/* [<][>][^][v][top][bottom][index][help] */
DEFINITIONS
This source file includes following definitions.
- dir_read
- compare_names
- compare_names_for_qsort
- diff_dirs
- dir_loop
- find_dir_file_pathname
/* Read, sort and compare two directories. Used for GNU DIFF.
Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006-2007,
2009-2011 Free Software Foundation, Inc.
This file is part of GNU DIFF.
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 3 of the License, 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, see <http://www.gnu.org/licenses/>. */
#include "diff.h"
#include <error.h>
#include <exclude.h>
#include <filenamecat.h>
#include <setjmp.h>
#include <xalloc.h>
/* Read the directory named by DIR and store into DIRDATA a sorted vector
of filenames for its contents. DIR->desc == -1 means this directory is
known to be nonexistent, so set DIRDATA to an empty vector.
Return -1 (setting errno) if error, 0 otherwise. */
struct dirdata
{
size_t nnames; /* Number of names. */
char const **names; /* Sorted names of files in dir, followed by 0. */
char *data; /* Allocated storage for file names. */
};
/* Whether file names in directories should be compared with
locale-specific sorting. */
static bool locale_specific_sorting;
/* Where to go if locale-specific sorting fails. */
static jmp_buf failed_locale_specific_sorting;
static bool dir_loop (struct comparison const *, int);
static int compare_names_for_qsort (void const *, void const *);
/* Read a directory and get its vector of names. */
static bool
dir_read (struct file_data const *dir, struct dirdata *dirdata)
{
register struct dirent *next;
register size_t i;
/* Address of block containing the files that are described. */
char const **names;
/* Number of files in directory. */
size_t nnames;
/* Allocated and used storage for file name data. */
char *data;
size_t data_alloc, data_used;
dirdata->names = 0;
dirdata->data = 0;
nnames = 0;
data = 0;
if (dir->desc != -1)
{
/* Open the directory and check for errors. */
register DIR *reading = opendir (dir->name);
if (!reading)
return false;
/* Initialize the table of filenames. */
data_alloc = 512;
data_used = 0;
dirdata->data = data = xmalloc (data_alloc);
/* Read the directory entries, and insert the subfiles
into the `data' table. */
while ((errno = 0, (next = readdir (reading)) != 0))
{
char *d_name = next->d_name;
size_t d_size = _D_EXACT_NAMLEN (next) + 1;
/* Ignore "." and "..". */
if (d_name[0] == '.'
&& (d_name[1] == 0 || (d_name[1] == '.' && d_name[2] == 0)))
continue;
if (excluded_file_name (excluded, d_name))
continue;
while (data_alloc < data_used + d_size)
{
if (PTRDIFF_MAX / 2 <= data_alloc)
xalloc_die ();
dirdata->data = data = xrealloc (data, data_alloc *= 2);
}
memcpy (data + data_used, d_name, d_size);
data_used += d_size;
nnames++;
}
if (errno)
{
int e = errno;
closedir (reading);
errno = e;
return false;
}
#if CLOSEDIR_VOID
closedir (reading);
#else
if (closedir (reading) != 0)
return false;
#endif
}
/* Create the `names' table from the `data' table. */
if (PTRDIFF_MAX / sizeof *names - 1 <= nnames)
xalloc_die ();
dirdata->names = names = xmalloc ((nnames + 1) * sizeof *names);
dirdata->nnames = nnames;
for (i = 0; i < nnames; i++)
{
names[i] = data;
data += strlen (data) + 1;
}
names[nnames] = 0;
return true;
}
/* Compare file names, returning a value compatible with strcmp. */
static int
compare_names (char const *name1, char const *name2)
{
if (locale_specific_sorting)
{
int r;
errno = 0;
if (ignore_file_name_case)
r = strcasecoll (name1, name2);
else
r = strcoll (name1, name2);
if (errno)
{
error (0, errno, _("cannot compare file names `%s' and `%s'"),
name1, name2);
longjmp (failed_locale_specific_sorting, 1);
}
return r;
}
return file_name_cmp (name1, name2);
}
/* Compare names FILE1 and FILE2 when sorting a directory.
Prefer filtered comparison, breaking ties with file_name_cmp. */
static int
compare_names_for_qsort (void const *file1, void const *file2)
{
char const *const *f1 = file1;
char const *const *f2 = file2;
int diff = compare_names (*f1, *f2);
return diff ? diff : file_name_cmp (*f1, *f2);
}
/* Compare the contents of two directories named in CMP.
This is a top-level routine; it does everything necessary for diff
on two directories.
CMP->file[0].desc == -1 says directory CMP->file[0] doesn't exist,
but pretend it is empty. Likewise for CMP->file[1].
HANDLE_FILE is a caller-provided subroutine called to handle each file.
It gets three operands: CMP, name of file in dir 0, name of file in dir 1.
These names are relative to the original working directory.
For a file that appears in only one of the dirs, one of the name-args
to HANDLE_FILE is zero.
Returns the maximum of all the values returned by HANDLE_FILE,
or EXIT_TROUBLE if trouble is encountered in opening files. */
int
diff_dirs (struct comparison const *cmp,
int (*handle_file) (struct comparison const *,
char const *, char const *))
{
struct dirdata dirdata[2];
int volatile val = EXIT_SUCCESS;
int i;
if ((cmp->file[0].desc == -1 || dir_loop (cmp, 0))
&& (cmp->file[1].desc == -1 || dir_loop (cmp, 1)))
{
error (0, 0, _("%s: recursive directory loop"),
cmp->file[cmp->file[0].desc == -1].name);
return EXIT_TROUBLE;
}
/* Get contents of both dirs. */
for (i = 0; i < 2; i++)
if (! dir_read (&cmp->file[i], &dirdata[i]))
{
perror_with_name (cmp->file[i].name);
val = EXIT_TROUBLE;
}
if (val == EXIT_SUCCESS)
{
char const **volatile names[2];
names[0] = dirdata[0].names;
names[1] = dirdata[1].names;
/* Use locale-specific sorting if possible, else native byte order. */
locale_specific_sorting = true;
if (setjmp (failed_locale_specific_sorting))
locale_specific_sorting = false;
/* Sort the directories. */
for (i = 0; i < 2; i++)
qsort (names[i], dirdata[i].nnames, sizeof *dirdata[i].names,
compare_names_for_qsort);
/* If `-S name' was given, and this is the topmost level of comparison,
ignore all file names less than the specified starting name. */
if (starting_file && ! cmp->parent)
{
while (*names[0] && compare_names (*names[0], starting_file) < 0)
names[0]++;
while (*names[1] && compare_names (*names[1], starting_file) < 0)
names[1]++;
}
/* Loop while files remain in one or both dirs. */
while (*names[0] || *names[1])
{
/* Compare next name in dir 0 with next name in dir 1.
At the end of a dir,
pretend the "next name" in that dir is very large. */
int nameorder = (!*names[0] ? 1 : !*names[1] ? -1
: compare_names (*names[0], *names[1]));
/* Prefer a file_name_cmp match if available. This algorithm is
O(N**2), where N is the number of names in a directory
that compare_names says are all equal, but in practice N
is so small it's not worth tuning. */
if (nameorder == 0)
{
int raw_order = file_name_cmp (*names[0], *names[1]);
if (raw_order != 0)
{
int greater_side = raw_order < 0;
int lesser_side = 1 - greater_side;
char const **lesser = names[lesser_side];
char const *greater_name = *names[greater_side];
char const **p;
for (p = lesser + 1;
*p && compare_names (*p, greater_name) == 0;
p++)
{
int c = file_name_cmp (*p, greater_name);
if (0 <= c)
{
if (c == 0)
{
memmove (lesser + 1, lesser,
(char *) p - (char *) lesser);
*lesser = greater_name;
}
break;
}
}
}
}
int v1 = (*handle_file) (cmp,
0 < nameorder ? 0 : *names[0]++,
nameorder < 0 ? 0 : *names[1]++);
if (val < v1)
val = v1;
}
}
for (i = 0; i < 2; i++)
{
free (dirdata[i].names);
free (dirdata[i].data);
}
return val;
}
/* Return nonzero if CMP is looping recursively in argument I. */
static bool
dir_loop (struct comparison const *cmp, int i)
{
struct comparison const *p = cmp;
while ((p = p->parent))
if (0 < same_file (&p->file[i].stat, &cmp->file[i].stat))
return true;
return false;
}
/* Find a matching filename in a directory. */
char *
find_dir_file_pathname (char const *dir, char const *file)
{
char *val;
char const *match = file;
struct dirdata dirdata;
dirdata.names = NULL;
dirdata.data = NULL;
if (ignore_file_name_case)
{
struct file_data filedata;
filedata.name = dir;
filedata.desc = 0;
if (dir_read (&filedata, &dirdata))
{
locale_specific_sorting = true;
if (setjmp (failed_locale_specific_sorting))
match = file; /* longjmp may mess up MATCH. */
else
{
for (char const **p = dirdata.names; *p; p++)
if (compare_names (*p, file) == 0)
{
if (file_name_cmp (*p, file) == 0)
{
match = *p;
break;
}
if (match == file)
match = *p;
}
}
}
}
val = file_name_concat (dir, match, NULL);
free (dirdata.names);
free (dirdata.data);
return val;
}