Check in the pristine copy of ICU 4.6...

icu46/source/common/udatamem.c

+/*
+******************************************************************************
+*
+*   Copyright (C) 1999-2010, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+******************************************************************************/
+
+
+/*----------------------------------------------------------------------------------
+ *
+ *  UDataMemory     A class-like struct that serves as a handle to a piece of memory
+ *                  that contains some ICU data (resource, converters, whatever.)
+ *
+ *                  When an application opens ICU data (with udata_open, for example,
+ *                  a UDataMemory * is returned.
+ *
+ *----------------------------------------------------------------------------------*/
+
+#include "unicode/utypes.h"
+#include "cmemory.h"
+#include "unicode/udata.h"
+
+#include "udatamem.h"
+
+U_CFUNC void UDataMemory_init(UDataMemory *This) {
+    uprv_memset(This, 0, sizeof(UDataMemory));
+    This->length=-1;
+}
+
+
+U_CFUNC void UDatamemory_assign(UDataMemory *dest, UDataMemory *source) {
+    /* UDataMemory Assignment.  Destination UDataMemory must be initialized first.  */
+    UBool mallocedFlag = dest->heapAllocated;
+    uprv_memcpy(dest, source, sizeof(UDataMemory));
+    dest->heapAllocated = mallocedFlag;
+}
+
+U_CFUNC UDataMemory *UDataMemory_createNewInstance(UErrorCode *pErr) {
+    UDataMemory *This;
+
+    if (U_FAILURE(*pErr)) {
+        return NULL;
+    }
+    This = uprv_malloc(sizeof(UDataMemory));
+    if (This == NULL) {
+        *pErr = U_MEMORY_ALLOCATION_ERROR; }
+    else {
+        UDataMemory_init(This);
+        This->heapAllocated = TRUE;
+    }
+    return This;
+}
+
+
+U_CFUNC const DataHeader *
+UDataMemory_normalizeDataPointer(const void *p) {
+    /* allow the data to be optionally prepended with an alignment-forcing double value */
+    const DataHeader *pdh = (const DataHeader *)p;
+    if(pdh==NULL || (pdh->dataHeader.magic1==0xda && pdh->dataHeader.magic2==0x27)) {
+        return pdh;
+    } else {
+#ifdef OS400
+        /*
+        TODO: Fix this once the compiler implements this feature. Keep in sync with genccode.c
+
+        This is here because this platform can't currently put
+        const data into the read-only pages of an object or
+        shared library (service program). Only strings are allowed in read-only
+        pages, so we use char * strings to store the data.
+
+        In order to prevent the beginning of the data from ever matching the
+        magic numbers we must skip the initial double.
+        [grhoten 4/24/2003]
+        */
+        return (const DataHeader *)*((const void **)p+1);
+#else
+        return (const DataHeader *)((const double *)p+1);
+#endif
+    }
+}
+
+
+U_CFUNC void UDataMemory_setData (UDataMemory *This, const void *dataAddr) {
+    This->pHeader = UDataMemory_normalizeDataPointer(dataAddr);
+}
+
+
+U_CAPI void U_EXPORT2
+udata_close(UDataMemory *pData) {
+    if(pData!=NULL) {
+        uprv_unmapFile(pData);
+        if(pData->heapAllocated ) {
+            uprv_free(pData);
+        } else {
+            UDataMemory_init(pData);
+        }
+    }
+}
+
+U_CAPI const void * U_EXPORT2
+udata_getMemory(UDataMemory *pData) {
+    if(pData!=NULL && pData->pHeader!=NULL) {
+        return (char *)(pData->pHeader)+udata_getHeaderSize(pData->pHeader);
+    } else {
+        return NULL;
+    }
+}
+
+/**
+ * Get the length of the data item if possible.
+ * The length may be up to 15 bytes larger than the actual data.
+ *
+ * TODO Consider making this function public.
+ * It would have to return the actual length in more cases.
+ * For example, the length of the last item in a .dat package could be
+ * computed from the size of the whole .dat package minus the offset of the
+ * last item.
+ * The size of a file that was directly memory-mapped could be determined
+ * using some system API.
+ *
+ * In order to get perfect values for all data items, we may have to add a
+ * length field to UDataInfo, but that complicates data generation
+ * and may be overkill.
+ *
+ * @param pData The data item.
+ * @return the length of the data item, or -1 if not known
+ * @internal Currently used only in cintltst/udatatst.c
+ */
+U_CAPI int32_t U_EXPORT2
+udata_getLength(const UDataMemory *pData) {
+    if(pData!=NULL && pData->pHeader!=NULL && pData->length>=0) {
+        /*
+         * subtract the header size,
+         * return only the size of the actual data starting at udata_getMemory()
+         */
+        return pData->length-udata_getHeaderSize(pData->pHeader);
+    } else {
+        return -1;
+    }
+}
+
+/**
+ * Get the memory including the data header.
+ * Used in cintltst/udatatst.c
+ * @internal
+ */
+U_CAPI const void * U_EXPORT2
+udata_getRawMemory(const UDataMemory *pData) {
+    if(pData!=NULL && pData->pHeader!=NULL) {
+        return pData->pHeader;
+    } else {
+        return NULL;
+    }
+}
+
+U_CFUNC UBool UDataMemory_isLoaded(const UDataMemory *This) {
+    return This->pHeader != NULL;
+}