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      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 "SkScalar.h"
     14 #include "SkTArray.h"
     15 
     16 #include <stdarg.h>
     17 
     18 /*  Some helper functions for C strings
     19 */
     20 
     21 static bool SkStrStartsWith(const char string[], const char prefixStr[]) {
     22     SkASSERT(string);
     23     SkASSERT(prefixStr);
     24     return !strncmp(string, prefixStr, strlen(prefixStr));
     25 }
     26 static bool SkStrStartsWith(const char string[], const char prefixChar) {
     27     SkASSERT(string);
     28     return (prefixChar == *string);
     29 }
     30 
     31 bool SkStrEndsWith(const char string[], const char suffixStr[]);
     32 bool SkStrEndsWith(const char string[], const char suffixChar);
     33 
     34 int SkStrStartsWithOneOf(const char string[], const char prefixes[]);
     35 
     36 static int SkStrFind(const char string[], const char substring[]) {
     37     const char *first = strstr(string, substring);
     38     if (NULL == first) return -1;
     39     return SkToS32(first - &string[0]);
     40 }
     41 
     42 static bool SkStrContains(const char string[], const char substring[]) {
     43     SkASSERT(string);
     44     SkASSERT(substring);
     45     return (-1 != SkStrFind(string, substring));
     46 }
     47 static bool SkStrContains(const char string[], const char subchar) {
     48     SkASSERT(string);
     49     char tmp[2];
     50     tmp[0] = subchar;
     51     tmp[1] = '\0';
     52     return (-1 != SkStrFind(string, tmp));
     53 }
     54 
     55 static inline char *SkStrDup(const char string[]) {
     56     char *ret = (char *) sk_malloc_throw(strlen(string)+1);
     57     memcpy(ret,string,strlen(string)+1);
     58     return ret;
     59 }
     60 
     61 
     62 
     63 #define SkStrAppendU32_MaxSize  10
     64 char*   SkStrAppendU32(char buffer[], uint32_t);
     65 #define SkStrAppendU64_MaxSize  20
     66 char*   SkStrAppendU64(char buffer[], uint64_t, int minDigits);
     67 
     68 #define SkStrAppendS32_MaxSize  (SkStrAppendU32_MaxSize + 1)
     69 char*   SkStrAppendS32(char buffer[], int32_t);
     70 #define SkStrAppendS64_MaxSize  (SkStrAppendU64_MaxSize + 1)
     71 char*   SkStrAppendS64(char buffer[], int64_t, int minDigits);
     72 
     73 /**
     74  *  Floats have at most 8 significant digits, so we limit our %g to that.
     75  *  However, the total string could be 15 characters: -1.2345678e-005
     76  *
     77  *  In theory we should only expect up to 2 digits for the exponent, but on
     78  *  some platforms we have seen 3 (as in the example above).
     79  */
     80 #define SkStrAppendScalar_MaxSize  15
     81 
     82 /**
     83  *  Write the scaler in decimal format into buffer, and return a pointer to
     84  *  the next char after the last one written. Note: a terminating 0 is not
     85  *  written into buffer, which must be at least SkStrAppendScalar_MaxSize.
     86  *  Thus if the caller wants to add a 0 at the end, buffer must be at least
     87  *  SkStrAppendScalar_MaxSize + 1 bytes large.
     88  */
     89 #define SkStrAppendScalar SkStrAppendFloat
     90 
     91 char* SkStrAppendFloat(char buffer[], float);
     92 char* SkStrAppendFixed(char buffer[], SkFixed);
     93 
     94 /** \class SkString
     95 
     96     Light weight class for managing strings. Uses reference
     97     counting to make string assignments and copies very fast
     98     with no extra RAM cost. Assumes UTF8 encoding.
     99 */
    100 class SK_API SkString {
    101 public:
    102                 SkString();
    103     explicit    SkString(size_t len);
    104     explicit    SkString(const char text[]);
    105                 SkString(const char text[], size_t len);
    106                 SkString(const SkString&);
    107                 ~SkString();
    108 
    109     bool        isEmpty() const { return 0 == fRec->fLength; }
    110     size_t      size() const { return (size_t) fRec->fLength; }
    111     const char* c_str() const { return fRec->data(); }
    112     char operator[](size_t n) const { return this->c_str()[n]; }
    113 
    114     bool equals(const SkString&) const;
    115     bool equals(const char text[]) const;
    116     bool equals(const char text[], size_t len) const;
    117 
    118     bool startsWith(const char prefixStr[]) const {
    119         return SkStrStartsWith(fRec->data(), prefixStr);
    120     }
    121     bool startsWith(const char prefixChar) const {
    122         return SkStrStartsWith(fRec->data(), prefixChar);
    123     }
    124     bool endsWith(const char suffixStr[]) const {
    125         return SkStrEndsWith(fRec->data(), suffixStr);
    126     }
    127     bool endsWith(const char suffixChar) const {
    128         return SkStrEndsWith(fRec->data(), suffixChar);
    129     }
    130     bool contains(const char substring[]) const {
    131         return SkStrContains(fRec->data(), substring);
    132     }
    133     bool contains(const char subchar) const {
    134         return SkStrContains(fRec->data(), subchar);
    135     }
    136     int find(const char substring[]) const {
    137         return SkStrFind(fRec->data(), substring);
    138     }
    139 
    140     friend bool operator==(const SkString& a, const SkString& b) {
    141         return a.equals(b);
    142     }
    143     friend bool operator!=(const SkString& a, const SkString& b) {
    144         return !a.equals(b);
    145     }
    146 
    147     // these methods edit the string
    148 
    149     SkString& operator=(const SkString&);
    150     SkString& operator=(const char text[]);
    151 
    152     char* writable_str();
    153     char& operator[](size_t n) { return this->writable_str()[n]; }
    154 
    155     void reset();
    156     void resize(size_t len) { this->set(NULL, len); }
    157     void set(const SkString& src) { *this = src; }
    158     void set(const char text[]);
    159     void set(const char text[], size_t len);
    160     void setUTF16(const uint16_t[]);
    161     void setUTF16(const uint16_t[], size_t len);
    162 
    163     void insert(size_t offset, const SkString& src) { this->insert(offset, src.c_str(), src.size()); }
    164     void insert(size_t offset, const char text[]);
    165     void insert(size_t offset, const char text[], size_t len);
    166     void insertUnichar(size_t offset, SkUnichar);
    167     void insertS32(size_t offset, int32_t value);
    168     void insertS64(size_t offset, int64_t value, int minDigits = 0);
    169     void insertU32(size_t offset, uint32_t value);
    170     void insertU64(size_t offset, uint64_t value, int minDigits = 0);
    171     void insertHex(size_t offset, uint32_t value, int minDigits = 0);
    172     void insertScalar(size_t offset, SkScalar);
    173 
    174     void append(const SkString& str) { this->insert((size_t)-1, str); }
    175     void append(const char text[]) { this->insert((size_t)-1, text); }
    176     void append(const char text[], size_t len) { this->insert((size_t)-1, text, len); }
    177     void appendUnichar(SkUnichar uni) { this->insertUnichar((size_t)-1, uni); }
    178     void appendS32(int32_t value) { this->insertS32((size_t)-1, value); }
    179     void appendS64(int64_t value, int minDigits = 0) { this->insertS64((size_t)-1, value, minDigits); }
    180     void appendU32(uint32_t value) { this->insertU32((size_t)-1, value); }
    181     void appendU64(uint64_t value, int minDigits = 0) { this->insertU64((size_t)-1, value, minDigits); }
    182     void appendHex(uint32_t value, int minDigits = 0) { this->insertHex((size_t)-1, value, minDigits); }
    183     void appendScalar(SkScalar value) { this->insertScalar((size_t)-1, value); }
    184 
    185     void prepend(const SkString& str) { this->insert(0, str); }
    186     void prepend(const char text[]) { this->insert(0, text); }
    187     void prepend(const char text[], size_t len) { this->insert(0, text, len); }
    188     void prependUnichar(SkUnichar uni) { this->insertUnichar(0, uni); }
    189     void prependS32(int32_t value) { this->insertS32(0, value); }
    190     void prependS64(int32_t value, int minDigits = 0) { this->insertS64(0, value, minDigits); }
    191     void prependHex(uint32_t value, int minDigits = 0) { this->insertHex(0, value, minDigits); }
    192     void prependScalar(SkScalar value) { this->insertScalar((size_t)-1, value); }
    193 
    194     void printf(const char format[], ...) SK_PRINTF_LIKE(2, 3);
    195     void appendf(const char format[], ...) SK_PRINTF_LIKE(2, 3);
    196     void appendVAList(const char format[], va_list);
    197     void prependf(const char format[], ...) SK_PRINTF_LIKE(2, 3);
    198 
    199     void remove(size_t offset, size_t length);
    200 
    201     SkString& operator+=(const SkString& s) { this->append(s); return *this; }
    202     SkString& operator+=(const char text[]) { this->append(text); return *this; }
    203     SkString& operator+=(const char c) { this->append(&c, 1); return *this; }
    204 
    205     /**
    206      *  Swap contents between this and other. This function is guaranteed
    207      *  to never fail or throw.
    208      */
    209     void swap(SkString& other);
    210 
    211 private:
    212     struct Rec {
    213     public:
    214         uint32_t    fLength; // logically size_t, but we want it to stay 32bits
    215         int32_t     fRefCnt;
    216         char        fBeginningOfData;
    217 
    218         char* data() { return &fBeginningOfData; }
    219         const char* data() const { return &fBeginningOfData; }
    220     };
    221     Rec* fRec;
    222 
    223 #ifdef SK_DEBUG
    224     const char* fStr;
    225     void validate() const;
    226 #else
    227     void validate() const {}
    228 #endif
    229 
    230     static const Rec gEmptyRec;
    231     static Rec* AllocRec(const char text[], size_t len);
    232     static Rec* RefRec(Rec*);
    233 };
    234 
    235 /// Creates a new string and writes into it using a printf()-style format.
    236 SkString SkStringPrintf(const char* format, ...);
    237 
    238 // Specialized to take advantage of SkString's fast swap path. The unspecialized function is
    239 // declared in SkTypes.h and called by SkTSort.
    240 template <> inline void SkTSwap(SkString& a, SkString& b) {
    241     a.swap(b);
    242 }
    243 
    244 // Split str on any characters in delimiters into out.  (Think, strtok with a sane API.)
    245 void SkStrSplit(const char* str, const char* delimiters, SkTArray<SkString>* out);
    246 
    247 #endif
    248