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#include <event.h>
#include <hiredis.h>
/* Prototype for the error callback. */
typedef void (redisErrorCallback)(redisContext*);
/* This struct enables us to pass both the events and the
* redisContext to the read and write handlers. */
typedef struct redisEvents {
redisContext *context;
redisErrorCallback *err;
struct event rev, wev;
} redisEvents;
void redisLibEventRead(int fd, short event, void *arg) {
((void)fd); ((void)event);
redisEvents *e = arg;
/* Always re-schedule read events */
event_add(&e->rev,NULL);
if (redisBufferRead(e->context) == REDIS_ERR) {
/* Handle error. */
e->err(e->context);
} else {
/* If processing the replies/callbacks results in an error,
* invoke the error callback and abort. */
if (redisProcessCallbacks(e->context) == REDIS_ERR) {
e->err(e->context);
}
}
}
void redisLibEventWrite(int fd, short event, void *arg) {
((void)fd); ((void)event);
redisEvents *e = arg;
int done = 0;
if (redisBufferWrite(e->context, &done) == REDIS_ERR) {
/* Handle error */
e->err(e->context);
} else {
/* Schedule write event again when writing is not done. */
if (!done) {
event_add(&e->wev,NULL);
} else {
event_add(&e->rev,NULL);
}
}
}
/* Schedule to be notified on a write event, so the outgoing buffer
* can be flushed to the socket. */
void redisLibEventOnWrite(redisContext *c, void *privdata) {
((void)c);
redisEvents *e = privdata;
event_add(&e->wev,NULL);
}
/* Remove event handlers when the context gets disconnected. */
void redisLibEventOnDisconnect(redisContext *c, void *privdata) {
((void)c);
redisEvents *e = privdata;
event_del(&e->rev);
event_del(&e->wev);
}
/* Free the redisEvents struct when the context is free'd. */
void redisLibEventOnFree(redisContext *c, void *privdata) {
((void)c);
redisEvents *e = privdata;
free(e);
}
redisContext *redisLibEventConnect(const char *ip, int port, redisErrorCallback *err) {
redisEvents *e;
redisContext *c = redisConnectNonBlock(ip, port, NULL);
if (c->error != NULL) {
err(c);
return NULL;
}
/* Create container for context and r/w events */
e = malloc(sizeof(*e));
e->context = c;
e->err = err;
/* Register callbacks and events */
redisSetDisconnectCallback(e->context, redisLibEventOnDisconnect, e);
redisSetCommandCallback(e->context, redisLibEventOnWrite, e);
redisSetFreeCallback(e->context, redisLibEventOnFree, e);
event_set(&e->rev, e->context->fd, EV_READ, redisLibEventRead, e);
event_set(&e->wev, e->context->fd, EV_WRITE, redisLibEventWrite, e);
return e->context;
}
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