cJSON/cJSON_Utils.c

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#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "cJSON_Utils.h"
// JSON Pointer implementation:
static int cJSONUtils_Pstrcasecmp(const char *a,const char *e)
{
if (!a || !e) return (a==e)?0:1;
for (;*a && *e && *e!='/';a++,e++) {
if (*e=='~') {if (!(e[1]=='0' && *a=='~') && !(e[1]=='1' && *a=='/')) return 1; else e++;}
else if (tolower(*a)!=tolower(*e)) return 1;
}
if ((*e!=0 && *e!='/') != (*a!=0)) return 1;
return 0;
}
static int cJSONUtils_PointerEncodedstrlen(const char *s) {int l=0;for (;*s;s++,l++) if (*s=='~' || *s=='/') l++;return l;}
static void cJSONUtils_PointerEncodedstrcpy(char *d,const char *s)
{
for (;*s;s++)
{
if (*s=='/') {*d++='~';*d++='1';}
else if (*s=='~') {*d++='~';*d++='0';}
else *d++=*s;
}
*d=0;
}
char *cJSONUtils_FindPointerFromObjectTo(cJSON *object,cJSON *target)
{
if (object==target) return strdup("");
int type=object->type,c=0;
for (cJSON *obj=object->child;obj;obj=obj->next,c++)
{
char *found=cJSONUtils_FindPointerFromObjectTo(obj,target);
if (found)
{
if (type==cJSON_Array)
{
char *ret=(char*)malloc(strlen(found)+23);
sprintf(ret,"/%d%s",c,found);
free(found);
return ret;
}
else if (type==cJSON_Object)
{
char *ret=(char*)malloc(strlen(found)+cJSONUtils_PointerEncodedstrlen(obj->string)+2);
*ret='/';cJSONUtils_PointerEncodedstrcpy(ret+1,obj->string);
strcat(ret,found);
free(found);
return ret;
}
free(found);
return 0;
}
}
return 0;
}
cJSON *cJSONUtils_GetPointer(cJSON *object,const char *pointer)
{
while (*pointer++=='/' && object)
{
if (object->type==cJSON_Array)
{
int which=0; while (*pointer>='0' && *pointer<='9') which=(10*which) + *pointer++ - '0';
if (*pointer && *pointer!='/') return 0;
object=cJSON_GetArrayItem(object,which);
}
else if (object->type==cJSON_Object)
{
object=object->child; while (object && cJSONUtils_Pstrcasecmp(object->string,pointer)) object=object->next; // GetObjectItem.
while (*pointer && *pointer!='/') pointer++;
}
else return 0;
}
return object;
}
// JSON Patch implementation.
static void cJSONUtils_InplaceDecodePointerString(char *string)
{
char *s2=string;
for (;*string;s2++,string++) *s2=(*string!='~')?(*string):((*(++string)=='0')?'~':'/');
*s2=0;
}
static cJSON *cJSONUtils_PatchDetach(cJSON *object,const char *path)
{
char *parentptr=0,*childptr=0;cJSON *parent=0;
parentptr=strdup(path); childptr=strrchr(parentptr,'/'); if (childptr) *childptr++=0;
parent=cJSONUtils_GetPointer(object,parentptr);
cJSONUtils_InplaceDecodePointerString(childptr);
cJSON *ret=0;
if (!parent) ret=0; // Couldn't find object to remove child from.
else if (parent->type==cJSON_Array) ret=cJSON_DetachItemFromArray(parent,atoi(childptr));
else if (parent->type==cJSON_Object) ret=cJSON_DetachItemFromObject(parent,childptr);
free(parentptr);
return ret;
}
static int cJSONUtils_Compare(cJSON *a,cJSON *b)
{
if (a->type!=b->type) return -1; // mismatched type.
switch (a->type)
{
case cJSON_Number: return (a->valueint!=b->valueint || a->valuedouble!=b->valuedouble)?-2:0; // numeric mismatch.
case cJSON_String: return (strcmp(a->valuestring,b->valuestring)!=0)?-3:0; // string mismatch.
case cJSON_Array: for (a=a->child,b=b->child;a && b;a=a->next,b=b->next) {int err=cJSONUtils_Compare(a,b);if (err) return err;}
return (a || b)?-4:0; // array size mismatch.
case cJSON_Object:
if (cJSON_GetArraySize(a)!=cJSON_GetArraySize(b)) return -5; // object length mismatch.
for (a=a->child;a;a=a->next)
{
int err=0;cJSON *s=cJSON_GetObjectItem(b,a->string); if (!s) return -6; // missing object member.
err=cJSONUtils_Compare(a,s);if (err) return err;
}
return 0;
default: break;
}
return 0;
}
static int cJSONUtils_ApplyPatch(cJSON *object,cJSON *patch)
{
cJSON *op=0,*path=0,*value=0;int opcode=0;
op=cJSON_GetObjectItem(patch,"op");
path=cJSON_GetObjectItem(patch,"path");
if (!op || !path) return 2; // malformed patch.
if (!strcmp(op->valuestring,"add")) opcode=0;
else if (!strcmp(op->valuestring,"remove")) opcode=1;
else if (!strcmp(op->valuestring,"replace"))opcode=2;
else if (!strcmp(op->valuestring,"move")) opcode=3;
else if (!strcmp(op->valuestring,"copy")) opcode=4;
else if (!strcmp(op->valuestring,"test")) return cJSONUtils_Compare(cJSONUtils_GetPointer(object,path->valuestring),cJSON_GetObjectItem(patch,"value"));
else return 3; // unknown opcode.
if (opcode==1 || opcode==2) // Remove/Replace
{
cJSON_Delete(cJSONUtils_PatchDetach(object,path->valuestring)); // Get rid of old.
if (opcode==1) return 0; // For Remove, this is job done.
}
if (opcode==3 || opcode==4) // Copy/Move uses "from".
{
cJSON *from=cJSON_GetObjectItem(patch,"from"); if (!from) return 4; // missing "from" for copy/move.
if (opcode==3) value=cJSONUtils_PatchDetach(object,from->valuestring);
if (opcode==4) value=cJSONUtils_GetPointer(object,from->valuestring);
if (!value) return 5; // missing "from" for copy/move.
if (opcode==4) value=cJSON_Duplicate(value,1);
if (!value) return 6; // out of memory for copy/move.
}
else // Add/Replace uses "value".
{
value=cJSON_GetObjectItem(patch,"value");
if (!value) return 7; // missing "value" for add/replace.
value=cJSON_Duplicate(value,1);
if (!value) return 8; // out of memory for add/replace.
}
// Now, just add "value" to "path".
char *parentptr=0,*childptr=0;cJSON *parent=0;
parentptr=strdup(path->valuestring); childptr=strrchr(parentptr,'/'); if (childptr) *childptr++=0;
parent=cJSONUtils_GetPointer(object,parentptr);
cJSONUtils_InplaceDecodePointerString(childptr);
// add, remove, replace, move, copy, test.
if (!parent) {free(parentptr); return 9;} // Couldn't find object to add to.
else if (parent->type==cJSON_Array)
{
if (!strcmp(childptr,"-")) cJSON_AddItemToArray(parent,value);
else cJSON_InsertItemInArray(parent,atoi(childptr),value);
}
else if (parent->type==cJSON_Object)
{
cJSON_DeleteItemFromObject(parent,childptr);
cJSON_AddItemToObject(parent,childptr,value);
}
free(parentptr);
return 0;
}
int cJSONUtils_ApplyPatches(cJSON *object,cJSON *patches)
{
int err;
if (!patches->type==cJSON_Array) return 1; // malformed patches.
if (patches) patches=patches->child;
while (patches)
{
if ((err=cJSONUtils_ApplyPatch(object,patches))) return err;
patches=patches->next;
}
return 0;
}
static void cJSONUtils_GeneratePatch(cJSON *patches,const char *op,const char *path,const char *suffix,cJSON *val)
{
cJSON *patch=cJSON_CreateObject();
cJSON_AddItemToObject(patch,"op",cJSON_CreateString(op));
if (suffix)
{
char *newpath=(char*)malloc(strlen(path)+cJSONUtils_PointerEncodedstrlen(suffix)+2);
cJSONUtils_PointerEncodedstrcpy(newpath+sprintf(newpath,"%s/",path),suffix);
cJSON_AddItemToObject(patch,"path",cJSON_CreateString(newpath));
free(newpath);
}
else cJSON_AddItemToObject(patch,"path",cJSON_CreateString(path));
if (val) cJSON_AddItemToObject(patch,"value",cJSON_Duplicate(val,1));
cJSON_AddItemToArray(patches,patch);
}
void cJSONUtils_AddPatchToArray(cJSON *array,const char *op,const char *path,cJSON *val) {cJSONUtils_GeneratePatch(array,op,path,0,val);}
static void cJSONUtils_CompareToPatch(cJSON *patches,const char *path,cJSON *from,cJSON *to)
{
if (from->type!=to->type) {cJSONUtils_GeneratePatch(patches,"replace",path,0,to); return; }
switch (from->type)
{
case cJSON_Number:
if (from->valueint!=to->valueint || from->valuedouble!=to->valuedouble)
cJSONUtils_GeneratePatch(patches,"replace",path,0,to);
return;
case cJSON_String:
if (strcmp(from->valuestring,to->valuestring)!=0)
cJSONUtils_GeneratePatch(patches,"replace",path,0,to);
return;
case cJSON_Array:
{
int c;char *newpath=(char*)malloc(strlen(path)+23); // Allow space for 64bit int.
for (c=0,from=from->child,to=to->child;from && to;from=from->next,to=to->next,c++){
sprintf(newpath,"%s/%d",path,c); cJSONUtils_CompareToPatch(patches,newpath,from,to);
}
for (;from;from=from->next,c++) {sprintf(newpath,"%d",c); cJSONUtils_GeneratePatch(patches,"remove",path,newpath,0); }
for (;to;to=to->next,c++) cJSONUtils_GeneratePatch(patches,"add",path,"-",to);
free(newpath);
return;
}
case cJSON_Object:
for (cJSON *a=from->child;a;a=a->next)
{
if (!cJSON_GetObjectItem(to,a->string)) cJSONUtils_GeneratePatch(patches,"remove",path,a->string,0);
}
for (cJSON *a=to->child;a;a=a->next)
{
cJSON *other=cJSON_GetObjectItem(from,a->string);
if (!other) cJSONUtils_GeneratePatch(patches,"add",path,a->string,a);
else
{
char *newpath=(char*)malloc(strlen(path)+cJSONUtils_PointerEncodedstrlen(a->string)+2);
cJSONUtils_PointerEncodedstrcpy(newpath+sprintf(newpath,"%s/",path),a->string);
cJSONUtils_CompareToPatch(patches,newpath,other,a);
free(newpath);
}
}
return;
default: break;
}
}
cJSON* cJSONUtils_GeneratePatches(cJSON *from,cJSON *to)
{
cJSON *patches=cJSON_CreateArray();
cJSONUtils_CompareToPatch(patches,"",from,to);
return patches;
}