miniffs.c 4.2 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. miniffs_seterror(MINIFFS_FILE_NOT_FOUND);
  27. goto free_and_exit;
  28. }
  29. ret->offset = 0;
  30. goto exit;
  31. free_and_exit:
  32. free(ret);
  33. ret = NULL;
  34. exit:
  35. return ret;
  36. }
  37. int miniffs_close(file_t *file)
  38. {
  39. /* Let's poison the struct */
  40. file->private_data = NULL;
  41. file->offset = 0;
  42. file->fent = NULL;
  43. free(file);
  44. }
  45. void *miniffs_map(file_t *file)
  46. {
  47. miniffs_t *fs = (miniffs_t *)file->private_data;
  48. return miniffs_getfileaddr(fs, file->fent);
  49. }
  50. uint8_t miniffs_read(file_t *file)
  51. {
  52. miniffs_t *fs = (miniffs_t *) file->private_data;
  53. uint8_t *filePtr = miniffs_getfileaddr(fs, file->fent);
  54. uint8_t ret = filePtr[file->offset];
  55. file->offset++;
  56. if (file->offset >= file->fent->size)
  57. {
  58. miniffs_seterror(MINIFFS_END_OF_FILE);
  59. file->offset = file->fent->size - 1;
  60. }
  61. return ret;
  62. }
  63. int miniffs_read_blocks(void *ptr, size_t size, size_t nmemb, file_t *file)
  64. {
  65. int i;
  66. miniffs_t *fs = (miniffs_t *) file->private_data;
  67. uint8_t *filePtr = miniffs_getfileaddr(fs, file->fent);
  68. size_t fileOffset = file->offset;
  69. size_t bufferOffset = 0;
  70. int blockCount = 0;
  71. for(i = 0; i < nmemb; i++)
  72. {
  73. if (file->fent->size > (fileOffset + size))
  74. {
  75. memcpy(ptr + bufferOffset, &filePtr[fileOffset], size);
  76. bufferOffset += size;
  77. fileOffset += size;
  78. blockCount++;
  79. }
  80. }
  81. file->offset = fileOffset;
  82. return blockCount;
  83. }
  84. int miniffs_seek(file_t *file, size_t offset, int whence)
  85. {
  86. switch(whence)
  87. {
  88. default:
  89. miniffs_seterror(MINIFFS_INVALID_PARAMS);
  90. return -1;
  91. case MFFS_SEEK_SET:
  92. file->offset = offset;
  93. break;
  94. case MFFS_SEEK_CUR:
  95. file->offset += offset;
  96. break;
  97. case MFFS_SEEK_END:
  98. file->offset = file->fent->size - offset;
  99. break;
  100. }
  101. }
  102. size_t miniffs_tell(file_t *file)
  103. {
  104. return file->offset;
  105. }
  106. miniffs_error_t miniffs_geterror()
  107. {
  108. return last_error;
  109. }
  110. /* Private API */
  111. bool miniffs_isvalidfs(miniffs_t *fs)
  112. {
  113. return (fs->header->magic == MINIFFS_MAGIC) &&
  114. (fs->header->fs_version_major == MINIFFS_VERSION_MAJOR) &&
  115. (fs->header->fs_version_minor == MINIFFS_VERSION_MINOR) &&
  116. (fs->header->fs_filename_len == MINIFFS_FILENAME_LENGTH) &&
  117. (fs->header->fs_extention_len == MINIFFS_EXTENSION_LENGTH);
  118. }
  119. static void make_fullname(char *name, char *ext, char *out)
  120. {
  121. uint8_t nameLen = strnlen(name, MINIFFS_FILENAME_LENGTH);
  122. uint8_t extLen = strnlen(ext, MINIFFS_EXTENSION_LENGTH);
  123. memcpy(out, name, nameLen);
  124. memcpy(out + nameLen, ".", 1);
  125. memcpy(out + nameLen + 1, ext, extLen);
  126. }
  127. fileentry_t *miniffs_findfile(miniffs_t *fs, const char *filename)
  128. {
  129. int i;
  130. char entryFullName[MINIFFS_FULLNAME_LENGTH];
  131. uint8_t filenameLength = strlen(filename);
  132. fileentry_t *ret = NULL;
  133. if (filenameLength > MINIFFS_FULLNAME_LENGTH)
  134. {
  135. miniffs_seterror(MINIFFS_INVALID_NAME);
  136. goto exit;
  137. }
  138. for(i = 0; i < fs->header->entry_count; i++)
  139. {
  140. fileentry_t *cur = &fs->header->fent[i];
  141. make_fullname(cur->name, cur->ext, entryFullName);
  142. if (memcmp(filename, entryFullName, filenameLength) == 0)
  143. {
  144. /* File found! */
  145. ret = cur;
  146. break;
  147. }
  148. }
  149. exit:
  150. return ret;
  151. }
  152. void miniffs_seterror(miniffs_error_t err)
  153. {
  154. last_error = err;
  155. }