1 | /* gdbmreorg.c - Reorganize the database file. */
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2 |
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3 | /* This file is part of GDBM, the GNU data base manager, by Philip A. Nelson.
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4 | Copyright (C) 1990, 1991, 1993 Free Software Foundation, Inc.
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5 |
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6 | GDBM is free software; you can redistribute it and/or modify
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7 | it under the terms of the GNU General Public License as published by
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8 | the Free Software Foundation; either version 2, or (at your option)
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9 | any later version.
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10 |
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11 | GDBM is distributed in the hope that it will be useful,
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12 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 | GNU General Public License for more details.
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15 |
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16 | You should have received a copy of the GNU General Public License
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17 | along with GDBM; see the file COPYING. If not, write to
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18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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19 |
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20 | You may contact the author by:
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21 | e-mail: [email protected]
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22 | us-mail: Philip A. Nelson
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23 | Computer Science Department
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24 | Western Washington University
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25 | Bellingham, WA 98226
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26 |
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27 | ************************************************************************/
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28 |
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29 |
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30 | /* include system configuration before all else. */
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31 | #include "autoconf.h"
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32 |
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33 | #include "gdbmdefs.h"
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34 | #include "gdbmerrno.h"
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35 | #include "extern.h"
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36 |
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37 | #if !HAVE_RENAME
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38 |
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39 | /* Rename takes OLD_NAME and renames it as NEW_NAME. If it can not rename
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40 | the file a non-zero value is returned. OLD_NAME is guaranteed to
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41 | remain if it can't be renamed. It assumes NEW_NAME always exists (due
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42 | to being used in gdbm). */
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43 |
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44 | static int
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45 | _gdbm_rename (old_name, new_name)
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46 | char* old_name;
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47 | char* new_name;
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48 | {
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49 | if (unlink (new_name) != 0)
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50 | return -1;
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51 |
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52 | if (link (old_name, new_name) != 0)
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53 | return -1;
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54 |
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55 | unlink (old_name);
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56 | return 0;
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57 |
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58 | }
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59 |
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60 | #define rename _gdbm_rename
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61 | #endif
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62 |
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63 |
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64 |
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65 | /* Reorganize the database. This requires creating a new file and inserting
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66 | all the elements in the old file DBF into the new file. The new file
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67 | is then renamed to the same name as the old file and DBF is updated to
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68 | contain all the correct information about the new file. If an error
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69 | is detected, the return value is negative. The value zero is returned
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70 | after a successful reorganization. */
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71 |
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72 | int
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73 | gdbm_reorganize (dbf)
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74 | gdbm_file_info *dbf;
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75 |
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76 | {
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77 | gdbm_file_info *new_dbf; /* The new file. */
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78 | char *new_name; /* A temporary name. */
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79 | int len; /* Used in new_name construction. */
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80 | datum key, nextkey, data; /* For the sequential sweep. */
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81 | struct stat fileinfo; /* Information about the file. */
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82 | int index; /* Use in moving the bucket cache. */
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83 |
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84 |
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85 | /* Readers can not reorganize! */
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86 | if (dbf->read_write == GDBM_READER)
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87 | {
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88 | gdbm_errno = GDBM_READER_CANT_REORGANIZE;
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89 | return -1;
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90 | }
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91 |
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92 | /* Initialize the gdbm_errno variable. */
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93 | gdbm_errno = GDBM_NO_ERROR;
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94 |
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95 | /* Construct new name for temporary file. */
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96 | len = strlen (dbf->name);
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97 | new_name = (char *) malloc (len + 3);
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98 | if (new_name == NULL)
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99 | {
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100 | gdbm_errno = GDBM_MALLOC_ERROR;
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101 | return -1;
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102 | }
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103 | strcpy (&new_name[0], dbf->name);
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104 | new_name[len+2] = 0;
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105 | new_name[len+1] = '#';
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106 | while ( (len > 0) && new_name[len-1] != '/')
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107 | {
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108 | new_name[len] = new_name[len-1];
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109 | len -= 1;
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110 | }
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111 | new_name[len] = '#';
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112 |
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113 | /* Get the mode for the old file and open the new database. */
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114 | fstat (dbf->desc, &fileinfo);
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115 | new_dbf = gdbm_open (new_name, dbf->header->block_size, GDBM_WRCREAT,
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116 | fileinfo.st_mode, dbf->fatal_err);
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117 |
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118 | if (new_dbf == NULL)
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119 | {
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120 | free (new_name);
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121 | gdbm_errno = GDBM_REORGANIZE_FAILED;
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122 | return -1;
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123 | }
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124 |
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125 |
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126 | /* For each item in the old database, add an entry in the new. */
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127 | key = gdbm_firstkey (dbf);
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128 |
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129 | while (key.dptr != NULL)
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130 | {
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131 | data = gdbm_fetch (dbf, key);
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132 | if (data.dptr != NULL)
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133 | {
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134 | /* Add the data to the new file. */
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135 | if (gdbm_store (new_dbf, key, data, GDBM_INSERT) != 0)
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136 | {
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137 | gdbm_close (new_dbf);
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138 | gdbm_errno = GDBM_REORGANIZE_FAILED;
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139 | unlink (new_name);
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140 | free (new_name);
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141 | return -1;
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142 | }
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143 | }
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144 | else
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145 | {
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146 | /* ERROR! Abort and don't finish reorganize. */
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147 | gdbm_close (new_dbf);
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148 | gdbm_errno = GDBM_REORGANIZE_FAILED;
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149 | unlink (new_name);
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150 | free (new_name);
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151 | return -1;
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152 | }
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153 | nextkey = gdbm_nextkey (dbf, key);
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154 | free (key.dptr);
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155 | free (data.dptr);
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156 | key = nextkey;
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157 | }
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158 |
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159 | /* Write everything. */
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160 | _gdbm_end_update (new_dbf);
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161 | gdbm_sync (new_dbf);
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162 |
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163 |
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164 | /* Move the new file to old name. */
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165 |
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166 | #ifdef MSDOS
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167 | if (close (new_dbf->desc)
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168 | || unlink (dbf->name)
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169 | || rename (new_name, dbf->name)
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170 | || (new_dbf->desc = open (dbf->name, O_RDWR|O_BINARY)) < 0)
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171 | #else /* not MSDOS */
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172 | if (rename (new_name, dbf->name) != 0)
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173 | #endif /* not MSDOS */
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174 | {
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175 | gdbm_errno = GDBM_REORGANIZE_FAILED;
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176 | gdbm_close (new_dbf);
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177 | free (new_name);
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178 | return -1;
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179 | }
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180 |
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181 | /* Fix up DBF to have the correct information for the new file. */
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182 | if (dbf->file_locking)
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183 | {
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184 | #ifdef MSDOS
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185 | if (dbf->need_filelock) {
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186 | UNLOCK_FILE(dbf);
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187 | }
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188 | #else
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189 | UNLOCK_FILE(dbf);
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190 | #endif
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191 | }
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192 | close (dbf->desc);
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193 | free (dbf->header);
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194 | free (dbf->dir);
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195 |
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196 | if (dbf->bucket_cache != NULL) {
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197 | for (index = 0; index < dbf->cache_size; index++) {
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198 | if (dbf->bucket_cache[index].ca_bucket != NULL)
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199 | free (dbf->bucket_cache[index].ca_bucket);
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200 | if (dbf->bucket_cache[index].ca_data.dptr != NULL)
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201 | free (dbf->bucket_cache[index].ca_data.dptr);
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202 | }
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203 | free (dbf->bucket_cache);
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204 | }
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205 |
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206 | dbf->desc = new_dbf->desc;
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207 | dbf->header = new_dbf->header;
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208 | dbf->dir = new_dbf->dir;
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209 | dbf->bucket = new_dbf->bucket;
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210 | dbf->bucket_dir = new_dbf->bucket_dir;
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211 | dbf->last_read = new_dbf->last_read;
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212 | dbf->bucket_cache = new_dbf->bucket_cache;
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213 | dbf->cache_size = new_dbf->cache_size;
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214 | dbf->header_changed = new_dbf->header_changed;
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215 | dbf->directory_changed = new_dbf->directory_changed;
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216 | dbf->bucket_changed = new_dbf->bucket_changed;
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217 | dbf->second_changed = new_dbf->second_changed;
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218 |
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219 | free (new_dbf->name);
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220 | free (new_dbf);
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221 | free (new_name);
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222 |
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223 | /* Make sure the new database is all on disk. */
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224 | fsync (dbf->desc);
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225 |
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226 | /* Force the right stuff for a correct bucket cache. */
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227 | dbf->cache_entry = &dbf->bucket_cache[0];
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228 | _gdbm_get_bucket (dbf, 0);
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229 |
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230 | return 0;
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231 | }
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