1 2 /* 3 * Copyright 2006 The Android Open Source Project 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10 #ifndef SkString_DEFINED 11 #define SkString_DEFINED 12 13 #include "../private/SkTArray.h" 14 #include "SkScalar.h" 15 #include "SkRefCnt.h" 16 17 #include <atomic> 18 #include <stdarg.h> 19 20 /* Some helper functions for C strings 21 */ 22 23 static bool SkStrStartsWith(const char string[], const char prefixStr[]) { 24 SkASSERT(string); 25 SkASSERT(prefixStr); 26 return !strncmp(string, prefixStr, strlen(prefixStr)); 27 } 28 static bool SkStrStartsWith(const char string[], const char prefixChar) { 29 SkASSERT(string); 30 return (prefixChar == *string); 31 } 32 33 bool SkStrEndsWith(const char string[], const char suffixStr[]); 34 bool SkStrEndsWith(const char string[], const char suffixChar); 35 36 int SkStrStartsWithOneOf(const char string[], const char prefixes[]); 37 38 static int SkStrFind(const char string[], const char substring[]) { 39 const char *first = strstr(string, substring); 40 if (nullptr == first) return -1; 41 return SkToInt(first - &string[0]); 42 } 43 44 static int SkStrFindLastOf(const char string[], const char subchar) { 45 const char* last = strrchr(string, subchar); 46 if (nullptr == last) return -1; 47 return SkToInt(last - &string[0]); 48 } 49 50 static bool SkStrContains(const char string[], const char substring[]) { 51 SkASSERT(string); 52 SkASSERT(substring); 53 return (-1 != SkStrFind(string, substring)); 54 } 55 static bool SkStrContains(const char string[], const char subchar) { 56 SkASSERT(string); 57 char tmp[2]; 58 tmp[0] = subchar; 59 tmp[1] = '\0'; 60 return (-1 != SkStrFind(string, tmp)); 61 } 62 63 static inline char *SkStrDup(const char string[]) { 64 char *ret = (char *) sk_malloc_throw(strlen(string)+1); 65 memcpy(ret,string,strlen(string)+1); 66 return ret; 67 } 68 69 /* 70 * The SkStrAppend... methods will write into the provided buffer, assuming it is large enough. 71 * Each method has an associated const (e.g. SkStrAppendU32_MaxSize) which will be the largest 72 * value needed for that method's buffer. 73 * 74 * char storage[SkStrAppendU32_MaxSize]; 75 * SkStrAppendU32(storage, value); 76 * 77 * Note : none of the SkStrAppend... methods write a terminating 0 to their buffers. Instead, 78 * the methods return the ptr to the end of the written part of the buffer. This can be used 79 * to compute the length, and/or know where to write a 0 if that is desired. 80 * 81 * char storage[SkStrAppendU32_MaxSize + 1]; 82 * char* stop = SkStrAppendU32(storage, value); 83 * size_t len = stop - storage; 84 * *stop = 0; // valid, since storage was 1 byte larger than the max. 85 */ 86 87 #define SkStrAppendU32_MaxSize 10 88 char* SkStrAppendU32(char buffer[], uint32_t); 89 #define SkStrAppendU64_MaxSize 20 90 char* SkStrAppendU64(char buffer[], uint64_t, int minDigits); 91 92 #define SkStrAppendS32_MaxSize (SkStrAppendU32_MaxSize + 1) 93 char* SkStrAppendS32(char buffer[], int32_t); 94 #define SkStrAppendS64_MaxSize (SkStrAppendU64_MaxSize + 1) 95 char* SkStrAppendS64(char buffer[], int64_t, int minDigits); 96 97 /** 98 * Floats have at most 8 significant digits, so we limit our %g to that. 99 * However, the total string could be 15 characters: -1.2345678e-005 100 * 101 * In theory we should only expect up to 2 digits for the exponent, but on 102 * some platforms we have seen 3 (as in the example above). 103 */ 104 #define SkStrAppendScalar_MaxSize 15 105 106 /** 107 * Write the scaler in decimal format into buffer, and return a pointer to 108 * the next char after the last one written. Note: a terminating 0 is not 109 * written into buffer, which must be at least SkStrAppendScalar_MaxSize. 110 * Thus if the caller wants to add a 0 at the end, buffer must be at least 111 * SkStrAppendScalar_MaxSize + 1 bytes large. 112 */ 113 #define SkStrAppendScalar SkStrAppendFloat 114 115 char* SkStrAppendFloat(char buffer[], float); 116 117 /** \class SkString 118 119 Light weight class for managing strings. Uses reference 120 counting to make string assignments and copies very fast 121 with no extra RAM cost. Assumes UTF8 encoding. 122 */ 123 class SK_API SkString { 124 public: 125 SkString(); 126 explicit SkString(size_t len); 127 explicit SkString(const char text[]); 128 SkString(const char text[], size_t len); 129 SkString(const SkString&); 130 SkString(SkString&&); 131 ~SkString(); 132 133 bool isEmpty() const { return 0 == fRec->fLength; } 134 size_t size() const { return (size_t) fRec->fLength; } 135 const char* c_str() const { return fRec->data(); } 136 char operator[](size_t n) const { return this->c_str()[n]; } 137 138 bool equals(const SkString&) const; 139 bool equals(const char text[]) const; 140 bool equals(const char text[], size_t len) const; 141 142 bool startsWith(const char prefixStr[]) const { 143 return SkStrStartsWith(fRec->data(), prefixStr); 144 } 145 bool startsWith(const char prefixChar) const { 146 return SkStrStartsWith(fRec->data(), prefixChar); 147 } 148 bool endsWith(const char suffixStr[]) const { 149 return SkStrEndsWith(fRec->data(), suffixStr); 150 } 151 bool endsWith(const char suffixChar) const { 152 return SkStrEndsWith(fRec->data(), suffixChar); 153 } 154 bool contains(const char substring[]) const { 155 return SkStrContains(fRec->data(), substring); 156 } 157 bool contains(const char subchar) const { 158 return SkStrContains(fRec->data(), subchar); 159 } 160 int find(const char substring[]) const { 161 return SkStrFind(fRec->data(), substring); 162 } 163 int findLastOf(const char subchar) const { 164 return SkStrFindLastOf(fRec->data(), subchar); 165 } 166 167 friend bool operator==(const SkString& a, const SkString& b) { 168 return a.equals(b); 169 } 170 friend bool operator!=(const SkString& a, const SkString& b) { 171 return !a.equals(b); 172 } 173 174 // these methods edit the string 175 176 SkString& operator=(const SkString&); 177 SkString& operator=(SkString&&); 178 SkString& operator=(const char text[]); 179 180 char* writable_str(); 181 char& operator[](size_t n) { return this->writable_str()[n]; } 182 183 void reset(); 184 /** Destructive resize, does not preserve contents. */ 185 void resize(size_t len) { this->set(nullptr, len); } 186 void set(const SkString& src) { *this = src; } 187 void set(const char text[]); 188 void set(const char text[], size_t len); 189 190 void insert(size_t offset, const SkString& src) { this->insert(offset, src.c_str(), src.size()); } 191 void insert(size_t offset, const char text[]); 192 void insert(size_t offset, const char text[], size_t len); 193 void insertUnichar(size_t offset, SkUnichar); 194 void insertS32(size_t offset, int32_t value); 195 void insertS64(size_t offset, int64_t value, int minDigits = 0); 196 void insertU32(size_t offset, uint32_t value); 197 void insertU64(size_t offset, uint64_t value, int minDigits = 0); 198 void insertHex(size_t offset, uint32_t value, int minDigits = 0); 199 void insertScalar(size_t offset, SkScalar); 200 201 void append(const SkString& str) { this->insert((size_t)-1, str); } 202 void append(const char text[]) { this->insert((size_t)-1, text); } 203 void append(const char text[], size_t len) { this->insert((size_t)-1, text, len); } 204 void appendUnichar(SkUnichar uni) { this->insertUnichar((size_t)-1, uni); } 205 void appendS32(int32_t value) { this->insertS32((size_t)-1, value); } 206 void appendS64(int64_t value, int minDigits = 0) { this->insertS64((size_t)-1, value, minDigits); } 207 void appendU32(uint32_t value) { this->insertU32((size_t)-1, value); } 208 void appendU64(uint64_t value, int minDigits = 0) { this->insertU64((size_t)-1, value, minDigits); } 209 void appendHex(uint32_t value, int minDigits = 0) { this->insertHex((size_t)-1, value, minDigits); } 210 void appendScalar(SkScalar value) { this->insertScalar((size_t)-1, value); } 211 212 void prepend(const SkString& str) { this->insert(0, str); } 213 void prepend(const char text[]) { this->insert(0, text); } 214 void prepend(const char text[], size_t len) { this->insert(0, text, len); } 215 void prependUnichar(SkUnichar uni) { this->insertUnichar(0, uni); } 216 void prependS32(int32_t value) { this->insertS32(0, value); } 217 void prependS64(int32_t value, int minDigits = 0) { this->insertS64(0, value, minDigits); } 218 void prependHex(uint32_t value, int minDigits = 0) { this->insertHex(0, value, minDigits); } 219 void prependScalar(SkScalar value) { this->insertScalar((size_t)-1, value); } 220 221 void printf(const char format[], ...) SK_PRINTF_LIKE(2, 3); 222 void appendf(const char format[], ...) SK_PRINTF_LIKE(2, 3); 223 void appendVAList(const char format[], va_list); 224 void prependf(const char format[], ...) SK_PRINTF_LIKE(2, 3); 225 void prependVAList(const char format[], va_list); 226 227 void remove(size_t offset, size_t length); 228 229 SkString& operator+=(const SkString& s) { this->append(s); return *this; } 230 SkString& operator+=(const char text[]) { this->append(text); return *this; } 231 SkString& operator+=(const char c) { this->append(&c, 1); return *this; } 232 233 /** 234 * Swap contents between this and other. This function is guaranteed 235 * to never fail or throw. 236 */ 237 void swap(SkString& other); 238 239 private: 240 struct Rec { 241 public: 242 constexpr Rec(uint32_t len, int32_t refCnt) 243 : fLength(len), fRefCnt(refCnt), fBeginningOfData(0) 244 { } 245 static sk_sp<Rec> Make(const char text[], size_t len); 246 uint32_t fLength; // logically size_t, but we want it to stay 32bits 247 mutable std::atomic<int32_t> fRefCnt; 248 char fBeginningOfData; 249 250 char* data() { return &fBeginningOfData; } 251 const char* data() const { return &fBeginningOfData; } 252 253 void ref() const; 254 void unref() const; 255 bool unique() const; 256 private: 257 // Ensure the unsized delete is called. 258 void operator delete(void* p) { ::operator delete(p); } 259 }; 260 sk_sp<Rec> fRec; 261 262 #ifdef SK_DEBUG 263 void validate() const; 264 #else 265 void validate() const {} 266 #endif 267 268 static const Rec gEmptyRec; 269 }; 270 271 /// Creates a new string and writes into it using a printf()-style format. 272 SkString SkStringPrintf(const char* format, ...); 273 /// This makes it easier to write a caller as a VAR_ARGS function where the format string is 274 /// optional. 275 static inline SkString SkStringPrintf() { return SkString(); } 276 277 // Specialized to take advantage of SkString's fast swap path. The unspecialized function is 278 // declared in SkTypes.h and called by SkTSort. 279 template <> inline void SkTSwap(SkString& a, SkString& b) { 280 a.swap(b); 281 } 282 283 enum SkStrSplitMode { 284 // Strictly return all results. If the input is ",," and the separator is ',' this will return 285 // an array of three empty strings. 286 kStrict_SkStrSplitMode, 287 288 // Only nonempty results will be added to the results. Multiple separators will be 289 // coalesced. Separators at the beginning and end of the input will be ignored. If the input is 290 // ",," and the separator is ',', this will return an empty vector. 291 kCoalesce_SkStrSplitMode 292 }; 293 294 // Split str on any characters in delimiters into out. (Think, strtok with a sane API.) 295 void SkStrSplit(const char* str, const char* delimiters, SkStrSplitMode splitMode, 296 SkTArray<SkString>* out); 297 inline void SkStrSplit(const char* str, const char* delimiters, SkTArray<SkString>* out) { 298 SkStrSplit(str, delimiters, kCoalesce_SkStrSplitMode, out); 299 } 300 301 #endif 302
