1 /* cp-hash.c -- file copying (hash search routines)
2 Copyright (C) 89, 90, 91, 1995-2005 Free Software Foundation.
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. */
23 #include <sys/types.h>
32 /* Use ST_DEV and ST_INO as the key, FILENAME as the value.
33 These are used e.g., in copy.c to associate the destination name with
34 the source device/inode pair so that if we encounter a matching dev/ino
35 pair in the source tree we can arrange to create a hard link between
36 the corresponding names in the destination tree. */
41 /* Destination file name (of non-directory or pre-existing directory)
42 corresponding to the dev/ino of a copied file, or the destination file
43 name corresponding to a dev/ino pair for a newly-created directory. */
47 /* This table maps source dev/ino to destination file name.
48 We use it to preserve hard links when copying. */
49 static Hash_table *src_to_dest;
51 /* Initial size of the above hash table. */
52 #define INITIAL_TABLE_SIZE 103
55 src_to_dest_hash (void const *x, size_t table_size)
57 struct Src_to_dest const *p = x;
59 /* Ignoring the device number here should be fine. */
60 /* The cast to uintmax_t prevents negative remainders
61 if st_ino is negative. */
62 return (uintmax_t) p->st_ino % table_size;
65 /* Compare two Src_to_dest entries.
66 Return true if their keys are judged `equal'. */
68 src_to_dest_compare (void const *x, void const *y)
70 struct Src_to_dest const *a = x;
71 struct Src_to_dest const *b = y;
72 return SAME_INODE (*a, *b) ? true : false;
76 src_to_dest_free (void *x)
78 struct Src_to_dest *a = x;
83 /* Remove the entry matching INO/DEV from the table
84 that maps source ino/dev to destination file name. */
86 forget_created (ino_t ino, dev_t dev)
88 struct Src_to_dest probe;
89 struct Src_to_dest *ent;
95 ent = hash_delete (src_to_dest, &probe);
97 src_to_dest_free (ent);
100 /* Add FILE to the list of files that we have created.
101 Return true if successful. */
104 remember_created (char const *file)
108 if (stat (file, &sb) < 0)
110 error (0, errno, "%s", quote (file));
114 remember_copied (file, sb.st_ino, sb.st_dev);
118 /* If INO/DEV correspond to an already-copied source file, return the
119 name of the corresponding destination file. Otherwise, return NULL. */
122 src_to_dest_lookup (ino_t ino, dev_t dev)
124 struct Src_to_dest ent;
125 struct Src_to_dest const *e;
128 e = hash_lookup (src_to_dest, &ent);
129 return e ? e->name : NULL;
132 /* Add file NAME, copied from inode number INO and device number DEV,
133 to the list of files we have copied.
134 Return NULL if inserted, otherwise non-NULL. */
137 remember_copied (const char *name, ino_t ino, dev_t dev)
139 struct Src_to_dest *ent;
140 struct Src_to_dest *ent_from_table;
142 ent = xmalloc (sizeof *ent);
143 ent->name = xstrdup (name);
147 ent_from_table = hash_insert (src_to_dest, ent);
148 if (ent_from_table == NULL)
150 /* Insertion failed due to lack of memory. */
154 /* Determine whether there was already an entry in the table
155 with a matching key. If so, free ENT (it wasn't inserted) and
156 return the `name' from the table entry. */
157 if (ent_from_table != ent)
159 src_to_dest_free (ent);
160 return (char *) ent_from_table->name;
163 /* New key; insertion succeeded. */
167 /* Initialize the hash table. */
171 src_to_dest = hash_initialize (INITIAL_TABLE_SIZE, NULL,
175 if (src_to_dest == NULL)
179 /* Reset the hash structure in the global variable `htab' to
180 contain no entries. */
185 hash_free (src_to_dest);