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godot/thirdparty/icu4c/common/ucmndata.cpp

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// © 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 inteface 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) {
if(udh==NULL) {
return 0;
} else if(udh->info.isBigEndian==U_IS_BIG_ENDIAN) {
/* same endianness */
return udh->dataHeader.headerSize;
} else {
/* opposite endianness */
uint16_t x=udh->dataHeader.headerSize;
return (uint16_t)((x<<8)|(x>>8));
}
}
U_CFUNC uint16_t
udata_getInfoSize(const UDataInfo *info) {
if(info==NULL) {
return 0;
} else if(info->isBigEndian==U_IS_BIG_ENDIAN) {
/* same endianness */
return info->size;
} else {
/* opposite endianness */
uint16_t x=info->size;
return (uint16_t)((x<<8)|(x>>8));
}
}
/*-----------------------------------------------------------------------------*
* *
* 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. *
* *
*-----------------------------------------------------------------------------*/
typedef struct {
const char *entryName;
const DataHeader *pHeader;
} PointerTOCEntry;
typedef struct {
uint32_t count;
uint32_t reserved;
/**
* Variable-length array declared with length 1 to disable bounds checkers.
* The actual array length is in the count field.
*/
PointerTOCEntry entry[1];
} PointerTOC;
/* definition of OffsetTOC struct types moved to ucmndata.h */
/*-----------------------------------------------------------------------------*
* *
* entry point lookup implementations *
* *
*-----------------------------------------------------------------------------*/
#ifndef MIN
#define MIN(a,b) (((a)<(b)) ? (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) {
int32_t pl=*pPrefixLength;
int32_t cmp=0;
s1+=pl;
s2+=pl;
for(;;) {
int32_t c1=(uint8_t)*s1++;
int32_t c2=(uint8_t)*s2++;
cmp=c1-c2;
if(cmp!=0 || c1==0) { /* different or done */
break;
}
++pl; /* increment shared same-prefix length */
}
*pPrefixLength=pl;
return cmp;
}
static int32_t
offsetTOCPrefixBinarySearch(const char *s, const char *names,
const UDataOffsetTOCEntry *toc, int32_t count) {
int32_t start=0;
int32_t limit=count;
/*
* Remember the shared prefix between s, start and limit,
* and don't compare that shared prefix again.
* The shared prefix should get longer as we narrow the [start, limit[ range.
*/
int32_t startPrefixLength=0;
int32_t limitPrefixLength=0;
if(count==0) {
return -1;
}
/*
* Prime the prefix lengths so that we don't keep prefixLength at 0 until
* both the start and limit indexes have moved.
* At the same time, we find if s is one of the start and (limit-1) names,
* and if not, exclude them from the actual binary search.
*/
if(0==strcmpAfterPrefix(s, names+toc[0].nameOffset, &startPrefixLength)) {
return 0;
}
++start;
--limit;
if(0==strcmpAfterPrefix(s, names+toc[limit].nameOffset, &limitPrefixLength)) {
return limit;
}
while(start<limit) {
int32_t i=(start+limit)/2;
int32_t prefixLength=MIN(startPrefixLength, limitPrefixLength);
int32_t cmp=strcmpAfterPrefix(s, names+toc[i].nameOffset, &prefixLength);
if(cmp<0) {
limit=i;
limitPrefixLength=prefixLength;
} else if(cmp==0) {
return i;
} else {
start=i+1;
startPrefixLength=prefixLength;
}
}
return -1;
}
static int32_t
pointerTOCPrefixBinarySearch(const char *s, const PointerTOCEntry *toc, int32_t count) {
int32_t start=0;
int32_t limit=count;
/*
* Remember the shared prefix between s, start and limit,
* and don't compare that shared prefix again.
* The shared prefix should get longer as we narrow the [start, limit[ range.
*/
int32_t startPrefixLength=0;
int32_t limitPrefixLength=0;
if(count==0) {
return -1;
}
/*
* Prime the prefix lengths so that we don't keep prefixLength at 0 until
* both the start and limit indexes have moved.
* At the same time, we find if s is one of the start and (limit-1) names,
* and if not, exclude them from the actual binary search.
*/
if(0==strcmpAfterPrefix(s, toc[0].entryName, &startPrefixLength)) {
return 0;
}
++start;
--limit;
if(0==strcmpAfterPrefix(s, toc[limit].entryName, &limitPrefixLength)) {
return limit;
}
while(start<limit) {
int32_t i=(start+limit)/2;
int32_t prefixLength=MIN(startPrefixLength, limitPrefixLength);
int32_t cmp=strcmpAfterPrefix(s, toc[i].entryName, &prefixLength);
if(cmp<0) {
limit=i;
limitPrefixLength=prefixLength;
} else if(cmp==0) {
return i;
} else {
start=i+1;
startPrefixLength=prefixLength;
}
}
return -1;
}
U_CDECL_BEGIN
static uint32_t U_CALLCONV
offsetTOCEntryCount(const UDataMemory *pData) {
int32_t retVal=0;
const UDataOffsetTOC *toc = (UDataOffsetTOC *)pData->toc;
if (toc != NULL) {
retVal = toc->count;
}
return retVal;
}
static const DataHeader * U_CALLCONV
offsetTOCLookupFn(const UDataMemory *pData,
const char *tocEntryName,
int32_t *pLength,
UErrorCode *pErrorCode) {
(void)pErrorCode;
const UDataOffsetTOC *toc = (UDataOffsetTOC *)pData->toc;
if(toc!=NULL) {
const char *base=(const char *)toc;
int32_t number, count=(int32_t)toc->count;
/* perform a binary search for the data in the common data's table of contents */
#if defined (UDATA_DEBUG_DUMP)
/* list the contents of the TOC each time .. not recommended */
for(number=0; number<count; ++number) {
fprintf(stderr, "\tx%d: %s\n", number, &base[toc->entry[number].nameOffset]);
}
#endif
number=offsetTOCPrefixBinarySearch(tocEntryName, base, toc->entry, count);
if(number>=0) {
/* found it */
const UDataOffsetTOCEntry *entry=toc->entry+number;
#ifdef UDATA_DEBUG
fprintf(stderr, "%s: Found.\n", tocEntryName);
#endif
if((number+1) < count) {
*pLength = (int32_t)(entry[1].dataOffset - entry->dataOffset);
} else {
*pLength = -1;
}
return (const DataHeader *)(base+entry->dataOffset);
} else {
#ifdef UDATA_DEBUG
fprintf(stderr, "%s: Not found.\n", tocEntryName);
#endif
return NULL;
}
} else {
#ifdef UDATA_DEBUG
fprintf(stderr, "returning header\n");
#endif
return pData->pHeader;
}
}
static uint32_t U_CALLCONV pointerTOCEntryCount(const UDataMemory *pData) {
const PointerTOC *toc = (PointerTOC *)pData->toc;
return (uint32_t)((toc != NULL) ? (toc->count) : 0);
}
static const DataHeader * U_CALLCONV pointerTOCLookupFn(const UDataMemory *pData,
const char *name,
int32_t *pLength,
UErrorCode *pErrorCode) {
(void)pErrorCode;
if(pData->toc!=NULL) {
const PointerTOC *toc = (PointerTOC *)pData->toc;
int32_t number, count=(int32_t)toc->count;
#if defined (UDATA_DEBUG_DUMP)
/* list the contents of the TOC each time .. not recommended */
for(number=0; number<count; ++number) {
fprintf(stderr, "\tx%d: %s\n", number, toc->entry[number].entryName);
}
#endif
number=pointerTOCPrefixBinarySearch(name, toc->entry, count);
if(number>=0) {
/* found it */
#ifdef UDATA_DEBUG
fprintf(stderr, "%s: Found.\n", toc->entry[number].entryName);
#endif
*pLength=-1;
return UDataMemory_normalizeDataPointer(toc->entry[number].pHeader);
} else {
#ifdef UDATA_DEBUG
fprintf(stderr, "%s: Not found.\n", name);
#endif
return NULL;
}
} else {
return pData->pHeader;
}
}
U_CDECL_END
static const commonDataFuncs CmnDFuncs = {offsetTOCLookupFn, offsetTOCEntryCount};
static const commonDataFuncs ToCPFuncs = {pointerTOCLookupFn, pointerTOCEntryCount};
/*----------------------------------------------------------------------*
* *
* 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) {
if (U_FAILURE(*err)) {
return;
}
if(udm==NULL || udm->pHeader==NULL) {
*err=U_INVALID_FORMAT_ERROR;
} else if(!(udm->pHeader->dataHeader.magic1==0xda &&
udm->pHeader->dataHeader.magic2==0x27 &&
udm->pHeader->info.isBigEndian==U_IS_BIG_ENDIAN &&
udm->pHeader->info.charsetFamily==U_CHARSET_FAMILY)
) {
/* header not valid */
*err=U_INVALID_FORMAT_ERROR;
}
else if (udm->pHeader->info.dataFormat[0]==0x43 &&
udm->pHeader->info.dataFormat[1]==0x6d &&
udm->pHeader->info.dataFormat[2]==0x6e &&
udm->pHeader->info.dataFormat[3]==0x44 &&
udm->pHeader->info.formatVersion[0]==1
) {
/* dataFormat="CmnD" */
udm->vFuncs = &CmnDFuncs;
udm->toc=(const char *)udm->pHeader+udata_getHeaderSize(udm->pHeader);
}
else if(udm->pHeader->info.dataFormat[0]==0x54 &&
udm->pHeader->info.dataFormat[1]==0x6f &&
udm->pHeader->info.dataFormat[2]==0x43 &&
udm->pHeader->info.dataFormat[3]==0x50 &&
udm->pHeader->info.formatVersion[0]==1
) {
/* dataFormat="ToCP" */
udm->vFuncs = &ToCPFuncs;
udm->toc=(const char *)udm->pHeader+udata_getHeaderSize(udm->pHeader);
}
else {
/* dataFormat not recognized */
*err=U_INVALID_FORMAT_ERROR;
}
if (U_FAILURE(*err)) {
/* If the data is no good and we memory-mapped it ourselves,
* close the memory mapping so it doesn't leak. Note that this has
* no effect on non-memory mapped data, other than clearing fields in udm.
*/
udata_close(udm);
}
}
/*
* 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
*/
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