scuffed-code/icu4c/source/common/ucnv_io.c
2002-07-03 16:46:21 +00:00

747 lines
25 KiB
C

/*
******************************************************************************
*
* Copyright (C) 1999-2001, International Business Machines
* Corporation and others. All Rights Reserved.
*
******************************************************************************
*
*
* ucnv_io.c:
* initializes global variables and defines functions pertaining to file
* access, and name resolution aspect of the library.
*
* new implementation:
*
* created on: 1999nov22
* created by: Markus W. Scherer
*
* Use the binary cnvalias.icu (created from convrtrs.txt) to work
* with aliases for converter names.
*
* Date Name Description
* 11/22/1999 markus Created
* 06/28/2002 grhoten Major overhaul of the converter alias design.
* Now an alias can map to different converters
* depending on the specified standard.
*******************************************************************************
*/
#include "unicode/utypes.h"
#include "unicode/putil.h"
#include "unicode/ucnv.h" /* This file implements ucnv_xXXX() APIs */
#include "unicode/udata.h"
#include "umutex.h"
#include "cstring.h"
#include "cmemory.h"
#include "ucnv_io.h"
#include "ucln_cmn.h"
/* Format of cnvalias.icu -----------------------------------------------------
*
* cnvalias.icu is a binary, memory-mappable form of convrtrs.txt.
* This binary form contains several tables. All indexes are to uint16_t
* units, and not to the bytes (uint8_t units). Addressing everything on
* 16-bit boundaries allows us to store more information with small index
* numbers, which are also 16-bit in size. The majority of the table (except
* the string table) are 16-bit numbers.
*
* First there is the size of the Table of Contents (TOC). The TOC
* entries contain the size of each section. In order to find the offset
* you just need to sum up the previous offsets.
*
* 1) This section contains a list of converters. This list contains indexes
* into the string table for the converter name. The index of this list is
* also used by other sections, which are mentioned later on.
*
* 2) This section contains a list of tags. This list contains indexes
* into the string table for the tag name. The index of this list is
* also used by other sections, which are mentioned later on.
*
* 3) This section contains a list of sorted list of unique aliases. This
* list contains indexes into the string table for the alias name. The
* index of this list is also used by other sections, which are mentioned
* later on.
*
* 4) This section contains a list of mapped converter names. Consider this
* as a table that maps the 3rd section to the 1st section. This list contains
* indexes into the 1st section. The index of this list is the same index in
* the 3rd section. There is also some extra information in the high bits of
* each converter index in this table. Currently it's only used to say that
* an alias mapped to this converter is ambiguous. See UCNV_CONVERTER_INDEX_MASK
* and UCNV_AMBIGUOUS_ALIAS_MAP_BIT for more information. This section is
* the predigested form of the 5th section so that an alias lookup can be fast.
*
* 5) This section contains a 2D array with indexes to the 6th section. This
* section is the full form of all alias mappings. The column index is the
* index into the converter list (column header). The row index is the index
* to tag list (row header). This 2D array is the top part a 3D array. The
* third dimension is in the 6th section.
*
* 6) This is blob of variable length arrays. Each array starts with a size,
* and is followed by indexes to alias names in the string table. This is
* the third dimension to the section 5. No other section should be referencing
* this section.
*
* 7) Reserved at this time (There is no information). This _usually_ has a
* size of 0. Future versions may add more information here.
*
* 8) This is the string table. All strings are indexed on an even address.
* There are two reasons for this. First many chip architectures locate strings
* faster on even address boundaries. Second, since all indexes are 16-bit
* numbers, this string table can be 128KB in size instead of 64KB when we
* only have strings starting on an even address.
*
*
* Here is the concept of section 5 and 6. It's a 3D cube. Each tag
* has a unique alias among all converters. That same alias can
* be mentioned in other standards on different converters,
* but only one alias per tag can be unique.
*
*
* Converter Names (Usually in TR22 form)
* -------------------------------------------.
* T / /|
* a / / |
* g / / |
* s / / |
* / / |
* ------------------------------------------/ |
* A | | |
* l | | |
* i | | /
* a | | /
* s | | /
* e | | /
* s | |/
* -------------------------------------------
*
*
*
* Here is what it really looks like. It's like swiss cheese.
* There are holes. Some converters aren't recognized by
* a standard, or they are really old converters that the
* standard doesn't recognize anymore.
*
* Converter Names (Usually in TR22 form)
* -------------------------------------------.
* T /##########################################/|
* a / # # /#
* g / # ## ## ### # ### ### ### #/
* s / # ##### #### ## ## #/#
* / ### # # ## # # # ### # # #/##
* ------------------------------------------/# #
* A |### # # ## # # # ### # # #|# #
* l |# # # # # ## # #|# #
* i |# # # # # # #|#
* a |# #|#
* s | #|#
* e
* s
*
*/
static const char DATA_NAME[] = "cnvalias";
static const char DATA_TYPE[] = "icu";
static UDataMemory *aliasData=NULL;
static const uint16_t *converterList = NULL;
static const uint16_t *tagList = NULL;
static const uint16_t *aliasList = NULL;
static const uint16_t *untaggedConvArray = NULL;
static const uint16_t *taggedAliasArray = NULL;
static const uint16_t *taggedAliasLists = NULL;
static const uint16_t *stringTable = NULL;
static uint32_t converterListNum;
static uint32_t tagListNum;
static uint32_t aliasListNum;
static uint32_t untaggedConvArraySize;
static uint32_t taggedAliasArraySize;
static uint32_t taggedAliasListsSize;
static uint32_t stringTableSize;
static const char **availableConverters = NULL;
static uint16_t availableConverterCount = 0;
static char defaultConverterNameBuffer[UCNV_MAX_CONVERTER_NAME_LENGTH + 1]; /* +1 for NULL */
static const char *defaultConverterName = NULL;
#define GET_STRING(idx) (const char *)(stringTable + (idx))
#define NUM_RESERVED_TAGS 2
static UBool
isAcceptable(void *context,
const char *type, const char *name,
const UDataInfo *pInfo) {
return (UBool)(
pInfo->size>=20 &&
pInfo->isBigEndian==U_IS_BIG_ENDIAN &&
pInfo->charsetFamily==U_CHARSET_FAMILY &&
pInfo->dataFormat[0]==0x43 && /* dataFormat="CvAl" */
pInfo->dataFormat[1]==0x76 &&
pInfo->dataFormat[2]==0x41 &&
pInfo->dataFormat[3]==0x6c &&
pInfo->formatVersion[0]==3);
}
static UBool
haveAliasData(UErrorCode *pErrorCode) {
if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
return FALSE;
}
/* load converter alias data from file if necessary */
if(aliasData==NULL) {
UDataMemory *data = NULL;
const uint16_t *table = NULL;
uint32_t tableStart;
uint32_t currOffset;
uint32_t reservedSize1;
data = udata_openChoice(NULL, DATA_TYPE, DATA_NAME, isAcceptable, NULL, pErrorCode);
if(U_FAILURE(*pErrorCode)) {
return FALSE;
}
table = (const uint16_t *)udata_getMemory(data);
tableStart = ((const uint32_t *)(table))[0];
if (tableStart < 8) {
*pErrorCode = U_INVALID_FORMAT_ERROR;
return FALSE;
}
umtx_lock(NULL);
if(aliasData==NULL) {
aliasData = data;
data=NULL;
converterListNum = ((const uint32_t *)(table))[1];
tagListNum = ((const uint32_t *)(table))[2];
aliasListNum = ((const uint32_t *)(table))[3];
untaggedConvArraySize = ((const uint32_t *)(table))[4];
taggedAliasArraySize = ((const uint32_t *)(table))[5];
taggedAliasListsSize = ((const uint32_t *)(table))[6];
reservedSize1 = ((const uint32_t *)(table))[7]; /* reserved */
stringTableSize = ((const uint32_t *)(table))[8];
currOffset = tableStart * (sizeof(uint32_t)/sizeof(uint16_t)) + (sizeof(uint32_t)/sizeof(uint16_t));
converterList = table + currOffset;
currOffset += converterListNum;
tagList = table + currOffset;
currOffset += tagListNum;
aliasList = table + currOffset;
currOffset += aliasListNum;
untaggedConvArray = table + currOffset;
currOffset += untaggedConvArraySize;
taggedAliasArray = table + currOffset;
/* aliasLists is a 1's based array, but it has a padding character */
currOffset += taggedAliasArraySize;
taggedAliasLists = table + currOffset;
currOffset += taggedAliasListsSize;
/* reserved */
currOffset += reservedSize1;
stringTable = table + currOffset;
}
umtx_unlock(NULL);
/* if a different thread set it first, then close the extra data */
if(data!=NULL) {
udata_close(data); /* NULL if it was set correctly */
}
}
return TRUE;
}
static UBool
isAlias(const char *alias, UErrorCode *pErrorCode) {
if(alias==NULL) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
return FALSE;
} else if(*alias==0) {
return FALSE;
} else {
return TRUE;
}
}
UBool
ucnv_io_cleanup()
{
if (aliasData) {
udata_close(aliasData);
aliasData = NULL;
}
ucnv_io_flushAvailableConverterCache();
converterListNum = 0;
tagListNum = 0;
aliasListNum = 0;
untaggedConvArraySize = 0;
taggedAliasArraySize = 0;
taggedAliasListsSize = 0;
stringTableSize = 0;
converterList = NULL;
tagList = NULL;
aliasList = NULL;
untaggedConvArray = NULL;
taggedAliasArray = NULL;
taggedAliasLists = NULL;
stringTable = NULL;
defaultConverterName = NULL;
defaultConverterNameBuffer[0] = 0;
return TRUE; /* Everything was cleaned up */
}
static uint32_t getTagNumber(const char *tagname) {
if (tagList) {
uint32_t tagNum;
for (tagNum = 0; tagNum < tagListNum; tagNum++) {
if (!uprv_stricmp(GET_STRING(tagList[tagNum]), tagname)) {
return tagNum;
}
}
}
return UINT32_MAX;
}
/**
* Do a fuzzy compare of a two converter/alias names. The comparison
* is case-insensitive. It also ignores the characters '-', '_', and
* ' ' (dash, underscore, and space). Thus the strings "UTF-8",
* "utf_8", and "Utf 8" are exactly equivalent.
*
* This is a symmetrical (commutative) operation; order of arguments
* is insignificant. This is an important property for sorting the
* list (when the list is preprocessed into binary form) and for
* performing binary searches on it at run time.
*
* @param name1 a converter name or alias, zero-terminated
* @param name2 a converter name or alias, zero-terminated
* @return 0 if the names match, or a negative value if the name1
* lexically precedes name2, or a positive value if the name1
* lexically follows name2.
*/
U_CAPI int U_EXPORT2
ucnv_compareNames(const char *name1, const char *name2) {
int rc;
char c1, c2;
for (;;) {
/* Ignore delimiters '-', '_', and ' ' */
while ((c1 = *name1) == '-' || c1 == '_' || c1 == ' ') {
++name1;
}
while ((c2 = *name2) == '-' || c2 == '_' || c2 == ' ') {
++name2;
}
/* If we reach the ends of both strings then they match */
if ((c1|c2)==0) {
return 0;
}
/* Case-insensitive comparison */
rc = (int)(unsigned char)uprv_tolower(c1) -
(int)(unsigned char)uprv_tolower(c2);
if (rc != 0) {
return rc;
}
++name1;
++name2;
}
}
/*
* search for an alias
* return the converter number index for converterList
*/
static uint32_t
findConverter(const char *alias, UErrorCode *pErrorCode) {
uint32_t mid, start, limit;
int result;
/* do a binary search for the alias */
start = 0;
limit = untaggedConvArraySize - 1;
mid = limit;
/* Once mid == 0 we've already checked the 0'th element and we can stop */
while (start <= limit && mid != 0) {
mid = (uint32_t)((start + limit + 1) / 2); /* +1 is to round properly */
result = ucnv_compareNames(alias, GET_STRING(aliasList[mid]));
if (result < 0) {
limit = mid-1;
} else if (result > 0) {
start = mid+1;
} else {
/* Since the gencnval tool folds duplicates into one entry,
* this alias in aliasList is unique, but different standards
* may map an alias to different converters.
*/
if (untaggedConvArray[mid] & UCNV_AMBIGUOUS_ALIAS_MAP_BIT) {
*pErrorCode = U_AMBIGUOUS_ALIAS_WARNING;
}
return untaggedConvArray[mid] & UCNV_CONVERTER_INDEX_MASK;
}
}
return UINT32_MAX;
}
U_CFUNC const char *
ucnv_io_getConverterName(const char *alias, UErrorCode *pErrorCode) {
if(haveAliasData(pErrorCode) && isAlias(alias, pErrorCode)) {
uint32_t convNum = findConverter(alias, pErrorCode);
if (convNum < converterListNum) {
return GET_STRING(converterList[convNum]);
}
}
return NULL;
}
U_CFUNC uint16_t
ucnv_io_countAliases(const char *alias, UErrorCode *pErrorCode) {
if(haveAliasData(pErrorCode) && isAlias(alias, pErrorCode)) {
uint32_t convNum = findConverter(alias, pErrorCode);
if (convNum < converterListNum) {
/* tagListNum - 1 is the ALL tag */
int32_t listOffset = taggedAliasArray[(tagListNum - 1)*converterListNum + convNum];
if (listOffset) {
return taggedAliasLists[listOffset];
}
}
}
return 0;
}
U_CFUNC uint16_t
ucnv_io_getAliases(const char *alias, uint16_t start, const char **aliases, UErrorCode *pErrorCode) {
if(haveAliasData(pErrorCode) && isAlias(alias, pErrorCode)) {
uint32_t currAlias;
uint32_t convNum = findConverter(alias, pErrorCode);
if (convNum < converterListNum) {
/* tagListNum - 1 is the ALL tag */
int32_t listOffset = taggedAliasArray[(tagListNum - 1)*converterListNum + convNum];
if (listOffset) {
uint32_t listCount = taggedAliasLists[listOffset];
/* +1 to skip listCount */
const uint16_t *currList = taggedAliasLists + listOffset + 1;
for (currAlias = start; currAlias < listCount; currAlias++) {
aliases[currAlias] = GET_STRING(currList[currAlias]);
}
}
}
}
return 0;
}
U_CFUNC const char *
ucnv_io_getAlias(const char *alias, uint16_t n, UErrorCode *pErrorCode) {
if(haveAliasData(pErrorCode) && isAlias(alias, pErrorCode)) {
uint32_t convNum = findConverter(alias, pErrorCode);
if (convNum < converterListNum) {
/* tagListNum - 1 is the ALL tag */
int32_t listOffset = taggedAliasArray[(tagListNum - 1)*converterListNum + convNum];
if (listOffset) {
uint32_t listCount = taggedAliasLists[listOffset];
/* +1 to skip listCount */
const uint16_t *currList = taggedAliasLists + listOffset + 1;
if (n < listCount) {
return GET_STRING(currList[n]);
}
*pErrorCode = U_INDEX_OUTOFBOUNDS_ERROR;
}
}
}
return NULL;
}
U_CFUNC uint16_t
ucnv_io_countStandards(UErrorCode *pErrorCode) {
if (haveAliasData(pErrorCode)) {
/* Don't include the empty list */
return (uint16_t)(tagListNum - NUM_RESERVED_TAGS);
}
return 0;
}
U_CAPI const char * U_EXPORT2
ucnv_getStandard(uint16_t n, UErrorCode *pErrorCode) {
if (haveAliasData(pErrorCode)) {
if (n < tagListNum - NUM_RESERVED_TAGS) {
return GET_STRING(tagList[n]);
}
*pErrorCode = U_INDEX_OUTOFBOUNDS_ERROR;
}
return NULL;
}
U_CFUNC const char * U_EXPORT2
ucnv_getStandardName(const char *alias, const char *standard, UErrorCode *pErrorCode) {
if (haveAliasData(pErrorCode) && isAlias(alias, pErrorCode)) {
uint32_t idx;
uint32_t listOffset;
uint32_t convNum;
uint32_t tagNum = getTagNumber(standard);
UErrorCode myErr = U_ZERO_ERROR;
/* Make a quick guess. Hopefully they used a TR22 canonical alias. */
convNum = findConverter(alias, &myErr);
if (tagNum < (tagListNum - NUM_RESERVED_TAGS) && convNum < converterListNum) {
if (myErr == U_AMBIGUOUS_ALIAS_WARNING) {
/* Uh Oh! They used an ambiguous alias.
Hopefully the standard knows the alias.
This may take a while.
*/
for (idx = 0; idx < converterListNum; idx++) {
listOffset = taggedAliasArray[tagNum*converterListNum + idx];
if (listOffset) {
uint32_t currAlias;
uint32_t listCount = taggedAliasLists[listOffset];
/* +1 to skip listCount */
const uint16_t *currList = taggedAliasLists + listOffset + 1;
for (currAlias = 0; currAlias < listCount; currAlias++) {
if (currList[currAlias]
&& ucnv_compareNames(alias, GET_STRING(currList[currAlias]))==0)
{
if (currList[0]) {
return GET_STRING(currList[0]);
}
else {
/* Someone screwed up the alias table. */
return NULL;
}
}
}
}
}
/* The standard doesn't know about the alias */
*pErrorCode = U_AMBIGUOUS_ALIAS_WARNING;
}
listOffset = taggedAliasArray[tagNum*converterListNum + convNum];
if (listOffset && taggedAliasLists[listOffset + 1]) {
return GET_STRING(taggedAliasLists[listOffset + 1]);
}
/* else no default name */
}
/* else converter or tag not found */
}
return NULL;
}
void
ucnv_io_flushAvailableConverterCache() {
if (availableConverters) {
umtx_lock(NULL);
uprv_free((char **)availableConverters);
availableConverters = NULL;
umtx_unlock(NULL);
}
availableConverterCount = 0;
}
static UBool haveAvailableConverterList(UErrorCode *pErrorCode) {
if (availableConverters == NULL) {
uint16_t idx;
uint16_t localConverterCount;
UErrorCode status;
const char *converterName;
const char **localConverterList;
if (!haveAliasData(pErrorCode)) {
return FALSE;
}
/* We can't have more than "*converterTable" converters to open */
localConverterList = (const char **) uprv_malloc(converterListNum * sizeof(char*));
if (!localConverterList) {
*pErrorCode = U_MEMORY_ALLOCATION_ERROR;
return FALSE;
}
localConverterCount = 0;
for (idx = 0; idx < converterListNum; idx++) {
status = U_ZERO_ERROR;
converterName = GET_STRING(converterList[idx]);
ucnv_close(ucnv_open(converterName, &status));
if (U_SUCCESS(status)) {
localConverterList[localConverterCount++] = converterName;
}
}
umtx_lock(NULL);
if (availableConverters == NULL) {
availableConverters = localConverterList;
availableConverterCount = localConverterCount;
}
else {
uprv_free((char **)localConverterList);
}
umtx_unlock(NULL);
}
return TRUE;
}
U_CFUNC uint16_t
ucnv_io_countAvailableConverters(UErrorCode *pErrorCode) {
if (haveAvailableConverterList(pErrorCode)) {
return availableConverterCount;
}
return 0;
}
U_CFUNC const char *
ucnv_io_getAvailableConverter(uint16_t n, UErrorCode *pErrorCode) {
if (haveAvailableConverterList(pErrorCode)) {
if (n < availableConverterCount) {
return availableConverters[n];
}
*pErrorCode = U_INDEX_OUTOFBOUNDS_ERROR;
}
return NULL;
}
U_CFUNC void
ucnv_io_fillAvailableConverters(const char **aliases, UErrorCode *pErrorCode) {
if (haveAvailableConverterList(pErrorCode)) {
uint16_t count = 0;
while (count < availableConverterCount) {
*aliases++=availableConverters[count++];
}
}
}
U_CFUNC uint16_t
ucnv_io_countAvailableAliases(UErrorCode *pErrorCode) {
if (haveAliasData(pErrorCode)) {
return (uint16_t)aliasListNum;
}
return 0;
}
/* default converter name --------------------------------------------------- */
/*
* In order to be really thread-safe, the get function would have to take
* a buffer parameter and copy the current string inside a mutex block.
* This implementation only tries to be really thread-safe while
* setting the name.
* It assumes that setting a pointer is atomic.
*/
U_CFUNC const char *
ucnv_io_getDefaultConverterName() {
/* local variable to be thread-safe */
const char *name=defaultConverterName;
if(name==NULL) {
const char *codepage = uprv_getDefaultCodepage();
if(codepage!=NULL) {
UErrorCode errorCode=U_ZERO_ERROR;
name=ucnv_io_getConverterName(codepage, &errorCode);
if(U_FAILURE(errorCode) || name==NULL) {
name=codepage;
}
}
/* if the name is there, test it out */
if(name != NULL) {
UErrorCode errorCode = U_ZERO_ERROR;
UConverter *cnv = ucnv_open(name, &errorCode);
if(U_FAILURE(errorCode) || (cnv == NULL)) {
/* Panic time, let's use a fallback. */
#if (U_CHARSET_FAMILY == U_ASCII_FAMILY)
name = "US-ASCII";
/* there is no 'algorithmic' converter for EBCDIC */
#elif defined(OS390)
name = "ibm-1047-s390";
#else
name = "ibm-37";
#endif
}
ucnv_close(cnv);
}
if(name != NULL) {
umtx_lock(NULL);
/* Did find a name. And it works.*/
defaultConverterName=name;
umtx_unlock(NULL);
}
}
return name;
}
U_CFUNC void
ucnv_io_setDefaultConverterName(const char *converterName) {
if(converterName==NULL) {
/* reset to the default codepage */
defaultConverterName=NULL;
} else {
UErrorCode errorCode=U_ZERO_ERROR;
const char *name=ucnv_io_getConverterName(converterName, &errorCode);
if(U_SUCCESS(errorCode) && name!=NULL) {
defaultConverterName=name;
} else {
/* do not set the name if the alias lookup failed and it is too long */
int32_t length=(int32_t)(uprv_strlen(converterName));
if(length<sizeof(defaultConverterNameBuffer)) {
/* it was not found as an alias, so copy it - accept an empty name */
UBool didLock;
if(defaultConverterName==defaultConverterNameBuffer) {
umtx_lock(NULL);
didLock=TRUE;
} else {
didLock=FALSE;
}
uprv_memcpy(defaultConverterNameBuffer, converterName, length);
defaultConverterNameBuffer[length]=0;
defaultConverterName=defaultConverterNameBuffer;
if(didLock) {
umtx_unlock(NULL);
}
}
}
}
}
/*
* Hey, Emacs, please set the following:
*
* Local Variables:
* indent-tabs-mode: nil
* End:
*
*/