gistfile1.c

#include <sys/types.h>
#include <hiredis/hiredis.h>
#include <hiredis/async.h>

typedef struct redis_libuv_events {
    redisAsyncContext *context;
    uv_loop_t *loop;
    int reading;
    int writing;
    uv_prepare_t read_handle;
    uv_prepare_t write_handle;
} redis_libuv_events;


static void
redis_libuv_read_event(uv_prepare_t *handle, int status)
{
    redis_libuv_events *e = (redis_libuv_events *)handle->data;
    redisAsyncHandleRead(e->context);
}

static void
redis_libuv_write_event(uv_prepare_t *handle, int status)
{
    redis_libuv_events *e = (redis_libuv_events *)handle->data;
    redisAsyncHandleWrite(e->context);
}

static void
redis_libuv_add_read(void *privdata)
{
    redis_libuv_events *e = (redis_libuv_events *)privdata;
    if (!e->reading) {
        e->reading = 1;
        uv_prepare_start(&e->read_handle, redis_libuv_read_event);
    }
}

static void
redis_libuv_del_read(void *privdata)
{
    redis_libuv_events *e = (redis_libuv_events *)privdata;
    if (e->reading) {
        e->reading = 0;
        uv_prepare_stop(&e->read_handle);
    }
}

static void
redis_libuv_add_write(void *privdata)
{
    redis_libuv_events *e = (redis_libuv_events *)privdata;
    if (!e->writing) {
        e->writing = 1;
        uv_prepare_start(&e->write_handle, redis_libuv_write_event);
    }
}

static void
redis_libuv_del_write(void *privdata)
{
    redis_libuv_events *e = (redis_libuv_events *)privdata;
    if (e->writing) {
        e->writing = 0;
        uv_prepare_stop(&e->write_handle);
    }
}

static void
redis_libuv_cleanup(void *privdata)
{
    redis_libuv_events *e = (redis_libuv_events *)privdata;
    redis_libuv_del_read(privdata);
    redis_libuv_del_write(privdata);
    free(e);
}

static int
redis_libuv_attach(uv_loop_t *loop, redisAsyncContext *ac)
{
    redis_libuv_events *e;

    /* Nothing should be attached when something is already attached */
    if (ac->data != NULL)
        return REDIS_ERR;

    /* Create container for context and r/w events */
    e = malloc(sizeof(redis_libuv_events));
    e->context = ac;
    e->loop = loop;

    /* Register functions to start/stop listening for events */
    ac->ev.addRead = redis_libuv_add_read;
    ac->ev.delRead = redis_libuv_del_read;
    ac->ev.addWrite = redis_libuv_add_write;
    ac->ev.delWrite = redis_libuv_del_write;
    ac->ev.cleanup = redis_libuv_cleanup;
    ac->ev.data = e;

    /* Initialize read/write events */
    uv_prepare_init(e->loop, &e->read_handle);
    uv_prepare_init(e->loop, &e->write_handle);

    e->reading = 0;
    e->writing = 0;
    e->read_handle.data = e;
    e->write_handle.data = e;

    return REDIS_OK;
}