Using the basic stream object

Basic type

struct tnt_stream

struct tnt_stream {
    int alloc;
    ssize_t (* write)(struct tnt_stream * s, const char * buf, size_t size);
    ssize_t (* writev)(struct tnt_stream * s, struct iovec * iov, int count);
    ssize_t (* read)(struct tnt_stream * s, char * buf, size_t size);
    int (* read_reply)(struct tnt_stream * s, struct tnt_reply * r);
    void (* free)(struct tnt_stream * s);
    void * data;
    uint32_t wrcnt;
    uint64_t reqid;
};

int tnt_stream.alloc

Allocation mark, equals zero if memory isn’t allocated for the stream object. Otherwise not zero.

void * tnt_stream.data

Subclass data.

uint_32t tnt_stream.wrcnt

Counter of write operations.

uint_64t tnt_stream.reqid

Request ID number of a current operation. Incremented at every request compilation. Default is zero.

Working with a stream

void tnt_stream_free(struct tnt_stream *s)

Common free function for all stream objects.

uint32_t tnt_stream_reqid(struct tnt_stream *s, uint32_t reqid)

Increment and set the request ID that’ll be used to construct a query, and return the previous request ID.

ssize_t tnt_stream.write(struct tnt_stream * s, const char * buf, size_t size)

ssize_t tnt_stream.writev(struct tnt_stream * s, struct iovec * iov, int count)

Write a string or a vector to a stream. Here size is the string’s size (in bytes), and count is the number of records in the iov vector.

ssize_t tnt_stream.read(struct tnt_stream * s, char * buf, size_t size)

int tnt_stream.read_reply(struct tnt_stream * s, struct tnt_reply * r)

Read a reply from server. The read() function simply writes the reply to a string buffer, while the read_reply() function parses it and writes to a tnt_reply data structure.