#include <sys/types.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <signal.h>
#include <unistd.h>
#include <assert.h>
#include <event2/event.h>
#include <event2/event_compat.h>
#include <event2/http.h>
#include <event2/event_struct.h>
#include "common.h"
#include "http.h"
#include "render_struct.h"
#include "render.h"
#include "remote_node.h"
#include "remote_pool.h"
// XXX: replace with a common one
#include "render_remote.h"
#include "render_multi.h"
#define MIN_CHUNK_SIZE 4096
#define OVERFLOW_BUFFER 4096
// do not do any userland socket output buffering
#define HTTP_BUFFER 0
// what event_base we're using
static struct event_base *ev_base;
// our render node pool
static struct remote_pool remote_pool;
// info on a render request
struct render_request {
struct evhttp_request *http_request;
int headers_sent;
struct render_remote *render_info;
size_t bytes_sent;
int paused;
};
// cb func prototypes
static void _render_http_written (struct evhttp_request *request, void *arg);
static void _render_cleanup (struct render_request *ctx) {
if (ctx->render_info)
render_remote_free(ctx->render_info);
free(ctx);
}
static void _render_sent (void *arg) {
struct render_request *ctx = arg;
// send headers
evhttp_add_header(evhttp_request_get_output_headers(ctx->http_request), "Content-Type", "image/png");
evhttp_send_reply_start(ctx->http_request, HTTP_OK, "OK");
// setup flow-control
evhttp_set_reply_notify(ctx->http_request, HTTP_BUFFER, &_render_http_written, ctx);
ctx->headers_sent = 1;
INFO("render [%p]: sent headers", ctx);
}
static void _render_data (struct evbuffer *buf, void *arg) {
struct render_request *ctx = arg;
size_t buf_size = EVBUFFER_LENGTH(buf);
assert(buf_size > 0); // shouldn't happen anymore with the new render_remote
// check if we are paused
if (ctx->paused) {
// we are waiting for the HTTP send buffer to clear, so keep the data in the render buffer
INFO("render [%p]: delaying data: %zu:%zu bytes", ctx, buf_size, ctx->bytes_sent);
return;
}
// move chunk to http buffers
evhttp_send_reply_chunk(ctx->http_request, buf);
INFO("render [%p]: enqueued chunk: %zu/%zu bytes", ctx, buf_size, ctx->bytes_sent);
// mark ourself as paused until httpd tells us to continue
ctx->paused = 1;
// keep a tally of total sent bytes
ctx->bytes_sent += buf_size;
}
static void _render_done (void *arg) {
struct render_request *ctx = arg;
// send end
evhttp_send_reply_end(ctx->http_request);
INFO("render [%p]: done: %zu bytes", ctx, ctx->bytes_sent);
// the request is now done, clean up
_render_cleanup(ctx);
}
static void _render_fail (void *arg) {
struct render_request *ctx = arg;
if (ctx->headers_sent) {
// just terminate the PNG stream where it is
evhttp_send_reply_end(ctx->http_request);
} else {
evhttp_send_error(ctx->http_request, 500, "Internal Server Error");
}
INFO("render [%p]: failed", ctx);
_render_cleanup(ctx);
}
static void _render_http_lost (struct evhttp_request *req, void *arg) {
struct render_request *ctx = arg;
INFO("render [%p]: lost http connection", ctx);
// cancel
render_remote_cancel(ctx->render_info);
ctx->render_info = NULL;
_render_cleanup(ctx);
}
static void _render_http_written (struct evhttp_request *request, void *arg) {
struct render_request *ctx = arg;
INFO("render [%p]: http available for write", ctx);
// unpause ourself
ctx->paused = 0;
// any data waiting in the buffer?
render_remote_flush(ctx->render_info);
}
static void _http_render_execute (struct evhttp_request *request, u_int32_t img_w, u_int32_t img_h) {
// render request context
struct render_request *ctx = calloc(1, sizeof(struct render_request));
if (!ctx)
ERROR("calloc");
ctx->http_request = request;
ctx->headers_sent = 0;
ctx->bytes_sent = 0;
// render context
struct render render;
if (
render_init(&render)
|| render_set_mode(&render, RENDER_PNG)
|| render_set_size(&render, img_w, img_h)
|| render_region_full(&render)
)
ERROR("render_*");
// initiate the remote render operation
if ((ctx->render_info = render_remote(&render, &remote_pool,
&_render_sent,
&_render_data,
&_render_done,
&_render_fail,
ctx
)) == NULL)
ERROR("render_remote");
// set chunk size
render_remote_set_recv(ctx->render_info, MIN_CHUNK_SIZE, OVERFLOW_BUFFER);
// set close cb
evhttp_set_reply_abortcb(request, &_render_http_lost, ctx);
INFO("render [%p]: started", ctx);
return;
error:
evhttp_send_error(request, 500, "Internal Server Error");
_render_cleanup(ctx);
}
/*
* HTTP request handler
*/
void http_render (struct evhttp_request *request, void *arg) {
// gather some info about the request
const char *uri = evhttp_request_get_uri(request);
char *peer_address;
u_short peer_port;
evhttp_request_get_peer(request, &peer_address, &peer_port);
unsigned long int img_w = 256, img_h = 256;
// parse request arguments
struct http_qarg qarg_spec[] = {
{ "w", QARG_UINT, &img_w },
{ "h", QARG_UINT, &img_h },
{ NULL, QARG_END, NULL }
};
http_qarg_parse(request, qarg_spec);
// request log
INFO("REQ: [%s:%d] method=%d, uri=%s, img_w=%lu, img_h=%lu", peer_address, peer_port, evhttp_request_get_type(request), uri, img_w, img_h);
// do it
_http_render_execute(request, img_w, img_h);
}
struct event ev_sigint;
void sigint_handler (int signal, short event, void *arg) {
INFO("SIGINT: shutting down");
if (event_base_loopexit(ev_base, NULL))
err_exit("event_loopexit");
}
void signals_init () {
// handle SIGINT
signal_set(&ev_sigint, SIGINT, &sigint_handler, NULL);
signal_add(&ev_sigint, NULL);
// ignore SIGPIPE
struct sigaction sigpipe;
memset(&sigpipe, 0, sizeof(sigpipe));
sigpipe.sa_handler = SIG_IGN;
sigaction(SIGPIPE, &sigpipe, NULL);
}
void signals_deinit () {
signal_del(&ev_sigint);
}
void log_null (int severity, const char *msg) {
// ignore
}
int main (int argc, char **argv) {
// libevent init
ev_base = event_init();
if (!ev_base)
FATAL("event_init");
// set up our render node pool
remote_pool_init(&remote_pool);
// process arguments
int opt;
int enable_debug = 0;
char *host, *port;
while ((opt = getopt(argc, argv, "dp:r:")) != -1) {
switch (opt) {
case 'p':
// populate the pool from a file
if (remote_pool_load(&remote_pool, optarg))
return 1;
break;
case 'r':
// add the given render node to the pool
if (
parse_hostport(optarg, &host, &port)
|| remote_pool_add(&remote_pool, host, port)
)
return 1;
break;
case 'd':
// enable libevent debugging
enable_debug = 1;
break;
default:
err_exit("Usage: %s [-d] (-p pool_file | -r hostname[:port] | ...)", argv[0]);
}
}
int pool_size = remote_pool_size(&remote_pool);
if (!pool_size)
FATAL("No remote render nodes given");
INFO("Registered %d render nodes in our pool", pool_size);
// per default it is enabled
if (!enable_debug)
event_set_log_callback(&log_null);
// handle signals
signals_init();
// evhttp init
struct evhttp *http_server = evhttp_new(ev_base);
if (!http_server)
FATAL("evhttp_new");
// bind to the correct interface/port
if (evhttp_bind_socket(http_server, "0.0.0.0", 8117))
FATAL("evhttp_bind_socket");
// add our http request handler
evhttp_set_cb(http_server, "/render", &http_render, NULL);
// we shall now run
INFO("RUN 0.0.0.0:8117");
// run the libevent mainloop
if (event_base_dispatch(ev_base))
WARNING("event_dispatch");
INFO("SHUTDOWN");
// clean up
signals_deinit();
evhttp_free(http_server);
event_base_free(ev_base);
// successfull exit
return 0;
}