hb-blob.h 4.6 KB

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  1. /*
  2. * Copyright © 2009 Red Hat, Inc.
  3. *
  4. * This is part of HarfBuzz, a text shaping library.
  5. *
  6. * Permission is hereby granted, without written agreement and without
  7. * license or royalty fees, to use, copy, modify, and distribute this
  8. * software and its documentation for any purpose, provided that the
  9. * above copyright notice and the following two paragraphs appear in
  10. * all copies of this software.
  11. *
  12. * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  13. * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  14. * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  15. * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  16. * DAMAGE.
  17. *
  18. * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  19. * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  20. * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
  21. * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  22. * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  23. *
  24. * Red Hat Author(s): Behdad Esfahbod
  25. */
  26. #if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
  27. #error "Include <hb.h> instead."
  28. #endif
  29. #ifndef HB_BLOB_H
  30. #define HB_BLOB_H
  31. #include "hb-common.h"
  32. HB_BEGIN_DECLS
  33. /**
  34. * hb_memory_mode_t:
  35. * @HB_MEMORY_MODE_DUPLICATE: HarfBuzz immediately makes a copy of the data.
  36. * @HB_MEMORY_MODE_READONLY: HarfBuzz client will never modify the data,
  37. * and HarfBuzz will never modify the data.
  38. * @HB_MEMORY_MODE_WRITABLE: HarfBuzz client made a copy of the data solely
  39. * for HarfBuzz, so HarfBuzz may modify the data.
  40. * @HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE: See above
  41. *
  42. * Data type holding the memory modes available to
  43. * client programs.
  44. *
  45. * Regarding these various memory-modes:
  46. *
  47. * - In no case shall the HarfBuzz client modify memory
  48. * that is passed to HarfBuzz in a blob. If there is
  49. * any such possibility, @HB_MEMORY_MODE_DUPLICATE should be used
  50. * such that HarfBuzz makes a copy immediately,
  51. *
  52. * - Use @HB_MEMORY_MODE_READONLY otherwise, unless you really really
  53. * really know what you are doing,
  54. *
  55. * - @HB_MEMORY_MODE_WRITABLE is appropriate if you really made a
  56. * copy of data solely for the purpose of passing to
  57. * HarfBuzz and doing that just once (no reuse!),
  58. *
  59. * - If the font is mmap()ed, it's okay to use
  60. * @HB_MEMORY_READONLY_MAY_MAKE_WRITABLE, however, using that mode
  61. * correctly is very tricky. Use @HB_MEMORY_MODE_READONLY instead.
  62. **/
  63. typedef enum {
  64. HB_MEMORY_MODE_DUPLICATE,
  65. HB_MEMORY_MODE_READONLY,
  66. HB_MEMORY_MODE_WRITABLE,
  67. HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE
  68. } hb_memory_mode_t;
  69. /**
  70. * hb_blob_t:
  71. *
  72. * Data type for blobs. A blob wraps a chunk of binary
  73. * data and facilitates its lifecycle management between
  74. * a client program and HarfBuzz.
  75. *
  76. **/
  77. typedef struct hb_blob_t hb_blob_t;
  78. HB_EXTERN hb_blob_t *
  79. hb_blob_create (const char *data,
  80. unsigned int length,
  81. hb_memory_mode_t mode,
  82. void *user_data,
  83. hb_destroy_func_t destroy);
  84. HB_EXTERN hb_blob_t *
  85. hb_blob_create_or_fail (const char *data,
  86. unsigned int length,
  87. hb_memory_mode_t mode,
  88. void *user_data,
  89. hb_destroy_func_t destroy);
  90. HB_EXTERN hb_blob_t *
  91. hb_blob_create_from_file (const char *file_name);
  92. HB_EXTERN hb_blob_t *
  93. hb_blob_create_from_file_or_fail (const char *file_name);
  94. /* Always creates with MEMORY_MODE_READONLY.
  95. * Even if the parent blob is writable, we don't
  96. * want the user of the sub-blob to be able to
  97. * modify the parent data as that data may be
  98. * shared among multiple sub-blobs.
  99. */
  100. HB_EXTERN hb_blob_t *
  101. hb_blob_create_sub_blob (hb_blob_t *parent,
  102. unsigned int offset,
  103. unsigned int length);
  104. HB_EXTERN hb_blob_t *
  105. hb_blob_copy_writable_or_fail (hb_blob_t *blob);
  106. HB_EXTERN hb_blob_t *
  107. hb_blob_get_empty (void);
  108. HB_EXTERN hb_blob_t *
  109. hb_blob_reference (hb_blob_t *blob);
  110. HB_EXTERN void
  111. hb_blob_destroy (hb_blob_t *blob);
  112. HB_EXTERN hb_bool_t
  113. hb_blob_set_user_data (hb_blob_t *blob,
  114. hb_user_data_key_t *key,
  115. void * data,
  116. hb_destroy_func_t destroy,
  117. hb_bool_t replace);
  118. HB_EXTERN void *
  119. hb_blob_get_user_data (const hb_blob_t *blob,
  120. hb_user_data_key_t *key);
  121. HB_EXTERN void
  122. hb_blob_make_immutable (hb_blob_t *blob);
  123. HB_EXTERN hb_bool_t
  124. hb_blob_is_immutable (hb_blob_t *blob);
  125. HB_EXTERN unsigned int
  126. hb_blob_get_length (hb_blob_t *blob);
  127. HB_EXTERN const char *
  128. hb_blob_get_data (hb_blob_t *blob, unsigned int *length);
  129. HB_EXTERN char *
  130. hb_blob_get_data_writable (hb_blob_t *blob, unsigned int *length);
  131. HB_END_DECLS
  132. #endif /* HB_BLOB_H */