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     2018-04-01 Fix handle to be intptr_t not long to avoid truncation
  13                with WIN64 (where long is still 32 bits).
  14
  15     Copyright Kevlin Henney, 1997, 2003. All rights reserved.
  16
  17     Permission to use, copy, modify, and distribute this software and its
  18     documentation for any purpose is hereby granted without fee, provided
  19     that this copyright and permissions notice appear in all copies and
  20     derivatives.
  21
  22     This software is supplied "as is" without express or implied warranty.
  23
  24     But that said, if there are any problems please get in touch.
  25 */
  26
  27 #include <config.h>
  28 #ifdef __WIN32__
  29
  30 #include "msvc_dirent.h"
  31 #include <cerrno>
  32 #include <io.h> /* _findfirst and _findnext set errno iff they return -1 */
  33 #include <cstdlib>
  34 #include <cstring>
  35
  36 #ifdef __cplusplus
  37 extern "C"
  38 {
  39 #endif
  40
  41 struct DIR
  42 {
  43     intptr_t            handle; /* -1 for failed rewind */
  44     struct _finddata_t  info;
  45     struct dirent       result; /* d_name null iff first time */
  46     char                *name;  /* null-terminated char string */
  47 };
  48
  49 DIR *opendir(const char *name)
  50 {
  51     DIR *dir = 0;
  52
  53     if(name && name[0])
  54     {
  55         size_t base_length = strlen(name);
  56         const char *all = /* search pattern must end with suitable wildcard */
  57             strchr("/\\", name[base_length - 1]) ? "*" : "/*";
  58
  59         if((dir = (DIR *) malloc(sizeof *dir)) != 0 &&
  60            (dir->name = (char *) malloc(base_length + strlen(all) + 1)) != 0)
  61         {
  62             strcat(strcpy(dir->name, name), all);
  63
  64             if((dir->handle = _findfirst(dir->name, &dir->info)) != -1)
  65             {
  66                 dir->result.d_name = 0;
  67             }
  68             else /* rollback */
  69             {
  70                 free(dir->name);
  71                 free(dir);
  72                 dir = 0;
  73             }
  74         }
  75         else /* rollback */
  76         {
  77             free(dir);
  78             dir   = 0;
  79             errno = ENOMEM;
  80         }
  81     }
  82     else
  83     {
  84         errno = EINVAL;
  85     }
  86
  87     return dir;
  88 }
  89
  90 int closedir(DIR *dir)
  91 {
  92     int result = -1;
  93
  94     if(dir)
  95     {
  96         if(dir->handle != -1)
  97         {
  98             result = _findclose(dir->handle);
  99         }
 100
 101         free(dir->name);
 102         free(dir);
 103     }
 104
 105     if(result == -1) /* map all errors to EBADF */
 106     {
 107         errno = EBADF;
 108     }
 109
 110     return result;
 111 }
 112
 113 struct dirent *readdir(DIR *dir)
 114 {
 115     struct dirent *result = 0;
 116
 117     if(dir && dir->handle != -1)
 118     {
 119         if(!dir->result.d_name) {
 120             result = &dir->result;
 121             result->d_name = dir->info.name;
 122         } else {
 123             int orig_errno = errno;
 124             if (_findnext(dir->handle, &dir->info) != -1) {
 125                 result = &dir->result;
 126                 result->d_name = dir->info.name;
 127             } else if (errno == ENOENT) {
 128                 // _findnext sets errno to ENOENT when the end of the directory
 129                 // is reached.  However, according to POSIX, the value of errno
 130                 // should not be changed by this condition.  Therefore, we have
 131                 // to set it back to the original value.
 132                 errno = orig_errno;
 133             }
 134         }
 135     }
 136     else
 137     {
 138         errno = EBADF;
 139     }
 140
 141     return result;
 142 }
 143
 144 void rewinddir(DIR *dir)
 145 {
 146     if(dir && dir->handle != -1)
 147     {
 148         _findclose(dir->handle);
 149         dir->handle = _findfirst(dir->name, &dir->info);
 150         dir->result.d_name = 0;
 151     }
 152     else
 153     {
 154         errno = EBADF;
 155     }
 156 }
 157
 158 #ifdef __cplusplus
 159 }
 160 #endif
 161
 162 #endif