scuffed-code/icu4c/source/common/ustring.c
2000-08-29 22:45:46 +00:00

577 lines
13 KiB
C

/*
*******************************************************************************
*
* Copyright (C) 1998-1999, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
*
* File ustring.h
*
* Modification History:
*
* Date Name Description
* 12/07/98 bertrand Creation.
*******************************************************************************
*/
#include "unicode/ustring.h"
#include "unicode/utypes.h"
#include "cstring.h"
#include "umutex.h"
#include "unicode/ucnv.h"
/* forward declaractions of definitions for the shared default converter */
static UConverter *fgDefaultConverter = NULL;
static UConverter*
getDefaultConverter(void);
static void
releaseDefaultConverter(UConverter *converter);
/* ANSI string.h - style functions ------------------------------------------ */
#define MAX_STRLEN 0x0FFFFFFF
UChar*
u_strcat(UChar *dst,
const UChar *src)
{
UChar *anchor = dst; /* save a pointer to start of dst */
while(*dst != 0) { /* To end of first string */
++dst;
}
while((*dst = *src) != 0) { /* copy string 2 over */
++dst;
++src;
}
return anchor;
}
UChar*
u_strncat(UChar *dst,
const UChar *src,
int32_t n )
{
if(n > 0) {
UChar *anchor = dst; /* save a pointer to start of dst */
while(*dst != 0) { /* To end of first string */
++dst;
}
while((*dst = *src) != 0) { /* copy string 2 over */
++dst;
if(--n == 0) {
*dst = 0;
break;
}
++src;
}
return anchor;
} else {
return dst;
}
}
UChar*
u_strchr(const UChar *s,
UChar c)
{
while(*s != 0) {
if(*s == c) {
return (UChar *)s;
}
++s;
}
return NULL;
}
/* A Boyer-Moore algorithm would be better, but that would require a hashtable
because UChar is so big. This algorithm doesn't use a lot of extra memory.
*/
U_CAPI UChar * U_EXPORT2
u_strstr(const UChar *s, const UChar *substring) {
UChar *strItr, *subItr;
if (*substring == 0) {
return (UChar *)s;
}
do {
strItr = (UChar *)s;
subItr = (UChar *)substring;
/* Only one string iterator needs checking for null terminator */
while ((*strItr != 0) && (*strItr == *subItr)) {
strItr++;
subItr++;
}
if (*subItr == 0) { /* Was the end of the substring reached? */
return (UChar *)s;
}
s++;
} while (*strItr != 0); /* Was the end of the string reached? */
return NULL; /* No match */
}
U_CAPI UChar * U_EXPORT2
u_strchr32(const UChar *s, UChar32 c) {
if(!UTF_NEED_MULTIPLE_UCHAR(c)) {
return u_strchr(s, (UChar)c);
} else {
UChar buffer[UTF_MAX_CHAR_LENGTH + 1];
UTextOffset i = 0;
UTF_APPEND_CHAR_UNSAFE(buffer, i, c);
buffer[i] = 0;
return u_strstr(s, buffer);
}
}
int32_t
u_strcmp(const UChar *s1,
const UChar *s2)
{
int32_t rc;
for(;;) {
rc = (int32_t)*s1 - (int32_t)*s2;
if(rc != 0 || *s1 == 0) {
return rc;
}
++s1;
++s2;
}
}
int32_t
u_strncmp(const UChar *s1,
const UChar *s2,
int32_t n)
{
if(n > 0) {
int32_t rc;
for(;;) {
rc = (int32_t)*s1 - (int32_t)*s2;
if(rc != 0 || *s1 == 0 || --n == 0) {
return rc;
}
++s1;
++s2;
}
} else {
return 0;
}
}
UChar*
u_strcpy(UChar *dst,
const UChar *src)
{
UChar *anchor = dst; /* save a pointer to start of dst */
while((*dst = *src) != 0) { /* copy string 2 over */
++dst;
++src;
}
return anchor;
}
UChar*
u_strncpy(UChar *dst,
const UChar *src,
int32_t n)
{
UChar *anchor = dst; /* save a pointer to start of dst */
if(n > 0) {
while((*dst = *src) != 0) { /* copy string 2 over */
++dst;
if(--n == 0) {
*dst = 0;
break;
}
++src;
}
} else {
*dst = 0;
}
return anchor;
}
int32_t
u_strlen(const UChar *s)
{
# if U_SIZEOF_WCHAR_T == U_SIZEOF_UCHAR
return uprv_wcslen(s);
# else
const UChar *t = s;
while(*t != 0) {
++t;
}
return t - s;
#endif
}
/* conversions between char* and UChar* ------------------------------------- */
UChar* u_uastrcpy(UChar *ucs1,
const char *s2 )
{
UConverter *cnv = getDefaultConverter();
if(cnv != NULL) {
UErrorCode err = U_ZERO_ERROR;
ucnv_toUChars(cnv,
ucs1,
MAX_STRLEN,
s2,
uprv_strlen(s2),
&err);
releaseDefaultConverter(cnv);
if(U_FAILURE(err)) {
*ucs1 = 0;
}
} else {
*ucs1 = 0;
}
return ucs1;
}
/*
returns the minimum of (the length of the null-terminated string) and n.
*/
static int32_t u_astrnlen(const char *ucs1, int32_t n)
{
int32_t len = 0;
if (ucs1)
{
while (*(ucs1++) && n--)
{
len++;
}
}
return len;
}
UChar* u_uastrncpy(UChar *ucs1,
const char *s2 ,
int32_t n)
{
UChar *target = ucs1;
UConverter *cnv = getDefaultConverter();
if(cnv != NULL) {
UErrorCode err = U_ZERO_ERROR;
ucnv_reset(cnv);
ucnv_toUnicode(cnv,
&target,
ucs1+n,
&s2,
s2+u_astrnlen(s2, n),
NULL,
TRUE,
&err);
ucnv_reset(cnv); /* be good citizens */
releaseDefaultConverter(cnv);
if(U_FAILURE(err) && (err != U_BUFFER_OVERFLOW_ERROR) ) {
*ucs1 = 0; /* failure */
}
if(target < (ucs1+n)) { /* U_BUFFER_OVERFLOW_ERROR isn't an err, just means no termination will happen. */
*target = 0; /* terminate */
}
} else {
*ucs1 = 0;
}
return ucs1;
}
char* u_austrcpy(char *s1,
const UChar *ucs2 )
{
UConverter *cnv = getDefaultConverter();
if(cnv != NULL) {
UErrorCode err = U_ZERO_ERROR;
int32_t len = ucnv_fromUChars(cnv,
s1,
MAX_STRLEN,
ucs2,
-1,
&err);
releaseDefaultConverter(cnv);
s1[len] = 0;
} else {
*s1 = 0;
}
return s1;
}
/* mutexed access to a shared default converter ----------------------------- */
/* this is the same implementation as in unistr.cpp */
static UConverter*
getDefaultConverter()
{
UConverter *converter = NULL;
if(fgDefaultConverter != NULL) {
umtx_lock(NULL);
/* need to check to make sure it wasn't taken out from under us */
if(fgDefaultConverter != NULL) {
converter = fgDefaultConverter;
fgDefaultConverter = NULL;
}
umtx_unlock(NULL);
}
/* if the cache was empty, create a converter */
if(converter == NULL) {
UErrorCode status = U_ZERO_ERROR;
converter = ucnv_open(NULL, &status);
if(U_FAILURE(status)) {
return NULL;
}
}
return converter;
}
static void
releaseDefaultConverter(UConverter *converter)
{
if(fgDefaultConverter == NULL) {
umtx_lock(NULL);
if(fgDefaultConverter == NULL) {
fgDefaultConverter = converter;
converter = NULL;
}
umtx_unlock(NULL);
}
if(converter != NULL) {
ucnv_close(converter);
}
}
/* u_unescape & support fns ------------------------------------------------- */
/* This map must be in ASCENDING ORDER OF THE ESCAPE CODE */
static const UChar UNESCAPE_MAP[] = {
/*" 0x22, 0x22 */
/*' 0x27, 0x27 */
/*? 0x3F, 0x3F */
/*\ 0x5C, 0x5C */
/*a*/ 0x61, 0x07,
/*b*/ 0x62, 0x08,
/*f*/ 0x66, 0x0c,
/*n*/ 0x6E, 0x0a,
/*r*/ 0x72, 0x0d,
/*t*/ 0x74, 0x09,
/*v*/ 0x76, 0x0b
};
enum { UNESCAPE_MAP_LENGTH = sizeof(UNESCAPE_MAP) / sizeof(UNESCAPE_MAP[0]) };
/* Convert one octal digit to a numeric value 0..7, or -1 on failure */
static int8_t _digit8(UChar c) {
if (c >= 0x0030 && c <= 0x0037) {
return (int8_t)(c - 0x0030);
}
return -1;
}
/* Convert one hex digit to a numeric value 0..F, or -1 on failure */
static int8_t _digit16(UChar c) {
if (c >= 0x0030 && c <= 0x0039) {
return (int8_t)(c - 0x0030);
}
if (c >= 0x0041 && c <= 0x0046) {
return (int8_t)(c - (0x0041 - 10));
}
if (c >= 0x0061 && c <= 0x0066) {
return (int8_t)(c - (0x0061 - 10));
}
return -1;
}
/* Parse a single escape sequence. Although this method deals in
* UChars, it does not use C++ or UnicodeString. This allows it to
* be used from C contexts. */
U_CAPI UChar32 U_EXPORT2
u_unescapeAt(UNESCAPE_CHAR_AT charAt,
int32_t *offset,
int32_t length,
void *context) {
int32_t start = *offset;
UChar c;
UChar32 result = 0;
int8_t n = 0;
int8_t minDig = 0;
int8_t maxDig = 0;
int8_t bitsPerDigit = 4;
int8_t dig;
int32_t i;
/* Check that offset is in range */
if (*offset < 0 || *offset >= length) {
goto err;
}
/* Fetch first UChar after '\\' */
c = charAt((*offset)++, context);
/* Convert hexadecimal and octal escapes */
switch (c) {
case 0x0075 /*'u'*/:
minDig = maxDig = 4;
break;
case 0x0055 /*'U'*/:
minDig = maxDig = 8;
break;
case 0x0078 /*'x'*/:
minDig = 1;
maxDig = 2;
break;
default:
dig = _digit8(c);
if (dig >= 0) {
minDig = 1;
maxDig = 3;
n = 1; /* Already have first octal digit */
bitsPerDigit = 3;
result = dig;
}
break;
}
if (minDig != 0) {
while (*offset < length && n < maxDig) {
c = charAt(*offset, context);
dig = (int8_t)((bitsPerDigit == 3) ? _digit8(c) : _digit16(c));
if (dig < 0) {
break;
}
result = (result << bitsPerDigit) | dig;
++(*offset);
++n;
}
if (n < minDig) {
goto err;
}
return result;
}
/* Convert C-style escapes in table */
for (i=0; i<UNESCAPE_MAP_LENGTH; i+=2) {
if (c == UNESCAPE_MAP[i]) {
return UNESCAPE_MAP[i+1];
} else if (c < UNESCAPE_MAP[i]) {
break;
}
}
/* If no special forms are recognized, then consider
* the backslash to generically escape the next character.
* Deal with surrogate pairs. */
if (UTF_IS_FIRST_SURROGATE(c) && *offset < length) {
UChar c2 = charAt(*offset, context);
if (UTF_IS_SECOND_SURROGATE(c2)) {
++(*offset);
return UTF16_GET_PAIR_VALUE(c, c2);
}
}
return c;
err:
/* Invalid escape sequence */
*offset = start; /* Reset to initial value */
return (UChar32)0xFFFFFFFF;
}
/* u_unescapeAt() callback to return a UChar from a char* */
static UChar _charPtr_charAt(int32_t offset, void *context) {
UChar c16;
/* It would be more efficient to access the invariant tables
* directly but there is no API for that. */
u_charsToUChars(((char*) context) + offset, &c16, 1);
return c16;
}
/* Append an escape-free segment of the text; used by u_unescape() */
static void _appendUChars(UChar *dest, int32_t destCapacity,
const char *src, int32_t srcLen) {
if (destCapacity < 0) {
destCapacity = 0;
}
if (srcLen > destCapacity) {
srcLen = destCapacity;
}
u_charsToUChars(src, dest, srcLen);
}
/* Do an invariant conversion of char* -> UChar*, with escape parsing */
U_CAPI int32_t U_EXPORT2
u_unescape(const char *src, UChar *dest, int32_t destCapacity) {
const char *segment = src;
int32_t i = 0;
char c;
while ((c=*src) != 0) {
/* '\\' intentionally written as compiler-specific
* character constant to correspond to compiler-specific
* char* constants. */
if (c == '\\') {
int32_t lenParsed = 0;
UChar32 c32;
if (src != segment) {
if (dest != NULL) {
_appendUChars(dest + i, destCapacity - i,
segment, src - segment);
}
i += src - segment;
}
++src; /* advance past '\\' */
c32 = u_unescapeAt(_charPtr_charAt, &lenParsed, uprv_strlen(src), (void*)src);
if (lenParsed == 0) {
goto err;
}
src += lenParsed; /* advance past escape seq. */
if (dest != NULL && UTF_CHAR_LENGTH(c32) <= (destCapacity - i)) {
UTF_APPEND_CHAR_UNSAFE(dest, i, c32);
} else {
i += UTF_CHAR_LENGTH(c32);
}
segment = src;
} else {
++src;
}
}
if (src != segment) {
if (dest != NULL) {
_appendUChars(dest + i, destCapacity - i,
segment, src - segment);
}
i += src - segment;
}
if (dest != NULL && i < destCapacity) {
dest[i] = 0;
}
return i + 1; /* add 1 for zero term */
err:
if (dest != NULL && destCapacity > 0) {
*dest = 0;
}
return 0;
}