miniffs.c 5.2 KB

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  1. /******************************************************************************
  2. * MiniFFS : Mini Flat File System
  3. * miniffs.c: Shared code for all platforms.
  4. *
  5. * Copyright (c) 2008-2022 986-Studio. All rights reserved.
  6. *
  7. ******************************************************************************/
  8. #include <stdlib.h>
  9. #include <string.h>
  10. #define __miniffs_internal
  11. #include <miniffs.h>
  12. static miniffs_error_t last_error = MINIFFS_NOERROR;
  13. /* Public API */
  14. file_t *miniffs_open(miniffs_t *fs, const char *filename)
  15. {
  16. file_t *ret = (file_t *)calloc(1, sizeof(file_t));
  17. if (ret == NULL)
  18. {
  19. miniffs_seterror(MINIFFS_ALLOCATION_ERROR);
  20. goto exit;
  21. }
  22. ret->private_data = fs;
  23. ret->fent = miniffs_findfile(fs, filename);
  24. if (!ret->fent)
  25. {
  26. if (miniffs_geterror() != MINIFFS_INVALID_NAME)
  27. {
  28. miniffs_seterror(MINIFFS_FILE_NOT_FOUND);
  29. }
  30. goto free_and_exit;
  31. }
  32. ret->offset = 0;
  33. miniffs_seterror(MINIFFS_NOERROR);
  34. goto exit;
  35. free_and_exit:
  36. free(ret);
  37. ret = NULL;
  38. exit:
  39. return ret;
  40. }
  41. int miniffs_close(file_t *file)
  42. {
  43. /* Let's poison the struct */
  44. file->private_data = NULL;
  45. file->offset = 0;
  46. file->fent = NULL;
  47. free(file);
  48. miniffs_seterror(MINIFFS_NOERROR);
  49. }
  50. void *miniffs_map(file_t *file)
  51. {
  52. miniffs_t *fs = (miniffs_t *)file->private_data;
  53. miniffs_seterror(MINIFFS_NOERROR);
  54. return miniffs_getfileaddr(fs, file->fent);
  55. }
  56. uint8_t miniffs_read(file_t *file)
  57. {
  58. miniffs_t *fs = (miniffs_t *) file->private_data;
  59. uint8_t *filePtr = miniffs_getfileaddr(fs, file->fent);
  60. uint8_t ret = filePtr[file->offset];
  61. file->offset++;
  62. if (file->offset >= file->fent->size)
  63. {
  64. miniffs_seterror(MINIFFS_END_OF_FILE);
  65. file->offset = file->fent->size - 1;
  66. }
  67. else
  68. {
  69. miniffs_seterror(MINIFFS_NOERROR);
  70. }
  71. return ret;
  72. }
  73. int miniffs_read_blocks(void *ptr, size_t size, size_t nmemb, file_t *file)
  74. {
  75. int i;
  76. miniffs_t *fs = (miniffs_t *) file->private_data;
  77. uint8_t *filePtr = miniffs_getfileaddr(fs, file->fent);
  78. size_t fileOffset = file->offset;
  79. size_t bufferOffset = 0;
  80. int blockCount = 0;
  81. for(i = 0; i < nmemb; i++)
  82. {
  83. if (file->fent->size >= (fileOffset + size))
  84. {
  85. memcpy(ptr + bufferOffset, &filePtr[fileOffset], size);
  86. bufferOffset += size;
  87. fileOffset += size;
  88. blockCount++;
  89. }
  90. }
  91. file->offset = fileOffset;
  92. miniffs_seterror(MINIFFS_NOERROR);
  93. return blockCount;
  94. }
  95. int miniffs_seek(file_t *file, size_t offset, int whence)
  96. {
  97. bool noError = true;
  98. switch(whence) {
  99. default:
  100. miniffs_seterror(MINIFFS_INVALID_PARAMS);
  101. return -1;
  102. case MFFS_SEEK_SET:
  103. file->offset = offset;
  104. break;
  105. case MFFS_SEEK_CUR:
  106. file->offset += offset;
  107. break;
  108. case MFFS_SEEK_END:
  109. if (file->fent->size <= offset)
  110. {
  111. /* Negative boundary check */
  112. noError = false;
  113. miniffs_seterror(MINIFFS_SEEK_OUT_OF_BOUNDARIES);
  114. file->offset = 0;
  115. }
  116. else
  117. {
  118. file->offset = file->fent->size - 1 - offset;
  119. }
  120. break;
  121. }
  122. if (file->offset >= file->fent->size)
  123. {
  124. /* Positive Boundary check */
  125. noError = false;
  126. miniffs_seterror(MINIFFS_SEEK_OUT_OF_BOUNDARIES);
  127. file->offset = file->fent->size - 1;
  128. }
  129. if (noError)
  130. {
  131. miniffs_seterror(MINIFFS_NOERROR);
  132. }
  133. }
  134. size_t miniffs_tell(file_t *file)
  135. {
  136. miniffs_seterror(MINIFFS_NOERROR);
  137. return file->offset;
  138. }
  139. miniffs_error_t miniffs_geterror()
  140. {
  141. return last_error;
  142. }
  143. /* Private API */
  144. bool miniffs_isvalidfs(miniffs_t *fs)
  145. {
  146. return (fs->header->magic == MINIFFS_MAGIC) &&
  147. (fs->header->fs_version_major == MINIFFS_VERSION_MAJOR) &&
  148. (fs->header->fs_version_minor == MINIFFS_VERSION_MINOR) &&
  149. (fs->header->fs_filename_len == MINIFFS_FILENAME_LENGTH) &&
  150. (fs->header->fs_extention_len == MINIFFS_EXTENSION_LENGTH);
  151. }
  152. static void make_fullname(char *name, char *ext, char *out)
  153. {
  154. uint8_t nameLen = strnlen(name, MINIFFS_FILENAME_LENGTH);
  155. uint8_t extLen = strnlen(ext, MINIFFS_EXTENSION_LENGTH);
  156. memcpy(out, name, nameLen);
  157. memcpy(out + nameLen, ".", 1);
  158. memcpy(out + nameLen + 1, ext, extLen);
  159. }
  160. fileentry_t *miniffs_findfile(miniffs_t *fs, const char *filename)
  161. {
  162. int i;
  163. char entryFullName[MINIFFS_FULLNAME_LENGTH];
  164. uint8_t filenameLength = strlen(filename);
  165. fileentry_t *ret = NULL;
  166. if (filenameLength > MINIFFS_FULLNAME_LENGTH)
  167. {
  168. miniffs_seterror(MINIFFS_INVALID_NAME);
  169. goto exit;
  170. }
  171. for(i = 0; i < fs->header->entry_count; i++)
  172. {
  173. fileentry_t *cur = &fs->header->fent[i];
  174. make_fullname(cur->name, cur->ext, entryFullName);
  175. if (memcmp(filename, entryFullName, filenameLength) == 0)
  176. {
  177. /* File found! */
  178. ret = cur;
  179. break;
  180. }
  181. }
  182. exit:
  183. return ret;
  184. }
  185. void miniffs_seterror(miniffs_error_t err)
  186. {
  187. last_error = err;
  188. }