/* * ZeroMQ Protocol * Copyright (c) 2019 Andriy Gelman * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include <zmq.h> #include "url.h" #include "network.h" #include "libavutil/avstring.h" #include "libavutil/opt.h" #include "libavutil/time.h" #define ZMQ_STRERROR zmq_strerror(zmq_errno()) typedef struct ZMQContext { const AVClass *class; void *context; void *socket; int pkt_size; int pkt_size_overflow; /*keep track of the largest packet during overflow*/ } ZMQContext; #define OFFSET(x) offsetof(ZMQContext, x) #define D AV_OPT_FLAG_DECODING_PARAM #define E AV_OPT_FLAG_ENCODING_PARAM static const AVOption options[] = { { "pkt_size", "Maximum send/read packet size", OFFSET(pkt_size), AV_OPT_TYPE_INT, { .i64 = 131072 }, -1, INT_MAX, .flags = D | E }, { NULL } }; static int zmq_proto_wait(URLContext *h, void *socket, int write) { int ret; int ev = write ? ZMQ_POLLOUT : ZMQ_POLLIN; zmq_pollitem_t items = { .socket = socket, .fd = 0, .events = ev, .revents = 0 }; ret = zmq_poll(&items, 1, POLLING_TIME); if (ret == -1) { av_log(h, AV_LOG_ERROR, "Error occured during zmq_poll(): %s\n", ZMQ_STRERROR); return AVERROR_EXTERNAL; } return items.revents & ev ? 0 : AVERROR(EAGAIN); } static int zmq_proto_wait_timeout(URLContext *h, void *socket, int write, int64_t timeout, AVIOInterruptCB *int_cb) { int ret; int64_t wait_start = 0; while (1) { if (ff_check_interrupt(int_cb)) return AVERROR_EXIT; ret = zmq_proto_wait(h, socket, write); if (ret != AVERROR(EAGAIN)) return ret; if (timeout > 0) { if (!wait_start) wait_start = av_gettime_relative(); else if (av_gettime_relative() - wait_start > timeout) return AVERROR(ETIMEDOUT); } } } static int zmq_proto_open(URLContext *h, const char *uri, int flags) { int ret; ZMQContext *s = h->priv_data; s->pkt_size_overflow = 0; h->is_streamed = 1; if (s->pkt_size > 0) h->max_packet_size = s->pkt_size; s->context = zmq_ctx_new(); if (!s->context) { /*errno not set on failure during zmq_ctx_new()*/ av_log(h, AV_LOG_ERROR, "Error occured during zmq_ctx_new()\n"); return AVERROR_EXTERNAL; } av_strstart(uri, "zmq:", &uri); /*publish during write*/ if (h->flags & AVIO_FLAG_WRITE) { s->socket = zmq_socket(s->context, ZMQ_PUB); if (!s->socket) { av_log(h, AV_LOG_ERROR, "Error occured during zmq_socket(): %s\n", ZMQ_STRERROR); goto fail_term; } ret = zmq_bind(s->socket, uri); if (ret == -1) { av_log(h, AV_LOG_ERROR, "Error occured during zmq_bind(): %s\n", ZMQ_STRERROR); goto fail_close; } } /*subscribe for read*/ if (h->flags & AVIO_FLAG_READ) { s->socket = zmq_socket(s->context, ZMQ_SUB); if (!s->socket) { av_log(h, AV_LOG_ERROR, "Error occured during zmq_socket(): %s\n", ZMQ_STRERROR); goto fail_term; } ret = zmq_setsockopt(s->socket, ZMQ_SUBSCRIBE, "", 0); if (ret == -1) { av_log(h, AV_LOG_ERROR, "Error occured during zmq_setsockopt(): %s\n", ZMQ_STRERROR); goto fail_close; } ret = zmq_connect(s->socket, uri); if (ret == -1) { av_log(h, AV_LOG_ERROR, "Error occured during zmq_connect(): %s\n", ZMQ_STRERROR); goto fail_close; } } return 0; fail_close: zmq_close(s->socket); fail_term: zmq_ctx_term(s->context); return AVERROR_EXTERNAL; } static int zmq_proto_write(URLContext *h, const unsigned char *buf, int size) { int ret; ZMQContext *s = h->priv_data; ret = zmq_proto_wait_timeout(h, s->socket, 1, h->rw_timeout, &h->interrupt_callback); if (ret) return ret; ret = zmq_send(s->socket, buf, size, 0); if (ret == -1) { av_log(h, AV_LOG_ERROR, "Error occured during zmq_send(): %s\n", ZMQ_STRERROR); return AVERROR_EXTERNAL; } return ret; /*number of bytes sent*/ } static int zmq_proto_read(URLContext *h, unsigned char *buf, int size) { int ret; ZMQContext *s = h->priv_data; ret = zmq_proto_wait_timeout(h, s->socket, 0, h->rw_timeout, &h->interrupt_callback); if (ret) return ret; ret = zmq_recv(s->socket, buf, size, 0); if (ret == -1) { av_log(h, AV_LOG_ERROR, "Error occured during zmq_recv(): %s\n", ZMQ_STRERROR); return AVERROR_EXTERNAL; } if (ret > size) { s->pkt_size_overflow = FFMAX(s->pkt_size_overflow, ret); av_log(h, AV_LOG_WARNING, "Message exceeds available space in the buffer. Message will be truncated. Setting -pkt_size %d may resolve the issue.\n", s->pkt_size_overflow); ret = size; } return ret; /*number of bytes read*/ } static int zmq_proto_close(URLContext *h) { ZMQContext *s = h->priv_data; zmq_close(s->socket); zmq_ctx_term(s->context); return 0; } static const AVClass zmq_context_class = { .class_name = "zmq", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; const URLProtocol ff_libzmq_protocol = { .name = "zmq", .url_close = zmq_proto_close, .url_open = zmq_proto_open, .url_read = zmq_proto_read, .url_write = zmq_proto_write, .priv_data_size = sizeof(ZMQContext), .priv_data_class = &zmq_context_class, .flags = URL_PROTOCOL_FLAG_NETWORK, };