sal/osl/unx/tempfile.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <sys/time.h>
  25 #include "system.hxx"
  26 #include <osl/file.h>
  27 #include <osl/thread.h>
  28 #include <rtl/ustrbuf.h>
  29 #include <osl/diagnose.h>
  30 #include <sal/macros.h>
  31
  32 #include "file_url.hxx"
  33 #include "file_impl.hxx"
  34
  35 #include <cassert>
  36
  37 oslFileError SAL_CALL osl_getTempDirURL( rtl_uString** pustrTempDir )
  38 {
  39     oslFileError error;
  40     /* described in environ(7) */
  41     const char *pValue = getenv( "TMPDIR" );
  42     rtl_uString *ustrTempPath = nullptr;
  43
  44     if ( !pValue )
  45         pValue = getenv( "TEMP" );
  46
  47     if ( !pValue )
  48         pValue = getenv( "TMP" );
  49
  50     if ( !pValue )
  51         pValue = "/tmp";
  52
  53     auto nLen = strlen(pValue);
  54     while (nLen > 1 && pValue[nLen - 1] == '/') // Allow path consisting of single "/"
  55         --nLen;
  56     rtl_string2UString( &ustrTempPath, pValue, nLen, osl_getThreadTextEncoding(), OSTRING_TO_OUSTRING_CVTFLAGS );
  57     assert(ustrTempPath);
  58     error = osl_getFileURLFromSystemPath( ustrTempPath, pustrTempDir );
  59     rtl_uString_release( ustrTempPath );
  60
  61     return error;
  62 }
  63
  64 /******************************************************************
  65  * Generates a random unique file name. We're using the scheme
  66  * from the standard c-lib function mkstemp to generate a more
  67  * or less random unique file name
  68  *
  69  * @param rand_name
  70  *        receives the random name
  71  ******************************************************************/
  72
  73 const char LETTERS[]        = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
  74 const int  COUNT_OF_LETTERS = SAL_N_ELEMENTS(LETTERS) - 1;
  75
  76 #define RAND_NAME_LENGTH 6
  77
  78 static void osl_gen_random_name_impl_(rtl_uString** rand_name)
  79 {
  80     static uint64_t value;
  81
  82     char     buffer[RAND_NAME_LENGTH];
  83     struct   timeval tv;
  84     uint64_t v;
  85     int      i;
  86
  87     gettimeofday(&tv, nullptr);
  88
  89     value += (static_cast<uint64_t>(tv.tv_usec) << 16) ^ tv.tv_sec ^ getpid();
  90
  91     v = value;
  92
  93     for (i = 0; i < RAND_NAME_LENGTH; i++)
  94     {
  95         buffer[i] = LETTERS[v % COUNT_OF_LETTERS];
  96         v        /= COUNT_OF_LETTERS;
  97     }
  98
  99     rtl_string2UString(
 100             rand_name,
 101             buffer,
 102             RAND_NAME_LENGTH,
 103             RTL_TEXTENCODING_ASCII_US,
 104             OSTRING_TO_OUSTRING_CVTFLAGS);
 105
 106     assert(*rand_name);
 107 }
 108
 109 /*****************************************************************
 110  * Helper function
 111  * Either use the directory provided or the result of
 112  * osl_getTempDirUrl and return it as system path and file url
 113  ****************************************************************/
 114
 115 static oslFileError osl_setup_base_directory_impl_(
 116     rtl_uString*  pustrDirectoryURL,
 117     rtl_uString** ppustr_base_dir)
 118 {
 119     rtl_uString* dir_url = nullptr;
 120     rtl_uString* dir     = nullptr;
 121     oslFileError error   = osl_File_E_None;
 122
 123     if (pustrDirectoryURL)
 124         rtl_uString_assign(&dir_url, pustrDirectoryURL);
 125     else
 126         error = osl_getTempDirURL(&dir_url);
 127
 128     if (error == osl_File_E_None)
 129     {
 130         error = getSystemPathFromFileURL_Ex(dir_url, &dir);
 131         rtl_uString_release(dir_url);
 132     }
 133
 134     if (error == osl_File_E_None)
 135     {
 136         rtl_uString_assign(ppustr_base_dir, dir);
 137         rtl_uString_release(dir);
 138     }
 139
 140     return error;
 141 }
 142
 143 /*****************************************************************
 144  * osl_setup_createTempFile_impl
 145  * validate input parameter, setup variables
 146  ****************************************************************/
 147
 148  static oslFileError osl_setup_createTempFile_impl_(
 149      rtl_uString*   pustrDirectoryURL,
 150     oslFileHandle* pHandle,
 151     rtl_uString**  ppustrTempFileURL,
 152     rtl_uString**  ppustr_base_dir,
 153     bool*      b_delete_on_close)
 154  {
 155     oslFileError osl_error;
 156
 157     OSL_PRECOND(((nullptr != pHandle) || (nullptr != ppustrTempFileURL)), "Invalid parameter!");
 158
 159     if ((pHandle == nullptr) && (ppustrTempFileURL == nullptr))
 160     {
 161         osl_error = osl_File_E_INVAL;
 162     }
 163     else
 164     {
 165         osl_error = osl_setup_base_directory_impl_(
 166             pustrDirectoryURL, ppustr_base_dir);
 167
 168         *b_delete_on_close = (ppustrTempFileURL == nullptr);
 169     }
 170
 171     return osl_error;
 172  }
 173
 174 /*****************************************************************
 175  * Create a unique file in the specified directory and return
 176  * its name
 177  ****************************************************************/
 178
 179 static oslFileError osl_create_temp_file_impl_(
 180     const rtl_uString* pustr_base_directory,
 181     oslFileHandle* file_handle,
 182     rtl_uString** ppustr_temp_file_name)
 183 {
 184     rtl_uString*        rand_name        = nullptr;
 185     sal_uInt32          len_base_dir     = 0;
 186     rtl_uString*        tmp_file_path    = nullptr;
 187     rtl_uString*        tmp_file_url     = nullptr;
 188     sal_Int32           capacity         = 0;
 189     oslFileError        osl_error        = osl_File_E_None;
 190     sal_Int32           offset_file_name;
 191     const sal_Unicode*  puchr;
 192
 193     OSL_PRECOND(pustr_base_directory, "Invalid Parameter");
 194     OSL_PRECOND(file_handle, "Invalid Parameter");
 195     OSL_PRECOND(ppustr_temp_file_name, "Invalid Parameter");
 196
 197     len_base_dir = rtl_uString_getLength(pustr_base_directory);
 198
 199     rtl_uString_new_WithLength(
 200         &tmp_file_path,
 201         (len_base_dir + 1 + RAND_NAME_LENGTH));
 202     capacity = len_base_dir + 1 + RAND_NAME_LENGTH;
 203
 204     rtl_uStringbuffer_insert(
 205         &tmp_file_path,
 206         &capacity,
 207         0,
 208         rtl_uString_getStr(const_cast<rtl_uString*>(pustr_base_directory)),
 209         len_base_dir);
 210
 211     offset_file_name = len_base_dir;
 212
 213     puchr = rtl_uString_getStr(tmp_file_path);
 214
 215     /* ensure that the last character is a '/' */
 216
 217     if (puchr[len_base_dir - 1] != '/')
 218     {
 219         rtl_uStringbuffer_insert_ascii(
 220             &tmp_file_path,
 221             &capacity,
 222             len_base_dir,
 223             "/",
 224             1);
 225
 226         offset_file_name++;
 227     }
 228
 229     while(true) /* try until success */
 230     {
 231         osl_gen_random_name_impl_(&rand_name);
 232
 233         rtl_uStringbuffer_insert(
 234             &tmp_file_path,
 235             &capacity,
 236             offset_file_name,
 237             rtl_uString_getStr(rand_name),
 238             rtl_uString_getLength(rand_name));
 239
 240         osl_error = osl_getFileURLFromSystemPath(
 241             tmp_file_path, &tmp_file_url);
 242
 243         if (osl_error == osl_File_E_None)
 244         {
 245             osl_error = openFile(
 246                 tmp_file_url,
 247                 file_handle,
 248                 osl_File_OpenFlag_Read |
 249                 osl_File_OpenFlag_Write |
 250                 osl_File_OpenFlag_Create,
 251                 S_IRUSR | S_IWUSR);
 252         }
 253
 254         /* in case of error osl_File_E_EXIST we simply try again else we give up */
 255
 256         if (osl_error != osl_File_E_EXIST)
 257         {
 258             rtl_uString_release(rand_name);
 259
 260             if (tmp_file_url)
 261                 rtl_uString_release(tmp_file_url);
 262
 263             break;
 264         }
 265     } /* while(1) */
 266
 267     if (osl_error == osl_File_E_None)
 268         rtl_uString_assign(ppustr_temp_file_name, tmp_file_path);
 269
 270     rtl_uString_release(tmp_file_path);
 271
 272     return osl_error;
 273 }
 274
 275 oslFileError SAL_CALL osl_createTempFile(
 276     rtl_uString*   pustrDirectoryURL,
 277     oslFileHandle* pHandle,
 278     rtl_uString**  ppustrTempFileURL)
 279 {
 280     rtl_uString*  base_directory     = nullptr;
 281     oslFileHandle temp_file_handle = nullptr;
 282     bool      b_delete_on_close;
 283     oslFileError  osl_error;
 284
 285     osl_error = osl_setup_createTempFile_impl_(
 286         pustrDirectoryURL,
 287         pHandle,
 288         ppustrTempFileURL,
 289         &base_directory,
 290         &b_delete_on_close);
 291
 292     if (osl_error != osl_File_E_None)
 293         return osl_error;
 294
 295     rtl_uString*  temp_file_name = nullptr;
 296     osl_error = osl_create_temp_file_impl_(
 297         base_directory, &temp_file_handle, &temp_file_name);
 298
 299     rtl_uString* temp_file_url = nullptr;
 300     if (osl_error == osl_File_E_None)
 301     {
 302         osl_error = osl_getFileURLFromSystemPath(temp_file_name, &temp_file_url);
 303         rtl_uString_release(temp_file_name);
 304     }
 305
 306     if (osl_error == osl_File_E_None)
 307     {
 308         if (b_delete_on_close)
 309         {
 310             osl_error = osl_removeFile(temp_file_url);
 311
 312             if (osl_error == osl_File_E_None)
 313             {
 314                 *pHandle = temp_file_handle;
 315                 temp_file_handle = nullptr;
 316             }
 317         }
 318         else
 319         {
 320             if (pHandle)
 321             {
 322                 *pHandle = temp_file_handle;
 323                 temp_file_handle = nullptr;
 324             }
 325
 326             rtl_uString_assign(ppustrTempFileURL, temp_file_url);
 327         }
 328
 329         rtl_uString_release(temp_file_url);
 330     }
 331
 332     if (temp_file_handle)
 333         osl_closeFile(temp_file_handle);
 334
 335     rtl_uString_release(base_directory);
 336
 337     return osl_error;
 338 }
 339
 340 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */