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1 // Copyright 2014 PDFium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6 
7 #include "core/fxcrt/bytestring.h"
8 
9 #include <stddef.h>
10 
11 #include <algorithm>
12 #include <cctype>
13 #include <string>
14 #include <utility>
15 
16 #include "core/fxcrt/cfx_utf8decoder.h"
17 #include "core/fxcrt/fx_codepage.h"
18 #include "core/fxcrt/fx_extension.h"
19 #include "core/fxcrt/fx_safe_types.h"
20 #include "core/fxcrt/string_pool_template.h"
21 #include "third_party/base/numerics/safe_math.h"
22 #include "third_party/base/span.h"
23 #include "third_party/base/stl_util.h"
24 
25 template class fxcrt::StringDataTemplate<char>;
26 template class fxcrt::StringViewTemplate<char>;
27 template class fxcrt::StringPoolTemplate<ByteString>;
28 template struct std::hash<ByteString>;
29 
30 namespace {
31 
32 constexpr char kTrimChars[] = "\x09\x0a\x0b\x0c\x0d\x20";
33 
FX_strstr(const char * haystack,int haystack_len,const char * needle,int needle_len)34 const char* FX_strstr(const char* haystack,
35                       int haystack_len,
36                       const char* needle,
37                       int needle_len) {
38   if (needle_len > haystack_len || needle_len == 0) {
39     return nullptr;
40   }
41   const char* end_ptr = haystack + haystack_len - needle_len;
42   while (haystack <= end_ptr) {
43     int i = 0;
44     while (1) {
45       if (haystack[i] != needle[i]) {
46         break;
47       }
48       i++;
49       if (i == needle_len) {
50         return haystack;
51       }
52     }
53     haystack++;
54   }
55   return nullptr;
56 }
57 
58 }  // namespace
59 
60 namespace fxcrt {
61 
62 static_assert(sizeof(ByteString) <= sizeof(char*),
63               "Strings must not require more space than pointers");
64 
65 #define FORCE_ANSI 0x10000
66 #define FORCE_UNICODE 0x20000
67 #define FORCE_INT64 0x40000
68 
69 // static
FormatInteger(int i)70 ByteString ByteString::FormatInteger(int i) {
71   char buf[32];
72   FXSYS_snprintf(buf, sizeof(buf), "%d", i);
73   return ByteString(buf);
74 }
75 
76 // static
FormatFloat(float f)77 ByteString ByteString::FormatFloat(float f) {
78   char buf[32];
79   return ByteString(buf, FloatToString(f, buf));
80 }
81 
82 // static
FormatV(const char * pFormat,va_list argList)83 ByteString ByteString::FormatV(const char* pFormat, va_list argList) {
84   va_list argListCopy;
85   va_copy(argListCopy, argList);
86   int nMaxLen = vsnprintf(nullptr, 0, pFormat, argListCopy);
87   va_end(argListCopy);
88 
89   if (nMaxLen <= 0)
90     return ByteString();
91 
92   ByteString ret;
93   {
94     // Span's lifetime must end before ReleaseBuffer() below.
95     pdfium::span<char> buf = ret.GetBuffer(nMaxLen);
96 
97     // In the following two calls, there's always space in the buffer for
98     // a terminating NUL that's not included in nMaxLen.
99     memset(buf.data(), 0, nMaxLen + 1);
100     va_copy(argListCopy, argList);
101     vsnprintf(buf.data(), nMaxLen + 1, pFormat, argListCopy);
102     va_end(argListCopy);
103   }
104   ret.ReleaseBuffer(ret.GetStringLength());
105   return ret;
106 }
107 
108 // static
Format(const char * pFormat,...)109 ByteString ByteString::Format(const char* pFormat, ...) {
110   va_list argList;
111   va_start(argList, pFormat);
112   ByteString ret = FormatV(pFormat, argList);
113   va_end(argList);
114 
115   return ret;
116 }
117 
ByteString(const char * pStr,size_t nLen)118 ByteString::ByteString(const char* pStr, size_t nLen) {
119   if (nLen)
120     m_pData.Reset(StringData::Create(pStr, nLen));
121 }
122 
ByteString(const uint8_t * pStr,size_t nLen)123 ByteString::ByteString(const uint8_t* pStr, size_t nLen) {
124   if (nLen)
125     m_pData.Reset(
126         StringData::Create(reinterpret_cast<const char*>(pStr), nLen));
127 }
128 
129 ByteString::ByteString() = default;
130 
ByteString(const ByteString & other)131 ByteString::ByteString(const ByteString& other) : m_pData(other.m_pData) {}
132 
ByteString(ByteString && other)133 ByteString::ByteString(ByteString&& other) noexcept {
134   m_pData.Swap(other.m_pData);
135 }
136 
ByteString(char ch)137 ByteString::ByteString(char ch) {
138   m_pData.Reset(StringData::Create(1));
139   m_pData->m_String[0] = ch;
140 }
141 
ByteString(const char * ptr)142 ByteString::ByteString(const char* ptr)
143     : ByteString(ptr, ptr ? strlen(ptr) : 0) {}
144 
ByteString(ByteStringView bstrc)145 ByteString::ByteString(ByteStringView bstrc) {
146   if (!bstrc.IsEmpty()) {
147     m_pData.Reset(
148         StringData::Create(bstrc.unterminated_c_str(), bstrc.GetLength()));
149   }
150 }
151 
ByteString(ByteStringView str1,ByteStringView str2)152 ByteString::ByteString(ByteStringView str1, ByteStringView str2) {
153   FX_SAFE_SIZE_T nSafeLen = str1.GetLength();
154   nSafeLen += str2.GetLength();
155 
156   size_t nNewLen = nSafeLen.ValueOrDie();
157   if (nNewLen == 0)
158     return;
159 
160   m_pData.Reset(StringData::Create(nNewLen));
161   m_pData->CopyContents(str1.unterminated_c_str(), str1.GetLength());
162   m_pData->CopyContentsAt(str1.GetLength(), str2.unterminated_c_str(),
163                           str2.GetLength());
164 }
165 
ByteString(const std::initializer_list<ByteStringView> & list)166 ByteString::ByteString(const std::initializer_list<ByteStringView>& list) {
167   FX_SAFE_SIZE_T nSafeLen = 0;
168   for (const auto& item : list)
169     nSafeLen += item.GetLength();
170 
171   size_t nNewLen = nSafeLen.ValueOrDie();
172   if (nNewLen == 0)
173     return;
174 
175   m_pData.Reset(StringData::Create(nNewLen));
176 
177   size_t nOffset = 0;
178   for (const auto& item : list) {
179     m_pData->CopyContentsAt(nOffset, item.unterminated_c_str(),
180                             item.GetLength());
181     nOffset += item.GetLength();
182   }
183 }
184 
ByteString(const std::ostringstream & outStream)185 ByteString::ByteString(const std::ostringstream& outStream) {
186   std::string str = outStream.str();
187   if (str.length() > 0)
188     m_pData.Reset(StringData::Create(str.c_str(), str.length()));
189 }
190 
~ByteString()191 ByteString::~ByteString() {}
192 
operator =(const char * str)193 ByteString& ByteString::operator=(const char* str) {
194   if (!str || !str[0])
195     clear();
196   else
197     AssignCopy(str, strlen(str));
198 
199   return *this;
200 }
201 
operator =(ByteStringView str)202 ByteString& ByteString::operator=(ByteStringView str) {
203   if (str.IsEmpty())
204     clear();
205   else
206     AssignCopy(str.unterminated_c_str(), str.GetLength());
207 
208   return *this;
209 }
210 
operator =(const ByteString & that)211 ByteString& ByteString::operator=(const ByteString& that) {
212   if (m_pData != that.m_pData)
213     m_pData = that.m_pData;
214 
215   return *this;
216 }
217 
operator =(ByteString && that)218 ByteString& ByteString::operator=(ByteString&& that) {
219   if (m_pData != that.m_pData)
220     m_pData = std::move(that.m_pData);
221 
222   return *this;
223 }
224 
operator +=(const char * str)225 ByteString& ByteString::operator+=(const char* str) {
226   if (str)
227     Concat(str, strlen(str));
228 
229   return *this;
230 }
231 
operator +=(char ch)232 ByteString& ByteString::operator+=(char ch) {
233   Concat(&ch, 1);
234   return *this;
235 }
236 
operator +=(const ByteString & str)237 ByteString& ByteString::operator+=(const ByteString& str) {
238   if (str.m_pData)
239     Concat(str.m_pData->m_String, str.m_pData->m_nDataLength);
240 
241   return *this;
242 }
243 
operator +=(ByteStringView str)244 ByteString& ByteString::operator+=(ByteStringView str) {
245   if (!str.IsEmpty())
246     Concat(str.unterminated_c_str(), str.GetLength());
247 
248   return *this;
249 }
250 
operator ==(const char * ptr) const251 bool ByteString::operator==(const char* ptr) const {
252   if (!m_pData)
253     return !ptr || !ptr[0];
254 
255   if (!ptr)
256     return m_pData->m_nDataLength == 0;
257 
258   return strlen(ptr) == m_pData->m_nDataLength &&
259          memcmp(ptr, m_pData->m_String, m_pData->m_nDataLength) == 0;
260 }
261 
operator ==(ByteStringView str) const262 bool ByteString::operator==(ByteStringView str) const {
263   if (!m_pData)
264     return str.IsEmpty();
265 
266   return m_pData->m_nDataLength == str.GetLength() &&
267          memcmp(m_pData->m_String, str.unterminated_c_str(), str.GetLength()) ==
268              0;
269 }
270 
operator ==(const ByteString & other) const271 bool ByteString::operator==(const ByteString& other) const {
272   if (m_pData == other.m_pData)
273     return true;
274 
275   if (IsEmpty())
276     return other.IsEmpty();
277 
278   if (other.IsEmpty())
279     return false;
280 
281   return other.m_pData->m_nDataLength == m_pData->m_nDataLength &&
282          memcmp(other.m_pData->m_String, m_pData->m_String,
283                 m_pData->m_nDataLength) == 0;
284 }
285 
operator <(const char * ptr) const286 bool ByteString::operator<(const char* ptr) const {
287   if (!m_pData && !ptr)
288     return false;
289   if (c_str() == ptr)
290     return false;
291 
292   size_t len = GetLength();
293   size_t other_len = ptr ? strlen(ptr) : 0;
294   int result = memcmp(c_str(), ptr, std::min(len, other_len));
295   return result < 0 || (result == 0 && len < other_len);
296 }
297 
operator <(ByteStringView str) const298 bool ByteString::operator<(ByteStringView str) const {
299   return Compare(str) < 0;
300 }
301 
operator <(const ByteString & other) const302 bool ByteString::operator<(const ByteString& other) const {
303   if (m_pData == other.m_pData)
304     return false;
305 
306   size_t len = GetLength();
307   size_t other_len = other.GetLength();
308   int result = memcmp(c_str(), other.c_str(), std::min(len, other_len));
309   return result < 0 || (result == 0 && len < other_len);
310 }
311 
EqualNoCase(ByteStringView str) const312 bool ByteString::EqualNoCase(ByteStringView str) const {
313   if (!m_pData)
314     return str.IsEmpty();
315 
316   size_t len = str.GetLength();
317   if (m_pData->m_nDataLength != len)
318     return false;
319 
320   const uint8_t* pThis = (const uint8_t*)m_pData->m_String;
321   const uint8_t* pThat = str.raw_str();
322   for (size_t i = 0; i < len; i++) {
323     if ((*pThis) != (*pThat)) {
324       uint8_t bThis = tolower(*pThis);
325       uint8_t bThat = tolower(*pThat);
326       if (bThis != bThat)
327         return false;
328     }
329     pThis++;
330     pThat++;
331   }
332   return true;
333 }
334 
AssignCopy(const char * pSrcData,size_t nSrcLen)335 void ByteString::AssignCopy(const char* pSrcData, size_t nSrcLen) {
336   AllocBeforeWrite(nSrcLen);
337   m_pData->CopyContents(pSrcData, nSrcLen);
338   m_pData->m_nDataLength = nSrcLen;
339 }
340 
ReallocBeforeWrite(size_t nNewLength)341 void ByteString::ReallocBeforeWrite(size_t nNewLength) {
342   if (m_pData && m_pData->CanOperateInPlace(nNewLength))
343     return;
344 
345   if (nNewLength == 0) {
346     clear();
347     return;
348   }
349 
350   RetainPtr<StringData> pNewData(StringData::Create(nNewLength));
351   if (m_pData) {
352     size_t nCopyLength = std::min(m_pData->m_nDataLength, nNewLength);
353     pNewData->CopyContents(m_pData->m_String, nCopyLength);
354     pNewData->m_nDataLength = nCopyLength;
355   } else {
356     pNewData->m_nDataLength = 0;
357   }
358   pNewData->m_String[pNewData->m_nDataLength] = 0;
359   m_pData.Swap(pNewData);
360 }
361 
AllocBeforeWrite(size_t nNewLength)362 void ByteString::AllocBeforeWrite(size_t nNewLength) {
363   if (m_pData && m_pData->CanOperateInPlace(nNewLength))
364     return;
365 
366   if (nNewLength == 0) {
367     clear();
368     return;
369   }
370 
371   m_pData.Reset(StringData::Create(nNewLength));
372 }
373 
ReleaseBuffer(size_t nNewLength)374 void ByteString::ReleaseBuffer(size_t nNewLength) {
375   if (!m_pData)
376     return;
377 
378   nNewLength = std::min(nNewLength, m_pData->m_nAllocLength);
379   if (nNewLength == 0) {
380     clear();
381     return;
382   }
383 
384   ASSERT(m_pData->m_nRefs == 1);
385   m_pData->m_nDataLength = nNewLength;
386   m_pData->m_String[nNewLength] = 0;
387   if (m_pData->m_nAllocLength - nNewLength >= 32) {
388     // Over arbitrary threshold, so pay the price to relocate.  Force copy to
389     // always occur by holding a second reference to the string.
390     ByteString preserve(*this);
391     ReallocBeforeWrite(nNewLength);
392   }
393 }
394 
Reserve(size_t len)395 void ByteString::Reserve(size_t len) {
396   GetBuffer(len);
397 }
398 
GetBuffer(size_t nMinBufLength)399 pdfium::span<char> ByteString::GetBuffer(size_t nMinBufLength) {
400   if (!m_pData) {
401     if (nMinBufLength == 0)
402       return pdfium::span<char>();
403 
404     m_pData.Reset(StringData::Create(nMinBufLength));
405     m_pData->m_nDataLength = 0;
406     m_pData->m_String[0] = 0;
407     return pdfium::span<char>(m_pData->m_String, m_pData->m_nAllocLength);
408   }
409 
410   if (m_pData->CanOperateInPlace(nMinBufLength))
411     return pdfium::span<char>(m_pData->m_String, m_pData->m_nAllocLength);
412 
413   nMinBufLength = std::max(nMinBufLength, m_pData->m_nDataLength);
414   if (nMinBufLength == 0)
415     return pdfium::span<char>();
416 
417   RetainPtr<StringData> pNewData(StringData::Create(nMinBufLength));
418   pNewData->CopyContents(*m_pData);
419   pNewData->m_nDataLength = m_pData->m_nDataLength;
420   m_pData.Swap(pNewData);
421   return pdfium::span<char>(m_pData->m_String, m_pData->m_nAllocLength);
422 }
423 
Delete(size_t index,size_t count)424 size_t ByteString::Delete(size_t index, size_t count) {
425   if (!m_pData)
426     return 0;
427 
428   size_t old_length = m_pData->m_nDataLength;
429   if (count == 0 || index != pdfium::clamp<size_t>(index, 0, old_length))
430     return old_length;
431 
432   size_t removal_length = index + count;
433   if (removal_length > old_length)
434     return old_length;
435 
436   ReallocBeforeWrite(old_length);
437   size_t chars_to_copy = old_length - removal_length + 1;
438   memmove(m_pData->m_String + index, m_pData->m_String + removal_length,
439           chars_to_copy);
440   m_pData->m_nDataLength = old_length - count;
441   return m_pData->m_nDataLength;
442 }
443 
Concat(const char * pSrcData,size_t nSrcLen)444 void ByteString::Concat(const char* pSrcData, size_t nSrcLen) {
445   if (!pSrcData || nSrcLen == 0)
446     return;
447 
448   if (!m_pData) {
449     m_pData.Reset(StringData::Create(pSrcData, nSrcLen));
450     return;
451   }
452 
453   if (m_pData->CanOperateInPlace(m_pData->m_nDataLength + nSrcLen)) {
454     m_pData->CopyContentsAt(m_pData->m_nDataLength, pSrcData, nSrcLen);
455     m_pData->m_nDataLength += nSrcLen;
456     return;
457   }
458 
459   size_t nConcatLen = std::max(m_pData->m_nDataLength / 2, nSrcLen);
460   RetainPtr<StringData> pNewData(
461       StringData::Create(m_pData->m_nDataLength + nConcatLen));
462   pNewData->CopyContents(*m_pData);
463   pNewData->CopyContentsAt(m_pData->m_nDataLength, pSrcData, nSrcLen);
464   pNewData->m_nDataLength = m_pData->m_nDataLength + nSrcLen;
465   m_pData.Swap(pNewData);
466 }
467 
ReferenceCountForTesting() const468 intptr_t ByteString::ReferenceCountForTesting() const {
469   return m_pData ? m_pData->m_nRefs : 0;
470 }
471 
Substr(size_t first,size_t count) const472 ByteString ByteString::Substr(size_t first, size_t count) const {
473   if (!m_pData)
474     return ByteString();
475 
476   if (!IsValidIndex(first))
477     return ByteString();
478 
479   if (count == 0 || !IsValidLength(count))
480     return ByteString();
481 
482   if (!IsValidIndex(first + count - 1))
483     return ByteString();
484 
485   if (first == 0 && count == m_pData->m_nDataLength)
486     return *this;
487 
488   ByteString dest;
489   AllocCopy(dest, count, first);
490   return dest;
491 }
492 
First(size_t count) const493 ByteString ByteString::First(size_t count) const {
494   if (count == 0 || !IsValidLength(count))
495     return ByteString();
496   return Substr(0, count);
497 }
498 
Last(size_t count) const499 ByteString ByteString::Last(size_t count) const {
500   if (count == 0 || !IsValidLength(count))
501     return ByteString();
502   return Substr(GetLength() - count, count);
503 }
504 
AllocCopy(ByteString & dest,size_t nCopyLen,size_t nCopyIndex) const505 void ByteString::AllocCopy(ByteString& dest,
506                            size_t nCopyLen,
507                            size_t nCopyIndex) const {
508   if (nCopyLen == 0)
509     return;
510 
511   RetainPtr<StringData> pNewData(
512       StringData::Create(m_pData->m_String + nCopyIndex, nCopyLen));
513   dest.m_pData.Swap(pNewData);
514 }
515 
SetAt(size_t index,char c)516 void ByteString::SetAt(size_t index, char c) {
517   ASSERT(IsValidIndex(index));
518   ReallocBeforeWrite(m_pData->m_nDataLength);
519   m_pData->m_String[index] = c;
520 }
521 
Insert(size_t index,char ch)522 size_t ByteString::Insert(size_t index, char ch) {
523   const size_t cur_length = GetLength();
524   if (!IsValidLength(index))
525     return cur_length;
526 
527   const size_t new_length = cur_length + 1;
528   ReallocBeforeWrite(new_length);
529   memmove(m_pData->m_String + index + 1, m_pData->m_String + index,
530           new_length - index);
531   m_pData->m_String[index] = ch;
532   m_pData->m_nDataLength = new_length;
533   return new_length;
534 }
535 
Find(char ch,size_t start) const536 Optional<size_t> ByteString::Find(char ch, size_t start) const {
537   if (!m_pData)
538     return pdfium::nullopt;
539 
540   if (!IsValidIndex(start))
541     return pdfium::nullopt;
542 
543   const char* pStr = static_cast<const char*>(
544       memchr(m_pData->m_String + start, ch, m_pData->m_nDataLength - start));
545   return pStr ? Optional<size_t>(static_cast<size_t>(pStr - m_pData->m_String))
546               : pdfium::nullopt;
547 }
548 
Find(ByteStringView subStr,size_t start) const549 Optional<size_t> ByteString::Find(ByteStringView subStr, size_t start) const {
550   if (!m_pData)
551     return pdfium::nullopt;
552 
553   if (!IsValidIndex(start))
554     return pdfium::nullopt;
555 
556   const char* pStr =
557       FX_strstr(m_pData->m_String + start, m_pData->m_nDataLength - start,
558                 subStr.unterminated_c_str(), subStr.GetLength());
559   return pStr ? Optional<size_t>(static_cast<size_t>(pStr - m_pData->m_String))
560               : pdfium::nullopt;
561 }
562 
ReverseFind(char ch) const563 Optional<size_t> ByteString::ReverseFind(char ch) const {
564   if (!m_pData)
565     return pdfium::nullopt;
566 
567   size_t nLength = m_pData->m_nDataLength;
568   while (nLength--) {
569     if (m_pData->m_String[nLength] == ch)
570       return nLength;
571   }
572   return pdfium::nullopt;
573 }
574 
MakeLower()575 void ByteString::MakeLower() {
576   if (!m_pData)
577     return;
578 
579   ReallocBeforeWrite(m_pData->m_nDataLength);
580   FXSYS_strlwr(m_pData->m_String);
581 }
582 
MakeUpper()583 void ByteString::MakeUpper() {
584   if (!m_pData)
585     return;
586 
587   ReallocBeforeWrite(m_pData->m_nDataLength);
588   FXSYS_strupr(m_pData->m_String);
589 }
590 
Remove(char chRemove)591 size_t ByteString::Remove(char chRemove) {
592   if (!m_pData || m_pData->m_nDataLength == 0)
593     return 0;
594 
595   char* pstrSource = m_pData->m_String;
596   char* pstrEnd = m_pData->m_String + m_pData->m_nDataLength;
597   while (pstrSource < pstrEnd) {
598     if (*pstrSource == chRemove)
599       break;
600     pstrSource++;
601   }
602   if (pstrSource == pstrEnd)
603     return 0;
604 
605   ptrdiff_t copied = pstrSource - m_pData->m_String;
606   ReallocBeforeWrite(m_pData->m_nDataLength);
607   pstrSource = m_pData->m_String + copied;
608   pstrEnd = m_pData->m_String + m_pData->m_nDataLength;
609 
610   char* pstrDest = pstrSource;
611   while (pstrSource < pstrEnd) {
612     if (*pstrSource != chRemove) {
613       *pstrDest = *pstrSource;
614       pstrDest++;
615     }
616     pstrSource++;
617   }
618 
619   *pstrDest = 0;
620   size_t nCount = static_cast<size_t>(pstrSource - pstrDest);
621   m_pData->m_nDataLength -= nCount;
622   return nCount;
623 }
624 
Replace(ByteStringView pOld,ByteStringView pNew)625 size_t ByteString::Replace(ByteStringView pOld, ByteStringView pNew) {
626   if (!m_pData || pOld.IsEmpty())
627     return 0;
628 
629   size_t nSourceLen = pOld.GetLength();
630   size_t nReplacementLen = pNew.GetLength();
631   size_t nCount = 0;
632   const char* pStart = m_pData->m_String;
633   char* pEnd = m_pData->m_String + m_pData->m_nDataLength;
634   while (1) {
635     const char* pTarget = FX_strstr(pStart, static_cast<int>(pEnd - pStart),
636                                     pOld.unterminated_c_str(), nSourceLen);
637     if (!pTarget)
638       break;
639 
640     nCount++;
641     pStart = pTarget + nSourceLen;
642   }
643   if (nCount == 0)
644     return 0;
645 
646   size_t nNewLength =
647       m_pData->m_nDataLength + (nReplacementLen - nSourceLen) * nCount;
648 
649   if (nNewLength == 0) {
650     clear();
651     return nCount;
652   }
653 
654   RetainPtr<StringData> pNewData(StringData::Create(nNewLength));
655   pStart = m_pData->m_String;
656   char* pDest = pNewData->m_String;
657   for (size_t i = 0; i < nCount; i++) {
658     const char* pTarget = FX_strstr(pStart, static_cast<int>(pEnd - pStart),
659                                     pOld.unterminated_c_str(), nSourceLen);
660     memcpy(pDest, pStart, pTarget - pStart);
661     pDest += pTarget - pStart;
662     memcpy(pDest, pNew.unterminated_c_str(), pNew.GetLength());
663     pDest += pNew.GetLength();
664     pStart = pTarget + nSourceLen;
665   }
666   memcpy(pDest, pStart, pEnd - pStart);
667   m_pData.Swap(pNewData);
668   return nCount;
669 }
670 
Compare(ByteStringView str) const671 int ByteString::Compare(ByteStringView str) const {
672   if (!m_pData)
673     return str.IsEmpty() ? 0 : -1;
674 
675   size_t this_len = m_pData->m_nDataLength;
676   size_t that_len = str.GetLength();
677   size_t min_len = std::min(this_len, that_len);
678   int result = memcmp(m_pData->m_String, str.unterminated_c_str(), min_len);
679   if (result != 0)
680     return result;
681   if (this_len == that_len)
682     return 0;
683   return this_len < that_len ? -1 : 1;
684 }
685 
Trim()686 void ByteString::Trim() {
687   TrimRight(kTrimChars);
688   TrimLeft(kTrimChars);
689 }
690 
Trim(char target)691 void ByteString::Trim(char target) {
692   ByteStringView targets(target);
693   TrimRight(targets);
694   TrimLeft(targets);
695 }
696 
Trim(ByteStringView targets)697 void ByteString::Trim(ByteStringView targets) {
698   TrimRight(targets);
699   TrimLeft(targets);
700 }
701 
TrimLeft()702 void ByteString::TrimLeft() {
703   TrimLeft(kTrimChars);
704 }
705 
TrimLeft(char target)706 void ByteString::TrimLeft(char target) {
707   TrimLeft(ByteStringView(target));
708 }
709 
TrimLeft(ByteStringView targets)710 void ByteString::TrimLeft(ByteStringView targets) {
711   if (!m_pData || targets.IsEmpty())
712     return;
713 
714   size_t len = GetLength();
715   if (len == 0)
716     return;
717 
718   size_t pos = 0;
719   while (pos < len) {
720     size_t i = 0;
721     while (i < targets.GetLength() && targets[i] != m_pData->m_String[pos])
722       i++;
723     if (i == targets.GetLength())
724       break;
725     pos++;
726   }
727   if (pos) {
728     ReallocBeforeWrite(len);
729     size_t nDataLength = len - pos;
730     memmove(m_pData->m_String, m_pData->m_String + pos,
731             (nDataLength + 1) * sizeof(char));
732     m_pData->m_nDataLength = nDataLength;
733   }
734 }
735 
TrimRight()736 void ByteString::TrimRight() {
737   TrimRight(kTrimChars);
738 }
739 
TrimRight(char target)740 void ByteString::TrimRight(char target) {
741   TrimRight(ByteStringView(target));
742 }
743 
TrimRight(ByteStringView targets)744 void ByteString::TrimRight(ByteStringView targets) {
745   if (!m_pData || targets.IsEmpty())
746     return;
747 
748   size_t pos = GetLength();
749   if (pos == 0)
750     return;
751 
752   while (pos) {
753     size_t i = 0;
754     while (i < targets.GetLength() && targets[i] != m_pData->m_String[pos - 1])
755       i++;
756     if (i == targets.GetLength())
757       break;
758     pos--;
759   }
760   if (pos < m_pData->m_nDataLength) {
761     ReallocBeforeWrite(m_pData->m_nDataLength);
762     m_pData->m_String[pos] = 0;
763     m_pData->m_nDataLength = pos;
764   }
765 }
766 
operator <<(std::ostream & os,const ByteString & str)767 std::ostream& operator<<(std::ostream& os, const ByteString& str) {
768   return os.write(str.c_str(), str.GetLength());
769 }
770 
operator <<(std::ostream & os,ByteStringView str)771 std::ostream& operator<<(std::ostream& os, ByteStringView str) {
772   return os.write(str.unterminated_c_str(), str.GetLength());
773 }
774 
775 }  // namespace fxcrt
776 
FX_HashCode_GetA(ByteStringView str,bool bIgnoreCase)777 uint32_t FX_HashCode_GetA(ByteStringView str, bool bIgnoreCase) {
778   uint32_t dwHashCode = 0;
779   if (bIgnoreCase) {
780     for (ByteStringView::UnsignedType c : str)
781       dwHashCode = 31 * dwHashCode + tolower(c);
782   } else {
783     for (ByteStringView::UnsignedType c : str)
784       dwHashCode = 31 * dwHashCode + c;
785   }
786   return dwHashCode;
787 }
788 
FX_HashCode_GetAsIfW(ByteStringView str,bool bIgnoreCase)789 uint32_t FX_HashCode_GetAsIfW(ByteStringView str, bool bIgnoreCase) {
790   uint32_t dwHashCode = 0;
791   if (bIgnoreCase) {
792     for (ByteStringView::UnsignedType c : str)
793       dwHashCode = 1313 * dwHashCode + FXSYS_towlower(c);
794   } else {
795     for (ByteStringView::UnsignedType c : str)
796       dwHashCode = 1313 * dwHashCode + c;
797   }
798   return dwHashCode;
799 }
800