notfastjson项目介绍

项目地址 https://github.com/kafmws/notfastjson

notfastjson

© 2019 kafm (wdxdesperado@qq.com)

简介

简单 不是很快的 JSON解析库 C语言实现

• ANSI C标准，跨平台 / 编译器
• 递归下降解析器
• 支持UTF-8字符
• number类型数字解析仅支持C语言double类型范围
• 参考 从零开始的 JSON 库教程 @ Milo Yip

构建

原项目Win平台下使用VS编写，使用<crtdbg.h>及_CRTDBG_MAP_ALLOC宏检测内存泄漏
使用宏

#define EXPECT_EQ_BASE(equality, expect, actual, format) 
    do {
        test_count++;
        if (equality)
            test_pass++;
        else {
            fprintf(stderr, "%s:%d: expect: " format " actual: " format "
", __FILE__, __LINE__, expect, actual);
            main_ret = 1;
        }
    } while(0)

构建简单单元测试

JSON类型

类型	enum 表示
null	JSON_NULL
bool	JSON_TRUE / JSON_FALSE
number	JSON_NUMBER
string	JSON_STRING
array	JSON_ARRAY
object	JSON_OBJECT

数据结构

typedef struct nfjson_value nfjson_value;

typedef struct { char *s; size_t len; } nfjson_string;

struct nfjson_value {
    union {
        nfjson_string s;
        struct { nfjson_value *e; size_t len; }a;/* type == JSON_ARRAY */
        hash_table *hto;/* type == JSON_OBJECT */
        double n;/* type == JSON_NUMBER */
    }u;
    nfjson_type type;
};

typedef struct {
    const char *json;/*the parsing position in the json*/
    char *stack;/*parsing buffer*/
    size_t size;/*size of stack*/
    size_t top;/*pointer of stack*/
}nfjson_context;

类型	意义/实现方式
nfjson_context	JSON字符串解析信息
nfjson_value	解析出的JSON值
nfjson_string	UTF-8字符串值
hash_table	通用hash表， 内置使用以nfjson_string为key类型， nfjson_value为value类型使用
nfjson_context 中 stack	任意类型动态堆栈， 用作string，array类型解析缓冲区

文件目录

|-- access.c .h				//getter & setter
|-- hash_table.c .h			//hash_table
|-- memory.c .h				//manage memory
|-- nfjson.h				//define data structure, error code & json type
|-- parse.c .h				//recursive-descent json parser
|-- pch.c .h				//VS required
|-- test.c .h				//unit testing

其它

• 内存管理 malloc，realloc，free，nfjson_string_free及递归nfjson_free
• 缓冲堆栈 realloc扩容，任意类型，悬浮指针问题
• 哈希支持 任意类型，按需配置

示例

nfjson_value val;

nfjson_parse(&val, 
				" { "
				""n" : null , "
				""f" : false , "
				""t" : true , "
				""i" : 123 , "
				""s" : "abc", "
				""a" : [ 1, 2, 3 ],"
				""o" : { "1" : 1, "2" : 2, "3" : 3 }"
				"}"
);
nfjson_get_type(&val) == JSON_OBJECT;
nfjson_get_object_size(&val) == 7;
nfjson_string []s = 
			{ {"n", 1},{"f", 1},{"t", 1},{"i", 1},{"s", 1},{"a", 1},{"o", 1}, };

//access { "n" : null }
nfjson_value *v = nfjson_get_object_value(&s[0]);
nfjson_get_type(&v) == JSON_NULL;
//access { "i" : 123 }
v = nfjson_get_object_value(&s[3]);
nfjson_get_number(&v) == 123;
//access 1 in { "a" : [1, 2, 3] }
v = nfjson_get_object_value(&s[5]);
nfjson_get_type(&val) == JSON_ARRAY;
nfjson_get_array_size(&val) == 3;
v = nfjson_get_array_element(&v, 1);
nfjson_get_type(&val) == JSON_NUMBER;
nfjson_get_number(&v) == 1;

更多示例见 test.c

---

notfastjson

© 2019 kafm (wdxdesperado@qq.com)

Introduction

a simple and not fast json parsing library writed in C

• standard ANSI C，cross-platform / compiler
• recursive decent parser
• UTF-8 char support
• number in range of doublein C only
• based on json-tutorial @ Milo Yip

Build

write in Windows with Visual Studio，using <crtdbg.h>& macro _CRTDBG_MAP_ALLOCto detect memory leaks
using following marco

static int test_count = 0;
static int test_pass = 0;
#define EXPECT_EQ_BASE(equality, expect, actual, format) 
    do {
        test_count++;
        if (equality)
            test_pass++;
        else {
            fprintf(stderr, "%s:%d: expect: " format " actual: " format "
", __FILE__, __LINE__, expect, actual);
            main_ret = 1;
        }
    } while(0)

build simple unit testing.

JSON type

type	enum
null	JSON_NULL
bool	JSON_TRUE / JSON_FALSE
number	JSON_NUMBER
string	JSON_STRING
array	JSON_ARRAY
object	JSON_OBJECT

Data Structure

typedef struct nfjson_value nfjson_value;

typedef struct { char *s; size_t len; } nfjson_string;

struct nfjson_value {
    union {
        nfjson_string s;
        struct { nfjson_value *e; size_t len; }a;/* type == JSON_ARRAY */
        hash_table *hto;/* type == JSON_OBJECT */
        double n;/* type == JSON_NUMBER */
    }u;
    nfjson_type type;
};

typedef struct {
    const char *json;/*the parsing position in the json*/
    char *stack;/*parsing buffer*/
    size_t size;/*size of stack*/
    size_t top;/*pointer of stack*/
}nfjson_context;

type define	meaning/implement
nfjson_context	JSON string context in parsing
nfjson_value	json value
nfjson_string	UTF-8 string
hash_table	a hash table, using nfjson_string as key and nfjson_value as value
stack in nfjson_context	dynamic stack for any type, as a buffer for json string type and json array type in parsing

file index

|-- access.c .h				//getter & setter
|-- hash_table.c .h			//hash_table
|-- memory.c .h				//manage memory
|-- nfjson.h				//define data structure, error code & json type
|-- parse.c .h				//recursive-descent json parser
|-- pch.c .h				//VS required
|-- test.c .h				//unit testing

Other

• memory managment malloc，realloc，free，nfjson_string_free& recursive nfjson_free
• buffer stack reallocdynamic expansion，support any type，suspensive pointer problem
• hash table support support any type，on-demand configure

examples

nfjson_value val;

nfjson_parse(&val, 
				" { "
				""n" : null , "
				""f" : false , "
				""t" : true , "
				""i" : 123 , "
				""s" : "abc", "
				""a" : [ 1, 2, 3 ],"
				""o" : { "1" : 1, "2" : 2, "3" : 3 }"
				"}"
);
nfjson_get_type(&val) == JSON_OBJECT;
nfjson_get_object_size(&val) == 7;
nfjson_string []s = 
			{ {"n", 1},{"f", 1},{"t", 1},{"i", 1},{"s", 1},{"a", 1},{"o", 1}, };

//access { "n" : null }
nfjson_value *v = nfjson_get_object_value(&s[0]);
nfjson_get_type(&v) == JSON_NULL;
//access { "i" : 123 }
v = nfjson_get_object_value(&s[3]);
nfjson_get_number(&v) == 123;
//access 1 in { "a" : [1, 2, 3] }
v = nfjson_get_object_value(&s[5]);
nfjson_get_type(&val) == JSON_ARRAY;
nfjson_get_array_size(&val) == 3;
v = nfjson_get_array_element(&v, 1);
nfjson_get_type(&val) == JSON_NUMBER;
nfjson_get_number(&v) == 1;

for more examples, see test.c