| /* |
| * Copyright 2006 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "include/core/SkString.h" |
| #include "include/private/SkTPin.h" |
| #include "include/private/SkTo.h" |
| #include "src/core/SkSafeMath.h" |
| #include "src/core/SkUtils.h" |
| #include "src/utils/SkUTF.h" |
| |
| #include <cstdio> |
| #include <new> |
| #include <string_view> |
| #include <utility> |
| #include <vector> |
| |
| // number of bytes (on the stack) to receive the printf result |
| static const size_t kBufferSize = 1024; |
| |
| struct StringBuffer { |
| char* fText; |
| int fLength; |
| }; |
| |
| template <int SIZE> |
| static StringBuffer apply_format_string(const char* format, va_list args, char (&stackBuffer)[SIZE], |
| SkString* heapBuffer) SK_PRINTF_LIKE(1, 0); |
| |
| template <int SIZE> |
| static StringBuffer apply_format_string(const char* format, va_list args, char (&stackBuffer)[SIZE], |
| SkString* heapBuffer) { |
| // First, attempt to print directly to the stack buffer. |
| va_list argsCopy; |
| va_copy(argsCopy, args); |
| int outLength = std::vsnprintf(stackBuffer, SIZE, format, args); |
| if (outLength < 0) { |
| SkDebugf("SkString: vsnprintf reported error."); |
| va_end(argsCopy); |
| return {stackBuffer, 0}; |
| } |
| if (outLength < SIZE) { |
| va_end(argsCopy); |
| return {stackBuffer, outLength}; |
| } |
| |
| // Our text was too long to fit on the stack! However, we now know how much space we need to |
| // format it. Format the string into our heap buffer. `set` automatically reserves an extra |
| // byte at the end of the buffer for a null terminator, so we don't need to add one here. |
| heapBuffer->set(nullptr, outLength); |
| char* heapBufferDest = heapBuffer->writable_str(); |
| SkDEBUGCODE(int checkLength =) std::vsnprintf(heapBufferDest, outLength + 1, format, argsCopy); |
| SkASSERT(checkLength == outLength); |
| va_end(argsCopy); |
| return {heapBufferDest, outLength}; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| bool SkStrEndsWith(const char string[], const char suffixStr[]) { |
| SkASSERT(string); |
| SkASSERT(suffixStr); |
| size_t strLen = strlen(string); |
| size_t suffixLen = strlen(suffixStr); |
| return strLen >= suffixLen && |
| !strncmp(string + strLen - suffixLen, suffixStr, suffixLen); |
| } |
| |
| bool SkStrEndsWith(const char string[], const char suffixChar) { |
| SkASSERT(string); |
| size_t strLen = strlen(string); |
| if (0 == strLen) { |
| return false; |
| } else { |
| return (suffixChar == string[strLen-1]); |
| } |
| } |
| |
| int SkStrStartsWithOneOf(const char string[], const char prefixes[]) { |
| int index = 0; |
| do { |
| const char* limit = strchr(prefixes, '\0'); |
| if (!strncmp(string, prefixes, limit - prefixes)) { |
| return index; |
| } |
| prefixes = limit + 1; |
| index++; |
| } while (prefixes[0]); |
| return -1; |
| } |
| |
| char* SkStrAppendU32(char string[], uint32_t dec) { |
| SkDEBUGCODE(char* start = string;) |
| |
| char buffer[kSkStrAppendU32_MaxSize]; |
| char* p = buffer + sizeof(buffer); |
| |
| do { |
| *--p = SkToU8('0' + dec % 10); |
| dec /= 10; |
| } while (dec != 0); |
| |
| SkASSERT(p >= buffer); |
| size_t cp_len = buffer + sizeof(buffer) - p; |
| memcpy(string, p, cp_len); |
| string += cp_len; |
| |
| SkASSERT(string - start <= kSkStrAppendU32_MaxSize); |
| return string; |
| } |
| |
| char* SkStrAppendS32(char string[], int32_t dec) { |
| uint32_t udec = dec; |
| if (dec < 0) { |
| *string++ = '-'; |
| udec = ~udec + 1; // udec = -udec, but silences some warnings that are trying to be helpful |
| } |
| return SkStrAppendU32(string, udec); |
| } |
| |
| char* SkStrAppendU64(char string[], uint64_t dec, int minDigits) { |
| SkDEBUGCODE(char* start = string;) |
| |
| char buffer[kSkStrAppendU64_MaxSize]; |
| char* p = buffer + sizeof(buffer); |
| |
| do { |
| *--p = SkToU8('0' + (int32_t) (dec % 10)); |
| dec /= 10; |
| minDigits--; |
| } while (dec != 0); |
| |
| while (minDigits > 0) { |
| *--p = '0'; |
| minDigits--; |
| } |
| |
| SkASSERT(p >= buffer); |
| size_t cp_len = buffer + sizeof(buffer) - p; |
| memcpy(string, p, cp_len); |
| string += cp_len; |
| |
| SkASSERT(string - start <= kSkStrAppendU64_MaxSize); |
| return string; |
| } |
| |
| char* SkStrAppendS64(char string[], int64_t dec, int minDigits) { |
| uint64_t udec = dec; |
| if (dec < 0) { |
| *string++ = '-'; |
| udec = ~udec + 1; // udec = -udec, but silences some warnings that are trying to be helpful |
| } |
| return SkStrAppendU64(string, udec, minDigits); |
| } |
| |
| char* SkStrAppendScalar(char string[], SkScalar value) { |
| // Handle infinity and NaN ourselves to ensure consistent cross-platform results. |
| // (e.g.: `inf` versus `1.#INF00`, `nan` versus `-nan` for high-bit-set NaNs) |
| if (SkScalarIsNaN(value)) { |
| strcpy(string, "nan"); |
| return string + 3; |
| } |
| if (!SkScalarIsFinite(value)) { |
| if (value > 0) { |
| strcpy(string, "inf"); |
| return string + 3; |
| } else { |
| strcpy(string, "-inf"); |
| return string + 4; |
| } |
| } |
| |
| // since floats have at most 8 significant digits, we limit our %g to that. |
| static const char gFormat[] = "%.8g"; |
| // make it 1 larger for the terminating 0 |
| char buffer[kSkStrAppendScalar_MaxSize + 1]; |
| int len = snprintf(buffer, sizeof(buffer), gFormat, value); |
| memcpy(string, buffer, len); |
| SkASSERT(len <= kSkStrAppendScalar_MaxSize); |
| return string + len; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| const SkString::Rec SkString::gEmptyRec(0, 0); |
| |
| #define SizeOfRec() (gEmptyRec.data() - (const char*)&gEmptyRec) |
| |
| static uint32_t trim_size_t_to_u32(size_t value) { |
| if (sizeof(size_t) > sizeof(uint32_t)) { |
| if (value > UINT32_MAX) { |
| value = UINT32_MAX; |
| } |
| } |
| return (uint32_t)value; |
| } |
| |
| static size_t check_add32(size_t base, size_t extra) { |
| SkASSERT(base <= UINT32_MAX); |
| if (sizeof(size_t) > sizeof(uint32_t)) { |
| if (base + extra > UINT32_MAX) { |
| extra = UINT32_MAX - base; |
| } |
| } |
| return extra; |
| } |
| |
| sk_sp<SkString::Rec> SkString::Rec::Make(const char text[], size_t len) { |
| if (0 == len) { |
| return sk_sp<SkString::Rec>(const_cast<Rec*>(&gEmptyRec)); |
| } |
| |
| SkSafeMath safe; |
| // We store a 32bit version of the length |
| uint32_t stringLen = safe.castTo<uint32_t>(len); |
| // Add SizeOfRec() for our overhead and 1 for null-termination |
| size_t allocationSize = safe.add(len, SizeOfRec() + sizeof(char)); |
| // Align up to a multiple of 4 |
| allocationSize = safe.alignUp(allocationSize, 4); |
| |
| SkASSERT_RELEASE(safe.ok()); |
| |
| void* storage = ::operator new (allocationSize); |
| sk_sp<Rec> rec(new (storage) Rec(stringLen, 1)); |
| if (text) { |
| memcpy(rec->data(), text, len); |
| } |
| rec->data()[len] = 0; |
| return rec; |
| } |
| |
| void SkString::Rec::ref() const { |
| if (this == &SkString::gEmptyRec) { |
| return; |
| } |
| SkAssertResult(this->fRefCnt.fetch_add(+1, std::memory_order_relaxed)); |
| } |
| |
| void SkString::Rec::unref() const { |
| if (this == &SkString::gEmptyRec) { |
| return; |
| } |
| int32_t oldRefCnt = this->fRefCnt.fetch_add(-1, std::memory_order_acq_rel); |
| SkASSERT(oldRefCnt); |
| if (1 == oldRefCnt) { |
| delete this; |
| } |
| } |
| |
| bool SkString::Rec::unique() const { |
| return fRefCnt.load(std::memory_order_acquire) == 1; |
| } |
| |
| #ifdef SK_DEBUG |
| int32_t SkString::Rec::getRefCnt() const { |
| return fRefCnt.load(std::memory_order_relaxed); |
| } |
| |
| const SkString& SkString::validate() const { |
| // make sure no one has written over our global |
| SkASSERT(0 == gEmptyRec.fLength); |
| SkASSERT(0 == gEmptyRec.getRefCnt()); |
| SkASSERT(0 == gEmptyRec.data()[0]); |
| |
| if (fRec.get() != &gEmptyRec) { |
| SkASSERT(fRec->fLength > 0); |
| SkASSERT(fRec->getRefCnt() > 0); |
| SkASSERT(0 == fRec->data()[fRec->fLength]); |
| } |
| return *this; |
| } |
| #endif |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| SkString::SkString() : fRec(const_cast<Rec*>(&gEmptyRec)) { |
| } |
| |
| SkString::SkString(size_t len) { |
| fRec = Rec::Make(nullptr, len); |
| } |
| |
| SkString::SkString(const char text[]) { |
| size_t len = text ? strlen(text) : 0; |
| |
| fRec = Rec::Make(text, len); |
| } |
| |
| SkString::SkString(const char text[], size_t len) { |
| fRec = Rec::Make(text, len); |
| } |
| |
| SkString::SkString(const SkString& src) : fRec(src.validate().fRec) {} |
| |
| SkString::SkString(SkString&& src) : fRec(std::move(src.validate().fRec)) { |
| src.fRec.reset(const_cast<Rec*>(&gEmptyRec)); |
| } |
| |
| SkString::SkString(const std::string& src) { |
| fRec = Rec::Make(src.c_str(), src.size()); |
| } |
| |
| SkString::SkString(std::string_view src) { |
| fRec = Rec::Make(src.data(), src.length()); |
| } |
| |
| SkString::~SkString() { |
| this->validate(); |
| } |
| |
| bool SkString::equals(const SkString& src) const { |
| return fRec == src.fRec || this->equals(src.c_str(), src.size()); |
| } |
| |
| bool SkString::equals(const char text[]) const { |
| return this->equals(text, text ? strlen(text) : 0); |
| } |
| |
| bool SkString::equals(const char text[], size_t len) const { |
| SkASSERT(len == 0 || text != nullptr); |
| |
| return fRec->fLength == len && !sk_careful_memcmp(fRec->data(), text, len); |
| } |
| |
| SkString& SkString::operator=(const SkString& src) { |
| this->validate(); |
| fRec = src.fRec; // sk_sp<Rec>::operator=(const sk_sp<Ref>&) checks for self-assignment. |
| return *this; |
| } |
| |
| SkString& SkString::operator=(SkString&& src) { |
| this->validate(); |
| |
| if (fRec != src.fRec) { |
| this->swap(src); |
| } |
| return *this; |
| } |
| |
| SkString& SkString::operator=(const char text[]) { |
| this->validate(); |
| return *this = SkString(text); |
| } |
| |
| void SkString::reset() { |
| this->validate(); |
| fRec.reset(const_cast<Rec*>(&gEmptyRec)); |
| } |
| |
| char* SkString::writable_str() { |
| this->validate(); |
| |
| if (fRec->fLength) { |
| if (!fRec->unique()) { |
| fRec = Rec::Make(fRec->data(), fRec->fLength); |
| } |
| } |
| return fRec->data(); |
| } |
| |
| void SkString::resize(size_t len) { |
| len = trim_size_t_to_u32(len); |
| if (0 == len) { |
| this->reset(); |
| } else if (fRec->unique() && ((len >> 2) <= (fRec->fLength >> 2))) { |
| // Use less of the buffer we have without allocating a smaller one. |
| char* p = this->writable_str(); |
| p[len] = '\0'; |
| fRec->fLength = SkToU32(len); |
| } else { |
| SkString newString(len); |
| char* dest = newString.writable_str(); |
| int copyLen = std::min<uint32_t>(len, this->size()); |
| memcpy(dest, this->c_str(), copyLen); |
| dest[copyLen] = '\0'; |
| this->swap(newString); |
| } |
| } |
| |
| void SkString::set(const char text[]) { |
| this->set(text, text ? strlen(text) : 0); |
| } |
| |
| void SkString::set(const char text[], size_t len) { |
| len = trim_size_t_to_u32(len); |
| if (0 == len) { |
| this->reset(); |
| } else if (fRec->unique() && ((len >> 2) <= (fRec->fLength >> 2))) { |
| // Use less of the buffer we have without allocating a smaller one. |
| char* p = this->writable_str(); |
| if (text) { |
| memcpy(p, text, len); |
| } |
| p[len] = '\0'; |
| fRec->fLength = SkToU32(len); |
| } else { |
| SkString tmp(text, len); |
| this->swap(tmp); |
| } |
| } |
| |
| void SkString::insert(size_t offset, const char text[]) { |
| this->insert(offset, text, text ? strlen(text) : 0); |
| } |
| |
| void SkString::insert(size_t offset, const char text[], size_t len) { |
| if (len) { |
| size_t length = fRec->fLength; |
| if (offset > length) { |
| offset = length; |
| } |
| |
| // Check if length + len exceeds 32bits, we trim len |
| len = check_add32(length, len); |
| if (0 == len) { |
| return; |
| } |
| |
| /* If we're the only owner, and we have room in our allocation for the insert, |
| do it in place, rather than allocating a new buffer. |
| |
| To know we have room, compare the allocated sizes |
| beforeAlloc = SkAlign4(length + 1) |
| afterAlloc = SkAligh4(length + 1 + len) |
| but SkAlign4(x) is (x + 3) >> 2 << 2 |
| which is equivalent for testing to (length + 1 + 3) >> 2 == (length + 1 + 3 + len) >> 2 |
| and we can then eliminate the +1+3 since that doesn't affec the answer |
| */ |
| if (fRec->unique() && (length >> 2) == ((length + len) >> 2)) { |
| char* dst = this->writable_str(); |
| |
| if (offset < length) { |
| memmove(dst + offset + len, dst + offset, length - offset); |
| } |
| memcpy(dst + offset, text, len); |
| |
| dst[length + len] = 0; |
| fRec->fLength = SkToU32(length + len); |
| } else { |
| /* Seems we should use realloc here, since that is safe if it fails |
| (we have the original data), and might be faster than alloc/copy/free. |
| */ |
| SkString tmp(fRec->fLength + len); |
| char* dst = tmp.writable_str(); |
| |
| if (offset > 0) { |
| memcpy(dst, fRec->data(), offset); |
| } |
| memcpy(dst + offset, text, len); |
| if (offset < fRec->fLength) { |
| memcpy(dst + offset + len, fRec->data() + offset, |
| fRec->fLength - offset); |
| } |
| |
| this->swap(tmp); |
| } |
| } |
| } |
| |
| void SkString::insertUnichar(size_t offset, SkUnichar uni) { |
| char buffer[SkUTF::kMaxBytesInUTF8Sequence]; |
| size_t len = SkUTF::ToUTF8(uni, buffer); |
| |
| if (len) { |
| this->insert(offset, buffer, len); |
| } |
| } |
| |
| void SkString::insertS32(size_t offset, int32_t dec) { |
| char buffer[kSkStrAppendS32_MaxSize]; |
| char* stop = SkStrAppendS32(buffer, dec); |
| this->insert(offset, buffer, stop - buffer); |
| } |
| |
| void SkString::insertS64(size_t offset, int64_t dec, int minDigits) { |
| char buffer[kSkStrAppendS64_MaxSize]; |
| char* stop = SkStrAppendS64(buffer, dec, minDigits); |
| this->insert(offset, buffer, stop - buffer); |
| } |
| |
| void SkString::insertU32(size_t offset, uint32_t dec) { |
| char buffer[kSkStrAppendU32_MaxSize]; |
| char* stop = SkStrAppendU32(buffer, dec); |
| this->insert(offset, buffer, stop - buffer); |
| } |
| |
| void SkString::insertU64(size_t offset, uint64_t dec, int minDigits) { |
| char buffer[kSkStrAppendU64_MaxSize]; |
| char* stop = SkStrAppendU64(buffer, dec, minDigits); |
| this->insert(offset, buffer, stop - buffer); |
| } |
| |
| void SkString::insertHex(size_t offset, uint32_t hex, int minDigits) { |
| minDigits = SkTPin(minDigits, 0, 8); |
| |
| char buffer[8]; |
| char* p = buffer + sizeof(buffer); |
| |
| do { |
| *--p = SkHexadecimalDigits::gUpper[hex & 0xF]; |
| hex >>= 4; |
| minDigits -= 1; |
| } while (hex != 0); |
| |
| while (--minDigits >= 0) { |
| *--p = '0'; |
| } |
| |
| SkASSERT(p >= buffer); |
| this->insert(offset, p, buffer + sizeof(buffer) - p); |
| } |
| |
| void SkString::insertScalar(size_t offset, SkScalar value) { |
| char buffer[kSkStrAppendScalar_MaxSize]; |
| char* stop = SkStrAppendScalar(buffer, value); |
| this->insert(offset, buffer, stop - buffer); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| void SkString::printf(const char format[], ...) { |
| va_list args; |
| va_start(args, format); |
| this->printVAList(format, args); |
| va_end(args); |
| } |
| |
| void SkString::printVAList(const char format[], va_list args) { |
| char stackBuffer[kBufferSize]; |
| StringBuffer result = apply_format_string(format, args, stackBuffer, this); |
| |
| if (result.fText == stackBuffer) { |
| this->set(result.fText, result.fLength); |
| } |
| } |
| |
| void SkString::appendf(const char format[], ...) { |
| va_list args; |
| va_start(args, format); |
| this->appendVAList(format, args); |
| va_end(args); |
| } |
| |
| void SkString::appendVAList(const char format[], va_list args) { |
| if (this->isEmpty()) { |
| this->printVAList(format, args); |
| return; |
| } |
| |
| SkString overflow; |
| char stackBuffer[kBufferSize]; |
| StringBuffer result = apply_format_string(format, args, stackBuffer, &overflow); |
| |
| this->append(result.fText, result.fLength); |
| } |
| |
| void SkString::prependf(const char format[], ...) { |
| va_list args; |
| va_start(args, format); |
| this->prependVAList(format, args); |
| va_end(args); |
| } |
| |
| void SkString::prependVAList(const char format[], va_list args) { |
| if (this->isEmpty()) { |
| this->printVAList(format, args); |
| return; |
| } |
| |
| SkString overflow; |
| char stackBuffer[kBufferSize]; |
| StringBuffer result = apply_format_string(format, args, stackBuffer, &overflow); |
| |
| this->prepend(result.fText, result.fLength); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| void SkString::remove(size_t offset, size_t length) { |
| size_t size = this->size(); |
| |
| if (offset < size) { |
| if (length > size - offset) { |
| length = size - offset; |
| } |
| SkASSERT(length <= size); |
| SkASSERT(offset <= size - length); |
| if (length > 0) { |
| SkString tmp(size - length); |
| char* dst = tmp.writable_str(); |
| const char* src = this->c_str(); |
| |
| if (offset) { |
| memcpy(dst, src, offset); |
| } |
| size_t tail = size - (offset + length); |
| if (tail) { |
| memcpy(dst + offset, src + (offset + length), tail); |
| } |
| SkASSERT(dst[tmp.size()] == 0); |
| this->swap(tmp); |
| } |
| } |
| } |
| |
| void SkString::swap(SkString& other) { |
| this->validate(); |
| other.validate(); |
| |
| using std::swap; |
| swap(fRec, other.fRec); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| SkString SkStringPrintf(const char* format, ...) { |
| SkString formattedOutput; |
| va_list args; |
| va_start(args, format); |
| formattedOutput.printVAList(format, args); |
| va_end(args); |
| return formattedOutput; |
| } |
| |
| void SkStrSplit(const char* str, const char* delimiters, SkStrSplitMode splitMode, |
| SkTArray<SkString>* out) { |
| if (splitMode == kCoalesce_SkStrSplitMode) { |
| // Skip any delimiters. |
| str += strspn(str, delimiters); |
| } |
| if (!*str) { |
| return; |
| } |
| |
| while (true) { |
| // Find a token. |
| const size_t len = strcspn(str, delimiters); |
| if (splitMode == kStrict_SkStrSplitMode || len > 0) { |
| out->push_back().set(str, len); |
| str += len; |
| } |
| |
| if (!*str) { |
| return; |
| } |
| if (splitMode == kCoalesce_SkStrSplitMode) { |
| // Skip any delimiters. |
| str += strspn(str, delimiters); |
| } else { |
| // Skip one delimiter. |
| str += 1; |
| } |
| } |
| } |