1/* Read, sort and compare two directories.  Used for GNU DIFF.
2   Copyright (C) 1988, 1989, 1992, 1993, 1994 Free Software Foundation, Inc.
3
4This file is part of GNU DIFF.
5
6GNU DIFF is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public License as published by
8the Free Software Foundation; either version 2, or (at your option)
9any later version.
10
11GNU DIFF is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14GNU General Public License for more details.
15
16*/
17
18#include "diff.h"
19
20/* Read the directory named by DIR and store into DIRDATA a sorted vector
21   of filenames for its contents.  DIR->desc == -1 means this directory is
22   known to be nonexistent, so set DIRDATA to an empty vector.
23   Return -1 (setting errno) if error, 0 otherwise.  */
24
25struct dirdata
26{
27  char const **names;	/* Sorted names of files in dir, 0-terminated.  */
28  char *data;	/* Allocated storage for file names.  */
29};
30
31static int compare_names PARAMS((void const *, void const *));
32static int dir_sort PARAMS((struct file_data const *, struct dirdata *));
33
34#ifdef _WIN32
35#define CLOSEDIR_VOID 1
36#endif
37
38static int
39dir_sort (dir, dirdata)
40     struct file_data const *dir;
41     struct dirdata *dirdata;
42{
43  register struct dirent *next;
44  register int i;
45
46  /* Address of block containing the files that are described.  */
47  char const **names;
48
49  /* Number of files in directory.  */
50  size_t nnames;
51
52  /* Allocated and used storage for file name data.  */
53  char *data;
54  size_t data_alloc, data_used;
55
56  dirdata->names = 0;
57  dirdata->data = 0;
58  nnames = 0;
59  data = 0;
60
61  if (dir->desc != -1)
62    {
63      /* Open the directory and check for errors.  */
64      register DIR *reading = CVS_OPENDIR (dir->name);
65      if (!reading)
66	return -1;
67
68      /* Initialize the table of filenames.  */
69
70      data_alloc = max (1, (size_t) dir->stat.st_size);
71      data_used = 0;
72      dirdata->data = data = xmalloc (data_alloc);
73
74      /* Read the directory entries, and insert the subfiles
75	 into the `data' table.  */
76
77      while ((errno = 0, (next = CVS_READDIR (reading)) != 0))
78	{
79	  char *d_name = next->d_name;
80	  size_t d_size = NAMLEN (next) + 1;
81
82	  /* Ignore the files `.' and `..' */
83	  if (d_name[0] == '.'
84	      && (d_name[1] == 0 || (d_name[1] == '.' && d_name[2] == 0)))
85	    continue;
86
87	  if (excluded_filename (d_name))
88	    continue;
89
90	  while (data_alloc < data_used + d_size)
91	    dirdata->data = data = xrealloc (data, data_alloc *= 2);
92	  memcpy (data + data_used, d_name, d_size);
93	  data_used += d_size;
94	  nnames++;
95	}
96      if (errno)
97	{
98	  int e = errno;
99	  CVS_CLOSEDIR (reading);
100	  errno = e;
101	  return -1;
102	}
103#if CLOSEDIR_VOID
104      CVS_CLOSEDIR (reading);
105#else
106      if (CVS_CLOSEDIR (reading) != 0)
107	return -1;
108#endif
109    }
110
111  /* Create the `names' table from the `data' table.  */
112  dirdata->names = names = (char const **) xmalloc (sizeof (char *)
113						    * (nnames + 1));
114  for (i = 0;  i < nnames;  i++)
115    {
116      names[i] = data;
117      data += strlen (data) + 1;
118    }
119  names[nnames] = 0;
120
121  /* Sort the table.  */
122  qsort (names, nnames, sizeof (char *), compare_names);
123
124  return 0;
125}
126
127/* Sort the files now in the table.  */
128
129static int
130compare_names (file1, file2)
131     void const *file1, *file2;
132{
133  return filename_cmp (* (char const *const *) file1,
134		       * (char const *const *) file2);
135}
136
137/* Compare the contents of two directories named in FILEVEC[0] and FILEVEC[1].
138   This is a top-level routine; it does everything necessary for diff
139   on two directories.
140
141   FILEVEC[0].desc == -1 says directory FILEVEC[0] doesn't exist,
142   but pretend it is empty.  Likewise for FILEVEC[1].
143
144   HANDLE_FILE is a caller-provided subroutine called to handle each file.
145   It gets five operands: dir and name (rel to original working dir) of file
146   in dir 0, dir and name pathname of file in dir 1, and the recursion depth.
147
148   For a file that appears in only one of the dirs, one of the name-args
149   to HANDLE_FILE is zero.
150
151   DEPTH is the current depth in recursion, used for skipping top-level
152   files by the -S option.
153
154   Returns the maximum of all the values returned by HANDLE_FILE,
155   or 2 if trouble is encountered in opening files.  */
156
157int
158diff_dirs (filevec, handle_file, depth)
159     struct file_data const filevec[];
160     int (*handle_file) PARAMS((char const *, char const *, char const *, char const *, int));
161     int depth;
162{
163  struct dirdata dirdata[2];
164  int val = 0;			/* Return value.  */
165  int i;
166
167  /* Get sorted contents of both dirs.  */
168  for (i = 0; i < 2; i++)
169    if (dir_sort (&filevec[i], &dirdata[i]) != 0)
170      {
171	perror_with_name (filevec[i].name);
172	val = 2;
173      }
174
175  if (val == 0)
176    {
177      register char const * const *names0 = dirdata[0].names;
178      register char const * const *names1 = dirdata[1].names;
179      char const *name0 = filevec[0].name;
180      char const *name1 = filevec[1].name;
181
182      /* If `-S name' was given, and this is the topmost level of comparison,
183	 ignore all file names less than the specified starting name.  */
184
185      if (dir_start_file && depth == 0)
186	{
187	  while (*names0 && filename_cmp (*names0, dir_start_file) < 0)
188	    names0++;
189	  while (*names1 && filename_cmp (*names1, dir_start_file) < 0)
190	    names1++;
191	}
192
193      /* Loop while files remain in one or both dirs.  */
194      while (*names0 || *names1)
195	{
196	  /* Compare next name in dir 0 with next name in dir 1.
197	     At the end of a dir,
198	     pretend the "next name" in that dir is very large.  */
199	  int nameorder = (!*names0 ? 1 : !*names1 ? -1
200			   : filename_cmp (*names0, *names1));
201	  int v1 = (*handle_file) (name0, 0 < nameorder ? 0 : *names0++,
202				   name1, nameorder < 0 ? 0 : *names1++,
203				   depth + 1);
204	  if (v1 > val)
205	    val = v1;
206	}
207    }
208
209  for (i = 0; i < 2; i++)
210    {
211      if (dirdata[i].names)
212	free (dirdata[i].names);
213      if (dirdata[i].data)
214	free (dirdata[i].data);
215    }
216
217  return val;
218}
219