chromium/third_party/icu/source/common/ucmndata.cpp

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
******************************************************************************
*
*   Copyright (C) 1999-2011, International Business Machines
*   Corporation and others.  All Rights Reserved.
*
******************************************************************************/


/*------------------------------------------------------------------------------
 *
 *   UCommonData   An abstract interface for dealing with ICU Common Data Files.
 *                 ICU Common Data Files are a grouping of a number of individual
 *                 data items (resources, converters, tables, anything) into a
 *                 single file or dll.  The combined format includes a table of
 *                 contents for locating the individual items by name.
 *
 *                 Two formats for the table of contents are supported, which is
 *                 why there is an abstract interface involved.
 *
 */

#include "unicode/utypes.h"
#include "unicode/udata.h"
#include "cstring.h"
#include "ucmndata.h"
#include "udatamem.h"

#if defined(UDATA_DEBUG) || defined(UDATA_DEBUG_DUMP)
#   include <stdio.h>
#endif

U_CFUNC uint16_t
udata_getHeaderSize(const DataHeader *udh) { … }

U_CFUNC uint16_t
udata_getInfoSize(const UDataInfo *info) { … }

/*-----------------------------------------------------------------------------*
 *                                                                             *
 *  Pointer TOCs.   TODO: This form of table-of-contents should be removed     *
 *                  because DLLs must be relocated on loading to correct the   *
 *                  pointer values and this operation makes shared memory      *
 *                  mapping of the data much less likely to work.              *
 *                                                                             *
 *-----------------------------------------------------------------------------*/
PointerTOCEntry;


PointerTOC;


/* definition of OffsetTOC struct types moved to ucmndata.h */

/*-----------------------------------------------------------------------------*
 *                                                                             *
 *    entry point lookup implementations                                       *
 *                                                                             *
 *-----------------------------------------------------------------------------*/

#ifndef MIN
#define MIN(a,b) …
#endif

/**
 * Compare strings where we know the shared prefix length,
 * and advance the prefix length as we find that the strings share even more characters.
 */
static int32_t
strcmpAfterPrefix(const char *s1, const char *s2, int32_t *pPrefixLength) { … }

static int32_t
offsetTOCPrefixBinarySearch(const char *s, const char *names,
                            const UDataOffsetTOCEntry *toc, int32_t count) { … }

static int32_t
pointerTOCPrefixBinarySearch(const char *s, const PointerTOCEntry *toc, int32_t count) { … }

U_CDECL_BEGIN
static uint32_t U_CALLCONV
offsetTOCEntryCount(const UDataMemory *pData) { … }

static const DataHeader * U_CALLCONV
offsetTOCLookupFn(const UDataMemory *pData,
                  const char *tocEntryName,
                  int32_t *pLength,
                  UErrorCode *pErrorCode) { … }


static uint32_t U_CALLCONV pointerTOCEntryCount(const UDataMemory *pData) { … }

static const DataHeader * U_CALLCONV pointerTOCLookupFn(const UDataMemory *pData,
                   const char *name,
                   int32_t *pLength,
                   UErrorCode *pErrorCode) { … }
U_CDECL_END


static const commonDataFuncs CmnDFuncs = …;
static const commonDataFuncs ToCPFuncs = …;



/*----------------------------------------------------------------------*
 *                                                                      *
 *  checkCommonData   Validate the format of a common data file.        *
 *                    Fill in the virtual function ptr based on TOC type *
 *                    If the data is invalid, close the UDataMemory     *
 *                    and set the appropriate error code.               *
 *                                                                      *
 *----------------------------------------------------------------------*/
U_CFUNC void udata_checkCommonData(UDataMemory *udm, UErrorCode *err) { … }

/*
 * TODO: Add a udata_swapPackageHeader() function that swaps an ICU .dat package
 * header but not its sub-items.
 * This function will be needed for automatic runtime swapping.
 * Sub-items should not be swapped to limit the swapping to the parts of the
 * package that are actually used.
 *
 * Since lengths of items are implicit in the order and offsets of their
 * ToC entries, and since offsets are relative to the start of the ToC,
 * a swapped version may need to generate a different data structure
 * with pointers to the original data items and with their lengths
 * (-1 for the last one if it is not known), and maybe even pointers to the
 * swapped versions of the items.
 * These pointers to swapped versions would establish a cache;
 * instead, each open data item could simply own the storage for its swapped
 * data. This fits better with the current design.
 *
 * markus 2003sep18 Jitterbug 2235
 */