MQTT 内存缓存

5 请教MQTT如何动态配置发送缓存

发布于 2021-08-10 09:16:02 浏览：434 订阅该版

3 个回答

Jone 2021-08-10

写了还是懒

leefeng 2021-08-10

This guy hasn't written anything yet

Jone 2021-08-10

写了还是懒

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leefeng 2021-08-10

This guy hasn't written anything yet

leefeng 2021-08-10

This guy hasn't written anything yet

作者回复最新的代码已经可以直接用mqtt_set_write_buf_size()来动态申请了，
原文如下：
你看我最新的代码，可以切换到stable分支，可以动态去调整的，即使你知道怎么去申请、释放client内部的内存，但也请不要在外部操作，因为它是由client内部维护的。
```c
static uint32_t mqtt_write_buf_malloc(mqtt_client_t* c, uint32_t size)
{
    MQTT_ROBUSTNESS_CHECK(c, 0);
    
    if (NULL != c->mqtt_write_buf)
        platform_memory_free(c->mqtt_write_buf);
    
    c->mqtt_write_buf_size = size;

/* limit the size of the read buffer */
    if ((MQTT_MIN_PAYLOAD_SIZE >= c->mqtt_write_buf_size) || (MQTT_MAX_PAYLOAD_SIZE <= c->mqtt_write_buf_size))
        c->mqtt_write_buf_size = MQTT_DEFAULT_BUF_SIZE;
    
    c->mqtt_write_buf = (uint8_t*) platform_memory_alloc(c->mqtt_write_buf_size);
    
    if (NULL == c->mqtt_write_buf) {
        MQTT_LOG_E("%s:%d %s()... malloc write buf failed...", __FILE__, __LINE__, __FUNCTION__);
        RETURN_ERROR(MQTT_MEM_NOT_ENOUGH_ERROR);
    }
    return c->mqtt_write_buf_size;
}

uint32_t mqtt_set_write_buf_size(mqtt_client_t *c, uint32_t size) 
{ 
    return mqtt_write_buf_malloc(c, size);
}
```