1 /* cp-hash.c -- file copying (hash search routines)
2 Copyright (C) 89, 90, 91, 1995-2009 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>.
17 Written by Torbjorn Granlund, Sweden (tege@sics.se).
18 Rewritten to use lib/hash.c by Jim Meyering. */
22 #include <sys/types.h>
29 /* Use ST_DEV and ST_INO as the key, FILENAME as the value.
30 These are used e.g., in copy.c to associate the destination name with
31 the source device/inode pair so that if we encounter a matching dev/ino
32 pair in the source tree we can arrange to create a hard link between
33 the corresponding names in the destination tree. */
38 /* Destination file name (of non-directory or pre-existing directory)
39 corresponding to the dev/ino of a copied file, or the destination file
40 name corresponding to a dev/ino pair for a newly-created directory. */
44 /* This table maps source dev/ino to destination file name.
45 We use it to preserve hard links when copying. */
46 static Hash_table
*src_to_dest
;
48 /* Initial size of the above hash table. */
49 #define INITIAL_TABLE_SIZE 103
52 src_to_dest_hash (void const *x
, size_t table_size
)
54 struct Src_to_dest
const *p
= x
;
56 /* Ignoring the device number here should be fine. */
57 /* The cast to uintmax_t prevents negative remainders
58 if st_ino is negative. */
59 return (uintmax_t) p
->st_ino
% table_size
;
62 /* Compare two Src_to_dest entries.
63 Return true if their keys are judged `equal'. */
65 src_to_dest_compare (void const *x
, void const *y
)
67 struct Src_to_dest
const *a
= x
;
68 struct Src_to_dest
const *b
= y
;
69 return SAME_INODE (*a
, *b
) ? true : false;
73 src_to_dest_free (void *x
)
75 struct Src_to_dest
*a
= x
;
80 /* Remove the entry matching INO/DEV from the table
81 that maps source ino/dev to destination file name. */
83 forget_created (ino_t ino
, dev_t dev
)
85 struct Src_to_dest probe
;
86 struct Src_to_dest
*ent
;
92 ent
= hash_delete (src_to_dest
, &probe
);
94 src_to_dest_free (ent
);
97 /* If INO/DEV correspond to an already-copied source file, return the
98 name of the corresponding destination file. Otherwise, return NULL. */
101 src_to_dest_lookup (ino_t ino
, dev_t dev
)
103 struct Src_to_dest ent
;
104 struct Src_to_dest
const *e
;
107 e
= hash_lookup (src_to_dest
, &ent
);
108 return e
? e
->name
: NULL
;
111 /* Add file NAME, copied from inode number INO and device number DEV,
112 to the list of files we have copied.
113 Return NULL if inserted, otherwise non-NULL. */
116 remember_copied (const char *name
, ino_t ino
, dev_t dev
)
118 struct Src_to_dest
*ent
;
119 struct Src_to_dest
*ent_from_table
;
121 ent
= xmalloc (sizeof *ent
);
122 ent
->name
= xstrdup (name
);
126 ent_from_table
= hash_insert (src_to_dest
, ent
);
127 if (ent_from_table
== NULL
)
129 /* Insertion failed due to lack of memory. */
133 /* Determine whether there was already an entry in the table
134 with a matching key. If so, free ENT (it wasn't inserted) and
135 return the `name' from the table entry. */
136 if (ent_from_table
!= ent
)
138 src_to_dest_free (ent
);
139 return (char *) ent_from_table
->name
;
142 /* New key; insertion succeeded. */
146 /* Initialize the hash table. */
150 src_to_dest
= hash_initialize (INITIAL_TABLE_SIZE
, NULL
,
154 if (src_to_dest
== NULL
)
158 /* Reset the hash structure in the global variable `htab' to
159 contain no entries. */
164 hash_free (src_to_dest
);