1508 lines
44 KiB
Diff
1508 lines
44 KiB
Diff
|
This patch remembers backup file names patch has already created
|
||
|
in a binary tree, and prevents patch from overwriting backup
|
||
|
files it has created before. The bug can be reproduced as follows:
|
||
|
|
||
|
$ cat > f
|
||
|
< one
|
||
|
|
||
|
$ cat > f.patch
|
||
|
<--- f.orig 2003-04-09 01:48:01.000000000 +0200
|
||
|
<+++ f 2003-04-09 01:49:17.000000000 +0200
|
||
|
<@@ -2 +2 @@
|
||
|
<-one
|
||
|
<+two
|
||
|
<--- f.orig 2003-04-09 01:48:01.000000000 +0200
|
||
|
<+++ f 2003-04-09 01:49:17.000000000 +0200
|
||
|
<@@ -2 +2 @@
|
||
|
<-two
|
||
|
<+three
|
||
|
|
||
|
$ patch -p0 < f.patch
|
||
|
> patching file f
|
||
|
> Hunk #1 succeeded at 1 (offset -1 lines).
|
||
|
> patching file f
|
||
|
> Hunk #1 succeeded at 1 (offset -1 lines).
|
||
|
|
||
|
$ cat f.orig
|
||
|
> one
|
||
|
|
||
|
$ rm f f.orig f.patch
|
||
|
|
||
|
|
||
|
Here is another test case with hard links between source files.
|
||
|
|
||
|
$ cat > f
|
||
|
< one
|
||
|
|
||
|
$ ln f g
|
||
|
$ cat > fg.patch
|
||
|
<--- f.orig 2003-04-09 01:48:01.000000000 +0200
|
||
|
<+++ f 2003-04-09 01:49:17.000000000 +0200
|
||
|
<@@ -2 +2 @@
|
||
|
<-one
|
||
|
<+two
|
||
|
<--- g.orig 2003-04-09 01:48:01.000000000 +0200
|
||
|
<+++ g 2003-04-09 01:49:17.000000000 +0200
|
||
|
<@@ -2 +2 @@
|
||
|
<-one
|
||
|
<+two
|
||
|
|
||
|
$ patch -p0 < fg.patch
|
||
|
> patching file f
|
||
|
> Hunk #1 succeeded at 1 (offset -1 lines).
|
||
|
> patching file g
|
||
|
> Hunk #1 succeeded at 1 (offset -1 lines).
|
||
|
|
||
|
$ cat f.orig
|
||
|
> one
|
||
|
|
||
|
$ cat g.orig
|
||
|
> one
|
||
|
|
||
|
$ rm f f.orig g g.orig fg.patch
|
||
|
|
||
|
This test case failed with a Permission denied error with a previous
|
||
|
version of this patch:
|
||
|
|
||
|
$ echo 1 > f
|
||
|
$ echo 2 > f.new
|
||
|
$ diff -Nu f f.new > f.diff
|
||
|
$ mv f.new f
|
||
|
$ echo 3 > f.new
|
||
|
$ diff -Nu f f.new >> f.diff
|
||
|
$ rm f.new
|
||
|
$ echo 1 > f
|
||
|
$ chmod a=r f
|
||
|
$ strace -o ../log patch -p0 --backup < f.diff
|
||
|
> patching file f
|
||
|
> patching file f
|
||
|
|
||
|
Index: patch-2.5.9/Makefile.in
|
||
|
===================================================================
|
||
|
--- patch-2.5.9.orig/Makefile.in
|
||
|
+++ patch-2.5.9/Makefile.in
|
||
|
@@ -62,7 +62,7 @@ CONFIG_STATUS = config.status
|
||
|
SHELL = /bin/sh
|
||
|
|
||
|
LIBSRCS = error.c malloc.c memchr.c mkdir.c \
|
||
|
- realloc.c rmdir.c strcasecmp.c strncasecmp.c
|
||
|
+ realloc.c rmdir.c strcasecmp.c strncasecmp.c hash.c
|
||
|
SRCS = $(LIBSRCS) \
|
||
|
addext.c argmatch.c backupfile.c \
|
||
|
basename.c dirname.c \
|
||
|
@@ -78,12 +78,12 @@ OBJS = $(LIBOBJS) \
|
||
|
maketime.$(OBJEXT) partime.$(OBJEXT) \
|
||
|
patch.$(OBJEXT) pch.$(OBJEXT) \
|
||
|
quote.$(OBJEXT) quotearg.$(OBJEXT) quotesys.$(OBJEXT) \
|
||
|
- util.$(OBJEXT) version.$(OBJEXT) xmalloc.$(OBJEXT)
|
||
|
+ util.$(OBJEXT) version.$(OBJEXT) xmalloc.$(OBJEXT) hash.$(OBJEXT)
|
||
|
HDRS = argmatch.h backupfile.h common.h dirname.h \
|
||
|
error.h getopt.h gettext.h \
|
||
|
inp.h maketime.h partime.h pch.h \
|
||
|
quote.h quotearg.h quotesys.h \
|
||
|
- unlocked-io.h util.h version.h xalloc.h
|
||
|
+ unlocked-io.h util.h version.h xalloc.h hash.h
|
||
|
MISC = AUTHORS COPYING ChangeLog INSTALL Makefile.in NEWS README \
|
||
|
aclocal.m4 \
|
||
|
config.hin configure configure.ac \
|
||
|
Index: patch-2.5.9/configure.ac
|
||
|
===================================================================
|
||
|
--- patch-2.5.9.orig/configure.ac
|
||
|
+++ patch-2.5.9/configure.ac
|
||
|
@@ -64,6 +64,9 @@ gl_GETOPT
|
||
|
gl_PREREQ_XMALLOC
|
||
|
gl_QUOTE
|
||
|
gl_QUOTEARG
|
||
|
+gl_HASH
|
||
|
+
|
||
|
+ag_CHECK_NANOSECOND_STAT
|
||
|
|
||
|
dnl This should be in gnulib, but isn't for some reason.
|
||
|
AC_DEFUN([jm_PREREQ_ADDEXT],
|
||
|
Index: patch-2.5.9/m4/hash.m4
|
||
|
===================================================================
|
||
|
--- /dev/null
|
||
|
+++ patch-2.5.9/m4/hash.m4
|
||
|
@@ -0,0 +1,15 @@
|
||
|
+# hash.m4 serial 1
|
||
|
+dnl Copyright (C) 2002 Free Software Foundation, Inc.
|
||
|
+dnl This file is free software, distributed under the terms of the GNU
|
||
|
+dnl General Public License. As a special exception to the GNU General
|
||
|
+dnl Public License, this file may be distributed as part of a program
|
||
|
+dnl that contains a configuration script generated by Autoconf, under
|
||
|
+dnl the same distribution terms as the rest of that program.
|
||
|
+
|
||
|
+AC_DEFUN([gl_HASH],
|
||
|
+[
|
||
|
+ dnl Prerequisites of lib/hash.c.
|
||
|
+ AC_CHECK_HEADERS_ONCE(stdlib.h)
|
||
|
+ AC_HEADER_STDBOOL
|
||
|
+ AC_CHECK_DECLS_ONCE(free malloc)
|
||
|
+])
|
||
|
Index: patch-2.5.9/util.c
|
||
|
===================================================================
|
||
|
--- patch-2.5.9.orig/util.c
|
||
|
+++ patch-2.5.9/util.c
|
||
|
@@ -45,9 +45,17 @@
|
||
|
# define raise(sig) kill (getpid (), sig)
|
||
|
#endif
|
||
|
|
||
|
+#if defined(HAVE_STAT_TIMEVAL)
|
||
|
+#include <time.h>
|
||
|
+#endif
|
||
|
+
|
||
|
#include <stdarg.h>
|
||
|
+#include <hash.h>
|
||
|
|
||
|
static void makedirs (char *);
|
||
|
+static bool fid_search (const char *, const struct stat *, bool);
|
||
|
+# define fid_exists(name, pst) fid_search (name, pst, false)
|
||
|
+# define insert_fid(name) fid_search (name, NULL, true)
|
||
|
|
||
|
/* Move a file FROM (where *FROM_NEEDS_REMOVAL is nonzero if FROM
|
||
|
needs removal when cleaning up at the end of execution)
|
||
|
@@ -64,7 +72,7 @@ move_file (char const *from, int volatil
|
||
|
struct stat to_st;
|
||
|
int to_errno = ! backup ? -1 : stat (to, &to_st) == 0 ? 0 : errno;
|
||
|
|
||
|
- if (backup)
|
||
|
+ if (backup && (to_errno || ! fid_exists (to, &to_st)))
|
||
|
{
|
||
|
int try_makedirs_errno = 0;
|
||
|
char *bakname;
|
||
|
@@ -123,6 +131,7 @@ move_file (char const *from, int volatil
|
||
|
quotearg_n (0, to), quotearg_n (1, bakname));
|
||
|
while (rename (to, bakname) != 0)
|
||
|
{
|
||
|
+ /* FIXME: copy if errno == EXDEV */
|
||
|
if (errno != try_makedirs_errno)
|
||
|
pfatal ("Can't rename file %s to %s",
|
||
|
quotearg_n (0, to), quotearg_n (1, bakname));
|
||
|
@@ -133,6 +142,8 @@ move_file (char const *from, int volatil
|
||
|
|
||
|
free (bakname);
|
||
|
}
|
||
|
+ else
|
||
|
+ backup = false;
|
||
|
|
||
|
if (from)
|
||
|
{
|
||
|
@@ -165,6 +176,8 @@ move_file (char const *from, int volatil
|
||
|
if (! to_dir_known_to_exist)
|
||
|
makedirs (to);
|
||
|
copy_file (from, to, 0, mode);
|
||
|
+ if (backup)
|
||
|
+ insert_fid (to);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
@@ -173,6 +186,8 @@ move_file (char const *from, int volatil
|
||
|
}
|
||
|
|
||
|
rename_succeeded:
|
||
|
+ if (backup)
|
||
|
+ insert_fid (to);
|
||
|
/* Do not clear *FROM_NEEDS_REMOVAL if it's possible that the
|
||
|
rename returned zero because FROM and TO are hard links to
|
||
|
the same file. */
|
||
|
@@ -1011,3 +1026,105 @@ Fseek (FILE *stream, file_offset offset,
|
||
|
if (file_seek (stream, offset, ptrname) != 0)
|
||
|
pfatal ("fseek");
|
||
|
}
|
||
|
+
|
||
|
+typedef struct
|
||
|
+{
|
||
|
+ dev_t fid_dev;
|
||
|
+ ino_t fid_ino;
|
||
|
+ time_t fid_mtime;
|
||
|
+ unsigned long fid_mtimensec;
|
||
|
+} file_id;
|
||
|
+
|
||
|
+unsigned
|
||
|
+file_id_hasher (file_id *entry, unsigned table_size)
|
||
|
+{
|
||
|
+ return ((unsigned long) entry->fid_ino +
|
||
|
+ (unsigned long) entry->fid_dev +
|
||
|
+ (unsigned long) entry->fid_mtime +
|
||
|
+ (unsigned long) entry->fid_mtimensec) % table_size;
|
||
|
+}
|
||
|
+
|
||
|
+bool
|
||
|
+file_id_comparator (file_id *entry1, file_id *entry2)
|
||
|
+{
|
||
|
+ return (entry1->fid_dev == entry2->fid_dev &&
|
||
|
+ entry1->fid_ino == entry2->fid_ino &&
|
||
|
+ entry1->fid_mtime == entry2->fid_mtime &&
|
||
|
+ entry1->fid_mtimensec == entry2->fid_mtimensec);
|
||
|
+}
|
||
|
+
|
||
|
+void
|
||
|
+file_id_freer (file_id *entry)
|
||
|
+{
|
||
|
+ free (entry);
|
||
|
+}
|
||
|
+
|
||
|
+Hash_table *file_id_hash;
|
||
|
+
|
||
|
+/* Check if the file identified by FILENAME and PST was already seen. If the
|
||
|
+ file was already seen, returns TRUE. If the file has not yet been seen
|
||
|
+ and INSERT is TRUE, it is inserted. PST or FILENAME may be NULL (but not
|
||
|
+ both of them). */
|
||
|
+
|
||
|
+static bool
|
||
|
+fid_search (const char *filename, const struct stat *pst, bool insert)
|
||
|
+{
|
||
|
+ struct stat st;
|
||
|
+
|
||
|
+ if (!file_id_hash)
|
||
|
+ {
|
||
|
+ file_id_hash = hash_initialize (0, NULL, (Hash_hasher) file_id_hasher,
|
||
|
+ (Hash_comparator) file_id_comparator,
|
||
|
+ (Hash_data_freer) file_id_freer);
|
||
|
+ if (!file_id_hash)
|
||
|
+ pfatal ("hash_initialize");
|
||
|
+ }
|
||
|
+
|
||
|
+ if (!pst)
|
||
|
+ {
|
||
|
+ if (stat (filename, &st) != 0)
|
||
|
+ pfatal ("%s", quotearg (filename));
|
||
|
+ pst = &st;
|
||
|
+ }
|
||
|
+
|
||
|
+ if (insert)
|
||
|
+ {
|
||
|
+ file_id *pfid = xmalloc (sizeof (file_id)), *old_pfid;
|
||
|
+ pfid->fid_dev = pst->st_dev;
|
||
|
+ pfid->fid_ino = pst->st_ino;
|
||
|
+ pfid->fid_mtime = pst->st_mtime;
|
||
|
+#if defined(HAVE_STAT_NSEC)
|
||
|
+ pfid->fid_mtimensec = pst->st_mtimensec;
|
||
|
+#elif defined(HAVE_STAT_TIMEVAL)
|
||
|
+ pfid->fid_mtimensec = pst->st_mtim.tv_nsec;
|
||
|
+#else
|
||
|
+ pfid->fid_mtimensec = 0;
|
||
|
+#endif
|
||
|
+ old_pfid = hash_insert (file_id_hash, pfid);
|
||
|
+ if (!old_pfid)
|
||
|
+ pfatal ("hash_insert");
|
||
|
+ else if (old_pfid != pfid)
|
||
|
+ {
|
||
|
+ free (pfid);
|
||
|
+ return true;
|
||
|
+ }
|
||
|
+ else
|
||
|
+ return false;
|
||
|
+ }
|
||
|
+ else
|
||
|
+ {
|
||
|
+ file_id fid;
|
||
|
+ fid.fid_dev = pst->st_dev;
|
||
|
+ fid.fid_ino = pst->st_ino;
|
||
|
+ fid.fid_mtime = pst->st_mtime;
|
||
|
+#if defined(HAVE_STAT_NSEC)
|
||
|
+ fid.fid_mtimensec = pst->st_mtimensec;
|
||
|
+#elif defined(HAVE_STAT_TIMEVAL)
|
||
|
+ fid.fid_mtimensec = pst->st_mtim.tv_nsec;
|
||
|
+#else
|
||
|
+ fid.fid_mtimensec = 0;
|
||
|
+#endif
|
||
|
+ return hash_lookup (file_id_hash, &fid) != 0;
|
||
|
+ }
|
||
|
+}
|
||
|
+
|
||
|
Index: patch-2.5.9/hash.c
|
||
|
===================================================================
|
||
|
--- /dev/null
|
||
|
+++ patch-2.5.9/hash.c
|
||
|
@@ -0,0 +1,1051 @@
|
||
|
+/* hash - hashing table processing.
|
||
|
+
|
||
|
+ Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 Free Software
|
||
|
+ Foundation, Inc.
|
||
|
+
|
||
|
+ Written by Jim Meyering, 1992.
|
||
|
+
|
||
|
+ This program is free software; you can redistribute it and/or modify
|
||
|
+ it under the terms of the GNU General Public License as published by
|
||
|
+ the Free Software Foundation; either version 2, or (at your option)
|
||
|
+ any later version.
|
||
|
+
|
||
|
+ This program is distributed in the hope that it will be useful,
|
||
|
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
+ GNU General Public License for more details.
|
||
|
+
|
||
|
+ You should have received a copy of the GNU General Public License
|
||
|
+ along with this program; if not, write to the Free Software Foundation,
|
||
|
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
|
||
|
+
|
||
|
+/* A generic hash table package. */
|
||
|
+
|
||
|
+/* Define USE_OBSTACK to 1 if you want the allocator to use obstacks instead
|
||
|
+ of malloc. If you change USE_OBSTACK, you have to recompile! */
|
||
|
+
|
||
|
+#if HAVE_CONFIG_H
|
||
|
+# include <config.h>
|
||
|
+#endif
|
||
|
+#if HAVE_STDLIB_H
|
||
|
+# include <stdlib.h>
|
||
|
+#endif
|
||
|
+
|
||
|
+#include <limits.h>
|
||
|
+#include <stdbool.h>
|
||
|
+#include <stdio.h>
|
||
|
+
|
||
|
+#ifndef HAVE_DECL_FREE
|
||
|
+"this configure-time declaration test was not run"
|
||
|
+#endif
|
||
|
+#if !HAVE_DECL_FREE
|
||
|
+void free ();
|
||
|
+#endif
|
||
|
+
|
||
|
+#ifndef HAVE_DECL_MALLOC
|
||
|
+"this configure-time declaration test was not run"
|
||
|
+#endif
|
||
|
+#if !HAVE_DECL_MALLOC
|
||
|
+char *malloc ();
|
||
|
+#endif
|
||
|
+
|
||
|
+#if USE_OBSTACK
|
||
|
+# include "obstack.h"
|
||
|
+# ifndef obstack_chunk_alloc
|
||
|
+# define obstack_chunk_alloc malloc
|
||
|
+# endif
|
||
|
+# ifndef obstack_chunk_free
|
||
|
+# define obstack_chunk_free free
|
||
|
+# endif
|
||
|
+#endif
|
||
|
+
|
||
|
+#include "hash.h"
|
||
|
+
|
||
|
+struct hash_table
|
||
|
+ {
|
||
|
+ /* The array of buckets starts at BUCKET and extends to BUCKET_LIMIT-1,
|
||
|
+ for a possibility of N_BUCKETS. Among those, N_BUCKETS_USED buckets
|
||
|
+ are not empty, there are N_ENTRIES active entries in the table. */
|
||
|
+ struct hash_entry *bucket;
|
||
|
+ struct hash_entry *bucket_limit;
|
||
|
+ unsigned n_buckets;
|
||
|
+ unsigned n_buckets_used;
|
||
|
+ unsigned n_entries;
|
||
|
+
|
||
|
+ /* Tuning arguments, kept in a physicaly separate structure. */
|
||
|
+ const Hash_tuning *tuning;
|
||
|
+
|
||
|
+ /* Three functions are given to `hash_initialize', see the documentation
|
||
|
+ block for this function. In a word, HASHER randomizes a user entry
|
||
|
+ into a number up from 0 up to some maximum minus 1; COMPARATOR returns
|
||
|
+ true if two user entries compare equally; and DATA_FREER is the cleanup
|
||
|
+ function for a user entry. */
|
||
|
+ Hash_hasher hasher;
|
||
|
+ Hash_comparator comparator;
|
||
|
+ Hash_data_freer data_freer;
|
||
|
+
|
||
|
+ /* A linked list of freed struct hash_entry structs. */
|
||
|
+ struct hash_entry *free_entry_list;
|
||
|
+
|
||
|
+#if USE_OBSTACK
|
||
|
+ /* Whenever obstacks are used, it is possible to allocate all overflowed
|
||
|
+ entries into a single stack, so they all can be freed in a single
|
||
|
+ operation. It is not clear if the speedup is worth the trouble. */
|
||
|
+ struct obstack entry_stack;
|
||
|
+#endif
|
||
|
+ };
|
||
|
+
|
||
|
+/* A hash table contains many internal entries, each holding a pointer to
|
||
|
+ some user provided data (also called a user entry). An entry indistinctly
|
||
|
+ refers to both the internal entry and its associated user entry. A user
|
||
|
+ entry contents may be hashed by a randomization function (the hashing
|
||
|
+ function, or just `hasher' for short) into a number (or `slot') between 0
|
||
|
+ and the current table size. At each slot position in the hash table,
|
||
|
+ starts a linked chain of entries for which the user data all hash to this
|
||
|
+ slot. A bucket is the collection of all entries hashing to the same slot.
|
||
|
+
|
||
|
+ A good `hasher' function will distribute entries rather evenly in buckets.
|
||
|
+ In the ideal case, the length of each bucket is roughly the number of
|
||
|
+ entries divided by the table size. Finding the slot for a data is usually
|
||
|
+ done in constant time by the `hasher', and the later finding of a precise
|
||
|
+ entry is linear in time with the size of the bucket. Consequently, a
|
||
|
+ larger hash table size (that is, a larger number of buckets) is prone to
|
||
|
+ yielding shorter chains, *given* the `hasher' function behaves properly.
|
||
|
+
|
||
|
+ Long buckets slow down the lookup algorithm. One might use big hash table
|
||
|
+ sizes in hope to reduce the average length of buckets, but this might
|
||
|
+ become inordinate, as unused slots in the hash table take some space. The
|
||
|
+ best bet is to make sure you are using a good `hasher' function (beware
|
||
|
+ that those are not that easy to write! :-), and to use a table size
|
||
|
+ larger than the actual number of entries. */
|
||
|
+
|
||
|
+/* If an insertion makes the ratio of nonempty buckets to table size larger
|
||
|
+ than the growth threshold (a number between 0.0 and 1.0), then increase
|
||
|
+ the table size by multiplying by the growth factor (a number greater than
|
||
|
+ 1.0). The growth threshold defaults to 0.8, and the growth factor
|
||
|
+ defaults to 1.414, meaning that the table will have doubled its size
|
||
|
+ every second time 80% of the buckets get used. */
|
||
|
+#define DEFAULT_GROWTH_THRESHOLD 0.8
|
||
|
+#define DEFAULT_GROWTH_FACTOR 1.414
|
||
|
+
|
||
|
+/* If a deletion empties a bucket and causes the ratio of used buckets to
|
||
|
+ table size to become smaller than the shrink threshold (a number between
|
||
|
+ 0.0 and 1.0), then shrink the table by multiplying by the shrink factor (a
|
||
|
+ number greater than the shrink threshold but smaller than 1.0). The shrink
|
||
|
+ threshold and factor default to 0.0 and 1.0, meaning that the table never
|
||
|
+ shrinks. */
|
||
|
+#define DEFAULT_SHRINK_THRESHOLD 0.0
|
||
|
+#define DEFAULT_SHRINK_FACTOR 1.0
|
||
|
+
|
||
|
+/* Use this to initialize or reset a TUNING structure to
|
||
|
+ some sensible values. */
|
||
|
+static const Hash_tuning default_tuning =
|
||
|
+ {
|
||
|
+ DEFAULT_SHRINK_THRESHOLD,
|
||
|
+ DEFAULT_SHRINK_FACTOR,
|
||
|
+ DEFAULT_GROWTH_THRESHOLD,
|
||
|
+ DEFAULT_GROWTH_FACTOR,
|
||
|
+ false
|
||
|
+ };
|
||
|
+
|
||
|
+/* Information and lookup. */
|
||
|
+
|
||
|
+/* The following few functions provide information about the overall hash
|
||
|
+ table organization: the number of entries, number of buckets and maximum
|
||
|
+ length of buckets. */
|
||
|
+
|
||
|
+/* Return the number of buckets in the hash table. The table size, the total
|
||
|
+ number of buckets (used plus unused), or the maximum number of slots, are
|
||
|
+ the same quantity. */
|
||
|
+
|
||
|
+unsigned
|
||
|
+hash_get_n_buckets (const Hash_table *table)
|
||
|
+{
|
||
|
+ return table->n_buckets;
|
||
|
+}
|
||
|
+
|
||
|
+/* Return the number of slots in use (non-empty buckets). */
|
||
|
+
|
||
|
+unsigned
|
||
|
+hash_get_n_buckets_used (const Hash_table *table)
|
||
|
+{
|
||
|
+ return table->n_buckets_used;
|
||
|
+}
|
||
|
+
|
||
|
+/* Return the number of active entries. */
|
||
|
+
|
||
|
+unsigned
|
||
|
+hash_get_n_entries (const Hash_table *table)
|
||
|
+{
|
||
|
+ return table->n_entries;
|
||
|
+}
|
||
|
+
|
||
|
+/* Return the length of the longest chain (bucket). */
|
||
|
+
|
||
|
+unsigned
|
||
|
+hash_get_max_bucket_length (const Hash_table *table)
|
||
|
+{
|
||
|
+ struct hash_entry *bucket;
|
||
|
+ unsigned max_bucket_length = 0;
|
||
|
+
|
||
|
+ for (bucket = table->bucket; bucket < table->bucket_limit; bucket++)
|
||
|
+ {
|
||
|
+ if (bucket->data)
|
||
|
+ {
|
||
|
+ struct hash_entry *cursor = bucket;
|
||
|
+ unsigned bucket_length = 1;
|
||
|
+
|
||
|
+ while (cursor = cursor->next, cursor)
|
||
|
+ bucket_length++;
|
||
|
+
|
||
|
+ if (bucket_length > max_bucket_length)
|
||
|
+ max_bucket_length = bucket_length;
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+ return max_bucket_length;
|
||
|
+}
|
||
|
+
|
||
|
+/* Do a mild validation of a hash table, by traversing it and checking two
|
||
|
+ statistics. */
|
||
|
+
|
||
|
+bool
|
||
|
+hash_table_ok (const Hash_table *table)
|
||
|
+{
|
||
|
+ struct hash_entry *bucket;
|
||
|
+ unsigned n_buckets_used = 0;
|
||
|
+ unsigned n_entries = 0;
|
||
|
+
|
||
|
+ for (bucket = table->bucket; bucket < table->bucket_limit; bucket++)
|
||
|
+ {
|
||
|
+ if (bucket->data)
|
||
|
+ {
|
||
|
+ struct hash_entry *cursor = bucket;
|
||
|
+
|
||
|
+ /* Count bucket head. */
|
||
|
+ n_buckets_used++;
|
||
|
+ n_entries++;
|
||
|
+
|
||
|
+ /* Count bucket overflow. */
|
||
|
+ while (cursor = cursor->next, cursor)
|
||
|
+ n_entries++;
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+ if (n_buckets_used == table->n_buckets_used && n_entries == table->n_entries)
|
||
|
+ return true;
|
||
|
+
|
||
|
+ return false;
|
||
|
+}
|
||
|
+
|
||
|
+void
|
||
|
+hash_print_statistics (const Hash_table *table, FILE *stream)
|
||
|
+{
|
||
|
+ unsigned n_entries = hash_get_n_entries (table);
|
||
|
+ unsigned n_buckets = hash_get_n_buckets (table);
|
||
|
+ unsigned n_buckets_used = hash_get_n_buckets_used (table);
|
||
|
+ unsigned max_bucket_length = hash_get_max_bucket_length (table);
|
||
|
+
|
||
|
+ fprintf (stream, "# entries: %u\n", n_entries);
|
||
|
+ fprintf (stream, "# buckets: %u\n", n_buckets);
|
||
|
+ fprintf (stream, "# buckets used: %u (%.2f%%)\n", n_buckets_used,
|
||
|
+ (100.0 * n_buckets_used) / n_buckets);
|
||
|
+ fprintf (stream, "max bucket length: %u\n", max_bucket_length);
|
||
|
+}
|
||
|
+
|
||
|
+/* If ENTRY matches an entry already in the hash table, return the
|
||
|
+ entry from the table. Otherwise, return NULL. */
|
||
|
+
|
||
|
+void *
|
||
|
+hash_lookup (const Hash_table *table, const void *entry)
|
||
|
+{
|
||
|
+ struct hash_entry *bucket
|
||
|
+ = table->bucket + table->hasher (entry, table->n_buckets);
|
||
|
+ struct hash_entry *cursor;
|
||
|
+
|
||
|
+ if (! (bucket < table->bucket_limit))
|
||
|
+ abort ();
|
||
|
+
|
||
|
+ if (bucket->data == NULL)
|
||
|
+ return NULL;
|
||
|
+
|
||
|
+ for (cursor = bucket; cursor; cursor = cursor->next)
|
||
|
+ if (table->comparator (entry, cursor->data))
|
||
|
+ return cursor->data;
|
||
|
+
|
||
|
+ return NULL;
|
||
|
+}
|
||
|
+
|
||
|
+/* Walking. */
|
||
|
+
|
||
|
+/* The functions in this page traverse the hash table and process the
|
||
|
+ contained entries. For the traversal to work properly, the hash table
|
||
|
+ should not be resized nor modified while any particular entry is being
|
||
|
+ processed. In particular, entries should not be added or removed. */
|
||
|
+
|
||
|
+/* Return the first data in the table, or NULL if the table is empty. */
|
||
|
+
|
||
|
+void *
|
||
|
+hash_get_first (const Hash_table *table)
|
||
|
+{
|
||
|
+ struct hash_entry *bucket;
|
||
|
+
|
||
|
+ if (table->n_entries == 0)
|
||
|
+ return NULL;
|
||
|
+
|
||
|
+ for (bucket = table->bucket; ; bucket++)
|
||
|
+ if (! (bucket < table->bucket_limit))
|
||
|
+ abort ();
|
||
|
+ else if (bucket->data)
|
||
|
+ return bucket->data;
|
||
|
+}
|
||
|
+
|
||
|
+/* Return the user data for the entry following ENTRY, where ENTRY has been
|
||
|
+ returned by a previous call to either `hash_get_first' or `hash_get_next'.
|
||
|
+ Return NULL if there are no more entries. */
|
||
|
+
|
||
|
+void *
|
||
|
+hash_get_next (const Hash_table *table, const void *entry)
|
||
|
+{
|
||
|
+ struct hash_entry *bucket
|
||
|
+ = table->bucket + table->hasher (entry, table->n_buckets);
|
||
|
+ struct hash_entry *cursor;
|
||
|
+
|
||
|
+ if (! (bucket < table->bucket_limit))
|
||
|
+ abort ();
|
||
|
+
|
||
|
+ /* Find next entry in the same bucket. */
|
||
|
+ for (cursor = bucket; cursor; cursor = cursor->next)
|
||
|
+ if (cursor->data == entry && cursor->next)
|
||
|
+ return cursor->next->data;
|
||
|
+
|
||
|
+ /* Find first entry in any subsequent bucket. */
|
||
|
+ while (++bucket < table->bucket_limit)
|
||
|
+ if (bucket->data)
|
||
|
+ return bucket->data;
|
||
|
+
|
||
|
+ /* None found. */
|
||
|
+ return NULL;
|
||
|
+}
|
||
|
+
|
||
|
+/* Fill BUFFER with pointers to active user entries in the hash table, then
|
||
|
+ return the number of pointers copied. Do not copy more than BUFFER_SIZE
|
||
|
+ pointers. */
|
||
|
+
|
||
|
+unsigned
|
||
|
+hash_get_entries (const Hash_table *table, void **buffer,
|
||
|
+ unsigned buffer_size)
|
||
|
+{
|
||
|
+ unsigned counter = 0;
|
||
|
+ struct hash_entry *bucket;
|
||
|
+ struct hash_entry *cursor;
|
||
|
+
|
||
|
+ for (bucket = table->bucket; bucket < table->bucket_limit; bucket++)
|
||
|
+ {
|
||
|
+ if (bucket->data)
|
||
|
+ {
|
||
|
+ for (cursor = bucket; cursor; cursor = cursor->next)
|
||
|
+ {
|
||
|
+ if (counter >= buffer_size)
|
||
|
+ return counter;
|
||
|
+ buffer[counter++] = cursor->data;
|
||
|
+ }
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+ return counter;
|
||
|
+}
|
||
|
+
|
||
|
+/* Call a PROCESSOR function for each entry of a hash table, and return the
|
||
|
+ number of entries for which the processor function returned success. A
|
||
|
+ pointer to some PROCESSOR_DATA which will be made available to each call to
|
||
|
+ the processor function. The PROCESSOR accepts two arguments: the first is
|
||
|
+ the user entry being walked into, the second is the value of PROCESSOR_DATA
|
||
|
+ as received. The walking continue for as long as the PROCESSOR function
|
||
|
+ returns nonzero. When it returns zero, the walking is interrupted. */
|
||
|
+
|
||
|
+unsigned
|
||
|
+hash_do_for_each (const Hash_table *table, Hash_processor processor,
|
||
|
+ void *processor_data)
|
||
|
+{
|
||
|
+ unsigned counter = 0;
|
||
|
+ struct hash_entry *bucket;
|
||
|
+ struct hash_entry *cursor;
|
||
|
+
|
||
|
+ for (bucket = table->bucket; bucket < table->bucket_limit; bucket++)
|
||
|
+ {
|
||
|
+ if (bucket->data)
|
||
|
+ {
|
||
|
+ for (cursor = bucket; cursor; cursor = cursor->next)
|
||
|
+ {
|
||
|
+ if (!(*processor) (cursor->data, processor_data))
|
||
|
+ return counter;
|
||
|
+ counter++;
|
||
|
+ }
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+ return counter;
|
||
|
+}
|
||
|
+
|
||
|
+/* Allocation and clean-up. */
|
||
|
+
|
||
|
+/* Return a hash index for a NUL-terminated STRING between 0 and N_BUCKETS-1.
|
||
|
+ This is a convenience routine for constructing other hashing functions. */
|
||
|
+
|
||
|
+#if USE_DIFF_HASH
|
||
|
+
|
||
|
+/* About hashings, Paul Eggert writes to me (FP), on 1994-01-01: "Please see
|
||
|
+ B. J. McKenzie, R. Harries & T. Bell, Selecting a hashing algorithm,
|
||
|
+ Software--practice & experience 20, 2 (Feb 1990), 209-224. Good hash
|
||
|
+ algorithms tend to be domain-specific, so what's good for [diffutils'] io.c
|
||
|
+ may not be good for your application." */
|
||
|
+
|
||
|
+unsigned
|
||
|
+hash_string (const char *string, unsigned n_buckets)
|
||
|
+{
|
||
|
+# define ROTATE_LEFT(Value, Shift) \
|
||
|
+ ((Value) << (Shift) | (Value) >> ((sizeof (unsigned) * CHAR_BIT) - (Shift)))
|
||
|
+# define HASH_ONE_CHAR(Value, Byte) \
|
||
|
+ ((Byte) + ROTATE_LEFT (Value, 7))
|
||
|
+
|
||
|
+ unsigned value = 0;
|
||
|
+
|
||
|
+ for (; *string; string++)
|
||
|
+ value = HASH_ONE_CHAR (value, *(const unsigned char *) string);
|
||
|
+ return value % n_buckets;
|
||
|
+
|
||
|
+# undef ROTATE_LEFT
|
||
|
+# undef HASH_ONE_CHAR
|
||
|
+}
|
||
|
+
|
||
|
+#else /* not USE_DIFF_HASH */
|
||
|
+
|
||
|
+/* This one comes from `recode', and performs a bit better than the above as
|
||
|
+ per a few experiments. It is inspired from a hashing routine found in the
|
||
|
+ very old Cyber `snoop', itself written in typical Greg Mansfield style.
|
||
|
+ (By the way, what happened to this excellent man? Is he still alive?) */
|
||
|
+
|
||
|
+unsigned
|
||
|
+hash_string (const char *string, unsigned n_buckets)
|
||
|
+{
|
||
|
+ unsigned value = 0;
|
||
|
+
|
||
|
+ while (*string)
|
||
|
+ value = ((value * 31 + (int) *(const unsigned char *) string++)
|
||
|
+ % n_buckets);
|
||
|
+ return value;
|
||
|
+}
|
||
|
+
|
||
|
+#endif /* not USE_DIFF_HASH */
|
||
|
+
|
||
|
+/* Return true if CANDIDATE is a prime number. CANDIDATE should be an odd
|
||
|
+ number at least equal to 11. */
|
||
|
+
|
||
|
+static bool
|
||
|
+is_prime (unsigned long candidate)
|
||
|
+{
|
||
|
+ unsigned long divisor = 3;
|
||
|
+ unsigned long square = divisor * divisor;
|
||
|
+
|
||
|
+ while (square < candidate && (candidate % divisor))
|
||
|
+ {
|
||
|
+ divisor++;
|
||
|
+ square += 4 * divisor;
|
||
|
+ divisor++;
|
||
|
+ }
|
||
|
+
|
||
|
+ return (candidate % divisor ? true : false);
|
||
|
+}
|
||
|
+
|
||
|
+/* Round a given CANDIDATE number up to the nearest prime, and return that
|
||
|
+ prime. Primes lower than 10 are merely skipped. */
|
||
|
+
|
||
|
+static unsigned long
|
||
|
+next_prime (unsigned long candidate)
|
||
|
+{
|
||
|
+ /* Skip small primes. */
|
||
|
+ if (candidate < 10)
|
||
|
+ candidate = 10;
|
||
|
+
|
||
|
+ /* Make it definitely odd. */
|
||
|
+ candidate |= 1;
|
||
|
+
|
||
|
+ while (!is_prime (candidate))
|
||
|
+ candidate += 2;
|
||
|
+
|
||
|
+ return candidate;
|
||
|
+}
|
||
|
+
|
||
|
+void
|
||
|
+hash_reset_tuning (Hash_tuning *tuning)
|
||
|
+{
|
||
|
+ *tuning = default_tuning;
|
||
|
+}
|
||
|
+
|
||
|
+/* For the given hash TABLE, check the user supplied tuning structure for
|
||
|
+ reasonable values, and return true if there is no gross error with it.
|
||
|
+ Otherwise, definitively reset the TUNING field to some acceptable default
|
||
|
+ in the hash table (that is, the user loses the right of further modifying
|
||
|
+ tuning arguments), and return false. */
|
||
|
+
|
||
|
+static bool
|
||
|
+check_tuning (Hash_table *table)
|
||
|
+{
|
||
|
+ const Hash_tuning *tuning = table->tuning;
|
||
|
+
|
||
|
+ if (tuning->growth_threshold > 0.0
|
||
|
+ && tuning->growth_threshold < 1.0
|
||
|
+ && tuning->growth_factor > 1.0
|
||
|
+ && tuning->shrink_threshold >= 0.0
|
||
|
+ && tuning->shrink_threshold < 1.0
|
||
|
+ && tuning->shrink_factor > tuning->shrink_threshold
|
||
|
+ && tuning->shrink_factor <= 1.0
|
||
|
+ && tuning->shrink_threshold < tuning->growth_threshold)
|
||
|
+ return true;
|
||
|
+
|
||
|
+ table->tuning = &default_tuning;
|
||
|
+ return false;
|
||
|
+}
|
||
|
+
|
||
|
+/* Allocate and return a new hash table, or NULL upon failure. The initial
|
||
|
+ number of buckets is automatically selected so as to _guarantee_ that you
|
||
|
+ may insert at least CANDIDATE different user entries before any growth of
|
||
|
+ the hash table size occurs. So, if have a reasonably tight a-priori upper
|
||
|
+ bound on the number of entries you intend to insert in the hash table, you
|
||
|
+ may save some table memory and insertion time, by specifying it here. If
|
||
|
+ the IS_N_BUCKETS field of the TUNING structure is true, the CANDIDATE
|
||
|
+ argument has its meaning changed to the wanted number of buckets.
|
||
|
+
|
||
|
+ TUNING points to a structure of user-supplied values, in case some fine
|
||
|
+ tuning is wanted over the default behavior of the hasher. If TUNING is
|
||
|
+ NULL, the default tuning parameters are used instead.
|
||
|
+
|
||
|
+ The user-supplied HASHER function should be provided. It accepts two
|
||
|
+ arguments ENTRY and TABLE_SIZE. It computes, by hashing ENTRY contents, a
|
||
|
+ slot number for that entry which should be in the range 0..TABLE_SIZE-1.
|
||
|
+ This slot number is then returned.
|
||
|
+
|
||
|
+ The user-supplied COMPARATOR function should be provided. It accepts two
|
||
|
+ arguments pointing to user data, it then returns true for a pair of entries
|
||
|
+ that compare equal, or false otherwise. This function is internally called
|
||
|
+ on entries which are already known to hash to the same bucket index.
|
||
|
+
|
||
|
+ The user-supplied DATA_FREER function, when not NULL, may be later called
|
||
|
+ with the user data as an argument, just before the entry containing the
|
||
|
+ data gets freed. This happens from within `hash_free' or `hash_clear'.
|
||
|
+ You should specify this function only if you want these functions to free
|
||
|
+ all of your `data' data. This is typically the case when your data is
|
||
|
+ simply an auxiliary struct that you have malloc'd to aggregate several
|
||
|
+ values. */
|
||
|
+
|
||
|
+Hash_table *
|
||
|
+hash_initialize (unsigned candidate, const Hash_tuning *tuning,
|
||
|
+ Hash_hasher hasher, Hash_comparator comparator,
|
||
|
+ Hash_data_freer data_freer)
|
||
|
+{
|
||
|
+ Hash_table *table;
|
||
|
+ struct hash_entry *bucket;
|
||
|
+
|
||
|
+ if (hasher == NULL || comparator == NULL)
|
||
|
+ return NULL;
|
||
|
+
|
||
|
+ table = (Hash_table *) malloc (sizeof (Hash_table));
|
||
|
+ if (table == NULL)
|
||
|
+ return NULL;
|
||
|
+
|
||
|
+ if (!tuning)
|
||
|
+ tuning = &default_tuning;
|
||
|
+ table->tuning = tuning;
|
||
|
+ if (!check_tuning (table))
|
||
|
+ {
|
||
|
+ /* Fail if the tuning options are invalid. This is the only occasion
|
||
|
+ when the user gets some feedback about it. Once the table is created,
|
||
|
+ if the user provides invalid tuning options, we silently revert to
|
||
|
+ using the defaults, and ignore further request to change the tuning
|
||
|
+ options. */
|
||
|
+ free (table);
|
||
|
+ return NULL;
|
||
|
+ }
|
||
|
+
|
||
|
+ table->n_buckets
|
||
|
+ = next_prime (tuning->is_n_buckets ? candidate
|
||
|
+ : (unsigned) (candidate / tuning->growth_threshold));
|
||
|
+
|
||
|
+ table->bucket = (struct hash_entry *)
|
||
|
+ malloc (table->n_buckets * sizeof (struct hash_entry));
|
||
|
+ if (table->bucket == NULL)
|
||
|
+ {
|
||
|
+ free (table);
|
||
|
+ return NULL;
|
||
|
+ }
|
||
|
+ table->bucket_limit = table->bucket + table->n_buckets;
|
||
|
+
|
||
|
+ for (bucket = table->bucket; bucket < table->bucket_limit; bucket++)
|
||
|
+ {
|
||
|
+ bucket->data = NULL;
|
||
|
+ bucket->next = NULL;
|
||
|
+ }
|
||
|
+ table->n_buckets_used = 0;
|
||
|
+ table->n_entries = 0;
|
||
|
+
|
||
|
+ table->hasher = hasher;
|
||
|
+ table->comparator = comparator;
|
||
|
+ table->data_freer = data_freer;
|
||
|
+
|
||
|
+ table->free_entry_list = NULL;
|
||
|
+#if USE_OBSTACK
|
||
|
+ obstack_init (&table->entry_stack);
|
||
|
+#endif
|
||
|
+ return table;
|
||
|
+}
|
||
|
+
|
||
|
+/* Make all buckets empty, placing any chained entries on the free list.
|
||
|
+ Apply the user-specified function data_freer (if any) to the datas of any
|
||
|
+ affected entries. */
|
||
|
+
|
||
|
+void
|
||
|
+hash_clear (Hash_table *table)
|
||
|
+{
|
||
|
+ struct hash_entry *bucket;
|
||
|
+
|
||
|
+ for (bucket = table->bucket; bucket < table->bucket_limit; bucket++)
|
||
|
+ {
|
||
|
+ if (bucket->data)
|
||
|
+ {
|
||
|
+ struct hash_entry *cursor;
|
||
|
+ struct hash_entry *next;
|
||
|
+
|
||
|
+ /* Free the bucket overflow. */
|
||
|
+ for (cursor = bucket->next; cursor; cursor = next)
|
||
|
+ {
|
||
|
+ if (table->data_freer)
|
||
|
+ (*table->data_freer) (cursor->data);
|
||
|
+ cursor->data = NULL;
|
||
|
+
|
||
|
+ next = cursor->next;
|
||
|
+ /* Relinking is done one entry at a time, as it is to be expected
|
||
|
+ that overflows are either rare or short. */
|
||
|
+ cursor->next = table->free_entry_list;
|
||
|
+ table->free_entry_list = cursor;
|
||
|
+ }
|
||
|
+
|
||
|
+ /* Free the bucket head. */
|
||
|
+ if (table->data_freer)
|
||
|
+ (*table->data_freer) (bucket->data);
|
||
|
+ bucket->data = NULL;
|
||
|
+ bucket->next = NULL;
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+ table->n_buckets_used = 0;
|
||
|
+ table->n_entries = 0;
|
||
|
+}
|
||
|
+
|
||
|
+/* Reclaim all storage associated with a hash table. If a data_freer
|
||
|
+ function has been supplied by the user when the hash table was created,
|
||
|
+ this function applies it to the data of each entry before freeing that
|
||
|
+ entry. */
|
||
|
+
|
||
|
+void
|
||
|
+hash_free (Hash_table *table)
|
||
|
+{
|
||
|
+ struct hash_entry *bucket;
|
||
|
+ struct hash_entry *cursor;
|
||
|
+ struct hash_entry *next;
|
||
|
+
|
||
|
+ /* Call the user data_freer function. */
|
||
|
+ if (table->data_freer && table->n_entries)
|
||
|
+ {
|
||
|
+ for (bucket = table->bucket; bucket < table->bucket_limit; bucket++)
|
||
|
+ {
|
||
|
+ if (bucket->data)
|
||
|
+ {
|
||
|
+ for (cursor = bucket; cursor; cursor = cursor->next)
|
||
|
+ {
|
||
|
+ (*table->data_freer) (cursor->data);
|
||
|
+ }
|
||
|
+ }
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+#if USE_OBSTACK
|
||
|
+
|
||
|
+ obstack_free (&table->entry_stack, NULL);
|
||
|
+
|
||
|
+#else
|
||
|
+
|
||
|
+ /* Free all bucket overflowed entries. */
|
||
|
+ for (bucket = table->bucket; bucket < table->bucket_limit; bucket++)
|
||
|
+ {
|
||
|
+ for (cursor = bucket->next; cursor; cursor = next)
|
||
|
+ {
|
||
|
+ next = cursor->next;
|
||
|
+ free (cursor);
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+ /* Also reclaim the internal list of previously freed entries. */
|
||
|
+ for (cursor = table->free_entry_list; cursor; cursor = next)
|
||
|
+ {
|
||
|
+ next = cursor->next;
|
||
|
+ free (cursor);
|
||
|
+ }
|
||
|
+
|
||
|
+#endif
|
||
|
+
|
||
|
+ /* Free the remainder of the hash table structure. */
|
||
|
+ free (table->bucket);
|
||
|
+ free (table);
|
||
|
+}
|
||
|
+
|
||
|
+/* Insertion and deletion. */
|
||
|
+
|
||
|
+/* Get a new hash entry for a bucket overflow, possibly by reclying a
|
||
|
+ previously freed one. If this is not possible, allocate a new one. */
|
||
|
+
|
||
|
+static struct hash_entry *
|
||
|
+allocate_entry (Hash_table *table)
|
||
|
+{
|
||
|
+ struct hash_entry *new;
|
||
|
+
|
||
|
+ if (table->free_entry_list)
|
||
|
+ {
|
||
|
+ new = table->free_entry_list;
|
||
|
+ table->free_entry_list = new->next;
|
||
|
+ }
|
||
|
+ else
|
||
|
+ {
|
||
|
+#if USE_OBSTACK
|
||
|
+ new = (struct hash_entry *)
|
||
|
+ obstack_alloc (&table->entry_stack, sizeof (struct hash_entry));
|
||
|
+#else
|
||
|
+ new = (struct hash_entry *) malloc (sizeof (struct hash_entry));
|
||
|
+#endif
|
||
|
+ }
|
||
|
+
|
||
|
+ return new;
|
||
|
+}
|
||
|
+
|
||
|
+/* Free a hash entry which was part of some bucket overflow,
|
||
|
+ saving it for later recycling. */
|
||
|
+
|
||
|
+static void
|
||
|
+free_entry (Hash_table *table, struct hash_entry *entry)
|
||
|
+{
|
||
|
+ entry->data = NULL;
|
||
|
+ entry->next = table->free_entry_list;
|
||
|
+ table->free_entry_list = entry;
|
||
|
+}
|
||
|
+
|
||
|
+/* This private function is used to help with insertion and deletion. When
|
||
|
+ ENTRY matches an entry in the table, return a pointer to the corresponding
|
||
|
+ user data and set *BUCKET_HEAD to the head of the selected bucket.
|
||
|
+ Otherwise, return NULL. When DELETE is true and ENTRY matches an entry in
|
||
|
+ the table, unlink the matching entry. */
|
||
|
+
|
||
|
+static void *
|
||
|
+hash_find_entry (Hash_table *table, const void *entry,
|
||
|
+ struct hash_entry **bucket_head, bool delete)
|
||
|
+{
|
||
|
+ struct hash_entry *bucket
|
||
|
+ = table->bucket + table->hasher (entry, table->n_buckets);
|
||
|
+ struct hash_entry *cursor;
|
||
|
+
|
||
|
+ if (! (bucket < table->bucket_limit))
|
||
|
+ abort ();
|
||
|
+
|
||
|
+ *bucket_head = bucket;
|
||
|
+
|
||
|
+ /* Test for empty bucket. */
|
||
|
+ if (bucket->data == NULL)
|
||
|
+ return NULL;
|
||
|
+
|
||
|
+ /* See if the entry is the first in the bucket. */
|
||
|
+ if ((*table->comparator) (entry, bucket->data))
|
||
|
+ {
|
||
|
+ void *data = bucket->data;
|
||
|
+
|
||
|
+ if (delete)
|
||
|
+ {
|
||
|
+ if (bucket->next)
|
||
|
+ {
|
||
|
+ struct hash_entry *next = bucket->next;
|
||
|
+
|
||
|
+ /* Bump the first overflow entry into the bucket head, then save
|
||
|
+ the previous first overflow entry for later recycling. */
|
||
|
+ *bucket = *next;
|
||
|
+ free_entry (table, next);
|
||
|
+ }
|
||
|
+ else
|
||
|
+ {
|
||
|
+ bucket->data = NULL;
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+ return data;
|
||
|
+ }
|
||
|
+
|
||
|
+ /* Scan the bucket overflow. */
|
||
|
+ for (cursor = bucket; cursor->next; cursor = cursor->next)
|
||
|
+ {
|
||
|
+ if ((*table->comparator) (entry, cursor->next->data))
|
||
|
+ {
|
||
|
+ void *data = cursor->next->data;
|
||
|
+
|
||
|
+ if (delete)
|
||
|
+ {
|
||
|
+ struct hash_entry *next = cursor->next;
|
||
|
+
|
||
|
+ /* Unlink the entry to delete, then save the freed entry for later
|
||
|
+ recycling. */
|
||
|
+ cursor->next = next->next;
|
||
|
+ free_entry (table, next);
|
||
|
+ }
|
||
|
+
|
||
|
+ return data;
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+ /* No entry found. */
|
||
|
+ return NULL;
|
||
|
+}
|
||
|
+
|
||
|
+/* For an already existing hash table, change the number of buckets through
|
||
|
+ specifying CANDIDATE. The contents of the hash table are preserved. The
|
||
|
+ new number of buckets is automatically selected so as to _guarantee_ that
|
||
|
+ the table may receive at least CANDIDATE different user entries, including
|
||
|
+ those already in the table, before any other growth of the hash table size
|
||
|
+ occurs. If TUNING->IS_N_BUCKETS is true, then CANDIDATE specifies the
|
||
|
+ exact number of buckets desired. */
|
||
|
+
|
||
|
+bool
|
||
|
+hash_rehash (Hash_table *table, unsigned candidate)
|
||
|
+{
|
||
|
+ Hash_table *new_table;
|
||
|
+ struct hash_entry *bucket;
|
||
|
+ struct hash_entry *cursor;
|
||
|
+ struct hash_entry *next;
|
||
|
+
|
||
|
+ new_table = hash_initialize (candidate, table->tuning, table->hasher,
|
||
|
+ table->comparator, table->data_freer);
|
||
|
+ if (new_table == NULL)
|
||
|
+ return false;
|
||
|
+
|
||
|
+ /* Merely reuse the extra old space into the new table. */
|
||
|
+#if USE_OBSTACK
|
||
|
+ obstack_free (&new_table->entry_stack, NULL);
|
||
|
+ new_table->entry_stack = table->entry_stack;
|
||
|
+#endif
|
||
|
+ new_table->free_entry_list = table->free_entry_list;
|
||
|
+
|
||
|
+ for (bucket = table->bucket; bucket < table->bucket_limit; bucket++)
|
||
|
+ if (bucket->data)
|
||
|
+ for (cursor = bucket; cursor; cursor = next)
|
||
|
+ {
|
||
|
+ void *data = cursor->data;
|
||
|
+ struct hash_entry *new_bucket
|
||
|
+ = (new_table->bucket
|
||
|
+ + new_table->hasher (data, new_table->n_buckets));
|
||
|
+
|
||
|
+ if (! (new_bucket < new_table->bucket_limit))
|
||
|
+ abort ();
|
||
|
+
|
||
|
+ next = cursor->next;
|
||
|
+
|
||
|
+ if (new_bucket->data)
|
||
|
+ {
|
||
|
+ if (cursor == bucket)
|
||
|
+ {
|
||
|
+ /* Allocate or recycle an entry, when moving from a bucket
|
||
|
+ header into a bucket overflow. */
|
||
|
+ struct hash_entry *new_entry = allocate_entry (new_table);
|
||
|
+
|
||
|
+ if (new_entry == NULL)
|
||
|
+ return false;
|
||
|
+
|
||
|
+ new_entry->data = data;
|
||
|
+ new_entry->next = new_bucket->next;
|
||
|
+ new_bucket->next = new_entry;
|
||
|
+ }
|
||
|
+ else
|
||
|
+ {
|
||
|
+ /* Merely relink an existing entry, when moving from a
|
||
|
+ bucket overflow into a bucket overflow. */
|
||
|
+ cursor->next = new_bucket->next;
|
||
|
+ new_bucket->next = cursor;
|
||
|
+ }
|
||
|
+ }
|
||
|
+ else
|
||
|
+ {
|
||
|
+ /* Free an existing entry, when moving from a bucket
|
||
|
+ overflow into a bucket header. Also take care of the
|
||
|
+ simple case of moving from a bucket header into a bucket
|
||
|
+ header. */
|
||
|
+ new_bucket->data = data;
|
||
|
+ new_table->n_buckets_used++;
|
||
|
+ if (cursor != bucket)
|
||
|
+ free_entry (new_table, cursor);
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+ free (table->bucket);
|
||
|
+ table->bucket = new_table->bucket;
|
||
|
+ table->bucket_limit = new_table->bucket_limit;
|
||
|
+ table->n_buckets = new_table->n_buckets;
|
||
|
+ table->n_buckets_used = new_table->n_buckets_used;
|
||
|
+ table->free_entry_list = new_table->free_entry_list;
|
||
|
+ /* table->n_entries already holds its value. */
|
||
|
+#if USE_OBSTACK
|
||
|
+ table->entry_stack = new_table->entry_stack;
|
||
|
+#endif
|
||
|
+ free (new_table);
|
||
|
+
|
||
|
+ return true;
|
||
|
+}
|
||
|
+
|
||
|
+/* If ENTRY matches an entry already in the hash table, return the pointer
|
||
|
+ to the entry from the table. Otherwise, insert ENTRY and return ENTRY.
|
||
|
+ Return NULL if the storage required for insertion cannot be allocated. */
|
||
|
+
|
||
|
+void *
|
||
|
+hash_insert (Hash_table *table, const void *entry)
|
||
|
+{
|
||
|
+ void *data;
|
||
|
+ struct hash_entry *bucket;
|
||
|
+
|
||
|
+ /* The caller cannot insert a NULL entry. */
|
||
|
+ if (! entry)
|
||
|
+ abort ();
|
||
|
+
|
||
|
+ /* If there's a matching entry already in the table, return that. */
|
||
|
+ if ((data = hash_find_entry (table, entry, &bucket, false)) != NULL)
|
||
|
+ return data;
|
||
|
+
|
||
|
+ /* ENTRY is not matched, it should be inserted. */
|
||
|
+
|
||
|
+ if (bucket->data)
|
||
|
+ {
|
||
|
+ struct hash_entry *new_entry = allocate_entry (table);
|
||
|
+
|
||
|
+ if (new_entry == NULL)
|
||
|
+ return NULL;
|
||
|
+
|
||
|
+ /* Add ENTRY in the overflow of the bucket. */
|
||
|
+
|
||
|
+ new_entry->data = (void *) entry;
|
||
|
+ new_entry->next = bucket->next;
|
||
|
+ bucket->next = new_entry;
|
||
|
+ table->n_entries++;
|
||
|
+ return (void *) entry;
|
||
|
+ }
|
||
|
+
|
||
|
+ /* Add ENTRY right in the bucket head. */
|
||
|
+
|
||
|
+ bucket->data = (void *) entry;
|
||
|
+ table->n_entries++;
|
||
|
+ table->n_buckets_used++;
|
||
|
+
|
||
|
+ /* If the growth threshold of the buckets in use has been reached, increase
|
||
|
+ the table size and rehash. There's no point in checking the number of
|
||
|
+ entries: if the hashing function is ill-conditioned, rehashing is not
|
||
|
+ likely to improve it. */
|
||
|
+
|
||
|
+ if (table->n_buckets_used
|
||
|
+ > table->tuning->growth_threshold * table->n_buckets)
|
||
|
+ {
|
||
|
+ /* Check more fully, before starting real work. If tuning arguments
|
||
|
+ became invalid, the second check will rely on proper defaults. */
|
||
|
+ check_tuning (table);
|
||
|
+ if (table->n_buckets_used
|
||
|
+ > table->tuning->growth_threshold * table->n_buckets)
|
||
|
+ {
|
||
|
+ const Hash_tuning *tuning = table->tuning;
|
||
|
+ unsigned candidate
|
||
|
+ = (unsigned) (tuning->is_n_buckets
|
||
|
+ ? (table->n_buckets * tuning->growth_factor)
|
||
|
+ : (table->n_buckets * tuning->growth_factor
|
||
|
+ * tuning->growth_threshold));
|
||
|
+
|
||
|
+ /* If the rehash fails, arrange to return NULL. */
|
||
|
+ if (!hash_rehash (table, candidate))
|
||
|
+ entry = NULL;
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+ return (void *) entry;
|
||
|
+}
|
||
|
+
|
||
|
+/* If ENTRY is already in the table, remove it and return the just-deleted
|
||
|
+ data (the user may want to deallocate its storage). If ENTRY is not in the
|
||
|
+ table, don't modify the table and return NULL. */
|
||
|
+
|
||
|
+void *
|
||
|
+hash_delete (Hash_table *table, const void *entry)
|
||
|
+{
|
||
|
+ void *data;
|
||
|
+ struct hash_entry *bucket;
|
||
|
+
|
||
|
+ data = hash_find_entry (table, entry, &bucket, true);
|
||
|
+ if (!data)
|
||
|
+ return NULL;
|
||
|
+
|
||
|
+ table->n_entries--;
|
||
|
+ if (!bucket->data)
|
||
|
+ {
|
||
|
+ table->n_buckets_used--;
|
||
|
+
|
||
|
+ /* If the shrink threshold of the buckets in use has been reached,
|
||
|
+ rehash into a smaller table. */
|
||
|
+
|
||
|
+ if (table->n_buckets_used
|
||
|
+ < table->tuning->shrink_threshold * table->n_buckets)
|
||
|
+ {
|
||
|
+ /* Check more fully, before starting real work. If tuning arguments
|
||
|
+ became invalid, the second check will rely on proper defaults. */
|
||
|
+ check_tuning (table);
|
||
|
+ if (table->n_buckets_used
|
||
|
+ < table->tuning->shrink_threshold * table->n_buckets)
|
||
|
+ {
|
||
|
+ const Hash_tuning *tuning = table->tuning;
|
||
|
+ unsigned candidate
|
||
|
+ = (unsigned) (tuning->is_n_buckets
|
||
|
+ ? table->n_buckets * tuning->shrink_factor
|
||
|
+ : (table->n_buckets * tuning->shrink_factor
|
||
|
+ * tuning->growth_threshold));
|
||
|
+
|
||
|
+ hash_rehash (table, candidate);
|
||
|
+ }
|
||
|
+ }
|
||
|
+ }
|
||
|
+
|
||
|
+ return data;
|
||
|
+}
|
||
|
+
|
||
|
+/* Testing. */
|
||
|
+
|
||
|
+#if TESTING
|
||
|
+
|
||
|
+void
|
||
|
+hash_print (const Hash_table *table)
|
||
|
+{
|
||
|
+ struct hash_entry *bucket;
|
||
|
+
|
||
|
+ for (bucket = table->bucket; bucket < table->bucket_limit; bucket++)
|
||
|
+ {
|
||
|
+ struct hash_entry *cursor;
|
||
|
+
|
||
|
+ if (bucket)
|
||
|
+ printf ("%d:\n", bucket - table->bucket);
|
||
|
+
|
||
|
+ for (cursor = bucket; cursor; cursor = cursor->next)
|
||
|
+ {
|
||
|
+ char *s = (char *) cursor->data;
|
||
|
+ /* FIXME */
|
||
|
+ if (s)
|
||
|
+ printf (" %s\n", s);
|
||
|
+ }
|
||
|
+ }
|
||
|
+}
|
||
|
+
|
||
|
+#endif /* TESTING */
|
||
|
Index: patch-2.5.9/hash.h
|
||
|
===================================================================
|
||
|
--- /dev/null
|
||
|
+++ patch-2.5.9/hash.h
|
||
|
@@ -0,0 +1,93 @@
|
||
|
+/* hash - hashing table processing.
|
||
|
+ Copyright (C) 1998, 1999, 2001 Free Software Foundation, Inc.
|
||
|
+ Written by Jim Meyering <meyering@ascend.com>, 1998.
|
||
|
+
|
||
|
+ This program is free software; you can redistribute it and/or modify
|
||
|
+ it under the terms of the GNU General Public License as published by
|
||
|
+ the Free Software Foundation; either version 2, or (at your option)
|
||
|
+ any later version.
|
||
|
+
|
||
|
+ This program is distributed in the hope that it will be useful,
|
||
|
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
+ GNU General Public License for more details.
|
||
|
+
|
||
|
+ You should have received a copy of the GNU General Public License
|
||
|
+ along with this program; if not, write to the Free Software Foundation,
|
||
|
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
|
||
|
+
|
||
|
+/* A generic hash table package. */
|
||
|
+
|
||
|
+/* Make sure USE_OBSTACK is defined to 1 if you want the allocator to use
|
||
|
+ obstacks instead of malloc, and recompile `hash.c' with same setting. */
|
||
|
+
|
||
|
+#ifndef HASH_H_
|
||
|
+# define HASH_H_
|
||
|
+
|
||
|
+# ifndef PARAMS
|
||
|
+# if PROTOTYPES || __STDC__
|
||
|
+# define PARAMS(Args) Args
|
||
|
+# else
|
||
|
+# define PARAMS(Args) ()
|
||
|
+# endif
|
||
|
+# endif
|
||
|
+
|
||
|
+typedef unsigned (*Hash_hasher) PARAMS ((const void *, unsigned));
|
||
|
+typedef bool (*Hash_comparator) PARAMS ((const void *, const void *));
|
||
|
+typedef void (*Hash_data_freer) PARAMS ((void *));
|
||
|
+typedef bool (*Hash_processor) PARAMS ((void *, void *));
|
||
|
+
|
||
|
+struct hash_entry
|
||
|
+ {
|
||
|
+ void *data;
|
||
|
+ struct hash_entry *next;
|
||
|
+ };
|
||
|
+
|
||
|
+struct hash_tuning
|
||
|
+ {
|
||
|
+ /* This structure is mainly used for `hash_initialize', see the block
|
||
|
+ documentation of `hash_reset_tuning' for more complete comments. */
|
||
|
+
|
||
|
+ float shrink_threshold; /* ratio of used buckets to trigger a shrink */
|
||
|
+ float shrink_factor; /* ratio of new smaller size to original size */
|
||
|
+ float growth_threshold; /* ratio of used buckets to trigger a growth */
|
||
|
+ float growth_factor; /* ratio of new bigger size to original size */
|
||
|
+ bool is_n_buckets; /* if CANDIDATE really means table size */
|
||
|
+ };
|
||
|
+
|
||
|
+typedef struct hash_tuning Hash_tuning;
|
||
|
+
|
||
|
+struct hash_table;
|
||
|
+
|
||
|
+typedef struct hash_table Hash_table;
|
||
|
+
|
||
|
+/* Information and lookup. */
|
||
|
+unsigned hash_get_n_buckets PARAMS ((const Hash_table *));
|
||
|
+unsigned hash_get_n_buckets_used PARAMS ((const Hash_table *));
|
||
|
+unsigned hash_get_n_entries PARAMS ((const Hash_table *));
|
||
|
+unsigned hash_get_max_bucket_length PARAMS ((const Hash_table *));
|
||
|
+bool hash_table_ok PARAMS ((const Hash_table *));
|
||
|
+void hash_print_statistics PARAMS ((const Hash_table *, FILE *));
|
||
|
+void *hash_lookup PARAMS ((const Hash_table *, const void *));
|
||
|
+
|
||
|
+/* Walking. */
|
||
|
+void *hash_get_first PARAMS ((const Hash_table *));
|
||
|
+void *hash_get_next PARAMS ((const Hash_table *, const void *));
|
||
|
+unsigned hash_get_entries PARAMS ((const Hash_table *, void **, unsigned));
|
||
|
+unsigned hash_do_for_each PARAMS ((const Hash_table *, Hash_processor, void *));
|
||
|
+
|
||
|
+/* Allocation and clean-up. */
|
||
|
+unsigned hash_string PARAMS ((const char *, unsigned));
|
||
|
+void hash_reset_tuning PARAMS ((Hash_tuning *));
|
||
|
+Hash_table *hash_initialize PARAMS ((unsigned, const Hash_tuning *,
|
||
|
+ Hash_hasher, Hash_comparator,
|
||
|
+ Hash_data_freer));
|
||
|
+void hash_clear PARAMS ((Hash_table *));
|
||
|
+void hash_free PARAMS ((Hash_table *));
|
||
|
+
|
||
|
+/* Insertion and deletion. */
|
||
|
+bool hash_rehash PARAMS ((Hash_table *, unsigned));
|
||
|
+void *hash_insert PARAMS ((Hash_table *, const void *));
|
||
|
+void *hash_delete PARAMS ((Hash_table *, const void *));
|
||
|
+
|
||
|
+#endif
|
||
|
Index: patch-2.5.9/m4/nanosecond_stat.m4
|
||
|
===================================================================
|
||
|
--- /dev/null
|
||
|
+++ patch-2.5.9/m4/nanosecond_stat.m4
|
||
|
@@ -0,0 +1,35 @@
|
||
|
+AC_DEFUN([ag_CHECK_NANOSECOND_STAT],
|
||
|
+ [AC_CACHE_CHECK([for nanosecond timestamps in struct stat],
|
||
|
+ [ac_cv_stat_nsec],
|
||
|
+ [AC_TRY_COMPILE(
|
||
|
+ [
|
||
|
+ #include <sys/types.h>
|
||
|
+ #include <sys/stat.h>
|
||
|
+ #include <unistd.h>
|
||
|
+ struct stat st;
|
||
|
+ ],
|
||
|
+ [ return st.st_atimensec + st.st_mtimensec + st.st_ctimensec; ],
|
||
|
+ [ac_cv_stat_nsec=yes],
|
||
|
+ [ac_cv_stat_nsec=no])
|
||
|
+ ])
|
||
|
+ if test $ac_cv_stat_nsec = yes; then
|
||
|
+ AC_DEFINE(HAVE_STAT_NSEC, 1, [Define to 1 if struct stat has nanosecond timestamps.])
|
||
|
+ fi
|
||
|
+
|
||
|
+ AC_CACHE_CHECK([for nanosecond timestamps in struct stat],
|
||
|
+ [ac_cv_stat_timeval],
|
||
|
+ [AC_TRY_COMPILE(
|
||
|
+ [
|
||
|
+ #include <time.h>
|
||
|
+ #include <sys/types.h>
|
||
|
+ #include <sys/stat.h>
|
||
|
+ #include <unistd.h>
|
||
|
+ struct stat st;
|
||
|
+ ],
|
||
|
+ [ return st.st_atim.tv_nsec + st.st_mtim.tv_nsec + st.st_ctim.tv_nsec; ],
|
||
|
+ [ac_cv_stat_timeval=yes],
|
||
|
+ [ac_cv_stat_timeval=no])
|
||
|
+ ])
|
||
|
+ if test $ac_cv_stat_timeval = yes; then
|
||
|
+ AC_DEFINE(HAVE_STAT_TIMEVAL, 1, [Define to 1 if struct stat comtains struct timeval's.])
|
||
|
+ fi])
|