte, pos, &table->array[i], hash_list)
405 if (hashes_equal(hash, lte->hash))
411 * Finds the dentry, lookup table entry, and stream index for a WIM file stream,
414 * This is only for pre-resolved dentries.
416 int lookup_resource(WIMStruct *w, const char *path,
418 struct dentry **dentry_ret,
419 struct lookup_table_entry **lte_ret,
420 unsigned *stream_idx_ret)
422 struct dentry *dentry;
423 struct lookup_table_entry *lte;
425 const char *stream_name = NULL;
428 if (lookup_flags & LOOKUP_FLAG_ADS_OK) {
429 stream_name = path_stream_name(path);
431 p = (char*)stream_name - 1;
436 dentry = get_dentry(w, path);
442 wimlib_assert(dentry->resolved);
445 if (!(lookup_flags & LOOKUP_FLAG_DIRECTORY_OK)
446 && dentry_is_directory(dentry))
450 size_t stream_name_len = strlen(stream_name);
451 for (u16 i = 0; i < dentry->num_ads; i++) {
452 if (ads_entry_has_name(&dentry->ads_entries[i],
457 lte = dentry->ads_entries[i].lte;
465 *dentry_ret = dentry;
469 *stream_idx_ret = stream_idx;
473 /* Resolve a dentry's lookup table entries
475 * This replaces the SHA1 hash fields (which are used to lookup an entry in the
476 * lookup table) with pointers directly to the lookup table entries. A circular
477 * linked list of streams sharing the same lookup table entry is created.
479 * This function always succeeds; unresolved lookup table entries are given a
482 int dentry_resolve_ltes(struct dentry *dentry, void *__table)
484 struct lookup_table *table = __table;
485 struct lookup_table_entry *lte;
487 if (dentry->resolved)
490 /* Resolve the default file stream */
491 lte = __lookup_resource(table, dentry->hash);
493 list_add(&dentry->lte_group_list.list, <e->lte_group_list);
495 INIT_LIST_HEAD(&dentry->lte_group_list.list);
497 dentry->lte_group_list.type = STREAM_TYPE_NORMAL;
498 dentry->resolved = true;
500 /* Resolve the alternate data streams */
501 if (dentry->ads_entries_status != ADS_ENTRIES_USER) {
502 for (u16 i = 0; i < dentry->num_ads; i++) {
503 struct ads_entry *cur_entry = &dentry->ads_entries[i];
505 lte = __lookup_resource(table, cur_entry->hash);
507 list_add(&cur_entry->lte_group_list.list,
508 <e->lte_group_list);
510 INIT_LIST_HEAD(&cur_entry->lte_group_list.list);
511 cur_entry->lte = lte;
512 cur_entry->lte_group_list.type = STREAM_TYPE_ADS;
518 /* Return the lookup table entry for the unnamed data stream of a dentry, or
519 * NULL if there is none.
521 * You'd think this would be easier than it actually is, since the unnamed data
522 * stream should be the one referenced from the dentry itself. Alas, if there
523 * are named data streams, Microsoft's "imagex.exe" program will put the unnamed
524 * data stream in one of the alternate data streams instead of inside the
525 * dentry. So we need to check the alternate data streams too.
527 * Also, note that a dentry may appear to have than one unnamed stream, but if
528 * the SHA1 message digest is all 0's then the corresponding stream does not
529 * really "count" (this is the case for the dentry's own file stream when the
530 * file stream that should be there is actually in one of the alternate stream
531 * entries.). This is despite the fact that we may need to extract such a
532 * missing entry as an empty file or empty named data stream.
534 struct lookup_table_entry *
535 dentry_unnamed_lte(const struct dentry *dentry,
536 const struct lookup_table *table)
538 if (dentry->resolved)
539 return dentry_unnamed_lte_resolved(dentry);
541 return dentry_unnamed_lte_unresolved(dentry, table);