cjson库，json数据解析

/* 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 <limits.h> #include <ctype.h> #include "cjson.h" static const char *ep; const char *cJSON_GetErrorPtr(void) {return 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 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(void) { 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->type&cJSON_IsReference) && c->child) cJSON_Delete(c->child); if (!(c->type&cJSON_IsReference) && 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; #ifdef CONFIG_CJSON_SUPPORT_64BIT char *longstr; int i=0,j=0; longstr = (char*)cJSON_malloc(20); while (num[i] != '\0' && num[i] >= '0' && num[i] <= '9' && j<19) { longstr[j++] = num[i++]; } longstr[j]='\0'; item->valuelonglong = atoll(longstr); cJSON_free(longstr); #endif 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) { char *str; double d=item->valuedouble; #ifdef CONFIG_CJSON_SUPPORT_64BIT long long l=item->valuelonglong; #endif if (fabs(((double)item->valueint)-d)<=DBL_EPSILON && d<=INT_MAX && d>=INT_MIN) { str=(char*)cJSON_malloc(21); /* 2^64+1 can be represented in 21 chars. */ if (str) sprintf(str,"%d",item->valueint); } else { str=(char*)cJSON_malloc(64); /* This is a nice tradeoff. */ if (str) { #ifdef CONFIG_CJSON_SUPPORT_64BIT if (l != (long long)d && l!=0) sprintf(str,"%lld",l); else if (fabs(floor(d)-d)<=DBL_EPSILON && fabs(d)<1.0e60)sprintf(str,"%.0f",d); #else if (fabs(floor(d)-d)<=DBL_EPSILON && fabs(d)<1.0e60)sprintf(str,"%.0f",d); #endif else if (fabs(d)<1.0e-6 || fabs(d)>1.0e9) sprintf(str,"%e",d); else sprintf(str,"%f",d); } } return str; } 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; } /* 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 *ptr=str+1;char *ptr2;char *out;int len=0;unsigned uc,uc2; if (*str!='\"') {ep=str;return 0;} /* not a string! */ while (*ptr!='\"' && *ptr && ++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) { 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 ((uc>=0xDC00 && uc<=0xDFFF) || uc==0) break; /* check for invalid. */ if (uc>=0xD800 && uc<=0xDBFF) /* UTF16 surrogate pairs. */ { if (ptr[1]!='\\' || ptr[2]!='u') break; /* missing second-half of surrogate. */ uc2=parse_hex4(ptr+3);ptr+=6; if (uc2<0xDC00 || uc2>0xDFFF) break; /* 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++; 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;unsigned char token; if (!str) return cJSON_strdup(""); ptr=str;while ((token=*ptr) && ++len) {if (strchr("\"\\\b\f\n\r\t",token)) len++; else if (token<32) len+=5;ptr++;} out=(char*)cJSON_malloc(len+3); if (!out) return 0;