X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=include%2Fwimlib%2Flookup_table.h;h=4252f3a5ccdac4cbca41b534b9bb687c6f7fef75;hb=34193844b60cf16bb0a04e344ddf47a0614a7643;hp=6a934e4931e3f0a9440a7164a1411284c023fd2d;hpb=26c7f8bb32e4a32001d409f1693e0df016270ed5;p=wimlib diff --git a/include/wimlib/lookup_table.h b/include/wimlib/lookup_table.h index 6a934e49..4252f3a5 100644 --- a/include/wimlib/lookup_table.h +++ b/include/wimlib/lookup_table.h @@ -1,48 +1,10 @@ #ifndef _WIMLIB_LOOKUP_TABLE_H #define _WIMLIB_LOOKUP_TABLE_H -#include "wimlib/assert.h" -#include "wimlib/dentry.h" #include "wimlib/list.h" +#include "wimlib/resource.h" #include "wimlib/sha1.h" #include "wimlib/types.h" -#include "wimlib/wim.h" - -#define LOOKUP_FLAG_ADS_OK 0x00000001 -#define LOOKUP_FLAG_DIRECTORY_OK 0x00000002 - - -/* The lookup table of a WIM file maps SHA1 message digests to streams of data. - * Here, the in-memory structure is implemented as a hash table. - * - * Given a SHA1 message digest, the mapped-to stream is specified by an offset - * in the WIM, an uncompressed and compressed size, and resource flags (see - * 'struct resource_entry'). But, we associate additional information, such as - * a reference count, with each stream, so the actual mapping is from SHA1 - * message digests to 'struct wim_lookup_table_entry's, each of which contains - * an embedded 'struct resource_entry'. - * - * Note: Everything will break horribly if there is a SHA1 collision. - */ -struct wim_lookup_table { - struct hlist_head *array; - u64 num_entries; - u64 capacity; - struct list_head *unhashed_streams; -}; - -#ifdef WITH_NTFS_3G - -struct _ntfs_volume; - -struct ntfs_location { - tchar *path; - utf16lechar *stream_name; - u16 stream_name_nchars; - struct _ntfs_volume *ntfs_vol; - bool is_reparse_point; -}; -#endif /* An enumerated type that identifies where the stream corresponding to this * lookup table entry is actually located. @@ -51,8 +13,7 @@ struct ntfs_location { * RESOURCE_IN_WIM since all the streams will initially be located in the WIM. * However, to handle situations such as image capture and image mount, we allow * the actual location of the stream to be somewhere else, such as an external - * file. - */ + * file. */ enum resource_location { /* The lookup table entry does not yet correspond to a stream; this is a * temporary state only. */ @@ -62,11 +23,11 @@ enum resource_location { * `struct wim_resource_spec' pointed to by @rspec. @offset_in_res * identifies the offset at which this particular stream begins in the * uncompressed data of the resource; this is normally 0, but in general - * a WIM resource may contain multiple streams. */ + * a WIM resource may be "packed" and potentially contain multiple + * streams. */ RESOURCE_IN_WIM, /* The stream is located in the external file named by @file_on_disk. - * On Windows, @file_on_disk may actually specify a named data stream. */ RESOURCE_IN_FILE_ON_DISK, @@ -90,51 +51,59 @@ enum resource_location { #endif #ifdef __WIN32__ + /* Windows only: the stream is located in the external file named by + * @file_on_disk, which is in the Windows NT namespace and may specify a + * named data stream. */ + RESOURCE_IN_WINNT_FILE_ON_DISK, + /* Windows only: the stream is located in the external file named by * @file_on_disk, but the file is encrypted and must be read using the * appropriate Windows API. */ RESOURCE_WIN32_ENCRYPTED, #endif +}; +struct stream_owner { + struct wim_inode *inode; + const utf16lechar *stream_name; }; -/* - * An entry in the lookup table in the WIM file. +/* Specification for a stream, which may be the contents of a file (unnamed data + * stream), a named data stream, reparse point data, or a WIM metadata resource. * - * It is used to find data streams for files in the WIM. - * - * Metadata resources and reparse point data buffers will also have lookup table - * entries associated with the data. - * - * The lookup_table_entry for a given dentry or alternate stream entry in the - * WIM is found using the SHA1 message digest field. - */ + * One instance of this structure is created for each entry in the WIM's lookup + * table, hence the name of the struct. Each of these entries contains the SHA1 + * message digest of a stream and the location of the stream data in the WIM + * file (size, location, flags). The in-memory lookup table is a map from SHA1 + * message digests to stream locations. */ struct wim_lookup_table_entry { - /* List of lookup table entries in this hash bucket */ + /* List node for a hash bucket of the lookup table. */ struct hlist_node hash_list; - /* Uncompressed size of the stream. */ + /* Uncompressed size of this stream. */ u64 size; /* Stream flags (WIM_RESHDR_FLAG_*). */ u32 flags : 8; - /* One of the `enum resource_location' values documented above. */ - u32 resource_location : 5; + /* One of the `enum resource_location' values documented above. */ + u32 resource_location : 4; /* 1 if this stream has not had a SHA1 message digest calculated for it - * yet */ + * yet. */ u32 unhashed : 1; - /* Temoorary files used for writing; set as documented for + /* Temoorary fields used when writing streams; set as documented for * prepare_stream_list_for_write(). */ u32 unique_size : 1; u32 will_be_in_output_wim : 1; /* Set to 1 when a metadata entry has its checksum changed; in such - * cases the hash is no longer valid to verify the data if the metadata - * resource is read again. */ + * cases the hash cannot be used to verify the data if the metadata + * resource is read again. (This could be avoided if we used separate + * fields for input/output checksum, but most stream entries wouldn't + * need this.) */ u32 dont_check_metadata_hash : 1; union { @@ -162,27 +131,36 @@ struct wim_lookup_table_entry { }; /* Number of times this lookup table entry is referenced by dentries in - * the WIM. */ + * the WIM. When a WIM's lookup table is read, this field is + * initialized from a corresponding entry; while it should be correct, + * in general it may not be. wim_recalculate_refcnts() recalculates the + * reference counts for all streams and is run before doing any + * deletions. */ u32 refcnt; - /* Actual reference count to this stream (only used while verifying an - * image). */ - u32 real_refcnt; - - /* When a WIM file is written, out_refcnt starts at 0 and is incremented - * whenever the stream pointed to by this lookup table entry needs to be - * written. The stream only need to be written when out_refcnt is - * nonzero, since otherwise it is not referenced by any dentries. */ + /* When a WIM file is written, this is set to the number of references + * (by dentries) to this stream in the output WIM file. + * + * During extraction, this is the number of slots in stream_owners (or + * inline_stream_owners) that have been filled. + * + * During image export, this is set to the number of references of this + * stream that originated from the source WIM. + * + * When mounting a WIM image read-write, this is set to the number of + * extra references to this stream preemptively taken to allow later + * saving the modified image as a new image and leaving the original + * image alone. */ u32 out_refcnt; #ifdef WITH_FUSE - /* Number of times this stream has been opened (used only during - * mounting) */ + /* Number of open file descriptors to this stream during a FUSE mount of + * the containing image. */ u16 num_opened_fds; #endif - /* Pointers to somewhere where the stream is actually located. See the - * comments for the @resource_location field above. */ + /* Specification of where this stream is actually located. Which member + * is valid is determined by the @resource_location field. */ union { struct { struct wim_resource_spec *rspec; @@ -191,7 +169,10 @@ struct wim_lookup_table_entry { tchar *file_on_disk; void *attached_buffer; #ifdef WITH_FUSE - tchar *staging_file_name; + struct { + char *staging_file_name; + int staging_dir_fd; + }; #endif #ifdef WITH_NTFS_3G struct ntfs_location *ntfs_loc; @@ -199,45 +180,56 @@ struct wim_lookup_table_entry { }; /* Links together streams that share the same underlying WIM resource. - * The head is wim_resource_spec.stream_list. */ + * The head is the `stream_list' member of `struct wim_resource_spec'. + */ struct list_head rspec_node; - /* This field is used for the special hardlink or symlink image - * extraction mode. In these mode, all identical files are linked - * together, and @extracted_file will be set to the filename of the - * first extracted file containing this stream. */ - tchar *extracted_file; - /* Temporary fields */ union { - /* Used temporarily during WIM file writing */ + /* Fields used temporarily during WIM file writing. */ struct { union { + /* List node used for stream size table. */ struct hlist_node hash_list_2; + + /* Metadata for the underlying packed resource + * in the WIM being written (only valid if + * WIM_RESHDR_FLAG_PACKED_STREAMS set in + * out_reshdr.flags). */ struct { u64 out_res_offset_in_wim; u64 out_res_size_in_wim; u64 out_res_uncompressed_size; }; }; + /* Links streams being written to the WIM. */ struct list_head write_streams_list; + /* Metadata for this stream in the WIM being written. + */ struct wim_reshdr out_reshdr; }; - /* Used temporarily during extraction */ + /* Used temporarily during extraction. This is an array of + * pointers to the inodes being extracted that use this stream. + */ union { - /* out_refcnt tracks number of slots filled */ - struct wim_dentry *inline_lte_dentries[8]; + /* Inodes to extract that reference this stream. + * out_refcnt tracks the number of slots filled. */ + struct stream_owner inline_stream_owners[3]; struct { - struct wim_dentry **lte_dentries; - unsigned long alloc_lte_dentries; + struct stream_owner *stream_owners; + u32 alloc_stream_owners; }; }; + + /* Actual reference count to this stream (only used while + * verifying an image). */ + u32 real_refcnt; }; - /* Temporary list fields */ + /* Temporary list fields. */ union { /* Links streams for writing lookup table. */ struct list_head lookup_table_list; @@ -247,6 +239,9 @@ struct wim_lookup_table_entry { /* Links streams being exported. */ struct list_head export_stream_list; + + /* Links original list of streams in the read-write mounted image. */ + struct list_head orig_stream_list; }; /* Links streams that are still unhashed after being been added to a @@ -254,29 +249,16 @@ struct wim_lookup_table_entry { struct list_head unhashed_list; }; -static inline bool -lte_is_partial(const struct wim_lookup_table_entry * lte) -{ - return lte->resource_location == RESOURCE_IN_WIM && - lte->size != lte->rspec->uncompressed_size; -} - -static inline bool -lte_filename_valid(const struct wim_lookup_table_entry *lte) -{ - return lte->resource_location == RESOURCE_IN_FILE_ON_DISK - #ifdef __WIN32__ - || lte->resource_location == RESOURCE_WIN32_ENCRYPTED - #endif - #ifdef WITH_FUSE - || lte->resource_location == RESOURCE_IN_STAGING_FILE - #endif - ; -} +/* Functions to allocate and free lookup tables */ extern struct wim_lookup_table * new_lookup_table(size_t capacity) _malloc_attribute; +extern void +free_lookup_table(struct wim_lookup_table *table); + +/* Functions to read or write the lookup table from/to a WIM file */ + extern int read_wim_lookup_table(WIMStruct *wim); @@ -285,24 +267,9 @@ write_wim_lookup_table_from_stream_list(struct list_head *stream_list, struct filedes *out_fd, u16 part_number, struct wim_reshdr *out_reshdr, - int write_resource_flags, - struct wimlib_lzx_context **comp_ctx); - -extern void -free_lookup_table(struct wim_lookup_table *table); + int write_resource_flags); -extern void -lookup_table_insert(struct wim_lookup_table *table, struct wim_lookup_table_entry *lte); - -/* Unlinks a lookup table entry from the table; does not free it. */ -static inline void -lookup_table_unlink(struct wim_lookup_table *table, struct wim_lookup_table_entry *lte) -{ - wimlib_assert(!lte->unhashed); - hlist_del(<e->hash_list); - wimlib_assert(table->num_entries != 0); - table->num_entries--; -} +/* Functions to create, clone, print, and free lookup table entries */ extern struct wim_lookup_table_entry * new_lookup_table_entry(void) _malloc_attribute; @@ -312,52 +279,64 @@ clone_lookup_table_entry(const struct wim_lookup_table_entry *lte) _malloc_attribute; extern void -print_lookup_table_entry(const struct wim_lookup_table_entry *lte, FILE *out); +lte_decrement_refcnt(struct wim_lookup_table_entry *lte, + struct wim_lookup_table *table); +#ifdef WITH_FUSE +extern void +lte_decrement_num_opened_fds(struct wim_lookup_table_entry *lte); +#endif extern void free_lookup_table_entry(struct wim_lookup_table_entry *lte); +/* Functions to insert and delete entries from a lookup table */ + extern void -lte_to_wimlib_resource_entry(const struct wim_lookup_table_entry *lte, - struct wimlib_resource_entry *wentry); +lookup_table_insert(struct wim_lookup_table *table, + struct wim_lookup_table_entry *lte); + +extern void +lookup_table_unlink(struct wim_lookup_table *table, + struct wim_lookup_table_entry *lte); + +/* Function to lookup a stream by SHA1 message digest */ +extern struct wim_lookup_table_entry * +lookup_stream(const struct wim_lookup_table *table, const u8 hash[]); + +/* Functions to iterate through the entries of a lookup table */ extern int for_lookup_table_entry(struct wim_lookup_table *table, int (*visitor)(struct wim_lookup_table_entry *, void *), void *arg); -extern int -sort_stream_list(struct list_head *stream_list, - size_t list_head_offset, - int (*compar)(const void *, const void*)); - -extern int -sort_stream_list_by_sequential_order(struct list_head *stream_list, - size_t list_head_offset); - extern int for_lookup_table_entry_pos_sorted(struct wim_lookup_table *table, int (*visitor)(struct wim_lookup_table_entry *, void *), void *arg); -extern struct wim_lookup_table_entry * -lookup_resource(const struct wim_lookup_table *table, const u8 hash[]); -extern int -wim_pathname_to_stream(WIMStruct *wim, const tchar *path, - int lookup_flags, - struct wim_dentry **dentry_ret, - struct wim_lookup_table_entry **lte_ret, - u16 *stream_idx_ret); + +/* Function to get a resource entry in stable format */ + +struct wimlib_resource_entry; extern void -lte_decrement_refcnt(struct wim_lookup_table_entry *lte, - struct wim_lookup_table *table); -#ifdef WITH_FUSE -extern void -lte_decrement_num_opened_fds(struct wim_lookup_table_entry *lte); -#endif +lte_to_wimlib_resource_entry(const struct wim_lookup_table_entry *lte, + struct wimlib_resource_entry *wentry); + +/* Functions to sort a list of lookup table entries */ +extern int +sort_stream_list(struct list_head *stream_list, + size_t list_head_offset, + int (*compar)(const void *, const void*)); + +extern int +sort_stream_list_by_sequential_order(struct list_head *stream_list, + size_t list_head_offset); + +/* Utility functions */ extern int lte_zero_out_refcnt(struct wim_lookup_table_entry *lte, void *ignore); @@ -365,8 +344,21 @@ lte_zero_out_refcnt(struct wim_lookup_table_entry *lte, void *ignore); extern int lte_zero_real_refcnt(struct wim_lookup_table_entry *lte, void *ignore); -extern int -lte_free_extracted_file(struct wim_lookup_table_entry *lte, void *ignore); +static inline bool +lte_is_partial(const struct wim_lookup_table_entry * lte) +{ + return lte->resource_location == RESOURCE_IN_WIM && + lte->size != lte->rspec->uncompressed_size; +} + +static inline const struct stream_owner * +stream_owners(struct wim_lookup_table_entry *stream) +{ + if (stream->out_refcnt <= ARRAY_LEN(stream->inline_stream_owners)) + return stream->inline_stream_owners; + else + return stream->stream_owners; +} static inline void lte_bind_wim_resource_spec(struct wim_lookup_table_entry *lte, @@ -381,126 +373,26 @@ static inline void lte_unbind_wim_resource_spec(struct wim_lookup_table_entry *lte) { list_del(<e->rspec_node); - lte->rspec = NULL; lte->resource_location = RESOURCE_NONEXISTENT; } -extern int -inode_resolve_ltes(struct wim_inode *inode, struct wim_lookup_table *table, - bool force); - -extern int -resource_not_found_error(const struct wim_inode *inode, const u8 *hash); - extern void -inode_unresolve_ltes(struct wim_inode *inode); - -static inline struct wim_lookup_table_entry * -inode_stream_lte_resolved(const struct wim_inode *inode, unsigned stream_idx) -{ - wimlib_assert(inode->i_resolved); - wimlib_assert(stream_idx <= inode->i_num_ads); - if (stream_idx == 0) - return inode->i_lte; - else - return inode->i_ads_entries[stream_idx - 1].lte; -} - -static inline struct wim_lookup_table_entry * -inode_stream_lte_unresolved(const struct wim_inode *inode, unsigned stream_idx, - const struct wim_lookup_table *table) -{ - wimlib_assert(!inode->i_resolved); - wimlib_assert(stream_idx <= inode->i_num_ads); - if (!table) - return NULL; - if (stream_idx == 0) - return lookup_resource(table, inode->i_hash); - else - return lookup_resource(table, - inode->i_ads_entries[ - stream_idx - 1].hash); -} - -extern struct wim_lookup_table_entry * -inode_stream_lte(const struct wim_inode *inode, unsigned stream_idx, - const struct wim_lookup_table *table); - -static inline const u8 * -inode_stream_hash_unresolved(const struct wim_inode *inode, unsigned stream_idx) -{ - wimlib_assert(!inode->i_resolved); - wimlib_assert(stream_idx <= inode->i_num_ads); - if (stream_idx == 0) - return inode->i_hash; - else - return inode->i_ads_entries[stream_idx - 1].hash; -} - - -static inline const u8 * -inode_stream_hash_resolved(const struct wim_inode *inode, unsigned stream_idx) -{ - struct wim_lookup_table_entry *lte; - lte = inode_stream_lte_resolved(inode, stream_idx); - if (lte) - return lte->hash; - else - return zero_hash; -} - -/* - * Returns the hash for stream @stream_idx of the inode, where stream_idx = 0 - * means the default un-named file stream, and stream_idx >= 1 corresponds to an - * alternate data stream. - * - * This works for both resolved and un-resolved dentries. - */ -static inline const u8 * -inode_stream_hash(const struct wim_inode *inode, unsigned stream_idx) -{ - if (inode->i_resolved) - return inode_stream_hash_resolved(inode, stream_idx); - else - return inode_stream_hash_unresolved(inode, stream_idx); -} - -static inline u16 -inode_stream_name_nbytes(const struct wim_inode *inode, unsigned stream_idx) -{ - wimlib_assert(stream_idx <= inode->i_num_ads); - if (stream_idx == 0) - return 0; - else - return inode->i_ads_entries[stream_idx - 1].stream_name_nbytes; -} +lte_put_resource(struct wim_lookup_table_entry *lte); extern struct wim_lookup_table_entry * -inode_unnamed_stream_resolved(const struct wim_inode *inode, u16 *stream_idx_ret); - -extern struct wim_lookup_table_entry * -inode_unnamed_lte_resolved(const struct wim_inode *inode); - -extern struct wim_lookup_table_entry * -inode_unnamed_lte_unresolved(const struct wim_inode *inode, - const struct wim_lookup_table *table); - -extern struct wim_lookup_table_entry * -inode_unnamed_lte(const struct wim_inode *inode, const struct wim_lookup_table *table); - -extern const u8 * -inode_unnamed_stream_hash(const struct wim_inode *inode); +new_stream_from_data_buffer(const void *buffer, size_t size, + struct wim_lookup_table *lookup_table); static inline void -lookup_table_insert_unhashed(struct wim_lookup_table *table, - struct wim_lookup_table_entry *lte, - struct wim_inode *back_inode, - u32 back_stream_id) +add_unhashed_stream(struct wim_lookup_table_entry *lte, + struct wim_inode *back_inode, + u32 back_stream_id, + struct list_head *unhashed_streams) { lte->unhashed = 1; lte->back_inode = back_inode; lte->back_stream_id = back_stream_id; - list_add_tail(<e->unhashed_list, table->unhashed_streams); + list_add_tail(<e->unhashed_list, unhashed_streams); } extern int