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Schema

Schema Definition

Schem is used to define CrossDB table and it's defined based on C struct with some CrossDB macro.

Basic Types

CrossDB Type and C Type Map

CrossDB Type Description C Type
INT integer char, short, int, long long, int8_t, int16_t, int32_t, int64_t
UINT unsinged integer unsigned char, unsigned short, unsigned int, unsigned long long, uint8_t uint16_t, uint32_t, uint64_t
FLOAT floating-point float, double
CHAR charater string char []
BYTE byte array unsiged char [], uint8_t [], struct

CrossDB Format

CrossDB Type CrossDB Formt Description
INT/UINT DFT default decimal
FLOAT DFT default floating-point
CHAR DFT default charater string
BYTE DFT default hexadecimal string
INT/UINT BOOL boolean
UINT HEX hexadecimal
INT/UINT TIMESTAMP/TS Timestamp: time_t, uin32_t, uint64_t
BTYE MAC MAC addrss: uint8_t [6], struct ether_addr
UINT IPv4 Host endian IPv4 address: uint32_t
BYTE IPv4 Network endian IPv4 address: struct in_addr, uint32_t
BYTE IPv6 Network endian IPv4 address: uint8_t [16], struct in_addr6

Example

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typedef struct {
    char            val_char;
    int64_t         val_int64;
    uint16_t        val_u16;
    uint8_t         val_u8;
    float           val_float;
    double          val_double;
    char            val_str[16];
    uint8_t         val_byte[64];

    char            val_bool;
    uint16_t        flags;
    time_t          birth;
    unsigned char   mac[6];
    uint32_t        ipAddrHost;
    struct in_addr  ipAddrNet;
    uint8_t         ip6Addr[16];
} basic_types_t;

Set CROSS_STRUCT_NAME to the struct name basic_types_t for CROSS_FIELD to define the schema entry. CROSS_END is used to mark the end of schema definition.

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#undef  CROSS_STRUCT_NAME
#define CROSS_STRUCT_NAME   basic_types_t
cross_field_t   basic_types_schema[] = {
    CROSS_FIELD (val_char,      INT,    DFT,  0),
    CROSS_FIELD (val_int64,     INT,    DFT,  0),
    CROSS_FIELD (val_u16,       UINT,   DFT,  0),
    CROSS_FIELD (val_u8,        UINT,   DFT,  0),
    CROSS_FIELD (val_float,     FLOAT,  DFT,  0),
    CROSS_FIELD (val_double,    FLOAT,  DFT,  0),
    CROSS_FIELD (val_str,       CHAR,   DFT,  0),
    CROSS_FIELD (val_byte,      BYTE,   DFT,  0),
    CROSS_FIELD (val_bool,      UINT,   BOOL, 0),
    CROSS_FIELD (flags,         UINT,   HEX,  0),
    CROSS_FIELD (birth,         UINT,   TS,   0),
    CROSS_FIELD (mac,           BYTE,   MAC,  0),
    CROSS_FIELD (ipAddrHost,    UINT,   IPv4, 0),
    CROSS_FIELD (ipAddrNet,     BYTE,   IPv4, 0),
    CROSS_FIELD (ip6Addr,       BYTEE,  IPv6, 0),
    CROSS_END (basic_types_t)
};

To keep struct and schema in header file, you can define them together like following way.

Define macro ROUTE_SCHEMA() in header file 

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// In header file
typedef struct {
    uint32_t            prefix;
    uint8_t             mask;
    uint32_t            nexthop;
    uint8_t             metric;
    char                intf[16];
    uint32_t            birth;
    uint32_t            flags;
} route_t;

#dfine ROUTE_SCHEMA()   \   
    CROSS_FIELD (prefix,    UINT,   IPv4, 0), \
    CROSS_FIELD (mask,      UINT,   DFT,  0), \
    CROSS_FIELD (nexthop,   UINT,   IPv4, 0), \
    CROSS_FIELD (metric,    UINT,   DFT,  0), \
    CROSS_FIELD (intf,      CHAR,   DFT,  0), \
    CROSS_FIELD (birth,     UINT,   TS,   0), \
    CROSS_FIELD (flags,     UINT,   HEX,  0), \
    CROSS_END (route_t)

Define schema in source file. CROSS_END can be define in route_schema also then you can reuse the macro ROUTE_SCHEMA() or combine them. 

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    // In source file
    #undef  CROSS_STRUCT_NAME
    #define CROSS_STRUCT_NAME   route_t
    cross_field_t   route_schema[] = {
        ROUTE_SCHEMA()
    }

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