1/*
2******************************************************************************
3*
4*   Copyright (C) 1999-2011, International Business Machines
5*   Corporation and others.  All Rights Reserved.
6*
7******************************************************************************/
8
9
10/*----------------------------------------------------------------------------------
11 *
12 *  UDataMemory     A class-like struct that serves as a handle to a piece of memory
13 *                  that contains some ICU data (resource, converters, whatever.)
14 *
15 *                  When an application opens ICU data (with udata_open, for example,
16 *                  a UDataMemory * is returned.
17 *
18 *----------------------------------------------------------------------------------*/
19
20#include "unicode/utypes.h"
21#include "cmemory.h"
22#include "unicode/udata.h"
23
24#include "udatamem.h"
25
26U_CFUNC void UDataMemory_init(UDataMemory *This) {
27    uprv_memset(This, 0, sizeof(UDataMemory));
28    This->length=-1;
29}
30
31
32U_CFUNC void UDatamemory_assign(UDataMemory *dest, UDataMemory *source) {
33    /* UDataMemory Assignment.  Destination UDataMemory must be initialized first.  */
34    UBool mallocedFlag = dest->heapAllocated;
35    uprv_memcpy(dest, source, sizeof(UDataMemory));
36    dest->heapAllocated = mallocedFlag;
37}
38
39U_CFUNC UDataMemory *UDataMemory_createNewInstance(UErrorCode *pErr) {
40    UDataMemory *This;
41
42    if (U_FAILURE(*pErr)) {
43        return NULL;
44    }
45    This = uprv_malloc(sizeof(UDataMemory));
46    if (This == NULL) {
47        *pErr = U_MEMORY_ALLOCATION_ERROR; }
48    else {
49        UDataMemory_init(This);
50        This->heapAllocated = TRUE;
51    }
52    return This;
53}
54
55
56U_CFUNC const DataHeader *
57UDataMemory_normalizeDataPointer(const void *p) {
58    /* allow the data to be optionally prepended with an alignment-forcing double value */
59    const DataHeader *pdh = (const DataHeader *)p;
60    if(pdh==NULL || (pdh->dataHeader.magic1==0xda && pdh->dataHeader.magic2==0x27)) {
61        return pdh;
62    } else {
63#if U_PLATFORM == U_PF_OS400
64        /*
65        TODO: Fix this once the compiler implements this feature. Keep in sync with genccode.c
66
67        This is here because this platform can't currently put
68        const data into the read-only pages of an object or
69        shared library (service program). Only strings are allowed in read-only
70        pages, so we use char * strings to store the data.
71
72        In order to prevent the beginning of the data from ever matching the
73        magic numbers we must skip the initial double.
74        [grhoten 4/24/2003]
75        */
76        return (const DataHeader *)*((const void **)p+1);
77#else
78        return (const DataHeader *)((const double *)p+1);
79#endif
80    }
81}
82
83
84U_CFUNC void UDataMemory_setData (UDataMemory *This, const void *dataAddr) {
85    This->pHeader = UDataMemory_normalizeDataPointer(dataAddr);
86}
87
88
89U_CAPI void U_EXPORT2
90udata_close(UDataMemory *pData) {
91    if(pData!=NULL) {
92        uprv_unmapFile(pData);
93        if(pData->heapAllocated ) {
94            uprv_free(pData);
95        } else {
96            UDataMemory_init(pData);
97        }
98    }
99}
100
101U_CAPI const void * U_EXPORT2
102udata_getMemory(UDataMemory *pData) {
103    if(pData!=NULL && pData->pHeader!=NULL) {
104        return (char *)(pData->pHeader)+udata_getHeaderSize(pData->pHeader);
105    } else {
106        return NULL;
107    }
108}
109
110/**
111 * Get the length of the data item if possible.
112 * The length may be up to 15 bytes larger than the actual data.
113 *
114 * TODO Consider making this function public.
115 * It would have to return the actual length in more cases.
116 * For example, the length of the last item in a .dat package could be
117 * computed from the size of the whole .dat package minus the offset of the
118 * last item.
119 * The size of a file that was directly memory-mapped could be determined
120 * using some system API.
121 *
122 * In order to get perfect values for all data items, we may have to add a
123 * length field to UDataInfo, but that complicates data generation
124 * and may be overkill.
125 *
126 * @param pData The data item.
127 * @return the length of the data item, or -1 if not known
128 * @internal Currently used only in cintltst/udatatst.c
129 */
130U_CAPI int32_t U_EXPORT2
131udata_getLength(const UDataMemory *pData) {
132    if(pData!=NULL && pData->pHeader!=NULL && pData->length>=0) {
133        /*
134         * subtract the header size,
135         * return only the size of the actual data starting at udata_getMemory()
136         */
137        return pData->length-udata_getHeaderSize(pData->pHeader);
138    } else {
139        return -1;
140    }
141}
142
143/**
144 * Get the memory including the data header.
145 * Used in cintltst/udatatst.c
146 * @internal
147 */
148U_CAPI const void * U_EXPORT2
149udata_getRawMemory(const UDataMemory *pData) {
150    if(pData!=NULL && pData->pHeader!=NULL) {
151        return pData->pHeader;
152    } else {
153        return NULL;
154    }
155}
156
157U_CFUNC UBool UDataMemory_isLoaded(const UDataMemory *This) {
158    return This->pHeader != NULL;
159}
160