scuffed-code/icu4c/source/common/unistr.cpp

/*
*******************************************************************************
* Copyright (C) 1999, International Business Machines Corporation and         *
* others. All Rights Reserved.                                                *
*******************************************************************************
*
* File unistr.cpp
*
* Modification History:
*
*   Date        Name        Description
*   09/25/98    stephen     Creation.
*   04/20/99    stephen     Overhauled per 4/16 code review.
*   07/09/99    stephen     Renamed {hi,lo},{byte,word} to icu_X for HP/UX
*   11/18/99    aliu        Added handleReplaceBetween() to make inherit from
*                           Replaceable.
*******************************************************************************
*/

#include "unicode/utypes.h"
#include "unicode/putil.h"
#include "unicode/locid.h"
#include "cstring.h"
#include "cmemory.h"
#include "unicode/ustring.h"
#include "mutex.h"
#include "unicode/unistr.h"

#if 0
//DEBUGGING
#include <iostream.h>

void
print(const UnicodeString& s,
      const char *name)
{
  UChar c;
  cout << name << ":|";
  for(int i = 0; i < s.length(); ++i) {
    c = s[i];
    if(c>= 0x007E || c < 0x0020)
      cout << "[0x" << hex << s[i] << "]";
    else
      cout << (char) s[i];
  }
  cout << '|' << endl;
}

void
print(const UChar *s,
      int32_t len,
      const char *name)
{
  UChar c;
  cout << name << ":|";
  for(int i = 0; i < len; ++i) {
    c = s[i];
    if(c>= 0x007E || c < 0x0020)
      cout << "[0x" << hex << s[i] << "]";
    else
      cout << (char) s[i];
  }
  cout << '|' << endl;
}
// END DEBUGGING
#endif

// Local function definitions for now

// need to copy areas that may overlap
inline void
us_arrayCopy(const UChar *src, int32_t srcStart,
         UChar *dst, int32_t dstStart, int32_t count)
{
  if(count>0) {
    uprv_memmove(dst+dstStart, src+srcStart, (size_t)(count*sizeof(*src)));
  }
}

UConverter* UnicodeString::fgDefaultConverter  = 0;

//========================================
// Constructors
//========================================
UnicodeString::UnicodeString()
  : fArray(fStackBuffer),
    fLength(0),
    fCapacity(US_STACKBUF_SIZE),
    fHashCode(kEmptyHashCode),
    fFlags(kShortString)
{}

UnicodeString::UnicodeString(int32_t capacity)
  : fArray(0),
    fLength(0),
    fCapacity(US_STACKBUF_SIZE),
    fHashCode(kEmptyHashCode),
    fFlags(0)
{
  allocate(capacity);
}

UnicodeString::UnicodeString(UChar ch)
  : fArray(fStackBuffer),
    fLength(1),
    fCapacity(US_STACKBUF_SIZE),
    fHashCode(kInvalidHashCode),
    fFlags(kShortString)
{
  fStackBuffer[0] = ch;
}

UnicodeString::UnicodeString(const UChar *text)
  : fArray(fStackBuffer),
    fLength(0),
    fCapacity(US_STACKBUF_SIZE),
    fHashCode(kEmptyHashCode),
    fFlags(kShortString)
{
  doReplace(0, 0, text, 0, u_strlen(text));
}

UnicodeString::UnicodeString(const UChar *text,
                             int32_t textLength)
  : fArray(fStackBuffer),
    fLength(0),
    fCapacity(US_STACKBUF_SIZE),
    fHashCode(kEmptyHashCode),
    fFlags(kShortString)
{
  doReplace(0, 0, text, 0, textLength);
}

UnicodeString::UnicodeString(bool_t isTerminated,
                             UChar *text,
                             int32_t textLength)
  : fArray(text),
    fLength(textLength),
    fCapacity(isTerminated ? textLength + 1 : textLength),
    fHashCode(kInvalidHashCode),
    fFlags(kReadonlyAlias)
{
  if(text == 0 || textLength < -1 || textLength == -1 && !isTerminated) {
    setToBogus();
  } else if(textLength == -1) {
    // text is terminated, or else it would have failed the above test
    fLength = u_strlen(text);
    fCapacity = fLength + 1;
  }
}

UnicodeString::UnicodeString(UChar *buff,
                             int32_t bufLength,
                             int32_t buffCapacity)
  : fArray(buff),
    fLength(bufLength),
    fCapacity(buffCapacity),
    fHashCode(kInvalidHashCode),
    fFlags(kWriteableAlias)
{
  if(buff == 0 || bufLength < 0 || bufLength > buffCapacity) {
    setToBogus();
  }
}

UnicodeString::UnicodeString(const char *codepageData,
                             const char *codepage)
  : fArray(fStackBuffer),
    fLength(0),
    fCapacity(US_STACKBUF_SIZE),
    fHashCode(kEmptyHashCode),
    fFlags(kShortString)
{
  if(codepageData != 0) {
    doCodepageCreate(codepageData, uprv_strlen(codepageData), codepage);
  }
}


UnicodeString::UnicodeString(const char *codepageData,
                             int32_t dataLength,
                             const char *codepage)
  : fArray(fStackBuffer),
    fLength(0),
    fCapacity(US_STACKBUF_SIZE),
    fHashCode(kEmptyHashCode),
    fFlags(kShortString)
{
  if(codepageData != 0) {
    doCodepageCreate(codepageData, dataLength, codepage);
  }
}

UnicodeString::UnicodeString(const UnicodeString& that)
  : fArray(fStackBuffer),
    fLength(0),
    fCapacity(US_STACKBUF_SIZE),
    fHashCode(kEmptyHashCode),
    fFlags(kShortString)
{
  *this = that;
}

//========================================
// array allocation
//========================================

bool_t
UnicodeString::allocate(int32_t capacity) {
  if(capacity <= US_STACKBUF_SIZE) {
    fArray = fStackBuffer;
    fCapacity = US_STACKBUF_SIZE;
    fFlags = kShortString;
  } else {
    // count bytes for the refCounter and the string capacity, and
    // round up to a multiple of 16; then divide by 4 and allocate int32_t's
    // to be safely aligned for the refCount
    int32_t words = ((sizeof(int32_t) + capacity * U_SIZEOF_UCHAR + 15) & ~15) >> 2;
    int32_t *array = new int32_t[words];
    if(array != 0) {
      // set initial refCount and point behind the refCount
      *array++ = 1;

      // have fArray point to the first UChar
      fArray = (UChar *)array;
      fCapacity = (words - 1) * (sizeof(int32_t) / U_SIZEOF_UCHAR);
      fFlags = kLongString;
    } else {
      fArray = 0;
      fCapacity = 0;
      fHashCode = kInvalidHashCode; // for constructor(capacity) to be correctly bogus
      fFlags = kIsBogus;
      return FALSE;
    }
  }
  return TRUE;
}

//========================================
// Destructor
//========================================
UnicodeString::~UnicodeString()
{
  releaseArray();
}

//========================================
// Assignment
//========================================
UnicodeString&
UnicodeString::operator= (const UnicodeString& src)
{
  // if assigning to ourselves, do nothing
  if(this == 0 || this == &src) {
    return *this;
  }

  // is the right side bogus?
  if(&src == 0 || src.isBogus()) {
    setToBogus();
    return *this;
  }

  // delete the current contents
  releaseArray();

  // we always copy the length and the hash code
  fLength = src.fLength;
  fHashCode = src.fHashCode;

  switch(src.fFlags) {
  case kShortString:
    // short string using the stack buffer, do the same
    fArray = fStackBuffer;
    fCapacity = US_STACKBUF_SIZE;
    fFlags = kShortString;
    if(fLength > 0) {
      uprv_memcpy(fStackBuffer, src.fArray, fLength * U_SIZEOF_UCHAR);
    }
    break;
  case kLongString:
    // src uses a refCounted string buffer, use that buffer with refCount
    // src is const, use a cast - we don't really change it
    ((UnicodeString &)src).addRef();
    // fall through to readonly alias copying: copy all fields
  case kReadonlyAlias:
    // src is a readonly alias, do the same
    fArray = src.fArray;
    fCapacity = src.fCapacity;
    fFlags = src.fFlags;
    break;
  case kWriteableAlias:
    // src is a writeable alias; we make a copy of that instead
    if(allocate(fLength)) {
      if(fLength > 0) {
        uprv_memcpy(fArray, src.fArray, fLength * U_SIZEOF_UCHAR);
      }
      break;
    }
    // if there is not enough memory, then fall through to setting to bogus
  default:
    // if src is bogus, set ourselves to bogus
    // do not call setToBogus() here because fArray and fFlags are not consistent here
    fArray = 0;
    fLength = 0;
    fCapacity = 0;
    fHashCode = kInvalidHashCode;
    fFlags = kIsBogus;
    break;
  }

  return *this;
}

//========================================
// Miscellaneous operations
//========================================
int32_t
UnicodeString::numDisplayCells( UTextOffset start,
                int32_t length,
                bool_t asian) const
{
  // pin indices to legal values
  pinIndices(start, length);

  UChar c;
  int32_t result = 0;
  UTextOffset limit = start + length;

  while(start < limit) {
    c = getArrayStart()[start];
    switch(Unicode::getCellWidth(c)) {
    case Unicode::ZERO_WIDTH:
      break;;

    case Unicode::HALF_WIDTH:
      result += 1;
      break;

    case Unicode::FULL_WIDTH:
      result += 2;
      break;

    case Unicode::NEUTRAL:
      result += (asian ? 2 : 1);
      break;
    }
    ++start;
  }

  return result;
}

UCharReference
UnicodeString::operator[] (UTextOffset pos)
{
  return UCharReference(this, pos);
}

//========================================
// Read-only implementation
//========================================
int8_t
UnicodeString::doCompare( UTextOffset start,
              int32_t length,
              const UChar *srcChars,
              UTextOffset srcStart,
              int32_t srcLength) const
{
  // compare illegal string values
  if(isBogus()) {
    if(srcChars==0) {
      return 0;
    } else {
      return -1;
    }
  } else if(srcChars==0) {
    return 1;
  }

  // pin indices to legal values
  pinIndices(start, length);

  // get the correct pointer
  const UChar *chars = getArrayStart();

  // are we comparing the same buffer contents?
  if(chars + start == srcChars + srcStart) {
    return 0;
  }

  UTextOffset minLength;
  int8_t lengthResult;

  // are we comparing different lengths?
  if(length != srcLength) {
    if(length < srcLength) {
      minLength = length;
      lengthResult = -1;
    } else {
      minLength = srcLength;
      lengthResult = 1;
    }
  } else {
    minLength = length;
    lengthResult = 0;
  }

  /*
   * note that uprv_memcmp() returns an int but we return an int8_t;
   * we need to take care not to truncate the result -
   * one way to do this is to right-shift the value to
   * move the sign bit into the lower 8 bits and making sure that this
   * does not become 0 itself
   */

  if(minLength > 0) {
    int32_t result;

    if(U_IS_BIG_ENDIAN) {
      // big-endian: byte comparison works
      result = uprv_memcmp(chars + start, srcChars + srcStart, minLength * sizeof(UChar));
      if(result != 0) {
        return (int8_t)(result >> 15 | 1);
      }
    } else {
      // little-endian: compare UChar units
      chars += start;
      srcChars += srcStart;
      do {
        result = ((int32_t)*chars - (int32_t)*srcChars);
        if(result != 0) {
          return (int8_t)(result >> 15 | 1);
        }
        ++chars;
        ++srcChars;
      } while(--minLength > 0);
    }
  }
  return lengthResult;
}

void
UnicodeString::doExtract(UTextOffset start,
             int32_t length,
             UChar *dst,
             UTextOffset dstStart) const
{
  // do not copy anything if we alias dst itself
  if(fArray + start != dst + dstStart) {
    // pin indices to legal values
    pinIndices(start, length);
    us_arrayCopy(getArrayStart(), start, dst, dstStart, length);
  }
}

UTextOffset 
UnicodeString::indexOf(const UChar *srcChars,
               UTextOffset srcStart,
               int32_t srcLength,
               UTextOffset start,
               int32_t length) const
{
  if(isBogus() || srcChars == 0 || srcStart < 0 || srcLength <= 0) {
    return -1;
  }

  // now we will only work with srcLength-1
  --srcLength;

  // get the indices within bounds
  pinIndices(start, length);

  // set length for the last possible match start position
  // note the --srcLength above
  length -= srcLength;

  if(length <= 0) {
    return -1;
  }

  const UChar *array = getArrayStart();
  UTextOffset limit = start + length;

  // search for the first char, then compare the rest of the string
  // increment srcStart here for that, matching the --srcLength above
  UChar ch = srcChars[srcStart++];

  do {
    if(array[start] == ch && (srcLength == 0 || compare(start + 1, srcLength, srcChars, srcStart, srcLength) == 0)) {
      return start;
    }
  } while(++start < limit);

  return -1;
}

UTextOffset
UnicodeString::doIndexOf(UChar c,
             UTextOffset start,
             int32_t length) const
{
  // pin indices
  pinIndices(start, length);
  if(length == 0) {
    return -1;
  }

  // find the first occurrence of c
  const UChar *begin = getArrayStart() + start;
  const UChar *limit = begin + length;

  do {
    if(*begin == c) {
      return begin - getArrayStart();
    }
  } while(++begin < limit);

  return -1;
}

UTextOffset 
UnicodeString::lastIndexOf(const UChar *srcChars,
               UTextOffset srcStart,
               int32_t srcLength,
               UTextOffset start,
               int32_t length) const
{
  if(isBogus() || srcChars == 0 || srcStart < 0 || srcLength <= 0) {
    return -1;
  }

  // now we will only work with srcLength-1
  --srcLength;

  // get the indices within bounds
  pinIndices(start, length);

  // set length for the last possible match start position
  // note the --srcLength above
  length -= srcLength;

  if(length <= 0) {
    return -1;
  }

  const UChar *array = getArrayStart();
  UTextOffset pos;

  // search for the first char, then compare the rest of the string
  // increment srcStart here for that, matching the --srcLength above
  UChar ch = srcChars[srcStart++];

  pos = start + length;
  do {
    if(array[--pos] == ch && (srcLength == 0 || compare(pos + 1, srcLength, srcChars, srcStart, srcLength) == 0)) {
      return pos;
    }
  } while(pos > start);

  return -1;
}

UTextOffset
UnicodeString::doLastIndexOf(UChar c,
                 UTextOffset start,
                 int32_t length) const
{
  if(isBogus()) {
    return -1;
  }

  // pin indices
  pinIndices(start, length);
  if(length == 0) {
    return -1;
  }

  const UChar *begin = getArrayStart() + start;
  const UChar *limit = begin + length;

  do {
    if(*--limit == c) {
      return limit - getArrayStart();
    }
  } while(limit > begin);

  return -1;
}

UnicodeString& 
UnicodeString::findAndReplace(UTextOffset start,
                  int32_t length,
                  const UnicodeString& oldText,
                  UTextOffset oldStart,
                  int32_t oldLength,
                  const UnicodeString& newText,
                  UTextOffset newStart,
                  int32_t newLength)
{
  if(isBogus() || oldText.isBogus() || newText.isBogus()) {
    return *this;
  }

  pinIndices(start, length);
  oldText.pinIndices(oldStart, oldLength);
  newText.pinIndices(newStart, newLength);

  if(oldLength == 0 || newLength == 0) {
    return *this;
  }

  while(length >= oldLength) {
    UTextOffset pos = indexOf(oldText, oldStart, oldLength, start, length);
    if(pos < 0) {
      // no more oldText's here: done
      break;
    } else {
      // we found oldText, replace it by newText and go beyond it
      replace(pos, oldLength, newText, newStart, newLength);
      length -= pos + oldLength - start;
      start = pos + newLength;
    }
  }

  return *this;
}


//========================================
// Write implementation
//========================================

void
UnicodeString::setToBogus()
{
  releaseArray();

  fArray = 0;
  fCapacity = fLength = 0;
  fHashCode = kInvalidHashCode;
  fFlags = kIsBogus;
}

// setTo() analogous to the readonly-aliasing constructor with the same signature
UnicodeString &
UnicodeString::setTo(bool_t isTerminated,
                     const UChar *text,
                     int32_t textLength)
{
  if(text == 0 || textLength < -1 || textLength == -1 && !isTerminated) {
    setToBogus();
    return *this;
  }

  releaseArray();

  fArray = (UChar *)text;
  if(textLength != -1) {
    fLength = textLength;
  } else {
    // text is terminated, or else it would have failed the above test
    fLength = u_strlen(text);
    fCapacity = fLength + 1;
  }

  fCapacity = isTerminated ? textLength + 1 : textLength;
  fHashCode = kInvalidHashCode;
  fFlags = kReadonlyAlias;
  return *this;
}

// setTo() analogous to the writeable-aliasing constructor with the same signature
UnicodeString &
UnicodeString::setTo(UChar *buffer,
                     int32_t buffLength,
                     int32_t buffCapacity) {
  if(buffer == 0 || buffLength < 0 || buffLength > buffCapacity) {
    setToBogus();
    return *this;
  }

  releaseArray();

  fArray = buffer;
  fLength = buffLength;
  fCapacity = buffCapacity;
  fHashCode = kInvalidHashCode;
  fFlags = kWriteableAlias;
  return *this;
}

UnicodeString&
UnicodeString::setCharAt(UTextOffset offset,
             UChar c)
{
  if(cloneArrayIfNeeded()) {
    if(offset < 0) {
      offset = 0;
    } else if(offset >= fLength) {
      offset = fLength - 1;
    }

    fArray[offset] = c;
    fHashCode = kInvalidHashCode;
  }
  return *this;
}

UnicodeString&
UnicodeString::toUpper()
{ return toUpper(Locale::getDefault()); }

UnicodeString&
UnicodeString::toLower()
{ return toLower(Locale::getDefault()); }

UnicodeString&
UnicodeString::toUpper(const Locale& locale)
{
  UTextOffset start = 0;
  UTextOffset limit = fLength;
  UChar c;
  UnicodeString lang;
  char langChars[16];

  if(!cloneArrayIfNeeded()) {
    return *this;
  }

  // get char * locale language
  locale.getLanguage(lang);
  lang.extract(0, lang.length(), langChars, "");
  langChars[lang.length()] = 0;

  // The German sharp S character (U+00DF)'s uppercase equivalent is
  // "SS", making it the only character that expands to two characters
  // when its case is changed (we don't automatically convert "SS" to
  // U+00DF going to lowercase because it can only be determined from
  // knowing the language whether a particular "SS" should map to
  // U+00DF or "ss").  So we make a preliminary pass through the
  // string looking for sharp S characters and then go back and make
  // room for the extra capital Ses if we find any.  [For performance,
  // we only do this extra work if the language is actually German]
  if(uprv_strcmp(langChars, "de") == 0) {
    UChar SS [] = { 0x0053, 0x0053 };
    while(start < limit) {
      c = getArrayStart()[start];

      // A sharp s needs to be replaced with two capital S's.
      if(c == 0x00DF) {
        doReplace(start, 1, SS, 0, 2);
        start++;
        limit++;
      } else {
        // Otherwise, the case conversion can be handled by the Unicode unit.
        fArray[start] = Unicode::toUpperCase(c);
      }

      // If no conversion is necessary, do nothing
      ++start;
    }
  } else if(uprv_strcmp(langChars, "tr") == 0) {
    // If the specfied language is Turkish, then we have to special-case
    // for the Turkish dotted and dotless Is.  The regular lowercase i
    // maps to the capital I with a dot (U+0130), and the lowercase i
    // without the dot (U+0131) maps to the regular capital I
    while(start < limit) {
      c = getArrayStart()[start];

      if(c == 0x0069/*'i'*/) {
        fArray[start] = 0x0130;
      } else if(c == 0x0131) {
        fArray[start] = 0x0049/*'I'*/;
      } else {
        fArray[start] = Unicode::toUpperCase(c);
      }
      ++start;
    }
  } else {
    UChar *array = getArrayStart();

    while(start < limit) {
      array[start] = Unicode::toUpperCase(array[start]);
      ++start;
    }
  }

  fHashCode = kInvalidHashCode;

  return *this;
}

UnicodeString&
UnicodeString::toLower(const Locale& locale)
{
  UTextOffset start = 0;
  UTextOffset limit = fLength;
  UChar c;
  UnicodeString lang;
  char langChars[16];

  if(!cloneArrayIfNeeded()) {
    return *this;
  }

  // get char * locale language
  locale.getLanguage(lang);
  lang.extract(0, lang.length(), langChars, "");
  langChars[lang.length()] = 0;

  // if the specfied language is Turkish, then we have to special-case
  // for the Turkish dotted and dotless Is.  The capital I with a dot
  // (U+0130) maps to the regular lowercase i, and the regular capital
  // I maps to the lowercase i without the dot (U+0131)
  if(uprv_strcmp(langChars, "tr") == 0) {
    while(start < limit) {
      c = getArrayStart()[start];
      if(c == 0x0049) // 'I'
        fArray[start] = 0x0131;
      else if(c == 0x0130)
        fArray[start] = 0x0069; // 'i'
      else {
        fArray[start] = Unicode::toLowerCase(c);
      }
      ++start;
    }
  } else if(uprv_strcmp(langChars, "el") == 0) {
    // if the specfied language is Greek, then we have to special-case
    // for the capital letter sigma (U+3A3), which has two lower-case
    // forms.  If the character following the capital sigma is a letter,
    // we use the medial form (U+3C3); otherwise, we use the final form
    // (U+3C2).
    while(start < limit) {
      c = getArrayStart()[start];
      if(c == 0x3a3) {
        if(start + 1 < limit && Unicode::isLetter(getArrayStart()[start + 1])) {
          fArray[start] = 0x3C3;
        } else {
          fArray[start] = 0x3C2;
        }
      } else {
        fArray[start] = Unicode::toLowerCase(c);
      }
      ++start;
    }
  } else {
    // if the specified language is anything other than Turkish or
    // Greek, we rely on the Unicode class to do all our case mapping--
    // there are no other special cases
    UChar *array = getArrayStart();

    while(start < limit) {
      array[start] = Unicode::toLowerCase(array[start]);
      ++start;
    }
  }

  fHashCode = kInvalidHashCode;

  return *this;
}

UnicodeString&
UnicodeString::doReplace( UTextOffset start,
              int32_t length,
              const UnicodeString& src,
              UTextOffset srcStart,
              int32_t srcLength)
{
  if(!src.isBogus()) {
    // pin the indices to legal values
    src.pinIndices(srcStart, srcLength);

    // get the characters from src
    // and replace the range in ourselves with them
    return doReplace(start, length, src.getArrayStart(), srcStart, srcLength);
  } else {
    // remove the range
    return doReplace(start, length, 0, 0, 0);
  }
}

UnicodeString&
UnicodeString::doReplace(UTextOffset start,
             int32_t length,
             const UChar *srcChars,
             UTextOffset srcStart,
             int32_t srcLength)
{
  // if we're bogus, set us to empty first
  if(isBogus()) {
    fArray = fStackBuffer;
    fLength = 0;
    fCapacity = US_STACKBUF_SIZE;
    fHashCode = kEmptyHashCode;
    fFlags = kShortString;
  }

  if(srcChars == 0) {
    srcStart = srcLength = 0;
  }

  int32_t *bufferToDelete = 0;

  // the following may change fArray but will not copy the current contents;
  // therefore we need to keep the current fArray
  UChar *oldArray = fArray;
  int32_t oldLength = fLength;

  // pin the indices to legal values
  pinIndices(start, length);

  // calculate the size of the string after the replace
  int32_t newSize = oldLength - length + srcLength;

  // clone our array and allocate a bigger array if needed
  if(!cloneArrayIfNeeded(newSize, newSize + (newSize >> 2) + kGrowSize,
                         FALSE, &bufferToDelete)
  ) {
    return *this;
  }

  // now do the replace

  if(fArray != oldArray) {
    // if fArray changed, then we need to copy everything except what will change
    us_arrayCopy(oldArray, 0, fArray, 0, start);
    us_arrayCopy(oldArray, start + length,
                 fArray, start + srcLength,
                 oldLength - (start + length));
  } else if(length != srcLength) {
    // fArray did not change; copy only the portion that isn't changing, leaving a hole
    us_arrayCopy(oldArray, start + length,
                 fArray, start + srcLength,
                 oldLength - (start + length));
  }

  // now fill in the hole with the new string
  us_arrayCopy(srcChars, srcStart, getArrayStart(), start, srcLength);

  fLength = newSize;
  fHashCode = kInvalidHashCode;

  // delayed delete in case srcChars == fArray when we started, and
  // to keep oldArray alive for the above operations
  delete [] bufferToDelete;

  return *this;
}

/**
 * Replaceable API
 */
void
UnicodeString::handleReplaceBetween(UTextOffset start,
                                    UTextOffset limit,
                                    const UnicodeString& text) {
    replaceBetween(start, limit, text);
}

UnicodeString&
UnicodeString::doReverse(UTextOffset start,
             int32_t length)
{
  // if we're bogus, do nothing
  if(isBogus() || !cloneArrayIfNeeded()) {
    return *this;
  }

  // pin the indices to legal values
  pinIndices(start, length);

  UChar *left = getArrayStart() + start;
  UChar *right = getArrayStart() + start + length;
  UChar swap;

  while(left < --right) {
    swap = *left;
    *left++ = *right;
    *right = swap;
  }

  fHashCode = kInvalidHashCode;

  return *this;
}

//========================================
// Hashing
//========================================
int32_t
UnicodeString::doHashCode()
{
  const UChar *key     = getArrayStart();
  int32_t len          = fLength;
  int32_t hash         = kInvalidHashCode;
  const UChar *limit   = key + len;

  /*
    We compute the hash by iterating sparsely over 64 (at most)
    characters spaced evenly through the string.  For each character,
    we multiply the previous hash value by a prime number and add the
    new character in, in the manner of an additive linear congruential
    random number generator, thus producing a pseudorandom
    deterministic value which should be well distributed over the
    output range. [LIU] */

  if(len <= 64) {
    while(key < limit) {
      hash = (hash * 37) + *key++;
    }
  } else {
    int32_t inc = (len+63)/64;

    while(key < limit) {
      hash = (hash * 37) + *key;
      key += inc;
    }
  }

  hash &= 0x7fffffff;
  if(hash == kInvalidHashCode) {
    hash = kEmptyHashCode;
  }

  fHashCode = hash;
  return fHashCode;
}

//========================================
// Codeset conversion
//========================================
int32_t
UnicodeString::extract(UTextOffset start,
                       int32_t length,
                       char *dst,
                       const char *codepage) const
{
  // if we're bogus or there's nothing to convert, do nothing
  if(isBogus() || length <= 0) {
    return 0;
  }

  // pin the indices to legal values
  pinIndices(start, length);

  int32_t convertedLen = 0;

  // set up the conversion parameters
  int32_t sourceLen        = length;
  const UChar *mySource    = getArrayStart() + start;
  const UChar *mySourceEnd = mySource + length;
  char *myTarget           = dst;
  char *myTargetLimit;
  UErrorCode status        = U_ZERO_ERROR;
  int32_t arraySize        = 0x0FFFFFFF;

  // create the converter
  UConverter *converter;

  // if the codepage is the default, use our cache
  if(codepage == 0) {
    converter = getDefaultConverter(status);
  } else if(*codepage == 0) {
    converter = 0;
  } else {
    converter = ucnv_open(codepage, &status);
  }

  // if we failed, set the appropriate flags and return
  // if it is an empty string, then use the "invariant character" conversion
  if(U_FAILURE(status)) {
    // close the converter
    if(codepage == 0) {
      releaseDefaultConverter(converter);
    } else {
      ucnv_close(converter);
    }
    return 0;
  }

  // perform the conversion
  if(converter == 0) {
    // use the "invariant characters" conversion
    if(length > fLength - start) {
      length = fLength - start;
    }
    u_UCharsToChars(mySource, myTarget, length);
    return length;
  }

  // there is no loop here since we assume the buffer is large enough
  myTargetLimit = myTarget + arraySize;

  /* Pin the limit to U_MAX_PTR.  NULL check is for AS/400. */
  if((myTargetLimit < myTarget) || (myTargetLimit == NULL)) {
    myTargetLimit = (char*)U_MAX_PTR;
  }

  ucnv_fromUnicode(converter, &myTarget,  myTargetLimit,
           &mySource, mySourceEnd, 0, TRUE, &status);

  // close the converter
  if(codepage == 0) {
    releaseDefaultConverter(converter);
  } else {
    ucnv_close(converter);
  }

  return (myTarget - dst);
}

void
UnicodeString::doCodepageCreate(const char *codepageData,
                int32_t dataLength,
                const char *codepage)
{
  // if there's nothing to convert, do nothing
  if(codepageData == 0 || dataLength <= 0) {
    return;
  }

  UErrorCode status = U_ZERO_ERROR;

  // create the converter
  // if the codepage is the default, use our cache
  // if it is an empty string, then use the "invariant character" conversion
  UConverter *converter = (codepage == 0 ?
                             getDefaultConverter(status) :
                             *codepage == 0 ?
                               0 :
                               ucnv_open(codepage, &status));

  // if we failed, set the appropriate flags and return
  if(U_FAILURE(status)) {
    // close the converter
    if(codepage == 0) {
      releaseDefaultConverter(converter);
    } else {
      ucnv_close(converter);
    }
    setToBogus();
    return;
  }

  fHashCode = kInvalidHashCode;

  // perform the conversion
  if(converter == 0) {
    // use the "invariant characters" conversion
    if(cloneArrayIfNeeded(dataLength, dataLength, FALSE)) {
      u_charsToUChars(codepageData, getArrayStart(), dataLength);
      fLength = dataLength;
    } else {
      setToBogus();
    }
    return;
  }

  // set up the conversion parameters
  const char *mySource     = codepageData;
  const char *mySourceEnd  = mySource + dataLength;
  UChar *myTarget;

  // estimate the size needed:
  // 1.25 UChar's per source byte should cover most cases
  int32_t arraySize = dataLength + (dataLength >> 2);

  // we do not care about the current contents
  bool_t doCopyArray = FALSE;
  for(;;) {
    if(!cloneArrayIfNeeded(arraySize, arraySize, doCopyArray)) {
      setToBogus();
      break;
    }

    // perform the conversion
    myTarget = fArray + fLength;
    ucnv_toUnicode(converter, &myTarget,  fArray + fCapacity,
           &mySource, mySourceEnd, 0, FALSE, &status);

    // update the conversion parameters
    fLength = myTarget - fArray;

    // allocate more space and copy data, if needed
    if(status == U_INDEX_OUTOFBOUNDS_ERROR) {
      // reset the error code
      status = U_ZERO_ERROR;

      // keep the previous conversion results
      doCopyArray = TRUE;

      // estimate the new size needed, larger than before
      // try 2 UChar's per remaining source byte
      arraySize = fLength + 2 * (mySourceEnd - mySource);
    } else {
      break;
    }
  }

  // close the converter
  if(codepage == 0) {
    releaseDefaultConverter(converter);
  } else {
    ucnv_close(converter);
  }
}

//========================================
// External Buffer
//========================================
// ### TODO:
// this is very, very dirty: we should not ever expose our array to the outside,
// and this also violates the const-ness of this object
// this must be removed when the resource bundle implementation does not need it any more!
const UChar*
UnicodeString::getUChars() const {
  // if we're bogus, do nothing
  if(isBogus()) {
    return 0;
  }

  if(fCapacity <= fLength || fArray[fLength] != 0) {
    if(((UnicodeString &)*this).cloneArrayIfNeeded(fLength + 1)) {
      fArray[fLength] = 0;
    }
  }
  return fArray;
}

//========================================
// Miscellaneous
//========================================
void
UnicodeString::pinIndices(UTextOffset& start,
              int32_t& length) const
{
  // pin indices
  if(length < 0 || start < 0) {
    start = length = 0;
  } else if(length > (fLength - start)) {
    length = (fLength - start);
  }
}

bool_t
UnicodeString::cloneArrayIfNeeded(int32_t newCapacity,
                                  int32_t growCapacity,
                                  bool_t doCopyArray,
                                  int32_t **pBufferToDelete) {
  // default parameters need to be static, therefore
  // the defaults are -1 to have convenience defaults
  if(newCapacity == -1) {
    newCapacity = fCapacity;
  }

  /*
   * We need to make a copy of the array if
   * the buffer is read-only, or
   * the buffer is refCounted (shared), and refCount>1, or
   * the buffer is too small.
   * Return FALSE if memory could not be allocated.
   */
  if(fFlags & kBufferIsReadonly ||
     fFlags & kRefCounted && refCount() > 1 ||
     newCapacity > fCapacity
  ) {
    // save old values
    UChar *array = fArray;
    uint16_t flags = fFlags;

    // check growCapacity for default value and use of the stack buffer
    if(growCapacity == -1) {
      growCapacity = newCapacity;
    } else if(newCapacity <= US_STACKBUF_SIZE && growCapacity > US_STACKBUF_SIZE) {
      growCapacity = US_STACKBUF_SIZE;
    }

    // allocate a new array
    if(allocate(growCapacity) ||
       newCapacity < growCapacity && allocate(newCapacity)
    ) {
      if(doCopyArray) {
        // copy the contents
        // do not copy more than what fits - it may be smaller than before
        if(fCapacity < fLength) {
          fLength = fCapacity;
        }
        us_arrayCopy(array, 0, fArray, 0, fLength);
      } else {
        fLength = 0;
      }

      // release the old array
      if(flags & kRefCounted) {
        // the array is refCounted; decrement and release if 0
        int32_t *pRefCount = ((int32_t *)array - 1);
        if(--*pRefCount == 0) {
          if(pBufferToDelete == 0) {
            delete [] pRefCount;
          } else {
            // the caller requested to delete it himself
            *pBufferToDelete = pRefCount;
          }
        }
      }
    } else {
      // not enough memory for growCapacity and not even for the smaller newCapacity
      // reset the old values for setToBogus() to release the array
      fArray = array;
      fFlags = flags;
      setToBogus();
      return FALSE;
    }
  }
  return TRUE;
}

// private function for C API
U_CFUNC int32_t
T_UnicodeString_length(const UnicodeString *s)
{
  return s->length();
}

// private function for C API
U_CFUNC int32_t
T_UnicodeString_extract(const UnicodeString *s, char *dst)
{
  return s->extract(0, s->length(), dst, "");
}


//========================================
// Default converter caching
//========================================

UConverter*
UnicodeString::getDefaultConverter(UErrorCode &status)
{
  UConverter *converter = 0;

  if(fgDefaultConverter != 0) {
    Mutex lock;

    // need to check to make sure it wasn't taken out from under us
    if(fgDefaultConverter != 0) {
      converter = fgDefaultConverter;
      fgDefaultConverter = 0;
    }
  }

  // if the cache was empty, create a converter
  if(converter == 0) {
    converter = ucnv_open(0, &status);
    if(U_FAILURE(status)) {
      return 0;
    }
  }

  return converter;
}

void
UnicodeString::releaseDefaultConverter(UConverter *converter)
{
  if(fgDefaultConverter == 0) {
    Mutex lock;

    if(fgDefaultConverter == 0) {
      fgDefaultConverter = converter;
      converter = 0;
    }
  }

  // it's safe to close a 0 converter
  ucnv_close(converter);
}

//========================================
// Streaming (to be removed)
//========================================

#include <iostream.h>
#include "unistrm.h"
#include "filestrm.h"


inline uint8_t
uprv_hibyte(uint16_t x)
{ return (uint8_t)(x >> 8); }

inline uint8_t
uprv_lobyte(uint16_t x)
{ return (uint8_t)(x & 0xff); }

inline uint16_t
uprv_hiword(uint32_t x)
{ return (uint16_t)(x >> 16); }

inline uint16_t
uprv_loword(uint32_t x)
{ return (uint16_t)(x & 0xffff); }

inline void
writeLong(FileStream *os,
      int32_t x)
{
  uint16_t word = uprv_hiword((uint32_t)x);
  T_FileStream_putc(os, uprv_hibyte(word));
  T_FileStream_putc(os, uprv_lobyte(word));
  word = uprv_loword((uint32_t)x);
  T_FileStream_putc(os, uprv_hibyte(word));
  T_FileStream_putc(os, uprv_lobyte(word));
}

inline int32_t
readLong(FileStream *is)
{
  int32_t x = 0;
  uint16_t byte;

  byte = T_FileStream_getc(is);
  x |= byte;
  byte = T_FileStream_getc(is);
  x = (x << 8) | byte;
  byte = T_FileStream_getc(is);
  x = (x << 8) | byte;
  byte = T_FileStream_getc(is);
  x = (x << 8) | byte;

  return x;
}

inline void
writeUChar(FileStream *os,
       UChar c)
{
  T_FileStream_putc(os, uprv_hibyte(c));
  T_FileStream_putc(os, uprv_lobyte(c));
}

inline UChar
readUChar(FileStream *is)
{
  UChar c = 0;
  uint16_t byte;

  byte = T_FileStream_getc(is);
  c |= byte;
  byte = T_FileStream_getc(is);
  c = (c << 8) | byte;

  return c;
}

void
UnicodeStringStreamer::streamOut(const UnicodeString *s,
                 FileStream *os)
{
  if(!T_FileStream_error(os)) {
    writeLong(os, s->fLength);
  }

  const UChar *c   = s->getArrayStart();
  const UChar *end = c + s->fLength;

  while(c != end && ! T_FileStream_error(os)) {
    writeUChar(os, *c++);
  }
}

void
UnicodeStringStreamer::streamIn(UnicodeString *s,
                FileStream *is)
{
  int32_t newSize;

  // handle error conditions
  if(T_FileStream_error(is) || T_FileStream_eof(is)) {
    s->setToBogus();
    return;
  }
  newSize = readLong(is);
  if((newSize < 0) || T_FileStream_error(is)
     || ((newSize > 0) && T_FileStream_eof(is))) {
    s->setToBogus(); //error condition
    return;
  }

  // clone s's array, if needed
  if(!s->cloneArrayIfNeeded(newSize, newSize, FALSE)) {
    return;
  }

  UChar *c = s->getArrayStart();
  UChar *end = c + newSize;

  while(c < end && ! (T_FileStream_error(is) || T_FileStream_eof(is))) {
    *c++ = readUChar(is);
  }

  // couldn't read all chars
  if(c < end) {
    s->setToBogus();
    return;
  }

  s->fLength = newSize;
}

// console IO

ostream&
operator<<(ostream& stream,
           const UnicodeString& s)
{
  if(s.length() > 0) {
    char buffer[200];
    UConverter *converter;
    UErrorCode errorCode = U_ZERO_ERROR;

    // use the default converter to convert chunks of text
    converter = UnicodeString::getDefaultConverter(errorCode);
    if(U_SUCCESS(errorCode)) {
      const UChar *us = s.getArrayStart(), *uLimit = us + s.length();
      char *s, *sLimit = buffer + sizeof(buffer);
      do {
        errorCode = U_ZERO_ERROR;
        s = buffer;
        ucnv_fromUnicode(converter, &s, sLimit, &us, uLimit, 0, FALSE, &errorCode);

        // write this chunk
        if(s > buffer) {
          stream.write(buffer, s - buffer);
        }
      } while(errorCode == U_INDEX_OUTOFBOUNDS_ERROR);
      UnicodeString::releaseDefaultConverter(converter);
    }
  }

  stream.flush();
  return stream;
}