The Tor Browser: intl/icu/source/common/uiter.cpp@129ffea94266 (annotated)

intl/icu/source/common/uiter.cpp@129ffea94266 (annotated)

intl/icu/source/common/uiter.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /*
 *******************************************************************************
 *
 *   Copyright (C) 2002-2012, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 *******************************************************************************
 *   file name:  uiter.cpp
 *   encoding:   US-ASCII
 *   tab size:   8 (not used)
 *   indentation:4
 *
 *   created on: 2002jan18
 *   created by: Markus W. Scherer
 */
 #include "unicode/utypes.h"
 #include "unicode/ustring.h"
 #include "unicode/chariter.h"
 #include "unicode/rep.h"
 #include "unicode/uiter.h"
 #include "unicode/utf.h"
 #include "unicode/utf8.h"
 #include "unicode/utf16.h"
 #include "cstring.h"
 U_NAMESPACE_USE
 #define IS_EVEN(n) (((n)&1)==0)
 #define IS_POINTER_EVEN(p) IS_EVEN((size_t)p)
 U_CDECL_BEGIN
 /* No-Op UCharIterator implementation for illegal input --------------------- */
 static int32_t U_CALLCONV
 noopGetIndex(UCharIterator * /*iter*/, UCharIteratorOrigin /*origin*/) {
     return 0;
 }
 static int32_t U_CALLCONV
 noopMove(UCharIterator * /*iter*/, int32_t /*delta*/, UCharIteratorOrigin /*origin*/) {
     return 0;
 }
 static UBool U_CALLCONV
 noopHasNext(UCharIterator * /*iter*/) {
     return FALSE;
 }
 static UChar32 U_CALLCONV
 noopCurrent(UCharIterator * /*iter*/) {
     return U_SENTINEL;
 }
 static uint32_t U_CALLCONV
 noopGetState(const UCharIterator * /*iter*/) {
     return UITER_NO_STATE;
 }
 static void U_CALLCONV
 noopSetState(UCharIterator * /*iter*/, uint32_t /*state*/, UErrorCode *pErrorCode) {
     *pErrorCode=U_UNSUPPORTED_ERROR;
 }
 static const UCharIterator noopIterator={
 , 0, 0, 0, 0, 0,
     noopGetIndex,
     noopMove,
     noopHasNext,
     noopHasNext,
     noopCurrent,
     noopCurrent,
     noopCurrent,
     NULL,
     noopGetState,
     noopSetState
 };
 /* UCharIterator implementation for simple strings -------------------------- */
 /*
  * This is an implementation of a code unit (UChar) iterator
  * for UChar * strings.
  *
  * The UCharIterator.context field holds a pointer to the string.
  */
 static int32_t U_CALLCONV
 stringIteratorGetIndex(UCharIterator *iter, UCharIteratorOrigin origin) {
     switch(origin) {
     case UITER_ZERO:
         return 0;
     case UITER_START:
         return iter->start;
     case UITER_CURRENT:
         return iter->index;
     case UITER_LIMIT:
         return iter->limit;
     case UITER_LENGTH:
         return iter->length;
     default:
         /* not a valid origin */
         /* Should never get here! */
         return -1;
     }
 }
 static int32_t U_CALLCONV
 stringIteratorMove(UCharIterator *iter, int32_t delta, UCharIteratorOrigin origin) {
     int32_t pos;
     switch(origin) {
     case UITER_ZERO:
         pos=delta;
         break;
     case UITER_START:
         pos=iter->start+delta;
         break;
     case UITER_CURRENT:
         pos=iter->index+delta;
         break;
     case UITER_LIMIT:
         pos=iter->limit+delta;
         break;
     case UITER_LENGTH:
         pos=iter->length+delta;
         break;
     default:
         return -1;  /* Error */
     }
     if(pos<iter->start) {
         pos=iter->start;
     } else if(pos>iter->limit) {
         pos=iter->limit;
     }
     return iter->index=pos;
 }
 static UBool U_CALLCONV
 stringIteratorHasNext(UCharIterator *iter) {
     return iter->index<iter->limit;
 }
 static UBool U_CALLCONV
 stringIteratorHasPrevious(UCharIterator *iter) {
     return iter->index>iter->start;
 }
 static UChar32 U_CALLCONV
 stringIteratorCurrent(UCharIterator *iter) {
     if(iter->index<iter->limit) {
         return ((const UChar *)(iter->context))[iter->index];
     } else {
         return U_SENTINEL;
     }
 }
 static UChar32 U_CALLCONV
 stringIteratorNext(UCharIterator *iter) {
     if(iter->index<iter->limit) {
         return ((const UChar *)(iter->context))[iter->index++];
     } else {
         return U_SENTINEL;
     }
 }
 static UChar32 U_CALLCONV
 stringIteratorPrevious(UCharIterator *iter) {
     if(iter->index>iter->start) {
         return ((const UChar *)(iter->context))[--iter->index];
     } else {
         return U_SENTINEL;
     }
 }
 static uint32_t U_CALLCONV
 stringIteratorGetState(const UCharIterator *iter) {
     return (uint32_t)iter->index;
 }
 static void U_CALLCONV
 stringIteratorSetState(UCharIterator *iter, uint32_t state, UErrorCode *pErrorCode) {
     if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
         /* do nothing */
     } else if(iter==NULL) {
         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
     } else if((int32_t)state<iter->start || iter->limit<(int32_t)state) {
         *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
     } else {
         iter->index=(int32_t)state;
     }
 }
 static const UCharIterator stringIterator={
 , 0, 0, 0, 0, 0,
     stringIteratorGetIndex,
     stringIteratorMove,
     stringIteratorHasNext,
     stringIteratorHasPrevious,
     stringIteratorCurrent,
     stringIteratorNext,
     stringIteratorPrevious,
     NULL,
     stringIteratorGetState,
     stringIteratorSetState
 };
 U_CAPI void U_EXPORT2
 uiter_setString(UCharIterator *iter, const UChar *s, int32_t length) {
     if(iter!=0) {
         if(s!=0 && length>=-1) {
             *iter=stringIterator;
             iter->context=s;
             if(length>=0) {
                 iter->length=length;
             } else {
                 iter->length=u_strlen(s);
             }
             iter->limit=iter->length;
         } else {
             *iter=noopIterator;
         }
     }
 }
 /* UCharIterator implementation for UTF-16BE strings ------------------------ */
 /*
  * This is an implementation of a code unit (UChar) iterator
  * for UTF-16BE strings, i.e., strings in byte-vectors where
  * each UChar is stored as a big-endian pair of bytes.
  *
  * The UCharIterator.context field holds a pointer to the string.
  * Everything works just like with a normal UChar iterator (uiter_setString),
  * except that UChars are assembled from byte pairs.
  */
 /* internal helper function */
 static inline UChar32
 utf16BEIteratorGet(UCharIterator *iter, int32_t index) {
     const uint8_t *p=(const uint8_t *)iter->context;
     return ((UChar)p[2*index]<<8)|(UChar)p[2*index+1];
 }
 static UChar32 U_CALLCONV
 utf16BEIteratorCurrent(UCharIterator *iter) {
     int32_t index;
     if((index=iter->index)<iter->limit) {
         return utf16BEIteratorGet(iter, index);
     } else {
         return U_SENTINEL;
     }
 }
 static UChar32 U_CALLCONV
 utf16BEIteratorNext(UCharIterator *iter) {
     int32_t index;
     if((index=iter->index)<iter->limit) {
         iter->index=index+1;
         return utf16BEIteratorGet(iter, index);
     } else {
         return U_SENTINEL;
     }
 }
 static UChar32 U_CALLCONV
 utf16BEIteratorPrevious(UCharIterator *iter) {
     int32_t index;
     if((index=iter->index)>iter->start) {
         iter->index=--index;
         return utf16BEIteratorGet(iter, index);
     } else {
         return U_SENTINEL;
     }
 }
 static const UCharIterator utf16BEIterator={
 , 0, 0, 0, 0, 0,
     stringIteratorGetIndex,
     stringIteratorMove,
     stringIteratorHasNext,
     stringIteratorHasPrevious,
     utf16BEIteratorCurrent,
     utf16BEIteratorNext,
     utf16BEIteratorPrevious,
     NULL,
     stringIteratorGetState,
     stringIteratorSetState
 };
 /*
  * Count the number of UChars in a UTF-16BE string before a terminating UChar NUL,
  * i.e., before a pair of 0 bytes where the first 0 byte is at an even
  * offset from s.
  */
 static int32_t
 utf16BE_strlen(const char *s) {
     if(IS_POINTER_EVEN(s)) {
         /*
          * even-aligned, call u_strlen(s)
          * we are probably on a little-endian machine, but searching for UChar NUL
          * does not care about endianness
          */
         return u_strlen((const UChar *)s);
     } else {
         /* odd-aligned, search for pair of 0 bytes */
         const char *p=s;
         while(!(*p==0 && p[1]==0)) {
             p+=2;
         }
         return (int32_t)((p-s)/2);
     }
 }
 U_CAPI void U_EXPORT2
 uiter_setUTF16BE(UCharIterator *iter, const char *s, int32_t length) {
     if(iter!=NULL) {
         /* allow only even-length strings (the input length counts bytes) */
         if(s!=NULL && (length==-1 || (length>=0 && IS_EVEN(length)))) {
             /* length/=2, except that >>=1 also works for -1 (-1/2==0, -1>>1==-1) */
             length>>=1;
             if(U_IS_BIG_ENDIAN && IS_POINTER_EVEN(s)) {
                 /* big-endian machine and 2-aligned UTF-16BE string: use normal UChar iterator */
                 uiter_setString(iter, (const UChar *)s, length);
                 return;
             }
             *iter=utf16BEIterator;
             iter->context=s;
             if(length>=0) {
                 iter->length=length;
             } else {
                 iter->length=utf16BE_strlen(s);
             }
             iter->limit=iter->length;
         } else {
             *iter=noopIterator;
         }
     }
 }
 /* UCharIterator wrapper around CharacterIterator --------------------------- */
 /*
  * This is wrapper code around a C++ CharacterIterator to
  * look like a C UCharIterator.
  *
  * The UCharIterator.context field holds a pointer to the CharacterIterator.
  */
 static int32_t U_CALLCONV
 characterIteratorGetIndex(UCharIterator *iter, UCharIteratorOrigin origin) {
     switch(origin) {
     case UITER_ZERO:
         return 0;
     case UITER_START:
         return ((CharacterIterator *)(iter->context))->startIndex();
     case UITER_CURRENT:
         return ((CharacterIterator *)(iter->context))->getIndex();
     case UITER_LIMIT:
         return ((CharacterIterator *)(iter->context))->endIndex();
     case UITER_LENGTH:
         return ((CharacterIterator *)(iter->context))->getLength();
     default:
         /* not a valid origin */
         /* Should never get here! */
         return -1;
     }
 }
 static int32_t U_CALLCONV
 characterIteratorMove(UCharIterator *iter, int32_t delta, UCharIteratorOrigin origin) {
     switch(origin) {
     case UITER_ZERO:
         ((CharacterIterator *)(iter->context))->setIndex(delta);
         return ((CharacterIterator *)(iter->context))->getIndex();
     case UITER_START:
     case UITER_CURRENT:
     case UITER_LIMIT:
         return ((CharacterIterator *)(iter->context))->move(delta, (CharacterIterator::EOrigin)origin);
     case UITER_LENGTH:
         ((CharacterIterator *)(iter->context))->setIndex(((CharacterIterator *)(iter->context))->getLength()+delta);
         return ((CharacterIterator *)(iter->context))->getIndex();
     default:
         /* not a valid origin */
         /* Should never get here! */
         return -1;
     }
 }
 static UBool U_CALLCONV
 characterIteratorHasNext(UCharIterator *iter) {
     return ((CharacterIterator *)(iter->context))->hasNext();
 }
 static UBool U_CALLCONV
 characterIteratorHasPrevious(UCharIterator *iter) {
     return ((CharacterIterator *)(iter->context))->hasPrevious();
 }
 static UChar32 U_CALLCONV
 characterIteratorCurrent(UCharIterator *iter) {
     UChar32 c;
     c=((CharacterIterator *)(iter->context))->current();
     if(c!=0xffff || ((CharacterIterator *)(iter->context))->hasNext()) {
         return c;
     } else {
         return U_SENTINEL;
     }
 }
 static UChar32 U_CALLCONV
 characterIteratorNext(UCharIterator *iter) {
     if(((CharacterIterator *)(iter->context))->hasNext()) {
         return ((CharacterIterator *)(iter->context))->nextPostInc();
     } else {
         return U_SENTINEL;
     }
 }
 static UChar32 U_CALLCONV
 characterIteratorPrevious(UCharIterator *iter) {
     if(((CharacterIterator *)(iter->context))->hasPrevious()) {
         return ((CharacterIterator *)(iter->context))->previous();
     } else {
         return U_SENTINEL;
     }
 }
 static uint32_t U_CALLCONV
 characterIteratorGetState(const UCharIterator *iter) {
     return ((CharacterIterator *)(iter->context))->getIndex();
 }
 static void U_CALLCONV
 characterIteratorSetState(UCharIterator *iter, uint32_t state, UErrorCode *pErrorCode) {
     if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
         /* do nothing */
     } else if(iter==NULL || iter->context==NULL) {
         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
     } else if((int32_t)state<((CharacterIterator *)(iter->context))->startIndex() || ((CharacterIterator *)(iter->context))->endIndex()<(int32_t)state) {
         *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
     } else {
         ((CharacterIterator *)(iter->context))->setIndex((int32_t)state);
     }
 }
 static const UCharIterator characterIteratorWrapper={
 , 0, 0, 0, 0, 0,
     characterIteratorGetIndex,
     characterIteratorMove,
     characterIteratorHasNext,
     characterIteratorHasPrevious,
     characterIteratorCurrent,
     characterIteratorNext,
     characterIteratorPrevious,
     NULL,
     characterIteratorGetState,
     characterIteratorSetState
 };
 U_CAPI void U_EXPORT2
 uiter_setCharacterIterator(UCharIterator *iter, CharacterIterator *charIter) {
     if(iter!=0) {
         if(charIter!=0) {
             *iter=characterIteratorWrapper;
             iter->context=charIter;
         } else {
             *iter=noopIterator;
         }
     }
 }
 /* UCharIterator wrapper around Replaceable --------------------------------- */
 /*
  * This is an implementation of a code unit (UChar) iterator
  * based on a Replaceable object.
  *
  * The UCharIterator.context field holds a pointer to the Replaceable.
  * UCharIterator.length and UCharIterator.index hold Replaceable.length()
  * and the iteration index.
  */
 static UChar32 U_CALLCONV
 replaceableIteratorCurrent(UCharIterator *iter) {
     if(iter->index<iter->limit) {
         return ((Replaceable *)(iter->context))->charAt(iter->index);
     } else {
         return U_SENTINEL;
     }
 }
 static UChar32 U_CALLCONV
 replaceableIteratorNext(UCharIterator *iter) {
     if(iter->index<iter->limit) {
         return ((Replaceable *)(iter->context))->charAt(iter->index++);
     } else {
         return U_SENTINEL;
     }
 }
 static UChar32 U_CALLCONV
 replaceableIteratorPrevious(UCharIterator *iter) {
     if(iter->index>iter->start) {
         return ((Replaceable *)(iter->context))->charAt(--iter->index);
     } else {
         return U_SENTINEL;
     }
 }
 static const UCharIterator replaceableIterator={
 , 0, 0, 0, 0, 0,
     stringIteratorGetIndex,
     stringIteratorMove,
     stringIteratorHasNext,
     stringIteratorHasPrevious,
     replaceableIteratorCurrent,
     replaceableIteratorNext,
     replaceableIteratorPrevious,
     NULL,
     stringIteratorGetState,
     stringIteratorSetState
 };
 U_CAPI void U_EXPORT2
 uiter_setReplaceable(UCharIterator *iter, const Replaceable *rep) {
     if(iter!=0) {
         if(rep!=0) {
             *iter=replaceableIterator;
             iter->context=rep;
             iter->limit=iter->length=rep->length();
         } else {
             *iter=noopIterator;
         }
     }
 }
 /* UCharIterator implementation for UTF-8 strings --------------------------- */
 /*
  * Possible, probably necessary only for an implementation for arbitrary
  * converters:
  * Maintain a buffer (ring buffer?) for a piece of converted 16-bit text.
  * This would require to turn reservedFn into a close function and
  * to introduce a uiter_close(iter).
  */
 #define UITER_CNV_CAPACITY 16
 /*
  * Minimal implementation:
  * Maintain a single-UChar buffer for an additional surrogate.
  * The caller must not modify start and limit because they are used internally.
  *
  * Use UCharIterator fields as follows:
  *   context        pointer to UTF-8 string
  *   length         UTF-16 length of the string; -1 until lazy evaluation
  *   start          current UTF-8 index
  *   index          current UTF-16 index; may be -1="unknown" after setState()
  *   limit          UTF-8 length of the string
  *   reservedField  supplementary code point
  *
  * Since UCharIterator delivers 16-bit code units, the iteration can be
  * currently in the middle of the byte sequence for a supplementary code point.
  * In this case, reservedField will contain that code point and start will
  * point to after the corresponding byte sequence. The UTF-16 index will be
  * one less than what it would otherwise be corresponding to the UTF-8 index.
  * Otherwise, reservedField will be 0.
  */
 /*
  * Possible optimization for NUL-terminated UTF-8 and UTF-16 strings:
  * Add implementations that do not call strlen() for iteration but check for NUL.
  */
 static int32_t U_CALLCONV
 utf8IteratorGetIndex(UCharIterator *iter, UCharIteratorOrigin origin) {
     switch(origin) {
     case UITER_ZERO:
     case UITER_START:
         return 0;
     case UITER_CURRENT:
         if(iter->index<0) {
             /* the current UTF-16 index is unknown after setState(), count from the beginning */
             const uint8_t *s;
             UChar32 c;
             int32_t i, limit, index;
             s=(const uint8_t *)iter->context;
             i=index=0;
             limit=iter->start; /* count up to the UTF-8 index */
             while(i<limit) {
                 U8_NEXT_OR_FFFD(s, i, limit, c);
                 index+=U16_LENGTH(c);
             }
             iter->start=i; /* just in case setState() did not get us to a code point boundary */
             if(i==iter->limit) {
                 iter->length=index; /* in case it was <0 or wrong */
             }
             if(iter->reservedField!=0) {
                 --index; /* we are in the middle of a supplementary code point */
             }
             iter->index=index;
         }
         return iter->index;
     case UITER_LIMIT:
     case UITER_LENGTH:
         if(iter->length<0) {
             const uint8_t *s;
             UChar32 c;
             int32_t i, limit, length;
             s=(const uint8_t *)iter->context;
             if(iter->index<0) {
                 /*
                  * the current UTF-16 index is unknown after setState(),
                  * we must first count from the beginning to here
                  */
                 i=length=0;
                 limit=iter->start;
                 /* count from the beginning to the current index */
                 while(i<limit) {
                     U8_NEXT_OR_FFFD(s, i, limit, c);
                     length+=U16_LENGTH(c);
                 }
                 /* assume i==limit==iter->start, set the UTF-16 index */
                 iter->start=i; /* just in case setState() did not get us to a code point boundary */
                 iter->index= iter->reservedField!=0 ? length-1 : length;
             } else {
                 i=iter->start;
                 length=iter->index;
                 if(iter->reservedField!=0) {
                     ++length;
                 }
             }
             /* count from the current index to the end */
             limit=iter->limit;
             while(i<limit) {
                 U8_NEXT_OR_FFFD(s, i, limit, c);
                 length+=U16_LENGTH(c);
             }
             iter->length=length;
         }
         return iter->length;
     default:
         /* not a valid origin */
         /* Should never get here! */
         return -1;
     }
 }
 static int32_t U_CALLCONV
 utf8IteratorMove(UCharIterator *iter, int32_t delta, UCharIteratorOrigin origin) {
     const uint8_t *s;
     UChar32 c;
     int32_t pos; /* requested UTF-16 index */
     int32_t i; /* UTF-8 index */
     UBool havePos;
     /* calculate the requested UTF-16 index */
     switch(origin) {
     case UITER_ZERO:
     case UITER_START:
         pos=delta;
         havePos=TRUE;
         /* iter->index<0 (unknown) is possible */
         break;
     case UITER_CURRENT:
         if(iter->index>=0) {
             pos=iter->index+delta;
             havePos=TRUE;
         } else {
             /* the current UTF-16 index is unknown after setState(), use only delta */
             pos=0;
             havePos=FALSE;
         }
         break;
     case UITER_LIMIT:
     case UITER_LENGTH:
         if(iter->length>=0) {
             pos=iter->length+delta;
             havePos=TRUE;
         } else {
             /* pin to the end, avoid counting the length */
             iter->index=-1;
             iter->start=iter->limit;
             iter->reservedField=0;
             if(delta>=0) {
                 return UITER_UNKNOWN_INDEX;
             } else {
                 /* the current UTF-16 index is unknown, use only delta */
                 pos=0;
                 havePos=FALSE;
             }
         }
         break;
     default:
         return -1;  /* Error */
     }
     if(havePos) {
         /* shortcuts: pinning to the edges of the string */
         if(pos<=0) {
             iter->index=iter->start=iter->reservedField=0;
             return 0;
         } else if(iter->length>=0 && pos>=iter->length) {
             iter->index=iter->length;
             iter->start=iter->limit;
             iter->reservedField=0;
             return iter->index;
         }
         /* minimize the number of U8_NEXT/PREV operations */
         if(iter->index<0 || pos<iter->index/2) {
             /* go forward from the start instead of backward from the current index */
             iter->index=iter->start=iter->reservedField=0;
         } else if(iter->length>=0 && (iter->length-pos)<(pos-iter->index)) {
             /*
              * if we have the UTF-16 index and length and the new position is
              * closer to the end than the current index,
              * then go backward from the end instead of forward from the current index
              */
             iter->index=iter->length;
             iter->start=iter->limit;
             iter->reservedField=0;
         }
         delta=pos-iter->index;
         if(delta==0) {
             return iter->index; /* nothing to do */
         }
     } else {
         /* move relative to unknown UTF-16 index */
         if(delta==0) {
             return UITER_UNKNOWN_INDEX; /* nothing to do */
         } else if(-delta>=iter->start) {
             /* moving backwards by more UChars than there are UTF-8 bytes, pin to 0 */
             iter->index=iter->start=iter->reservedField=0;
             return 0;
         } else if(delta>=(iter->limit-iter->start)) {
             /* moving forward by more UChars than the remaining UTF-8 bytes, pin to the end */
             iter->index=iter->length; /* may or may not be <0 (unknown) */
             iter->start=iter->limit;
             iter->reservedField=0;
             return iter->index>=0 ? iter->index : (int32_t)UITER_UNKNOWN_INDEX;
         }
     }
     /* delta!=0 */
     /* move towards the requested position, pin to the edges of the string */
     s=(const uint8_t *)iter->context;
     pos=iter->index; /* could be <0 (unknown) */
     i=iter->start;
     if(delta>0) {
         /* go forward */
         int32_t limit=iter->limit;
         if(iter->reservedField!=0) {
             iter->reservedField=0;
             ++pos;
             --delta;
         }
         while(delta>0 && i<limit) {
             U8_NEXT_OR_FFFD(s, i, limit, c);
             if(c<=0xffff) {
                 ++pos;
                 --delta;
             } else if(delta>=2) {
                 pos+=2;
                 delta-=2;
             } else /* delta==1 */ {
                 /* stop in the middle of a supplementary code point */
                 iter->reservedField=c;
                 ++pos;
                 break; /* delta=0; */
             }
         }
         if(i==limit) {
             if(iter->length<0 && iter->index>=0) {
                 iter->length= iter->reservedField==0 ? pos : pos+1;
             } else if(iter->index<0 && iter->length>=0) {
                 iter->index= iter->reservedField==0 ? iter->length : iter->length-1;
             }
         }
     } else /* delta<0 */ {
         /* go backward */
         if(iter->reservedField!=0) {
             iter->reservedField=0;
             i-=4; /* we stayed behind the supplementary code point; go before it now */
             --pos;
             ++delta;
         }
         while(delta<0 && i>0) {
             U8_PREV_OR_FFFD(s, 0, i, c);
             if(c<=0xffff) {
                 --pos;
                 ++delta;
             } else if(delta<=-2) {
                 pos-=2;
                 delta+=2;
             } else /* delta==-1 */ {
                 /* stop in the middle of a supplementary code point */
                 i+=4; /* back to behind this supplementary code point for consistent state */
                 iter->reservedField=c;
                 --pos;
                 break; /* delta=0; */
             }
         }
     }
     iter->start=i;
     if(iter->index>=0) {
         return iter->index=pos;
     } else {
         /* we started with index<0 (unknown) so pos is bogus */
         if(i<=1) {
             return iter->index=i; /* reached the beginning */
         } else {
             /* we still don't know the UTF-16 index */
             return UITER_UNKNOWN_INDEX;
         }
     }
 }
 static UBool U_CALLCONV
 utf8IteratorHasNext(UCharIterator *iter) {
     return iter->start<iter->limit || iter->reservedField!=0;
 }
 static UBool U_CALLCONV
 utf8IteratorHasPrevious(UCharIterator *iter) {
     return iter->start>0;
 }
 static UChar32 U_CALLCONV
 utf8IteratorCurrent(UCharIterator *iter) {
     if(iter->reservedField!=0) {
         return U16_TRAIL(iter->reservedField);
     } else if(iter->start<iter->limit) {
         const uint8_t *s=(const uint8_t *)iter->context;
         UChar32 c;
         int32_t i=iter->start;
         U8_NEXT_OR_FFFD(s, i, iter->limit, c);
         if(c<=0xffff) {
             return c;
         } else {
             return U16_LEAD(c);
         }
     } else {
         return U_SENTINEL;
     }
 }
 static UChar32 U_CALLCONV
 utf8IteratorNext(UCharIterator *iter) {
     int32_t index;
     if(iter->reservedField!=0) {
         UChar trail=U16_TRAIL(iter->reservedField);
         iter->reservedField=0;
         if((index=iter->index)>=0) {
             iter->index=index+1;
         }
         return trail;
     } else if(iter->start<iter->limit) {
         const uint8_t *s=(const uint8_t *)iter->context;
         UChar32 c;
         U8_NEXT_OR_FFFD(s, iter->start, iter->limit, c);
         if((index=iter->index)>=0) {
             iter->index=++index;
             if(iter->length<0 && iter->start==iter->limit) {
                 iter->length= c<=0xffff ? index : index+1;
             }
         } else if(iter->start==iter->limit && iter->length>=0) {
             iter->index= c<=0xffff ? iter->length : iter->length-1;
         }
         if(c<=0xffff) {
             return c;
         } else {
             iter->reservedField=c;
             return U16_LEAD(c);
         }
     } else {
         return U_SENTINEL;
     }
 }
 static UChar32 U_CALLCONV
 utf8IteratorPrevious(UCharIterator *iter) {
     int32_t index;
     if(iter->reservedField!=0) {
         UChar lead=U16_LEAD(iter->reservedField);
         iter->reservedField=0;
         iter->start-=4; /* we stayed behind the supplementary code point; go before it now */
         if((index=iter->index)>0) {
             iter->index=index-1;
         }
         return lead;
     } else if(iter->start>0) {
         const uint8_t *s=(const uint8_t *)iter->context;
         UChar32 c;
         U8_PREV_OR_FFFD(s, 0, iter->start, c);
         if((index=iter->index)>0) {
             iter->index=index-1;
         } else if(iter->start<=1) {
             iter->index= c<=0xffff ? iter->start : iter->start+1;
         }
         if(c<=0xffff) {
             return c;
         } else {
             iter->start+=4; /* back to behind this supplementary code point for consistent state */
             iter->reservedField=c;
             return U16_TRAIL(c);
         }
     } else {
         return U_SENTINEL;
     }
 }
 static uint32_t U_CALLCONV
 utf8IteratorGetState(const UCharIterator *iter) {
     uint32_t state=(uint32_t)(iter->start<<1);
     if(iter->reservedField!=0) {
         state|=1;
     }
     return state;
 }
 static void U_CALLCONV
 utf8IteratorSetState(UCharIterator *iter,
                      uint32_t state,
                      UErrorCode *pErrorCode)
 {
     if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
         /* do nothing */
     } else if(iter==NULL) {
         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
     } else if(state==utf8IteratorGetState(iter)) {
         /* setting to the current state: no-op */
     } else {
         int32_t index=(int32_t)(state>>1); /* UTF-8 index */
         state&=1; /* 1 if in surrogate pair, must be index>=4 */
         if((state==0 ? index<0 : index<4) || iter->limit<index) {
             *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
         } else {
             iter->start=index; /* restore UTF-8 byte index */
             if(index<=1) {
                 iter->index=index;
             } else {
                 iter->index=-1; /* unknown UTF-16 index */
             }
             if(state==0) {
                 iter->reservedField=0;
             } else {
                 /* verified index>=4 above */
                 UChar32 c;
                 U8_PREV_OR_FFFD((const uint8_t *)iter->context, 0, index, c);
                 if(c<=0xffff) {
                     *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
                 } else {
                     iter->reservedField=c;
                 }
             }
         }
     }
 }
 static const UCharIterator utf8Iterator={
 , 0, 0, 0, 0, 0,
     utf8IteratorGetIndex,
     utf8IteratorMove,
     utf8IteratorHasNext,
     utf8IteratorHasPrevious,
     utf8IteratorCurrent,
     utf8IteratorNext,
     utf8IteratorPrevious,
     NULL,
     utf8IteratorGetState,
     utf8IteratorSetState
 };
 U_CAPI void U_EXPORT2
 uiter_setUTF8(UCharIterator *iter, const char *s, int32_t length) {
     if(iter!=0) {
         if(s!=0 && length>=-1) {
             *iter=utf8Iterator;
             iter->context=s;
             if(length>=0) {
                 iter->limit=length;
             } else {
                 iter->limit=(int32_t)uprv_strlen(s);
             }
             iter->length= iter->limit<=1 ? iter->limit : -1;
         } else {
             *iter=noopIterator;
         }
     }
 }
 /* Helper functions --------------------------------------------------------- */
 U_CAPI UChar32 U_EXPORT2
 uiter_current32(UCharIterator *iter) {
     UChar32 c, c2;
     c=iter->current(iter);
     if(U16_IS_SURROGATE(c)) {
         if(U16_IS_SURROGATE_LEAD(c)) {
             /*
              * go to the next code unit
              * we know that we are not at the limit because c!=U_SENTINEL
              */
             iter->move(iter, 1, UITER_CURRENT);
             if(U16_IS_TRAIL(c2=iter->current(iter))) {
                 c=U16_GET_SUPPLEMENTARY(c, c2);
             }
             /* undo index movement */
             iter->move(iter, -1, UITER_CURRENT);
         } else {
             if(U16_IS_LEAD(c2=iter->previous(iter))) {
                 c=U16_GET_SUPPLEMENTARY(c2, c);
             }
             if(c2>=0) {
                 /* undo index movement */
                 iter->move(iter, 1, UITER_CURRENT);
             }
         }
     }
     return c;
 }
 U_CAPI UChar32 U_EXPORT2
 uiter_next32(UCharIterator *iter) {
     UChar32 c, c2;
     c=iter->next(iter);
     if(U16_IS_LEAD(c)) {
         if(U16_IS_TRAIL(c2=iter->next(iter))) {
             c=U16_GET_SUPPLEMENTARY(c, c2);
         } else if(c2>=0) {
             /* unmatched first surrogate, undo index movement */
             iter->move(iter, -1, UITER_CURRENT);
         }
     }
     return c;
 }
 U_CAPI UChar32 U_EXPORT2
 uiter_previous32(UCharIterator *iter) {
     UChar32 c, c2;
     c=iter->previous(iter);
     if(U16_IS_TRAIL(c)) {
         if(U16_IS_LEAD(c2=iter->previous(iter))) {
             c=U16_GET_SUPPLEMENTARY(c2, c);
         } else if(c2>=0) {
             /* unmatched second surrogate, undo index movement */
             iter->move(iter, 1, UITER_CURRENT);
         }
     }
     return c;
 }
 U_CAPI uint32_t U_EXPORT2
 uiter_getState(const UCharIterator *iter) {
     if(iter==NULL || iter->getState==NULL) {
         return UITER_NO_STATE;
     } else {
         return iter->getState(iter);
     }
 }
 U_CAPI void U_EXPORT2
 uiter_setState(UCharIterator *iter, uint32_t state, UErrorCode *pErrorCode) {
     if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
         /* do nothing */
     } else if(iter==NULL) {
         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
     } else if(iter->setState==NULL) {
         *pErrorCode=U_UNSUPPORTED_ERROR;
     } else {
         iter->setState(iter, state, pErrorCode);
     }
 }
 U_CDECL_END

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intl/icu/source/common/uiter.cpp@129ffea94266 (annotated)

intl/icu/source/common/uiter.cpp