xapian-core/common/msvc_dirent.cc

   1 /** @file msvc_dirent.cc
   2  *  @brief Implementation of dirent functions using WIN32 API.
   3  */
   4 /*
   5     Implementation of POSIX directory browsing functions and types for Win32.
   6
   7     Author:  Kevlin Henney (kevlin@acm.org, kevlin@curbralan.com)
   8     History: Created March 1997. Updated June 2003.
   9     Fixes since importing into Xapian:
  10     2008-03-04 Fixed readdir() not to set errno to ENOENT when the
  11                end of the directory is reached.
  12
  13     Copyright Kevlin Henney, 1997, 2003. All rights reserved.
  14
  15     Permission to use, copy, modify, and distribute this software and its
  16     documentation for any purpose is hereby granted without fee, provided
  17     that this copyright and permissions notice appear in all copies and
  18     derivatives.
  19
  20     This software is supplied "as is" without express or implied warranty.
  21
  22     But that said, if there are any problems please get in touch.
  23 */
  24
  25 #include <config.h>
  26 #ifdef __WIN32__
  27
  28 #include "msvc_dirent.h"
  29 #include <cerrno>
  30 #include <io.h> /* _findfirst and _findnext set errno iff they return -1 */
  31 #include <cstdlib>
  32 #include <cstring>
  33
  34 #ifdef __cplusplus
  35 extern "C"
  36 {
  37 #endif
  38
  39 struct DIR
  40 {
  41     long                handle; /* -1 for failed rewind */
  42     struct _finddata_t  info;
  43     struct dirent       result; /* d_name null iff first time */
  44     char                *name;  /* null-terminated char string */
  45 };
  46
  47 DIR *opendir(const char *name)
  48 {
  49     DIR *dir = 0;
  50
  51     if(name && name[0])
  52     {
  53         size_t base_length = strlen(name);
  54         const char *all = /* search pattern must end with suitable wildcard */
  55             strchr("/\\", name[base_length - 1]) ? "*" : "/*";
  56
  57         if((dir = (DIR *) malloc(sizeof *dir)) != 0 &&
  58            (dir->name = (char *) malloc(base_length + strlen(all) + 1)) != 0)
  59         {
  60             strcat(strcpy(dir->name, name), all);
  61
  62             if((dir->handle = (long) _findfirst(dir->name, &dir->info)) != -1)
  63             {
  64                 dir->result.d_name = 0;
  65             }
  66             else /* rollback */
  67             {
  68                 free(dir->name);
  69                 free(dir);
  70                 dir = 0;
  71             }
  72         }
  73         else /* rollback */
  74         {
  75             free(dir);
  76             dir   = 0;
  77             errno = ENOMEM;
  78         }
  79     }
  80     else
  81     {
  82         errno = EINVAL;
  83     }
  84
  85     return dir;
  86 }
  87
  88 int closedir(DIR *dir)
  89 {
  90     int result = -1;
  91
  92     if(dir)
  93     {
  94         if(dir->handle != -1)
  95         {
  96             result = _findclose(dir->handle);
  97         }
  98
  99         free(dir->name);
 100         free(dir);
 101     }
 102
 103     if(result == -1) /* map all errors to EBADF */
 104     {
 105         errno = EBADF;
 106     }
 107
 108     return result;
 109 }
 110
 111 struct dirent *readdir(DIR *dir)
 112 {
 113     struct dirent *result = 0;
 114
 115     if(dir && dir->handle != -1)
 116     {
 117         if(!dir->result.d_name) {
 118             result = &dir->result;
 119             result->d_name = dir->info.name;
 120         } else {
 121             int orig_errno = errno;
 122             if (_findnext(dir->handle, &dir->info) != -1) {
 123                 result = &dir->result;
 124                 result->d_name = dir->info.name;
 125             } else if (errno == ENOENT) {
 126                 // _findnext sets errno to ENOENT when the end of the directory
 127                 // is reached.  However, according to POSIX, the value of errno
 128                 // should not be changed by this condition.  Therefore, we have
 129                 // to set it back to the original value.
 130                 errno = orig_errno;
 131             }
 132         }
 133     }
 134     else
 135     {
 136         errno = EBADF;
 137     }
 138
 139     return result;
 140 }
 141
 142 void rewinddir(DIR *dir)
 143 {
 144     if(dir && dir->handle != -1)
 145     {
 146         _findclose(dir->handle);
 147         dir->handle = (long) _findfirst(dir->name, &dir->info);
 148         dir->result.d_name = 0;
 149     }
 150     else
 151     {
 152         errno = EBADF;
 153     }
 154 }
 155
 156 #ifdef __cplusplus
 157 }
 158 #endif
 159
 160 #endif