SkString.h File Reference

#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkTypes.h"
#include "include/private/base/SkTo.h"
#include "include/private/base/SkTypeTraits.h"
#include <atomic>
#include <cstdarg>
#include <cstdint>
#include <cstring>
#include <string>
#include <string_view>
#include <type_traits>

Go to the source code of this file.

Classes
class	SkString

Functions
static bool	SkStrStartsWith (const char string[], const char prefixStr[])
static bool	SkStrStartsWith (const char string[], const char prefixChar)
bool	SkStrEndsWith (const char string[], const char suffixStr[])
bool	SkStrEndsWith (const char string[], const char suffixChar)
int	SkStrStartsWithOneOf (const char string[], const char prefixes[])
static int	SkStrFind (const char string[], const char substring[])
static int	SkStrFindLastOf (const char string[], const char subchar)
static bool	SkStrContains (const char string[], const char substring[])
static bool	SkStrContains (const char string[], const char subchar)
char *	SkStrAppendU32 (char buffer[], uint32_t)
char *	SkStrAppendU64 (char buffer[], uint64_t, int minDigits)
char *	SkStrAppendS32 (char buffer[], int32_t)
char *	SkStrAppendS64 (char buffer[], int64_t, int minDigits)
char *	SkStrAppendScalar (char buffer[], SkScalar)
SK_API SkString	SkStringPrintf (const char *format,...) SK_PRINTF_LIKE(1
	Creates a new string and writes into it using a printf()-style format.
SK_API SkString static SkString	SkStringPrintf ()
static void	swap (SkString &a, SkString &b)

Variables
static constexpr int	kSkStrAppendU32_MaxSize = 10
static constexpr int	kSkStrAppendU64_MaxSize = 20
static constexpr int	kSkStrAppendS32_MaxSize = kSkStrAppendU32_MaxSize + 1
static constexpr int	kSkStrAppendS64_MaxSize = kSkStrAppendU64_MaxSize + 1
static constexpr int	kSkStrAppendScalar_MaxSize = 15

Function Documentation

SkStrAppendS32()

char * SkStrAppendS32	(	char	buffer[],
		int32_t	dec
	)

Definition at line 120 of file SkString.cpp.

                                                 {
    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);
}

SkStrAppendS64()

char * SkStrAppendS64	(	char	buffer[],
		int64_t	dec,
		int	minDigits
	)

Definition at line 155 of file SkString.cpp.

                                                                {
    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);
}

SkStrAppendScalar()

char * SkStrAppendScalar	(	char	buffer[],
		SkScalar	value
	)

Write the scalar in decimal format into buffer, and return a pointer to the next char after the last one written. Note: a terminating 0 is not written into buffer, which must be at least kSkStrAppendScalar_MaxSize. Thus if the caller wants to add a 0 at the end, buffer must be at least kSkStrAppendScalar_MaxSize + 1 bytes large.

Definition at line 164 of file SkString.cpp.

                                                       {
    // 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 (SkIsNaN(value)) {
        strcpy(string, "nan");
        return string + 3;
    }
    if (!SkIsFinite(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;
}

SkStrAppendU32()

char * SkStrAppendU32	(	char	buffer[],
		uint32_t	dec
	)

Definition at line 100 of file SkString.cpp.

                                                  {
    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;
}

SkStrAppendU64()

char * SkStrAppendU64	(	char	buffer[],
		uint64_t	dec,
		int	minDigits
	)

Definition at line 129 of file SkString.cpp.

                                                                 {
    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;
}

SkStrContains() [1/2]

static bool SkStrContains ( const char  string[], const char  subchar  )

inlinestatic

Definition at line 58 of file SkString.h.

                                                                          {
    SkASSERT(string);
    char tmp[2];
    tmp[0] = subchar;
    tmp[1] = '\0';
    return (-1 != SkStrFind(string, tmp));
}

SkStrContains() [2/2]

static bool SkStrContains ( const char  string[], const char  substring[]  )

inlinestatic

Definition at line 53 of file SkString.h.

                                                                              {
    SkASSERT(string);
    SkASSERT(substring);
    return (-1 != SkStrFind(string, substring));
}

SkStrEndsWith() [1/2]

bool SkStrEndsWith	(	const char	string[],
		const char	suffixChar
	)

Definition at line 77 of file SkString.cpp.

                                                               {
    SkASSERT(string);
    size_t  strLen = strlen(string);
    if (0 == strLen) {
        return false;
    } else {
        return (suffixChar == string[strLen-1]);
    }
}

SkStrEndsWith() [2/2]

bool SkStrEndsWith	(	const char	string[],
		const char	suffixStr[]
	)

Definition at line 68 of file SkString.cpp.

                                                                {
    SkASSERT(string);
    SkASSERT(suffixStr);
    size_t  strLen = strlen(string);
    size_t  suffixLen = strlen(suffixStr);
    return  strLen >= suffixLen &&
            !strncmp(string + strLen - suffixLen, suffixStr, suffixLen);
}

SkStrFind()

static int SkStrFind ( const char  string[], const char  substring[]  )

inlinestatic

Definition at line 41 of file SkString.h.

                                                                         {
    const char *first = strstr(string, substring);
    if (nullptr == first) return -1;
    return SkToInt(first - &string[0]);
}

SkStrFindLastOf()

static int SkStrFindLastOf ( const char  string[], const char  subchar  )

inlinestatic

Definition at line 47 of file SkString.h.

                                                                           {
    const char* last = strrchr(string, subchar);
    if (nullptr == last) return -1;
    return SkToInt(last - &string[0]);
}

SkStringPrintf() [1/2]

SK_API SkString static SkString SkStringPrintf ( )

inlinestatic

This makes it easier to write a caller as a VAR_ARGS function where the format string is optional.

Definition at line 287 of file SkString.h.

{ return SkString(); }

SkStringPrintf() [2/2]

SK_API SkString SkStringPrintf	(	const char *	format,
			...
	)

Creates a new string and writes into it using a printf()-style format.

SkStrStartsWith() [1/2]

static bool SkStrStartsWith ( const char  string[], const char  prefixChar  )

inlinestatic

Definition at line 31 of file SkString.h.

                                                                               {
    SkASSERT(string);
    return (prefixChar == *string);
}

SkStrStartsWith() [2/2]

static bool SkStrStartsWith ( const char  string[], const char  prefixStr[]  )

inlinestatic

Definition at line 26 of file SkString.h.

                                                                                {
    SkASSERT(string);
    SkASSERT(prefixStr);
    return !strncmp(string, prefixStr, strlen(prefixStr));
}

SkStrStartsWithOneOf()

int SkStrStartsWithOneOf	(	const char	string[],
		const char	prefixes[]
	)

Definition at line 87 of file SkString.cpp.

                                                                     {
    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;
}

swap()

static void swap ( SkString &  a, SkString &  b  )

inlinestatic

Definition at line 289 of file SkString.h.

                                                  {
    a.swap(b);
}

Variable Documentation

kSkStrAppendS32_MaxSize

constexpr int kSkStrAppendS32_MaxSize = kSkStrAppendU32_MaxSize + 1

staticconstexpr

Definition at line 89 of file SkString.h.

kSkStrAppendS64_MaxSize

constexpr int kSkStrAppendS64_MaxSize = kSkStrAppendU64_MaxSize + 1

staticconstexpr

Definition at line 91 of file SkString.h.

kSkStrAppendScalar_MaxSize

constexpr int kSkStrAppendScalar_MaxSize = 15

staticconstexpr

Floats have at most 8 significant digits, so we limit our g to that. However, the total string could be 15 characters: -1.2345678e-005

In theory we should only expect up to 2 digits for the exponent, but on some platforms we have seen 3 (as in the example above).

Definition at line 101 of file SkString.h.

kSkStrAppendU32_MaxSize

constexpr int kSkStrAppendU32_MaxSize = 10

staticconstexpr

Definition at line 84 of file SkString.h.

kSkStrAppendU64_MaxSize

constexpr int kSkStrAppendU64_MaxSize = 20

staticconstexpr

Definition at line 86 of file SkString.h.