/* This function is similar to sdscatprintf, but much faster as it does
* not rely on sprintf() family functions implemented by the libc that
* are often very slow. Moreover directly handling the sds string as
* new data is concatenated provides a performance improvement.
*
* However this function only handles an incompatible subset of printf-alike
* format specifiers:
*
* %s - C String
* %S - SDS string
* %i - signed int
* %I - 64 bit signed integer (long long, int64_t)
* %u - unsigned int
* %U - 64 bit unsigned integer (unsigned long long, uint64_t)
* %% - Verbatim "%" character.
*/
sds sdscatfmt(sds s, char const *fmt, ...) {
size_t initlen = sdslen(s);
const char *f = fmt;
int i;
va_list ap;
va_start(ap,fmt);
f = fmt; /* Next format specifier byte to process. */
i = initlen; /* Position of the next byte to write to dest str. */
while(*f) {
char next, *str;
size_t l;
long long num;
unsigned long long unum;
/* Make sure there is always space for at least 1 char. */
if (sdsavail(s)==0) {
s = sdsMakeRoomFor(s,1);
}
switch(*f) {
case '%':
next = *(f+1);
f++;
switch(next) {
case 's':
case 'S':
str = va_arg(ap,char*);
l = (next == 's') ? strlen(str) : sdslen(str);
if (sdsavail(s) < l) {
s = sdsMakeRoomFor(s,l);
}
memcpy(s+i,str,l);
sdsinclen(s,l);
i += l;
break;
case 'i':
case 'I':
if (next == 'i')
num = va_arg(ap,int);
else
num = va_arg(ap,long long);
{
char buf[SDS_LLSTR_SIZE];
l = sdsll2str(buf,num);
if (sdsavail(s) < l) {
s = sdsMakeRoomFor(s,l);
}
memcpy(s+i,buf,l);
sdsinclen(s,l);
i += l;
}
break;
case 'u':
case 'U':
if (next == 'u')
unum = va_arg(ap,unsigned int);
else
unum = va_arg(ap,unsigned long long);
{
char buf[SDS_LLSTR_SIZE];
l = sdsull2str(buf,unum);
if (sdsavail(s) < l) {
s = sdsMakeRoomFor(s,l);
}
memcpy(s+i,buf,l);
sdsinclen(s,l);
i += l;
}
break;
default: /* Handle %% and generally %<unknown>. */
s[i++] = next;
sdsinclen(s,1);
break;
}
break;
default:
s[i++] = *f;
sdsinclen(s,1);
break;
}
/* Create an sds string from a long long value. It is much faster than:
*
* sdscatprintf(sdsempty(),"%lld\n", value);
*/
sds sdsfromlonglong(long long value) {
char buf[SDS_LLSTR_SIZE];
int len = sdsll2str(buf,value);
return sdsnewlen(buf,len);
}
/* Create an sds string from a long long value. It is much faster than:
*
* sds_cat_printf(sds_empty(),"%lld\n", value);
*/
sds sds_from_long_long(long long value) {
char buf[SDS_LLSTR_SIZE];
int len = sdsll2str(buf,value);
return sds_new_len(buf,len);
}
/* This function is similar to sdscatprintf, but much faster as it does
* not rely on sprintf() family functions implemented by the libc that
* are often very slow. Moreover directly handling the sds string as
* new data is concatenated provides a performance improvement.
*
* However this function only handles an incompatible subset of printf-alike
* format specifiers:
*
* %s - C String
* %S - SDS string
* %i - signed int
* %I - 64 bit signed integer (PORT_LONGLONG, int64_t)
* %u - unsigned int
* %U - 64 bit unsigned integer (PORT_ULONGLONG, uint64_t)
* %% - Verbatim "%" character.
*/
sds sdscatfmt(sds s, char const *fmt, ...) {
struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
size_t initlen = sdslen(s);
const char *f = fmt;
int i;
va_list ap;
va_start(ap,fmt);
f = fmt; /* Next format specifier byte to process. */
i = (int)initlen; /* Position of the next byte to write to dest str. */
while(*f) {
char next, *str;
unsigned int l;
PORT_LONGLONG num;
PORT_ULONGLONG unum;
/* Make sure there is always space for at least 1 char. */
if (sh->free == 0) {
s = sdsMakeRoomFor(s,1);
sh = (void*) (s-(sizeof(struct sdshdr)));
}
switch(*f) {
case '%':
next = *(f+1);
f++;
switch(next) {
case 's':
case 'S':
str = va_arg(ap,char*);
l = (int)((next == 's') ? strlen(str) : sdslen(str));
if (sh->free < l) {
s = sdsMakeRoomFor(s,l);
sh = (void*) (s-(sizeof(struct sdshdr)));
}
memcpy(s+i,str,l);
sh->len += l;
sh->free -= l;
i += l;
break;
case 'i':
case 'I':
if (next == 'i')
num = va_arg(ap,int);
else
num = va_arg(ap,PORT_LONGLONG);
{
char buf[SDS_LLSTR_SIZE];
l = sdsll2str(buf,num);
if (sh->free < l) {
s = sdsMakeRoomFor(s,l);
sh = (void*) (s-(sizeof(struct sdshdr)));
}
memcpy(s+i,buf,l);
sh->len += l;
sh->free -= l;
i += l;
}
break;
case 'u':
case 'U':
if (next == 'u')
unum = va_arg(ap,unsigned int);
else
unum = va_arg(ap,PORT_ULONGLONG);
{
char buf[SDS_LLSTR_SIZE];
l = sdsull2str(buf,unum);
if (sh->free < l) {
s = sdsMakeRoomFor(s,l);
sh = (void*) (s-(sizeof(struct sdshdr)));
}
memcpy(s+i,buf,l);
sh->len += l;
sh->free -= l;
i += l;
}
break;
default: /* Handle %% and generally %<unknown>. */
s[i++] = next;
sh->len += 1;
sh->free -= 1;
break;
}
break;
default:
s[i++] = *f;
sh->len += 1;
sh->free -= 1;
break;
}
/* 字符串格式化输出，输入原字符串，格式，参数 */
sds sdscatfmt(sds s, char const *fmt, ...) {
struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
size_t initlen = sdslen(s);
const char *f = fmt;
int i;
va_list ap;
va_start(ap,fmt);
f = fmt; /* Next format specifier byte to process. */
i = initlen; /* Position of the next byte to write to dest str. */
//关键再次，以此比较输入的格式类型
while(*f) {
char next, *str;
unsigned int l;
long long num;
unsigned long long unum;
/* Make sure there is always space for at least 1 char. */
if (sh->free == 0) {
s = sdsMakeRoomFor(s,1);
sh = (void*) (s-(sizeof(struct sdshdr)));
}
switch(*f) {
case '%':
/*如果是%,记住百分号后面的类型操作值*/
next = *(f+1);
f++;
switch(next) {
case 's':
case 'S':
str = va_arg(ap,char*);
//判断普通的str,还是sds类型，计算长度的方法不一样
l = (next == 's') ? strlen(str) : sdslen(str);
if (sh->free < l) {
s = sdsMakeRoomFor(s,l);
sh = (void*) (s-(sizeof(struct sdshdr)));
}
//如果是字符串，直接复制到后面
memcpy(s+i,str,l);
sh->len += l;
sh->free -= l;
i += l;
break;
case 'i':
case 'I':
if (next == 'i')
num = va_arg(ap,int);
else
num = va_arg(ap,long long);
{
char buf[SDS_LLSTR_SIZE];
//如果是数字，调用添加数值字符串方法
l = sdsll2str(buf,num);
if (sh->free < l) {
s = sdsMakeRoomFor(s,l);
sh = (void*) (s-(sizeof(struct sdshdr)));
}
memcpy(s+i,buf,l);
sh->len += l;
sh->free -= l;
i += l;
}
break;
case 'u':
case 'U':
//无符号整型同上
if (next == 'u')
unum = va_arg(ap,unsigned int);
else
unum = va_arg(ap,unsigned long long);
{
char buf[SDS_LLSTR_SIZE];
l = sdsull2str(buf,unum);
if (sh->free < l) {
s = sdsMakeRoomFor(s,l);
sh = (void*) (s-(sizeof(struct sdshdr)));
}
memcpy(s+i,buf,l);
sh->len += l;
sh->free -= l;
i += l;
}
break;
default: /* Handle %% and generally %<unknown>. */
s[i++] = next;
sh->len += 1;
sh->free -= 1;
break;
}
break;
default:
//非操作类型，直接单字符添加
s[i++] = *f;
sh->len += 1;
sh->free -= 1;
break;
}
