libs-base/Source/GSICUString.m
2021-07-19 12:23:15 +02:00

505 lines
12 KiB
Objective-C

/** Implementation of GSICUString for GNUStep
Copyright (C) 2010 Free Software Foundation, Inc.
This file is part of the GNUstep Base Library.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110 USA.
$Date: 2010-09-18 16:09:58 +0100 (Sat, 18 Sep 2010) $ $Revision: 31371 $
*/
#import "common.h"
#if GS_USE_ICU == 1
#import "GSICUString.h"
/**
* The number of characters that we use per chunk when fetching a block of
* characters at once for iteration. Making this value larger will make UText
* iteration faster, at the cost of more memory. Making it larger than the
* size of a typical string will make it no faster but will still cost memory.
*/
static const NSUInteger chunkSize = 32;
/**
* Returns the number of UTF16 characters in a UText backed by an NSString.
*/
static int64_t
UTextNSStringNativeLength(UText *ut)
{
/* For constant strings the length is stored in ut->c, but for mutable
* strings this is set to -1 and we must check the length every time.
*/
return (-1 == ut->c) ? [(NSString*)ut->p length] : ut->c;
}
/**
* Loads a group of characters into the buffer that can be directly accessed by
* users of the UText. This is used for iteration but UText users.
*/
UBool
UTextNSStringAccess(UText *ut, int64_t nativeIndex, UBool forward)
{
NSString *str = (NSString*)ut->p;
NSInteger length = (-1 == ut->c) ? (NSInteger)[str length] : ut->c;
NSInteger nativeStart = ut->chunkNativeStart;
NSInteger nativeLimit = ut->chunkNativeLimit;
NSRange r;
if (forward)
{
if (nativeIndex < nativeLimit && nativeIndex >= nativeStart)
{
/* The chunk already contains the index, set the offset
* to match it.
*/
ut->chunkOffset = nativeIndex - nativeStart;
return TRUE;
}
if (nativeIndex >= length && nativeLimit >= length)
{
/* Asking for a position beyond the end of the string;
* Limit it to point just after the last character.
*/
ut->chunkOffset = ut->chunkLength;
return FALSE;
}
/* Set up to fill the chunk with characters from the string
* and to start at the beginning of that buffer.
*/
nativeStart = nativeIndex;
nativeLimit = nativeIndex + chunkSize;
if (nativeLimit > length)
{
nativeLimit = length;
}
r.location = nativeIndex;
r.length = nativeLimit - nativeIndex;
ut->chunkOffset = 0;
}
else
{
if (nativeIndex <= nativeLimit && nativeIndex > nativeStart)
{
/* The chunk already contains the index, set the offset
* to match it.
*/
ut->chunkOffset = nativeIndex - nativeStart;
return TRUE;
}
if (nativeIndex <= 0 && nativeStart <= 0)
{
/* Asking for a position beyond the start of the string;
* Limit it to position of the first character.
*/
ut->chunkOffset = 0;
return FALSE;
}
nativeLimit = nativeIndex;
if (nativeLimit > length)
{
nativeLimit = length;
}
nativeStart = nativeLimit - chunkSize;
if (nativeStart < 0)
{
nativeStart = 0;
}
r.location = nativeStart;
r.length = nativeLimit - nativeStart;
ut->chunkOffset = r.length;
}
[str getCharacters: ut->pExtra range: r];
ut->chunkNativeLimit = nativeLimit;
ut->chunkNativeStart = nativeStart;
ut->nativeIndexingLimit = r.length;
ut->chunkLength = r.length;
return TRUE;
}
/**
* Replaces characters in an NSString-backed UText.
*/
static int32_t
UTextNSMutableStringReplace(UText *ut,
int64_t nativeStart,
int64_t nativeLimit,
const UChar *replacementText,
int32_t replacmentLength,
UErrorCode *status)
{
NSMutableString *str = (NSMutableString*)ut->p;
NSRange r = NSMakeRange(nativeStart, nativeLimit-nativeStart);
NSString *replacement = [NSString alloc];
if (replacmentLength < 0)
{
replacement = [replacement initWithCString: (const char*)replacementText
encoding: NSUTF16StringEncoding];
}
else
{
replacement = [replacement
initWithCharactersNoCopy: (unichar*)replacementText
length: replacmentLength
freeWhenDone: NO];
}
[str replaceCharactersInRange: r withString: replacement];
// Setting the chunk length to 0 here forces UTextNSStringAccess to fetch
// the data from the string object.
ut->chunkLength = 0;
UTextNSStringAccess(ut, r.location + [replacement length] + 1, TRUE);
ut->chunkOffset++;
[replacement release];
if (NULL != status)
{
*status = 0;
}
return 0;
}
/**
* Reads some characters. This is roughly analogous to NSString's
* -getCharacters:range:.
*/
static int32_t
UTextNSStringExtract(UText *ut,
int64_t nativeStart,
int64_t nativeLimit,
UChar *dest,
int32_t destCapacity,
UErrorCode *status)
{
/* If we're loading no characters, we are expected to return the number of
* characters that we could load if requested.
*/
if (destCapacity <= 0)
{
return nativeLimit - nativeStart;
}
else
{
NSString *str = (NSString*)ut->p;
NSUInteger length = (-1 == ut->c) ? [str length] : ut->c;
NSRange r;
if (nativeLimit > length)
{
nativeLimit = length;
}
r = NSMakeRange(nativeStart, nativeLimit - nativeStart );
if (destCapacity < r.length)
{
r.length = destCapacity;
}
[str getCharacters: dest range: r];
if (destCapacity > r.length)
{
dest[r.length] = 0;
}
return r.length;
}
}
/**
* Copy or move some characters within a UText.
*/
void UTextNSStringCopy(UText *ut,
int64_t nativeStart,
int64_t nativeLimit,
int64_t nativeDest,
UBool move,
UErrorCode *status)
{
NSMutableString *str = (NSMutableString*)ut->p;
NSUInteger length = (-1 == ut->c) ? [str length] : ut->c;
NSRange r;
NSString *substr;
if (nativeLimit > length)
{
nativeLimit = length;
}
r = NSMakeRange(nativeStart, nativeLimit - nativeStart);
substr = [str substringWithRange: r];
[str insertString: substr atIndex: nativeDest];
if (move)
{
if (nativeDest < r.location)
{
r.location += r.length;
}
[str deleteCharactersInRange: r];
}
if (NULL != status)
{
*status = 0;
}
}
/**
* Destructor for the NSString-specific parts of the UText. Because UTexts can
* be allocated on the stack, or reused by different storage implementations,
* this does not destroy the UText itself.
*/
static void
UTextNStringClose(UText *ut)
{
ut->chunkContents = NULL;
[(NSString*)ut->p release];
ut->p = NULL;
}
/**
* Copies the UText object, optionally copying the NSString. This version is
* for NSString-backed UTexts, so uses -copy to copy the string if required.
* Typically, this should not actually copy the underlying storage, because it
* is immutable.
*/
UText*
UTextNSStringClone(UText *dest,
const UText *src,
UBool deep,
UErrorCode *status)
{
NSString *str = (NSString*)src->p;
if (deep)
{
str = [[str copy] autorelease];
}
return UTextInitWithNSString(dest, str);
}
/**
* Copies the UText object, optionally copying the NSMutableString.
*/
UText*
UTextNSMutableStringClone(UText *dest,
const UText *src,
UBool deep,
UErrorCode *status)
{
NSMutableString *str = (NSMutableString*)src->p;
UText *txt;
if (deep)
{
str = [str mutableCopy];
txt = UTextInitWithNSMutableString(dest, str);
[str release];
}
else
{
txt = UTextInitWithNSMutableString(dest, str);
}
return txt;
}
/**
* Returns the index of the current character in the temporary buffer.
*/
int64_t
UTextNSStringMapOffsetToNative(const UText *ut)
{
return ut->chunkNativeStart + ut->chunkOffset;
}
/**
* Vtable for NSString-backed UTexts.
*/
static const UTextFuncs NSStringFuncs =
{
sizeof(UTextFuncs), // Table size
0, 0, 0, // Reserved
UTextNSStringClone,
UTextNSStringNativeLength,
UTextNSStringAccess,
UTextNSStringExtract,
0, // Replace
UTextNSStringCopy,
UTextNSStringMapOffsetToNative,
0, // Map to UTF16
UTextNStringClose,
0, 0, 0 // Spare
};
/**
* Vtable for NSMutableString-backed UTexts.
*/
static const UTextFuncs NSMutableStringFuncs =
{
sizeof(UTextFuncs), // Table size
0, 0, 0, // Reserved
UTextNSMutableStringClone,
UTextNSStringNativeLength,
UTextNSStringAccess,
UTextNSStringExtract,
UTextNSMutableStringReplace,
UTextNSStringCopy,
UTextNSStringMapOffsetToNative,
0, // Map to UTF16
UTextNStringClose,
0, 0, 0 // Spare
};
UText*
UTextInitWithNSMutableString(UText *txt, NSMutableString *str)
{
UErrorCode status = 0;
txt = utext_setup(txt, chunkSize * sizeof(unichar), &status);
if (U_FAILURE(status))
{
return NULL;
}
txt->p = [str retain];
txt->pFuncs = &NSMutableStringFuncs;
txt->chunkContents = txt->pExtra;
txt->c = -1; // Need to fetch length every time
txt->providerProperties = 1<<UTEXT_PROVIDER_WRITABLE;
return txt;
}
UText*
UTextInitWithNSString(UText *txt, NSString *str)
{
UErrorCode status = 0;
txt = utext_setup(txt, 64, &status);
if (U_FAILURE(status))
{
return NULL;
}
txt->p = [str retain];
txt->pFuncs = &NSStringFuncs;
txt->chunkContents = txt->pExtra;
txt->c = [str length];
return txt;
}
@implementation GSUTextString
- (id) init
{
if (nil != (self = [super init]))
{
UText t = UTEXT_INITIALIZER;
memcpy(&txt, &t, sizeof(t));
}
return self;
}
- (NSUInteger) length
{
return utext_nativeLength(&txt);
}
- (unichar) characterAtIndex: (NSUInteger)idx
{
unichar c;
[self getCharacters: &c range: NSMakeRange(idx, 1)];
return c;
}
- (void) getCharacters: (unichar*)buffer range: (NSRange)r
{
UErrorCode status = 0;
utext_extract(&txt, r.location, r.location+r.length, buffer, r.length,
&status);
if (U_FAILURE(status))
{
_NSRangeExceptionRaise();
}
}
- (void) dealloc
{
utext_close(&txt);
[super dealloc];
}
@end
@implementation GSUTextMutableString
- (id) init
{
if (nil != (self = [super init]))
{
UText t = UTEXT_INITIALIZER;
memcpy(&txt, &t, sizeof(t));
}
return self;
}
- (NSUInteger) length
{
return utext_nativeLength(&txt);
}
- (unichar) characterAtIndex: (NSUInteger)idx
{
unichar c;
[self getCharacters: &c range: NSMakeRange(idx, 1)];
return c;
}
- (void) getCharacters: (unichar*)buffer range: (NSRange)r
{
UErrorCode status = 0;
utext_extract(&txt, r.location, r.location+r.length, buffer, r.length,
&status);
if (U_FAILURE(status))
{
_NSRangeExceptionRaise();
}
}
- (void) replaceCharactersInRange: (NSRange)r
withString: (NSString*)aString
{
NSUInteger length = [aString length];
UErrorCode status = 0;
TEMP_BUFFER(buffer, length);
[aString getCharacters: buffer range: NSMakeRange(0, length)];
utext_replace(&txt, r.location, r.location + r.length, buffer, length, &status);
}
- (void) dealloc
{
utext_close(&txt);
[super dealloc];
}
@end
#endif // HAV_ICU