cJSON/cJSON.c

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/*
Copyright (c) 2009 Dave Gamble
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
// cJSON
// JSON parser in C.
#include <string.h>
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <float.h>
#include "cJSON.h"
#if defined(WINDOWS) || defined(__WIN32__) || defined(WIN32) || defined(_WIN32)
#define strcasecmp stricmp
#define strdup _strdup
#endif
static void *(*cJSON_malloc)(size_t sz) = malloc;
static void (*cJSON_free)(void *ptr) = free;
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;
}
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()
{
cJSON* node = (cJSON*)cJSON_malloc(sizeof(cJSON));
if (node) memset(node,0,sizeof(cJSON));
return node;
}
// Delete a cJSON structure.
void cJSON_Delete(cJSON *c)
{
cJSON *next;
while (c)
{
next=c->next;
if (c->child) cJSON_Delete(c->child);
if (c->valuestring) cJSON_free(c->valuestring);
if (c->string) cJSON_free(c->string);
cJSON_free(c);
c=next;
}
}
// 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;
// Could use sscanf for this?
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++; 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)
{
char *str;
double d=item->valuedouble;
if (fabs(((double)item->valueint)-d)<=DBL_EPSILON)
{
str=(char*)cJSON_malloc(21); // 2^64+1 can be represented in 21 chars.
sprintf(str,"%d",item->valueint);
}
else
{
str=(char*)cJSON_malloc(64); // This is a nice tradeoff.
if (fabs(d)<1.0e-6 || fabs(d)>1.0e9) sprintf(str,"%e",d);
else sprintf(str,"%f",d);
}
return str;
}
// Parse the input text into an unescaped cstring, and populate item.
static const char firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };
static const char *parse_string(cJSON *item,const char *str)
{
const char *ptr=str+1;char *ptr2;char *out;int len=0;unsigned uc;
if (*str!='\"') return 0; // not a string!
while (*ptr!='\"' && *ptr>31 && ++len) if (*ptr++ == '\\') ptr++; // Skip escaped quotes.
out=(char*)cJSON_malloc(len+1); // This is how long we need for the string, roughly.
if (!out) return 0;
ptr=str+1;ptr2=out;
while (*ptr!='\"' && *ptr>31)
{
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. DOES NOT SUPPORT SURROGATE PAIRS CORRECTLY.
sscanf(ptr+1,"%4x",&uc); // get the unicode char.
len=3;if (uc<0x80) len=1;else if (uc<0x800) len=2;ptr2+=len;
switch (len) {
case 3: *--ptr2 =((uc | 0x80) & 0xBF); uc >>= 6;
case 2: *--ptr2 =((uc | 0x80) & 0xBF); uc >>= 6;
case 1: *--ptr2 =(uc | firstByteMark[len]);
}
ptr2+=len;ptr+=4;
break;
default: *ptr2++=*ptr; break;
}
ptr++;
}
}
*ptr2=0;
if (*ptr=='\"') ptr++;
item->valuestring=out;
item->type=cJSON_String;
return ptr;
}
// Render the cstring provided to an escaped version that can be printed.
static char *print_string_ptr(const char *str)
{
const char *ptr;char *ptr2,*out;int len=0;
ptr=str;while (*ptr && ++len) {if (*ptr<32 || *ptr=='\"' || *ptr=='\\') len++;ptr++;}
out=(char*)cJSON_malloc(len+3);
ptr2=out;ptr=str;
*ptr2++='\"';
while (*ptr)
{
if (*ptr>31 && *ptr!='\"' && *ptr!='\\') *ptr2++=*ptr++;
else
{
*ptr2++='\\';
switch (*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: ptr2--; break; // eviscerate with prejudice.
}
}
}
*ptr2++='\"';*ptr2++=0;
return out;
}
// Invote print_string_ptr (which is useful) on an item.
static char *print_string(cJSON *item) {return print_string_ptr(item->valuestring);}
// Predeclare these prototypes.
static const char *parse_value(cJSON *item,const char *value);
static char *print_value(cJSON *item,int depth);
static const char *parse_array(cJSON *item,const char *value);
static char *print_array(cJSON *item,int depth);
static const char *parse_object(cJSON *item,const char *value);
static char *print_object(cJSON *item,int depth);
// Utility to jump whitespace and cr/lf
static const char *skip(const char *in) {while (in && *in<=32) in++; return in;}
// Parse an object - create a new root, and populate.
cJSON *cJSON_Parse(const char *value)
{
cJSON *c=cJSON_New_Item();
if (!c) return 0; /* memory fail */
if (!parse_value(c,skip(value))) {cJSON_Delete(c);return 0;}
return c;
}
// Render a cJSON item/entity/structure to text.
char *cJSON_Print(cJSON *item) {return print_value(item,0);}
// Parser core - when encountering text, process appropriately.
static const char *parse_value(cJSON *item,const char *value)
{
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); }
if (*value=='-' || (*value>='0' && *value<='9')) { return parse_number(item,value); }
if (*value=='[') { return parse_array(item,value); }
if (*value=='{') { return parse_object(item,value); }
return 0; // failure.
}
// Render a value to text.
static char *print_value(cJSON *item,int depth)
{
char *out=0;
switch (item->type)
{
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);break;
case cJSON_String: out=print_string(item);break;
case cJSON_Array: out=print_array(item,depth);break;
case cJSON_Object: out=print_object(item,depth);break;
}
return out;
}
// Build an array from input text.
static const char *parse_array(cJSON *item,const char *value)
{
cJSON *child;
if (*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))); // 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)));
if (!value) return 0; // memory fail
}
if (*value==']') return value+1; // end of array
return 0; // malformed.
}
// Render an array to text
static char *print_array(cJSON *item,int depth)
{
char **entries;
char *out=0,*ptr,*ret;int len=5;
cJSON *child=item->child;
int numentries=0,i=0,fail=0;
// How many entries in the array?
while (child) numentries++,child=child->next;
// Allocate an array to hold the values for each
entries=(char**)cJSON_malloc(numentries*sizeof(char*));
if (!entries) return 0;
memset(entries,0,numentries*sizeof(char*));
// Retrieve all the results:
child=item->child;
while (child && !fail)
{
ret=print_value(child,depth+1);
entries[i++]=ret;
if (ret) len+=strlen(ret)+3; else fail=1;
child=child->next;
}
// If we didn't fail, try to malloc the output string
if (!fail) out=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++)
{
strcpy(ptr,entries[i]);ptr+=strlen(entries[i]);
if (i!=numentries-1) {*ptr++=',';*ptr++=' ';*ptr=0;}
cJSON_free(entries[i]);
}
cJSON_free(entries);
*ptr++=']';*ptr++=0;
return out;
}
// Build an object from the text.
static const char *parse_object(cJSON *item,const char *value)
{
cJSON *child;
if (*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();
value=skip(parse_string(child,skip(value)));
if (!value) return 0;
child->string=child->valuestring;child->valuestring=0;
if (*value!=':') return 0; // fail!
value=skip(parse_value(child,skip(value+1))); // 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_string(child,skip(value+1)));
if (!value) return 0;
child->string=child->valuestring;child->valuestring=0;
if (*value!=':') return 0; // fail!
value=skip(parse_value(child,skip(value+1))); // skip any spacing, get the value.
if (!value) return 0;
}
if (*value=='}') return value+1; // end of array
return 0; // malformed.
}
// Render an object to text.
static char *print_object(cJSON *item,int depth)
{
char **entries=0,**names=0;
char *out=0,*ptr,*ret,*str;int len=7,i=0,j;
cJSON *child=item->child;
int numentries=0,fail=0;
// Count the number of entries.
while (child) numentries++,child=child->next;
// 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,0,sizeof(char*)*numentries);
memset(names,0,sizeof(char*)*numentries);
// Collect all the results into our arrays:
child=item->child;depth++;len+=depth;
while (child)
{
names[i]=str=print_string_ptr(child->string);
entries[i++]=ret=print_value(child,depth);
if (str && ret) len+=strlen(ret)+strlen(str)+4+depth; 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]) free(names[i]);if (entries[i]) free(entries[i]);}
free(names);free(entries);
return 0;
}
// Compose the output:
*out='{';ptr=out+1;*ptr++='\n';*ptr=0;
for (i=0;i<numentries;i++)
{
for (j=0;j<depth;j++) *ptr++='\t';
strcpy(ptr,names[i]);ptr+=strlen(names[i]);
*ptr++=':';*ptr++='\t';
strcpy(ptr,entries[i]);ptr+=strlen(entries[i]);
if (i!=numentries-1) *ptr++=',';
*ptr++='\n';*ptr=0;
cJSON_free(names[i]);cJSON_free(entries[i]);
}
cJSON_free(names);cJSON_free(entries);
for (i=0;i<depth-1;i++) *ptr++='\t';
*ptr++='}';*ptr++=0;
return out;
}
// 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->child; while (c && item) item--,c=c->next; return c;}
cJSON *cJSON_GetObjectItem(cJSON *object,const char *string) {cJSON *c=object->child; while (c && strcasecmp(c->string,string)) c=c->next; return c;}
// Utility for array list handling.
static void suffix_object(cJSON *prev,cJSON *item) {prev->next=item;item->prev=prev;}
// Add item to array/object.
void cJSON_AddItemToArray(cJSON *array, cJSON *item) {cJSON *c=array->child;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->string) cJSON_free(item->string);item->string=cJSON_strdup(string);cJSON_AddItemToArray(object,item);}
// Create basic types:
cJSON *cJSON_CreateNull() {cJSON *item=cJSON_New_Item();item->type=cJSON_NULL;return item;}
cJSON *cJSON_CreateTrue() {cJSON *item=cJSON_New_Item();item->type=cJSON_True;return item;}
cJSON *cJSON_CreateFalse() {cJSON *item=cJSON_New_Item();item->type=cJSON_False;return item;}
cJSON *cJSON_CreateNumber(double num) {cJSON *item=cJSON_New_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();item->type=cJSON_String;item->valuestring=cJSON_strdup(string);return item;}
cJSON *cJSON_CreateArray() {cJSON *item=cJSON_New_Item();item->type=cJSON_Array;return item;}
cJSON *cJSON_CreateObject() {cJSON *item=cJSON_New_Item();item->type=cJSON_Object;return item;}
// Create Arrays:
cJSON *cJSON_CreateIntArray(int *numbers,int count) {int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;i<count;i++){n=cJSON_CreateNumber(numbers[i]);if(!i)a->child=n;else suffix_object(p,n);p=n;}return a;}
cJSON *cJSON_CreateFloatArray(float *numbers,int count) {int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;i<count;i++){n=cJSON_CreateNumber(numbers[i]);if(!i)a->child=n;else suffix_object(p,n);p=n;}return a;}
cJSON *cJSON_CreateDoubleArray(double *numbers,int count) {int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;i<count;i++){n=cJSON_CreateNumber(numbers[i]);if(!i)a->child=n;else suffix_object(p,n);p=n;}return a;}
cJSON *cJSON_CreateStringArray(const char **strings,int count) {int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;i<count;i++){n=cJSON_CreateString(strings[i]);if(!i)a->child=n;else suffix_object(p,n);p=n;}return a;}