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1 /*
2 ******************************************************************************
3 *
4 *   Copyright (C) 1999-2003, International Business Machines
5 *   Corporation and others.  All Rights Reserved.
6 *
7 ******************************************************************************/
8 
9 
10 /*----------------------------------------------------------------------------------
11  *
12  *   UCommonData   An abstract interface for dealing with ICU Common Data Files.
13  *                 ICU Common Data Files are a grouping of a number of individual
14  *                 data items (resources, converters, tables, anything) into a
15  *                 single file or dll.  The combined format includes a table of
16  *                 contents for locating the individual items by name.
17  *
18  *                 Two formats for the table of contents are supported, which is
19  *                 why there is an abstract inteface involved.
20  *
21  *                 These functions are part of the ICU internal implementation, and
22  *                 are not inteded to be used directly by applications.
23  */
24 
25 #ifndef __UCMNDATA_H__
26 #define __UCMNDATA_H__
27 
28 #include "unicode/udata.h"
29 #include "umapfile.h"
30 
31 
32 #define COMMON_DATA_NAME U_ICUDATA_NAME
33 
34 typedef struct  {
35     uint16_t    headerSize;
36     uint8_t     magic1;
37     uint8_t     magic2;
38 } MappedData;
39 
40 
41 typedef struct  {
42     MappedData  dataHeader;
43     UDataInfo   info;
44 } DataHeader;
45 
46 typedef struct {
47     uint32_t nameOffset;
48     uint32_t dataOffset;
49 } UDataOffsetTOCEntry;
50 
51 typedef struct {
52     uint32_t count;
53     UDataOffsetTOCEntry entry[2];    /* Actual size of array is from count. */
54 } UDataOffsetTOC;
55 
56 /**
57  * Get the header size from a const DataHeader *udh.
58  * Handles opposite-endian data.
59  *
60  * @internal
61  */
62 U_CFUNC uint16_t
63 udata_getHeaderSize(const DataHeader *udh);
64 
65 /**
66  * Get the UDataInfo.size from a const UDataInfo *info.
67  * Handles opposite-endian data.
68  *
69  * @internal
70  */
71 U_CFUNC uint16_t
72 udata_getInfoSize(const UDataInfo *info);
73 
74 /*
75  *  "Virtual" functions for data lookup.
76  *  To call one, given a UDataMemory *p, the code looks like this:
77  *     p->vFuncs.Lookup(p, tocEntryName, pErrorCode);
78  *          (I sure do wish this was written in C++, not C)
79  */
80 
81 typedef const DataHeader *
82 (* LookupFn)(const UDataMemory *pData,
83              const char *tocEntryName,
84              int32_t *pLength,
85              UErrorCode *pErrorCode);
86 
87 typedef uint32_t
88 (* NumEntriesFn)(const UDataMemory *pData);
89 
90 typedef struct {
91     LookupFn      Lookup;
92     NumEntriesFn  NumEntries;
93 } commonDataFuncs;
94 
95 
96 /*
97  *  Functions to check whether a UDataMemory refers to memory containing
98  *     a recognizable header and table of contents a Common Data Format
99  *
100  *     If a valid header and TOC are found,
101  *         set the CommonDataFuncs function dispatch vector in the UDataMemory
102  *             to point to the right functions for the TOC type.
103  *     otherwise
104  *         set an errorcode.
105  */
106 void   udata_checkCommonData(UDataMemory *pData, UErrorCode *pErrorCode);
107 
108 
109 #endif
110