Functions
td_json_client.h File Reference

Description

C interface for interaction with TDLib via JSON-serialized objects. Can be used to easily integrate TDLib with any programming language which supports calling C functions and is able to work with JSON.

The JSON serialization of TDLib API objects is straightforward: all API objects are represented as JSON objects with the same keys as the API object field names. The object type name is stored in the special field "@type" which is optional in places where type is uniquely determined by the context. Fields of Bool type are stored as Boolean, fields of int32, int53, and double types are stored as Number, fields of int64 and string types are stored as String, fields of bytes type are base64 encoded and then stored as String, fields of array type are stored as Array. The main TDLib interface is asynchronous. To match requests with a corresponding response a field "@extra" can be added to the request object. The corresponding response will have an "@extra" field with exactly the same value.

A TDLib client instance can be created through td_json_client_create. Requests then can be sent using td_json_client_send from any thread. New updates and request responses can be received through td_json_client_receive from any thread. This function must not be called simultaneously from two different threads. Also note that all updates and request responses must be applied in the order they were received to ensure consistency. Given this information, it's advisable to call this function from a dedicated thread. Some service TDLib requests can be executed synchronously from any thread by using td_json_client_execute. The TDLib client instance can be destroyed via td_json_client_destroy.

General pattern of usage:

void *client = td_json_client_create();
// somehow share the client with other threads, which will be able to send requests via td_json_client_send
const double WAIT_TIMEOUT = 10.0; // seconds
int is_closed = 0; // should be set to 1, when updateAuthorizationState with authorizationStateClosed is received
while (!is_closed) {
const char *result = td_json_client_receive(client, WAIT_TIMEOUT);
if (result) {
// parse the result as JSON object and process it as an incoming update or an answer to a previously sent request
}
}

Go to the source code of this file.

Functions

void * td_json_client_create ()
 
void td_json_client_send (void *client, const char *request)
 
const char * td_json_client_receive (void *client, double timeout)
 
const char * td_json_client_execute (void *client, const char *request)
 
void td_json_client_destroy (void *client)
 
int td_create_client_id ()
 
void td_send (int client_id, const char *request)
 
const char * td_receive (double timeout)
 
const char * td_execute (const char *request)
 

Function Documentation

◆ td_json_client_create()

void* td_json_client_create ( )

Creates a new instance of TDLib.

Returns
Pointer to the created instance of TDLib.

◆ td_json_client_send()

void td_json_client_send ( void *  client,
const char *  request 
)

Sends request to the TDLib client. May be called from any thread.

Parameters
[in]clientThe client.
[in]requestJSON-serialized null-terminated request to TDLib.

◆ td_json_client_receive()

const char* td_json_client_receive ( void *  client,
double  timeout 
)

Receives incoming updates and request responses from the TDLib client. May be called from any thread, but must not be called simultaneously from two different threads. Returned pointer will be deallocated by TDLib during next call to td_json_client_receive or td_json_client_execute in the same thread, so it can't be used after that.

Parameters
[in]clientThe client.
[in]timeoutThe maximum number of seconds allowed for this function to wait for new data.
Returns
JSON-serialized null-terminated incoming update or request response. May be NULL if the timeout expires.

◆ td_json_client_execute()

const char* td_json_client_execute ( void *  client,
const char *  request 
)

Synchronously executes TDLib request. May be called from any thread. Only a few requests can be executed synchronously. Returned pointer will be deallocated by TDLib during next call to td_json_client_receive or td_json_client_execute in the same thread, so it can't be used after that.

Parameters
[in]clientThe client. Currently ignored for all requests, so NULL can be passed.
[in]requestJSON-serialized null-terminated request to TDLib.
Returns
JSON-serialized null-terminated request response.

◆ td_json_client_destroy()

void td_json_client_destroy ( void *  client)

Destroys the TDLib client instance. After this is called the client instance must not be used anymore.

Parameters
[in]clientThe client.

◆ td_create_client_id()

int td_create_client_id ( )

Returns an opaque identifier of a new TDLib instance. The TDLib instance will not send updates until the first request is sent to it.

Returns
Opaque identifier of a new TDLib instance.

◆ td_send()

void td_send ( int  client_id,
const char *  request 
)

Sends request to the TDLib client. May be called from any thread.

Parameters
[in]client_idTDLib client identifier.
[in]requestJSON-serialized null-terminated request to TDLib.

◆ td_receive()

const char* td_receive ( double  timeout)

Receives incoming updates and request responses. Must not be called simultaneously from two different threads. The returned pointer can be used until the next call to td_receive or td_execute, after which it will be deallocated by TDLib.

Parameters
[in]timeoutThe maximum number of seconds allowed for this function to wait for new data.
Returns
JSON-serialized null-terminated incoming update or request response. May be NULL if the timeout expires.

◆ td_execute()

const char* td_execute ( const char *  request)

Synchronously executes a TDLib request. A request can be executed synchronously, only if it is documented with "Can be called synchronously". The returned pointer can be used until the next call to td_receive or td_execute, after which it will be deallocated by TDLib.

Parameters
[in]requestJSON-serialized null-terminated request to TDLib.
Returns
JSON-serialized null-terminated request response.