网络服务接口

网络服务 API 使用流从 JSON 请求中读取和写入数据。用于管理流的常量、原型、结构和枚举在以下部分中定义。

流定义

mcorest_api_json_read() 和 mcorest_api_json_write() 函数所使用的流原型和结构在文件include/mcorestapi.h 中定义如下：

    typedef int (* mcorest_api_stream_read_fn)(
        void *ctx, 
        char *buf, 
        int len
    );
     
    typedef int (* mcorest_api_stream_write_fn)(
        void *ctx, 
        const char *buf, 
        int len
    );
 
    typedef struct mcorest_api_stream_t_
    {
        void *ctx;  							/* 将传递给read_fn和write_fn的用户定义上下文。*/
        mcorest_api_stream_read_fn read_fn;  	/* 流读取函数 */
        mcorest_api_stream_write_fn write_fn;  	/* 流写入函数 */
 
    } mcorest_api_stream_t;

JSON 读取

mcorest_api_json_read_*() 函数所使用的 JSON 上下文结构在文件 include/mcorestapi.h 中定义如下：

    #define MCOREST_API_JSON_READER_BUFFER_SIZE 256
     
    typedef struct mcorest_api_json_read_ctx_t_
    {
        mcorest_api_stream_t *stream;  /* Stream to read JSON data from. */
         
        /* The following fields are for the JSON reader's internal use. */
        int stream_err;  /* Stream error flag. */
        int stream_end;  /* Stream end flag. */
        char buf[MCOREST_API_JSON_READER_BUFFER_SIZE];  /* Stream input buffer. */
        int buf_len;  /* Number of bytes available in the input buffer. */
        const char *buf_p;  /* Current buffer position pointer. */
        int obj_level;  /* Object nesting level. */
        int arr_level;  /* Array nesting level. */
        int read_escaped;  /* Escaped character read flag. */
     
    } mcorest_api_json_read_ctx_t;

JSON 令牌类型

在文件 include/mcorestapi.h 中定义了由函数 mcorest_api_json_read_next_token() 返回的可能令牌类型的枚举，如下所示：

    typedef enum MCOREST_API_JSON_TKN_TYPE_E_
    {
        MCOREST_API_JSON_TKN_UNKNOWN = 0,  /* Unknown token. */
        MCOREST_API_JSON_TKN_OBJECT_BGN,  /* Object start ('{'). */
        MCOREST_API_JSON_TKN_OBJECT_END,  /* Object end ('}'). */
        MCOREST_API_JSON_TKN_ARRAY_BGN,  /* Array start ('['). */
        MCOREST_API_JSON_TKN_ARRAY_END,  /* Array end (']'). */
        MCOREST_API_JSON_TKN_STRING,  /* Quoted string. */
        MCOREST_API_JSON_TKN_NUMBER,  /* Number (integer or real). */
        MCOREST_API_JSON_TKN_TRUE,  /* "true" literal. */
        MCOREST_API_JSON_TKN_FALSE,  /* "false" literal. */
        MCOREST_API_JSON_TKN_NULL  /* "null" literal. */
 
    } MCOREST_API_JSON_TKN_TYPE;

JSON 写入

mcorest_api_json_write_*() 函数所使用的 JSON 上下文结构在文件 include/mcorestapi.h 中定义如下：

    typedef struct mcorest_api_json_write_ctx_t_
    {
        mcorest_api_stream_t *stream;  /* Stream to write JSON data into. */
        int indent;  		/* Indentation level for pretty-printing. */
         
        /* The following fields are for the JSON encoder's internal use. */
        int first_entry;  	/* Non-zero if the next key is the first in the object/array. */
        int key_allowed;  	/* Non-zero if a key is allowed to be written. */
        int key_was_put;  	/* Non-zero if a key has just been written. */
        int obj_level;  	/* Object nesting level. */
        int arr_level;  	/* Array nesting level. */
     
    } mcorest_api_json_write_ctx_t;