#ifndef _WIMLIB_LOOKUP_TABLE_H #define _WIMLIB_LOOKUP_TABLE_H #include "wimlib_internal.h" #include "dentry.h" #include /* Size of each lookup table entry in the WIM file. */ #define WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE 50 #define LOOKUP_FLAG_ADS_OK 0x00000001 #define LOOKUP_FLAG_DIRECTORY_OK 0x00000002 #define LOOKUP_FLAG_FOLLOW_SYMLINKS 0x00000004 /* A lookup table that is used to translate the hash codes of dentries into the * offsets and sizes of uncompressed or compressed file resources. It is * implemented as a hash table. */ struct lookup_table { struct hlist_head *array; u64 num_entries; u64 capacity; }; struct wimlib_fd; /* * An entry in the lookup table in the WIM file. * * It is used to find data streams for files in the WIM. * * The lookup_table_entry for a given dentry in the WIM is found using the SHA1 * message digest field. */ struct lookup_table_entry { /* List of lookup table entries in this hash bucket */ struct hlist_node hash_list; /* @resource_entry is read from the lookup table in the WIM * file; it says where to find the file resource in the WIM * file, and whether it is compressed or not. */ struct resource_entry resource_entry; /* Currently ignored; set to 1 in new lookup table entries. */ u16 part_number; /* If %true, this lookup table entry corresponds to a symbolic link * reparse buffer. @symlink_reparse_data_buf will give the target of * the symbolic link. */ bool is_symlink; /* Number of times this lookup table entry is referenced by dentries. */ u32 refcnt; union { /* SHA1 hash of the file resource pointed to by this lookup * table entry */ u8 hash[WIM_HASH_SIZE]; /* First 4 or 8 bytes of the SHA1 hash, used for inserting the * entry into the hash table. Since the SHA1 hashes can be * considered random, we don't really need the full 20 byte hash * just to insert the entry in a hash table. */ size_t hash_short; }; /* If @file_on_disk != NULL, the file resource indicated by this lookup * table entry is not in the WIM file, but rather a file on disk; this * occurs for files that are added to the WIM. In that case, * file_on_disk is the name of the file in the outside filesystem. * It will not be compressed, and its size will be given by * resource_entry.size and resource_entry.original_size. */ union { char *file_on_disk; char *staging_file_name; void *symlink_buf; struct lookup_table_entry *next_lte_in_swm; }; union { struct { /* Used for wimlib_export. */ /* If (other_wim_fp != NULL), the file resource indicated * by this lookup table entry is in a different WIM * file, and other_wim_fp is the FILE* for it. */ FILE *other_wim_fp; /* Compression type used in other WIM. */ int other_wim_ctype; }; struct { /* Used for wimlib_mount */ /* File descriptors table for this data stream */ struct wimlib_fd **fds; u16 num_allocated_fds; u16 num_opened_fds; }; }; /* When a WIM file is written, out_refcnt starts at 0 and is incremented * whenever the file resource pointed to by this lookup table entry * needs to be written. Naturally, the file resource only need to be * written when out_refcnt is 0. Incrementing it further is needed to * find the correct reference count to write to the lookup table in the * output file, which may be less than the regular refcnt if not all * images in the WIM file are written. * * output_resource_entry is the struct resource_entry for the position of the * file resource when written to the output file. */ u32 out_refcnt; struct resource_entry output_resource_entry; /* Circular linked list of streams that share the same lookup table * entry * * This list of streams may include streams from different hard link * sets that happen to be the same. */ struct list_head lte_group_list; /* List of lookup table entries that correspond to streams that have * been extracted to the staging directory when modifying a read-write * mounted WIM. */ struct list_head staging_list; }; extern struct lookup_table *new_lookup_table(size_t capacity); extern void lookup_table_insert(struct lookup_table *table, struct lookup_table_entry *lte); /* Unlinks a lookup table entry from the table; does not free it. */ static inline void lookup_table_unlink(struct lookup_table *table, struct lookup_table_entry *lte) { hlist_del(<e->hash_list); table->num_entries--; } extern struct lookup_table_entry * lookup_table_decrement_refcnt(struct lookup_table* table, const u8 hash[]); extern struct lookup_table_entry * lte_decrement_refcnt(struct lookup_table_entry *lte, struct lookup_table *table); extern struct lookup_table_entry *new_lookup_table_entry(); extern int for_lookup_table_entry(struct lookup_table *table, int (*visitor)(struct lookup_table_entry *, void *), void *arg); extern struct lookup_table_entry * __lookup_resource(const struct lookup_table *table, const u8 hash[]); extern int lookup_resource(WIMStruct *w, const char *path, int lookup_flags, struct dentry **dentry_ret, struct lookup_table_entry **lte_ret, unsigned *stream_idx_ret); extern int zero_out_refcnts(struct lookup_table_entry *entry, void *ignore); extern int print_lookup_table_entry(struct lookup_table_entry *entry, void *ignore); extern int read_lookup_table(FILE *fp, u64 offset, u64 size, struct lookup_table **table_ret); extern void free_lookup_table(struct lookup_table *table); extern int write_lookup_table_entry(struct lookup_table_entry *lte, void *__out); extern void free_lookup_table_entry(struct lookup_table_entry *lte); extern int dentry_resolve_ltes(struct dentry *dentry, void *__table); /* Writes the lookup table to the output file. */ static inline int write_lookup_table(struct lookup_table *table, FILE *out) { return for_lookup_table_entry(table, write_lookup_table_entry, out); } /* Unlinks and frees an entry from a lookup table. */ static inline void lookup_table_remove(struct lookup_table *table, struct lookup_table_entry *lte) { lookup_table_unlink(table, lte); free_lookup_table_entry(lte); } static inline struct resource_entry* wim_metadata_resource_entry(WIMStruct *w) { return &w->image_metadata[ w->current_image - 1].metadata_lte->resource_entry; } #endif