cJSON source code reading

JSON

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cJSON.h

/* cJSON Types: */
#define cJSON_False  (1 << 0)
#define cJSON_True   (1 << 1)
#define cJSON_NULL   (1 << 2)
#define cJSON_Number (1 << 3)
#define cJSON_String (1 << 4)
#define cJSON_Array  (1 << 5)
#define cJSON_Object (1 << 6)
	
#define cJSON_IsReference 256
#define cJSON_StringIsConst 512

/* The cJSON structure: */
typedef struct cJSON {
	struct cJSON *next,*prev;	/* next/prev allow you to walk array/object chains. Alternatively,use GetArraySize/GetArrayItem/GetobjectItem */
	struct cJSON *child;		/* An array or object item will have a child pointer pointing to a chain of the items in the array/object. */

	int type;					/* The type of the item,as above. */

	char *valuestring;			/* The item's string,if type==cJSON_String */
	int valueint;				/* The item's number,if type==cJSON_Number */
	double valuedouble;			/* The item's number,if type==cJSON_Number */

	char *string;				/* The item's name string,if this item is the child of,or is in the list of subitems of an object. */
} cJSON;

/* You can customize memory allocation and deallocation */
typedef struct cJSON_Hooks {
      void *(*malloc_fn)(size_t sz);
      void (*free_fn)(void *ptr);
} cJSON_Hooks;

cJSON.c

/* Memory management */
static void *(*cJSON_malloc)(size_t sz) = malloc;
static void (*cJSON_free)(void *ptr) = free;

void cJSON_InitHooks(cJSON_Hooks* hooks)
{
    if (!hooks) { /* Reset hooks */
        cJSON_malloc = malloc;
        cJSON_free = free;
        return;
    }

	cJSON_malloc = (hooks->malloc_fn)?hooks->malloc_fn:malloc;
	cJSON_free	 = (hooks->free_fn)?hooks->free_fn:free;
}

/* Internal constructor. */
static cJSON *cJSON_New_Item(void)
{
    cJSON* node = (cJSON*)cJSON_malloc(sizeof(cJSON));
    if (node) memset(node,sizeof(cJSON));
    return node;
}


/* Delete a cJSON structure. */
void cJSON_Delete(cJSON *c)
{
    cJSON *next;
    while (c)
    {
	next=c->next;
	if (!(c->type&cJSON_IsReference) && c->child) cJSON_Delete(c->child);
	if (!(c->type&cJSON_IsReference) && c->valuestring) cJSON_free(c->valuestring);
	if (!(c->type&cJSON_StringIsConst) && c->string) cJSON_free(c->string);
	cJSON_free(c);
	c=next;
    }
}

/* String utility functions */
static const char *global_ep;

const char *cJSON_GetErrorPtr(void) {return global_ep;}

static int cJSON_strcasecmp(const char *s1,const char *s2)
{
	if (!s1) return (s1==s2)?0:1;if (!s2) return 1;
	for(; tolower(*s1) == tolower(*s2); ++s1,++s2)	if(*s1 == 0)	return 0;
	return tolower(*(const unsigned char *)s1) - tolower(*(const unsigned char *)s2);
}

static char* cJSON_strdup(const char* str)
{
      size_t len;
      char* copy;

      len = strlen(str) + 1;
      if (!(copy = (char*)cJSON_malloc(len))) return 0;
      memcpy(copy,str,len);
      return copy;
}

/* Return the minimum pow(2,n) > x */
static int pow2gt (int x)	{	--x;	x|=x>>1;	x|=x>>2;	x|=x>>4;	x|=x>>8;	x|=x>>16;	return x+1;	}

typedef struct {char *buffer; int length; int offset; } printbuffer;

static char* ensure(printbuffer *p,int needed)
{
	char *newbuffer;int newsize;
	if (!p || !p->buffer) return 0;
	needed+=p->offset;
	if (needed<=p->length) return p->buffer+p->offset;

	newsize=pow2gt(needed);
	newbuffer=(char*)cJSON_malloc(newsize);
	if (!newbuffer) {cJSON_free(p->buffer);p->length=0,p->buffer=0;return 0;}
	if (newbuffer) memcpy(newbuffer,p->buffer,p->length);
	cJSON_free(p->buffer);
	p->length=newsize;
	p->buffer=newbuffer;
	return newbuffer+p->offset;
}

static int update(printbuffer *p)
{
	char *str;
	if (!p || !p->buffer) return 0;
	str=p->buffer+p->offset;
	return p->offset+strlen(str);
}

char *cJSON_PrintBuffered(cJSON *item,int prebuffer,int fmt)
{
	printbuffer p;
	p.buffer=(char*)cJSON_malloc(prebuffer);
	p.length=prebuffer;
	p.offset=0;
	return print_value(item,fmt,&p);
}

static unsigned parse_hex4(const char *str)
{
	unsigned h=0;
	if (*str>='0' && *str<='9') h+=(*str)-'0'; else if (*str>='A' && *str<='F') h+=10+(*str)-'A'; else if (*str>='a' && *str<='f') h+=10+(*str)-'a'; else return 0;
	h=h<<4;str++;
	if (*str>='0' && *str<='9') h+=(*str)-'0'; else if (*str>='A' && *str<='F') h+=10+(*str)-'A'; else if (*str>='a' && *str<='f') h+=10+(*str)-'a'; else return 0;
	h=h<<4;str++;
	if (*str>='0' && *str<='9') h+=(*str)-'0'; else if (*str>='A' && *str<='F') h+=10+(*str)-'A'; else if (*str>='a' && *str<='f') h+=10+(*str)-'a'; else return 0;
	h=h<<4;str++;
	if (*str>='0' && *str<='9') h+=(*str)-'0'; else if (*str>='A' && *str<='F') h+=10+(*str)-'A'; else if (*str>='a' && *str<='f') h+=10+(*str)-'a'; else return 0;
	return h;
}

/* Utility to jump whitespace and cr/lf */
static const char *skip(const char *in) {while (in && *in && (unsigned char)*in<=32) in++; return in;}

/* Parse and print number */
/* Parse the input text to generate a number,and populate the result into item. */
static const char *parse_number(cJSON *item,const char *num)
{
	double n=0,sign=1,scale=0;int subscale=0,signsubscale=1;

	if (*num=='-') sign=-1,num++;	/* Has sign? */
	if (*num=='0') num++;			/* is zero */
	if (*num>='1' && *num<='9')	do	n=(n*10.0)+(*num++ -'0');	while (*num>='0' && *num<='9');	/* Number? */
	if (*num=='.' && num[1]>='0' && num[1]<='9') {num++;		do	n=(n*10.0)+(*num++ -'0'),scale--; while (*num>='0' && *num<='9');}	/* Fractional part? */
	if (*num=='e' || *num=='E')		/* Exponent? */
	{	num++;if (*num=='+') num++;	else if (*num=='-') signsubscale=-1,num++;		/* With sign? */
		while (*num>='0' && *num<='9') subscale=(subscale*10)+(*num++ - '0');	/* Number? */
	}

	n=sign*n*pow(10.0,(scale+subscale*signsubscale));	/* number = +/- number.fraction * 10^+/- exponent */
	
	item->valuedouble=n;
	item->valueint=(int)n;
	item->type=cJSON_Number;
	return num;
}

/* Render the number nicely from the given item into a string. */
static char *print_number(cJSON *item,printbuffer *p)
{
	char *str=0;
	double d=item->valuedouble;
	if (d==0)
	{
		if (p)	str=ensure(p,2);
		else	str=(char*)cJSON_malloc(2);	/* special case for 0. */
		if (str) strcpy(str,"0");
	}
	else if (fabs(((double)item->valueint)-d)<=DBL_EPSILON && d<=INT_MAX && d>=INT_MIN)
	{
		if (p)	str=ensure(p,21);
		else	str=(char*)cJSON_malloc(21);	/* 2^64+1 can be represented in 21 chars. */
		if (str)	sprintf(str,"%d",item->valueint);
	}
	else
	{
		if (p)	str=ensure(p,64);
		else	str=(char*)cJSON_malloc(64);	/* This is a nice tradeoff. */
		if (str)
		{
			if (d*0!=0)													sprintf(str,"null");	/* This checks for NaN and Infinity */
			else if (fabs(floor(d)-d)<=DBL_EPSILON && fabs(d)<1.0e60)	sprintf(str,"%.0f",d);
			else if (fabs(d)<1.0e-6 || fabs(d)>1.0e9)					sprintf(str,"%e",d);
			else														sprintf(str,"%f",d);
		}
	}
	return str;
}

/* Parse and print string */
/* Parse the input text into an unescaped cstring,and populate item. */
static const unsigned char firstByteMark[7] = { 0x00,0x00,0xC0,0xE0,0xF0,0xF8,0xFC };
static const char *parse_string(cJSON *item,const char *str,const char **ep)
{
	const char *ptr=str+1,*end_ptr=str+1;char *ptr2;char *out;int len=0;unsigned uc,uc2;
	if (*str!='\"') {*ep=str;return 0;}	/* not a string! */
	
	while (*end_ptr!='\"' && *end_ptr && ++len) if (*end_ptr++ == '\\') end_ptr++;	/* Skip escaped quotes. */
	
	out=(char*)cJSON_malloc(len+1);	/* This is how long we need for the string,roughly. */
	if (!out) return 0;
	item->valuestring=out; /* assign here so out will be deleted during cJSON_Delete() later */
	item->type=cJSON_String;
	
	ptr=str+1;ptr2=out;
	while (ptr < end_ptr)
	{
		if (*ptr!='\\') *ptr2++=*ptr++;
		else
		{
			ptr++;
			switch (*ptr)
			{
				case 'b': *ptr2++='\b';	break;
				case 'f': *ptr2++='\f';	break;
				case 'n': *ptr2++='\n';	break;
				case 'r': *ptr2++='\r';	break;
				case 't': *ptr2++='\t';	break;
				case 'u':	 /* transcode utf16 to utf8. */
					uc=parse_hex4(ptr+1);ptr+=4;	/* get the unicode char. */
					if (ptr >= end_ptr) {*ep=str;return 0;}	/* invalid */
					
					if ((uc>=0xDC00 && uc<=0xDFFF) || uc==0)    {*ep=str;return 0;}	/* check for invalid.   */
					
					if (uc>=0xD800 && uc<=0xDBFF)	/* UTF16 surrogate pairs.	*/
					{
						if (ptr+6 > end_ptr)    {*ep=str;return 0;}	/* invalid */
						if (ptr[1]!='\\' || ptr[2]!='u')    {*ep=str;return 0;}	/* missing second-half of surrogate.    */
						uc2=parse_hex4(ptr+3);ptr+=6;
						if (uc2<0xDC00 || uc2>0xDFFF)       {*ep=str;return 0;}	/* invalid second-half of surrogate.    */
						uc=0x10000 + (((uc&0x3FF)<<10) | (uc2&0x3FF));
					}

					len=4;if (uc<0x80) len=1;else if (uc<0x800) len=2;else if (uc<0x10000) len=3; ptr2+=len;
					
					switch (len) {
						case 4: *--ptr2 =((uc | 0x80) & 0xBF); uc >>= 6;
						case 3: *--ptr2 =((uc | 0x80) & 0xBF); uc >>= 6;
						case 2: *--ptr2 =((uc | 0x80) & 0xBF); uc >>= 6;
						case 1: *--ptr2 =(uc | firstByteMark[len]);
					}
					ptr2+=len;
					break;
				default:  *ptr2++=*ptr; break;
			}
			ptr++;
		}
	}
	*ptr2=0;
	if (*ptr=='\"') ptr++;
	return ptr;
}

/* Render the cstring provided to an escaped version that can be printed. */
static char *print_string_ptr(const char *str,printbuffer *p)
{
	const char *ptr;char *ptr2,*out;int len=0,flag=0;unsigned char token;

	if (!str)
	{
		if (p)	out=ensure(p,3);
		else	out=(char*)cJSON_malloc(3);
		if (!out) return 0;
		strcpy(out,"\"\"");
		return out;
	}
	
	for (ptr=str;*ptr;ptr++) flag|=((*ptr>0 && *ptr<32)||(*ptr=='\"')||(*ptr=='\\'))?1:0;
	if (!flag)
	{
		len=ptr-str;
		if (p) out=ensure(p,len+3);
		else		out=(char*)cJSON_malloc(len+3);
		if (!out) return 0;
		ptr2=out;*ptr2++='\"';
		strcpy(ptr2,str);
		ptr2[len]='\"';
		ptr2[len+1]=0;
		return out;
	}
	
	ptr=str;while ((token=*ptr) && ++len) {if (strchr("\"\\\b\f\n\r\t",token)) len++; else if (token<32) len+=5;ptr++;}
	
	if (p)	out=ensure(p,len+3);
	else	out=(char*)cJSON_malloc(len+3);
	if (!out) return 0;

	ptr2=out;ptr=str;
	*ptr2++='\"';
	while (*ptr)
	{
		if ((unsigned char)*ptr>31 && *ptr!='\"' && *ptr!='\\') *ptr2++=*ptr++;
		else
		{
			*ptr2++='\\';
			switch (token=*ptr++)
			{
				case '\\':	*ptr2++='\\';	break;
				case '\"':	*ptr2++='\"';	break;
				case '\b':	*ptr2++='b';	break;
				case '\f':	*ptr2++='f';	break;
				case '\n':	*ptr2++='n';	break;
				case '\r':	*ptr2++='r';	break;
				case '\t':	*ptr2++='t';	break;
				default: sprintf(ptr2,"u%04x",token);ptr2+=5;	break;	/* escape and print */
			}
		}
	}
	*ptr2++='\"';*ptr2++=0;
	return out;
}
/* InVote print_string_ptr (which is useful) on an item. */
static char *print_string(cJSON *item,printbuffer *p)	{return print_string_ptr(item->valuestring,p);}

/* Parse and print value */
/* Parser core - when encountering text,process appropriately. */
static const char *parse_value(cJSON *item,const char *value,const char **ep)
{
	if (!value)						return 0;	/* Fail on null. */
	if (!strncmp(value,"null",4))	{ item->type=cJSON_NULL;  return value+4; }
	if (!strncmp(value,"false",5))	{ item->type=cJSON_False; return value+5; }
	if (!strncmp(value,"true",4))	{ item->type=cJSON_True; item->valueint=1;	return value+4; }
	if (*value=='\"')				{ return parse_string(item,value,ep); }
	if (*value=='-' || (*value>='0' && *value<='9'))	{ return parse_number(item,value); }
	if (*value=='[')				{ return parse_array(item,ep); }
	if (*value=='{')				{ return parse_object(item,ep); }

	*ep=value;return 0;	/* failure. */
}

/* Render a value to text. */
static char *print_value(cJSON *item,int depth,int fmt,printbuffer *p)
{
	char *out=0;
	if (!item) return 0;
	if (p)
	{
		switch ((item->type)&255)
		{
			case cJSON_NULL:	{out=ensure(p,5);	if (out) strcpy(out,"null");	break;}
			case cJSON_False:	{out=ensure(p,6);	if (out) strcpy(out,"false");	break;}
			case cJSON_True:	{out=ensure(p,"true");	break;}
			case cJSON_Number:	out=print_number(item,p);break;
			case cJSON_String:	out=print_string(item,p);break;
			case cJSON_Array:	out=print_array(item,depth,p);break;
			case cJSON_Object:	out=print_object(item,p);break;
		}
	}
	else
	{
		switch ((item->type)&255)
		{
			case cJSON_NULL:	out=cJSON_strdup("null");	break;
			case cJSON_False:	out=cJSON_strdup("false");break;
			case cJSON_True:	out=cJSON_strdup("true"); break;
			case cJSON_Number:	out=print_number(item,0);break;
			case cJSON_String:	out=print_string(item,0);break;
			case cJSON_Array:	out=print_array(item,0);break;
			case cJSON_Object:	out=print_object(item,0);break;
		}
	}
	return out;
}

/* Parse and print array */
/* Build an array from input text. */
static const char *parse_array(cJSON *item,const char **ep)
{
	cJSON *child;
	if (*value!='[')	{*ep=value;return 0;}	/* not an array! */

	item->type=cJSON_Array;
	value=skip(value+1);
	if (*value==']') return value+1;	/* empty array. */

	item->child=child=cJSON_New_Item();
	if (!item->child) return 0;		 /* memory fail */
	value=skip(parse_value(child,skip(value),ep));	/* skip any spacing,get the value. */
	if (!value) return 0;

	while (*value==',')
	{
		cJSON *new_item;
		if (!(new_item=cJSON_New_Item())) return 0; 	/* memory fail */
		child->next=new_item;new_item->prev=child;child=new_item;
		value=skip(parse_value(child,skip(value+1),ep));
		if (!value) return 0;	/* memory fail */
	}

	if (*value==']') return value+1;	/* end of array */
	*ep=value;return 0;	/* malformed. */
}

/* Render an array to text */
static char *print_array(cJSON *item,printbuffer *p)
{
	char **entries;
	char *out=0,*ptr,*ret;int len=5;
	cJSON *child=item->child;
	int numentries=0,i=0,fail=0;
	size_t tmplen=0;
	
	/* How many entries in the array? */
	while (child) numentries++,child=child->next;
	/* Explicitly handle numentries==0 */
	if (!numentries)
	{
		if (p)	out=ensure(p,3);
		else	out=(char*)cJSON_malloc(3);
		if (out) strcpy(out,"[]");
		return out;
	}

	if (p)
	{
		/* Compose the output array. */
		i=p->offset;
		ptr=ensure(p,1);if (!ptr) return 0;	*ptr='[';	p->offset++;
		child=item->child;
		while (child && !fail)
		{
			print_value(child,depth+1,p);
			p->offset=update(p);
			if (child->next) {len=fmt?2:1;ptr=ensure(p,len+1);if (!ptr) return 0;*ptr++=',';if(fmt)*ptr++=' ';*ptr=0;p->offset+=len;}
			child=child->next;
		}
		ptr=ensure(p,2);if (!ptr) return 0;	*ptr++=']';*ptr=0;
		out=(p->buffer)+i;
	}
	else
	{
		/* Allocate an array to hold the values for each */
		entries=(char**)cJSON_malloc(numentries*sizeof(char*));
		if (!entries) return 0;
		memset(entries,numentries*sizeof(char*));
		/* Retrieve all the results: */
		child=item->child;
		while (child && !fail)
		{
			ret=print_value(child,0);
			entries[i++]=ret;
			if (ret) len+=strlen(ret)+2+(fmt?1:0); else fail=1;
			child=child->next;
		}
		
		/* If we didn't fail,try to malloc the output string */
		if (!fail)	out=(char*)cJSON_malloc(len);
		/* If that fails,we fail. */
		if (!out) fail=1;

		/* Handle failure. */
		if (fail)
		{
			for (i=0;i<numentries;i++) if (entries[i]) cJSON_free(entries[i]);
			cJSON_free(entries);
			return 0;
		}
		
		/* Compose the output array. */
		*out='[';
		ptr=out+1;*ptr=0;
		for (i=0;i<numentries;i++)
		{
			tmplen=strlen(entries[i]);memcpy(ptr,entries[i],tmplen);ptr+=tmplen;
			if (i!=numentries-1) {*ptr++=',';if(fmt)*ptr++=' ';*ptr=0;}
			cJSON_free(entries[i]);
		}
		cJSON_free(entries);
		*ptr++=']';*ptr++=0;
	}
	return out;	
}

/* Parse and print object */
/* Build an object from the text. */
static const char *parse_object(cJSON *item,const char **ep)
{
	cJSON *child;
	if (*value!='{')	{*ep=value;return 0;}	/* not an object! */
	
	item->type=cJSON_Object;
	value=skip(value+1);
	if (*value=='}') return value+1;	/* empty array. */
	
	item->child=child=cJSON_New_Item();
	if (!item->child) return 0;
	value=skip(parse_string(child,ep));
	if (!value) return 0;
	child->string=child->valuestring;child->valuestring=0;
	if (*value!=':') {*ep=value;return 0;}	/* fail! */
	value=skip(parse_value(child,get the value. */
	if (!value) return 0;
	
	while (*value==',')
	{
		cJSON *new_item;
		if (!(new_item=cJSON_New_Item()))	return 0; /* memory fail */
		child->next=new_item;new_item->prev=child;child=new_item;
		value=skip(parse_string(child,ep));
		if (!value) return 0;
		child->string=child->valuestring;child->valuestring=0;
		if (*value!=':') {*ep=value;return 0;}	/* fail! */
		value=skip(parse_value(child,get the value. */
		if (!value) return 0;
	}
	
	if (*value=='}') return value+1;	/* end of array */
	*ep=value;return 0;	/* malformed. */
}

/* Render an object to text. */
static char *print_object(cJSON *item,printbuffer *p)
{
	char **entries=0,**names=0;
	char *out=0,*ret,*str;int len=7,j;
	cJSON *child=item->child;
	int numentries=0,fail=0;
	size_t tmplen=0;
	/* Count the number of entries. */
	while (child) numentries++,child=child->next;
	/* Explicitly handle empty object case */
	if (!numentries)
	{
		if (p) out=ensure(p,fmt?depth+4:3);
		else	out=(char*)cJSON_malloc(fmt?depth+4:3);
		if (!out)	return 0;
		ptr=out;*ptr++='{';
		if (fmt) {*ptr++='\n';for (i=0;i<depth;i++) *ptr++='\t';}
		*ptr++='}';*ptr++=0;
		return out;
	}
	if (p)
	{
		/* Compose the output: */
		i=p->offset;
		len=fmt?2:1;	ptr=ensure(p,len+1);	if (!ptr) return 0;
		*ptr++='{';	if (fmt) *ptr++='\n';	*ptr=0;	p->offset+=len;
		child=item->child;depth++;
		while (child)
		{
			if (fmt)
			{
				ptr=ensure(p,depth);	if (!ptr) return 0;
				for (j=0;j<depth;j++) *ptr++='\t';
				p->offset+=depth;
			}
			print_string_ptr(child->string,p);
			p->offset=update(p);
			
			len=fmt?2:1;
			ptr=ensure(p,len);	if (!ptr) return 0;
			*ptr++=':';if (fmt) *ptr++='\t';
			p->offset+=len;
			
			print_value(child,p);
			p->offset=update(p);

			len=(fmt?1:0)+(child->next?1:0);
			ptr=ensure(p,len+1); if (!ptr) return 0;
			if (child->next) *ptr++=',';
			if (fmt) *ptr++='\n';*ptr=0;
			p->offset+=len;
			child=child->next;
		}
		ptr=ensure(p,fmt?(depth+1):2);	 if (!ptr) return 0;
		if (fmt)	for (i=0;i<depth-1;i++) *ptr++='\t';
		*ptr++='}';*ptr=0;
		out=(p->buffer)+i;
	}
	else
	{
		/* Allocate space for the names and the objects */
		entries=(char**)cJSON_malloc(numentries*sizeof(char*));
		if (!entries) return 0;
		names=(char**)cJSON_malloc(numentries*sizeof(char*));
		if (!names) {cJSON_free(entries);return 0;}
		memset(entries,sizeof(char*)*numentries);
		memset(names,sizeof(char*)*numentries);

		/* Collect all the results into our arrays: */
		child=item->child;depth++;if (fmt) len+=depth;
		while (child && !fail)
		{
			names[i]=str=print_string_ptr(child->string,0);
			entries[i++]=ret=print_value(child,0);
			if (str && ret) len+=strlen(ret)+strlen(str)+2+(fmt?2+depth:0); else fail=1;
			child=child->next;
		}
		
		/* Try to allocate the output string */
		if (!fail)	out=(char*)cJSON_malloc(len);
		if (!out) fail=1;

		/* Handle failure */
		if (fail)
		{
			for (i=0;i<numentries;i++) {if (names[i]) cJSON_free(names[i]);if (entries[i]) cJSON_free(entries[i]);}
			cJSON_free(names);cJSON_free(entries);
			return 0;
		}
		
		/* Compose the output: */
		*out='{';ptr=out+1;if (fmt)*ptr++='\n';*ptr=0;
		for (i=0;i<numentries;i++)
		{
			if (fmt) for (j=0;j<depth;j++) *ptr++='\t';
			tmplen=strlen(names[i]);memcpy(ptr,names[i],tmplen);ptr+=tmplen;
			*ptr++=':';if (fmt) *ptr++='\t';
			strcpy(ptr,entries[i]);ptr+=strlen(entries[i]);
			if (i!=numentries-1) *ptr++=',';
			if (fmt) *ptr++='\n';*ptr=0;
			cJSON_free(names[i]);cJSON_free(entries[i]);
		}
		
		cJSON_free(names);cJSON_free(entries);
		if (fmt) for (i=0;i<depth-1;i++) *ptr++='\t';
		*ptr++='}';*ptr++=0;
	}
	return out;	
}

/* Wrapper for parse and print */
/* Parse an object - create a new root,and populate. */
cJSON *cJSON_ParseWithOpts(const char *value,const char **return_parse_end,int require_null_terminated)
{
	const char *end=0,**ep=return_parse_end?return_parse_end:&global_ep;
	cJSON *c=cJSON_New_Item();
	*ep=0;
	if (!c) return 0;       /* memory fail */

	end=parse_value(c,ep);
	if (!end)	{cJSON_Delete(c);return 0;}	/* parse failure. ep is set. */

	/* if we require null-terminated JSON without appended garbage,skip and then check for a null terminator */
	if (require_null_terminated) {end=skip(end);if (*end) {cJSON_Delete(c);*ep=end;return 0;}}
	if (return_parse_end) *return_parse_end=end;
	return c;
}
/* Default options for cJSON_Parse */
cJSON *cJSON_Parse(const char *value) {return cJSON_ParseWithOpts(value,0);}

/* Render a cJSON item/entity/structure to text. */
char *cJSON_Print(cJSON *item)				{return print_value(item,1,0);}
char *cJSON_PrintUnformatted(cJSON *item)	{return print_value(item,0);}

/* JSON utility functions */
/* Get Array size/item / object item. */
int    cJSON_GetArraySize(cJSON *array)							{cJSON *c=array->child;int i=0;while(c)i++,c=c->next;return i;}
cJSON *cJSON_GetArrayItem(cJSON *array,int item)				{cJSON *c=array?array->child:0;while (c && item>0) item--,c=c->next; return c;}
cJSON *cJSON_GetobjectItem(cJSON *object,const char *string)	{cJSON *c=object?object->child:0;while (c && cJSON_strcasecmp(c->string,string)) c=c->next; return c;}
int cJSON_HasObjectItem(cJSON *object,const char *string)		{return cJSON_GetobjectItem(object,string)?1:0;}

/* Utility for array list handling. */
static void suffix_object(cJSON *prev,cJSON *item) {prev->next=item;item->prev=prev;}
/* Utility for handling references. */
static cJSON *create_reference(cJSON *item) {cJSON *ref=cJSON_New_Item();if (!ref) return 0;memcpy(ref,item,sizeof(cJSON));ref->string=0;ref->type|=cJSON_IsReference;ref->next=ref->prev=0;return ref;}

/* Add item to array/object. */
void   cJSON_AddItemToArray(cJSON *array,cJSON *item)						{cJSON *c=array->child;if (!item) return; if (!c) {array->child=item;} else {while (c && c->next) c=c->next; suffix_object(c,item);}}
void   cJSON_AddItemToObject(cJSON *object,const char *string,cJSON *item)	{if (!item) return; if (item->string) cJSON_free(item->string);item->string=cJSON_strdup(string);cJSON_AddItemToArray(object,item);}
void   cJSON_AddItemToObjectCS(cJSON *object,cJSON *item)	{if (!item) return; if (!(item->type&cJSON_StringIsConst) && item->string) cJSON_free(item->string);item->string=(char*)string;item->type|=cJSON_StringIsConst;cJSON_AddItemToArray(object,item);}
void	cJSON_AddItemReferencetoArray(cJSON *array,cJSON *item)						{cJSON_AddItemToArray(array,create_reference(item));}
void	cJSON_AddItemReferencetoObject(cJSON *object,cJSON *item)	{cJSON_AddItemToObject(object,string,create_reference(item));}

cJSON *cJSON_DetachItemFromArray(cJSON *array,int which)			{cJSON *c=array->child;while (c && which>0) c=c->next,which--;if (!c) return 0;
	if (c->prev) c->prev->next=c->next;if (c->next) c->next->prev=c->prev;if (c==array->child) array->child=c->next;c->prev=c->next=0;return c;}
void   cJSON_DeleteItemFromArray(cJSON *array,int which)			{cJSON_Delete(cJSON_DetachItemFromArray(array,which));}
cJSON *cJSON_DetachItemFromObject(cJSON *object,const char *string) {int i=0;cJSON *c=object->child;while (c && cJSON_strcasecmp(c->string,string)) i++,c=c->next;if (c) return cJSON_DetachItemFromArray(object,i);return 0;}
void   cJSON_DeleteItemFromObject(cJSON *object,const char *string) {cJSON_Delete(cJSON_DetachItemFromObject(object,string));}

/* Replace array/object items with new ones. */
void   cJSON_InsertItemInArray(cJSON *array,int which,cJSON *newitem)		{cJSON *c=array->child;while (c && which>0) c=c->next,which--;if (!c) {cJSON_AddItemToArray(array,newitem);return;}
	newitem->next=c;newitem->prev=c->prev;c->prev=newitem;if (c==array->child) array->child=newitem; else newitem->prev->next=newitem;}
void   cJSON_ReplaceItemInArray(cJSON *array,which--;if (!c) return;
	newitem->next=c->next;newitem->prev=c->prev;if (newitem->next) newitem->next->prev=newitem;
	if (c==array->child) array->child=newitem; else newitem->prev->next=newitem;c->next=c->prev=0;cJSON_Delete(c);}
void   cJSON_ReplaceItemInObject(cJSON *object,cJSON *newitem){int i=0;cJSON *c=object->child;while(c && cJSON_strcasecmp(c->string,string))i++,c=c->next;if(c){newitem->string=cJSON_strdup(string);cJSON_ReplaceItemInArray(object,i,newitem);}}

/* Create basic types: */
cJSON *cJSON_CreateNull(void)					{cJSON *item=cJSON_New_Item();if(item)item->type=cJSON_NULL;return item;}
cJSON *cJSON_CreateTrue(void)					{cJSON *item=cJSON_New_Item();if(item)item->type=cJSON_True;return item;}
cJSON *cJSON_CreateFalse(void)					{cJSON *item=cJSON_New_Item();if(item)item->type=cJSON_False;return item;}
cJSON *cJSON_CreateBool(int b)					{cJSON *item=cJSON_New_Item();if(item)item->type=b?cJSON_True:cJSON_False;return item;}
cJSON *cJSON_CreateNumber(double num)			{cJSON *item=cJSON_New_Item();if(item){item->type=cJSON_Number;item->valuedouble=num;item->valueint=(int)num;}return item;}
cJSON *cJSON_CreateString(const char *string)	{cJSON *item=cJSON_New_Item();if(item){item->type=cJSON_String;item->valuestring=cJSON_strdup(string);if(!item->valuestring){cJSON_Delete(item);return 0;}}return item;}
cJSON *cJSON_CreateArray(void)					{cJSON *item=cJSON_New_Item();if(item)item->type=cJSON_Array;return item;}
cJSON *cJSON_CreateObject(void)					{cJSON *item=cJSON_New_Item();if(item)item->type=cJSON_Object;return item;}

/* Create Arrays: */
cJSON *cJSON_CreateIntArray(const int *numbers,int count)		{int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;a && i<count;i++){n=cJSON_CreateNumber(numbers[i]);if(!n){cJSON_Delete(a);return 0;}if(!i)a->child=n;else suffix_object(p,n);p=n;}return a;}
cJSON *cJSON_CreateFloatArray(const float *numbers,int count)	{int i;cJSON *n=0,n);p=n;}return a;}
cJSON *cJSON_CreateDoubleArray(const double *numbers,n);p=n;}return a;}
cJSON *cJSON_CreateStringArray(const char **strings,*a=cJSON_CreateArray();for(i=0;a && i<count;i++){n=cJSON_CreateString(strings[i]);if(!n){cJSON_Delete(a);return 0;}if(!i)a->child=n;else suffix_object(p,n);p=n;}return a;}

/* Duplication */
cJSON *cJSON_Duplicate(cJSON *item,int recurse)
{
	cJSON *newitem,*cptr,*nptr=0,*newchild;
	/* Bail on bad ptr */
	if (!item) return 0;
	/* Create new item */
	newitem=cJSON_New_Item();
	if (!newitem) return 0;
	/* copy over all vars */
	newitem->type=item->type&(~cJSON_IsReference),newitem->valueint=item->valueint,newitem->valuedouble=item->valuedouble;
	if (item->valuestring)	{newitem->valuestring=cJSON_strdup(item->valuestring);	if (!newitem->valuestring)	{cJSON_Delete(newitem);return 0;}}
	if (item->string)		{newitem->string=cJSON_strdup(item->string);			if (!newitem->string)		{cJSON_Delete(newitem);return 0;}}
	/* If non-recursive,then we're done! */
	if (!recurse) return newitem;
	/* Walk the ->next chain for the child. */
	cptr=item->child;
	while (cptr)
	{
		newchild=cJSON_Duplicate(cptr,1);		/* Duplicate (with recurse) each item in the ->next chain */
		if (!newchild) {cJSON_Delete(newitem);return 0;}
		if (nptr)	{nptr->next=newchild,newchild->prev=nptr;nptr=newchild;}	/* If newitem->child already set,then crosswire ->prev and ->next and move on */
		else		{newitem->child=newchild;nptr=newchild;}					/* Set newitem->child and move to it */
		cptr=cptr->next;
	}
	return newitem;
}

void cJSON_Minify(char *json)
{
	char *into=json;
	while (*json)
	{
		if (*json==' ') json++;
		else if (*json=='\t') json++;	/* Whitespace characters. */
		else if (*json=='\r') json++;
		else if (*json=='\n') json++;
		else if (*json=='/' && json[1]=='/')  while (*json && *json!='\n') json++;	/* double-slash comments,to end of line. */
		else if (*json=='/' && json[1]=='*') {while (*json && !(*json=='*' && json[1]=='/')) json++;json+=2;}	/* multiline comments. */
		else if (*json=='\"'){*into++=*json++;while (*json && *json!='\"'){if (*json=='\\') *into++=*json++;*into++=*json++;}*into++=*json++;} /* string literals,which are \" sensitive. */
		else *into++=*json++;			/* All other characters. */
	}
	*into=0;	/* and null-terminate. */
}

Reference

https://github.com/DaveGamble/cJSON

原文地址：https://www.jb51.cc/json/289236.html