icuSources/common/ucmndata.h

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4 ******************************************************************************
   5 *
   6 *   Copyright (C) 1999-2011, International Business Machines
   7 *   Corporation and others.  All Rights Reserved.
   8 *
   9 ******************************************************************************/
  10
  11
  12 /*----------------------------------------------------------------------------------
  13  *
  14  *   UCommonData   An abstract interface for dealing with ICU Common Data Files.
  15  *                 ICU Common Data Files are a grouping of a number of individual
  16  *                 data items (resources, converters, tables, anything) into a
  17  *                 single file or dll.  The combined format includes a table of
  18  *                 contents for locating the individual items by name.
  19  *
  20  *                 Two formats for the table of contents are supported, which is
  21  *                 why there is an abstract inteface involved.
  22  *
  23  *                 These functions are part of the ICU internal implementation, and
  24  *                 are not inteded to be used directly by applications.
  25  */
  26
  27 #ifndef __UCMNDATA_H__
  28 #define __UCMNDATA_H__
  29
  30 #include "unicode/udata.h"
  31 #include "umapfile.h"
  32
  33
  34 #define COMMON_DATA_NAME U_ICUDATA_NAME
  35
  36 typedef struct  {
  37     uint16_t    headerSize;
  38     uint8_t     magic1;
  39     uint8_t     magic2;
  40 } MappedData;
  41
  42
  43 typedef struct  {
  44     MappedData  dataHeader;
  45     UDataInfo   info;
  46 } DataHeader;
  47
  48 typedef struct {
  49     uint32_t nameOffset;
  50     uint32_t dataOffset;
  51 } UDataOffsetTOCEntry;
  52
  53 typedef struct {
  54     uint32_t count;
  55     /**
  56      * Variable-length array declared with length 1 to disable bounds checkers.
  57      * The actual array length is in the count field.
  58      */
  59     UDataOffsetTOCEntry entry[1];
  60 } UDataOffsetTOC;
  61
  62 /**
  63  * Get the header size from a const DataHeader *udh.
  64  * Handles opposite-endian data.
  65  *
  66  * @internal
  67  */
  68 U_CFUNC uint16_t
  69 udata_getHeaderSize(const DataHeader *udh);
  70
  71 /**
  72  * Get the UDataInfo.size from a const UDataInfo *info.
  73  * Handles opposite-endian data.
  74  *
  75  * @internal
  76  */
  77 U_CFUNC uint16_t
  78 udata_getInfoSize(const UDataInfo *info);
  79
  80 U_CDECL_BEGIN
  81 /*
  82  *  "Virtual" functions for data lookup.
  83  *  To call one, given a UDataMemory *p, the code looks like this:
  84  *     p->vFuncs.Lookup(p, tocEntryName, pErrorCode);
  85  *          (I sure do wish this was written in C++, not C)
  86  */
  87
  88 typedef const DataHeader *
  89 (U_CALLCONV * LookupFn)(const UDataMemory *pData,
  90                         const char *tocEntryName,
  91                         int32_t *pLength,
  92                         UErrorCode *pErrorCode);
  93
  94 typedef uint32_t
  95 (U_CALLCONV * NumEntriesFn)(const UDataMemory *pData);
  96
  97 U_CDECL_END
  98
  99 typedef struct {
 100     LookupFn      Lookup;
 101     NumEntriesFn  NumEntries;
 102 } commonDataFuncs;
 103
 104
 105 /*
 106  *  Functions to check whether a UDataMemory refers to memory containing
 107  *     a recognizable header and table of contents a Common Data Format
 108  *
 109  *     If a valid header and TOC are found,
 110  *         set the CommonDataFuncs function dispatch vector in the UDataMemory
 111  *             to point to the right functions for the TOC type.
 112  *     otherwise
 113  *         set an errorcode.
 114  */
 115 U_CFUNC void udata_checkCommonData(UDataMemory *pData, UErrorCode *pErrorCode);
 116
 117 #endif