stv0g/libwebsockets
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

http service break into outer loop states

Browse source 
Previously we sat and looped to dump a file over http protocol.

Actually that's a source of blocking to the other sockets being serviced.

This patch breaks up the file service into a roundtrip around the poll()
loop for each 512-byte packet.  It doesn't make much difference if the
server is idle, but if it's busy it makes sure everyone else is getting
service while the file is sent.

It doesn't try to optimize multiple users of the file or to keep the
descriptor open, the point of this patch is to establish the breaking up
of the file send action into the poll loop.

On the user side, there are two differences:

 - context is now needed in the first argument to libwebsockets_serve_http_file()
that's not too bad since we provide context in the callback.

 - file send is now asynchronous to the user code, you get a new callback coming
in protocol 0 when it's done, LWS_CALLBACK_HTTP_FILE_COMPLETION

libwebsockets-test-server is updated accordingly.

Signed-off-by: Andy Green <andy.green@linaro.org>
This commit is contained in:
Andy Green 2013-01-15 13:40:23 +08:00
parent a50dd1af40
commit d280b6ecb3
7 changed files with 157 additions and 24 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
lib/handshake.c
View file

@ -549,6 +549,7 @@ libwebsocket_read(struct libwebsocket_context *context,
size_t n;
switch (wsi->state) {
case WSI_STATE_HTTP_ISSUING_FILE:
case WSI_STATE_HTTP:
wsi->state = WSI_STATE_HTTP_HEADERS;
wsi->parser_state = WSI_TOKEN_NAME_PART;
@ -692,6 +693,8 @@ libwebsocket_read(struct libwebsocket_context *context,
goto bail;
}
wsi->mode = LWS_CONNMODE_WS_SERVING;
lwsl_parser("accepted v%02d connection\n",
wsi->ietf_spec_revision);
@ -717,6 +720,7 @@ libwebsocket_read(struct libwebsocket_context *context,
break;
default:
lwsl_err("libwebsocket_read: Unhandled state\n");
break;
}

64
lib/libwebsockets.c
View file

@ -770,7 +770,7 @@ libwebsocket_create_new_server_wsi(struct libwebsocket_context *context)
new_wsi->state = WSI_STATE_HTTP;
new_wsi->name_buffer_pos = 0;
new_wsi->mode = LWS_CONNMODE_WS_SERVING;
new_wsi->mode = LWS_CONNMODE_HTTP_SERVING;
for (n = 0; n < WSI_TOKEN_COUNT; n++) {
new_wsi->utf8_token[n].token = NULL;
@ -1536,10 +1536,68 @@ libwebsocket_service_fd(struct libwebsocket_context *context,
wsi = wsi_from_fd(context, pollfd->fd);
if (wsi == NULL)
if (wsi == NULL) {
lwsl_debug("hm fd %d has NULL wsi\n", pollfd->fd);
return 0;
}
switch (wsi->mode) {
case LWS_CONNMODE_HTTP_SERVING:
/* handle http headers coming in */
/* any incoming data ready? */
if (pollfd->revents & POLLIN) {
#ifdef LWS_OPENSSL_SUPPORT
if (wsi->ssl)
len = SSL_read(wsi->ssl, buf, sizeof buf);
else
#endif
len = recv(pollfd->fd, buf, sizeof buf, 0);
if (len < 0) {
lwsl_debug("Socket read returned %d\n", len);
if (errno != EINTR && errno != EAGAIN)
libwebsocket_close_and_free_session(context,
wsi, LWS_CLOSE_STATUS_NOSTATUS);
return 1;
}
if (!len) {
libwebsocket_close_and_free_session(context, wsi,
LWS_CLOSE_STATUS_NOSTATUS);
return 0;
}
n = libwebsocket_read(context, wsi, buf, len);
if (n < 0)
/* we closed wsi */
return 1;
}
/* this handles POLLOUT for http serving fragments */
if (!(pollfd->revents & POLLOUT))
break;
/* one shot */
pollfd->events &= ~POLLOUT;
if (wsi->state != WSI_STATE_HTTP_ISSUING_FILE)
break;
if (libwebsockets_serve_http_file_fragment(context, wsi) < 0)
libwebsocket_close_and_free_session(context, wsi,
LWS_CLOSE_STATUS_NOSTATUS);
else
if (wsi->state == WSI_STATE_HTTP && wsi->protocol->callback)
if (wsi->protocol->callback(context, wsi, LWS_CALLBACK_HTTP_FILE_COMPLETION, wsi->user_space,
wsi->filepath, wsi->filepos))
libwebsocket_close_and_free_session(context, wsi, LWS_CLOSE_STATUS_NOSTATUS);
break;
case LWS_CONNMODE_SERVER_LISTENER:
/* pollin means a client has connected to us then */
@ -2258,6 +2316,8 @@ libwebsocket_service(struct libwebsocket_context *context, int timeout_ms)
if (n == 0) /* poll timeout */
return 0;
if (n < 0) {
/*
lwsl_err("Listen Socket dead\n");

10
lib/libwebsockets.h
View file

@ -92,6 +92,7 @@ enum libwebsocket_callback_reasons {
LWS_CALLBACK_CLIENT_WRITEABLE,
LWS_CALLBACK_SERVER_WRITEABLE,
LWS_CALLBACK_HTTP,
LWS_CALLBACK_HTTP_FILE_COMPLETION,
LWS_CALLBACK_BROADCAST,
LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION,
@ -378,6 +379,9 @@ struct libwebsocket_extension;
* total number of client connections allowed set
* by MAX_CLIENTS.
*
* LWS_CALLBACK_HTTP_FILE_COMPLETION: a file requested to be send down
* http link has completed.
*
* LWS_CALLBACK_CLIENT_WRITEABLE:
* LWS_CALLBACK_SERVER_WRITEABLE: If you call
* libwebsocket_callback_on_writable() on a connection, you will
@ -730,8 +734,12 @@ libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf, size_t len,
enum libwebsocket_write_protocol protocol);
LWS_EXTERN int
libwebsockets_serve_http_file(struct libwebsocket *wsi, const char *file,
libwebsockets_serve_http_file(struct libwebsocket_context *context,
struct libwebsocket *wsi, const char *file,
const char *content_type);
LWS_EXTERN int
libwebsockets_serve_http_file_fragment(struct libwebsocket_context *context,
struct libwebsocket *wsi);
/* notice - you need the pre- and post- padding allocation for buf below */

61
lib/parsers.c
View file

@ -1988,19 +1988,22 @@ send_raw:
* local files down the http link in a single step.
*/
int libwebsockets_serve_http_file(struct libwebsocket *wsi, const char *file,
int libwebsockets_serve_http_file(struct libwebsocket_context *context,
struct libwebsocket *wsi, const char *file,
const char *content_type)
{
int fd;
struct stat stat_buf;
char buf[512];
char *p = buf;
int n;
strncpy(wsi->filepath, file, sizeof wsi->filepath);
wsi->filepath[sizeof(wsi->filepath) - 1] = '\0';
#ifdef WIN32
fd = open(file, O_RDONLY | _O_BINARY);
fd = open(wsi->filepath, O_RDONLY | _O_BINARY);
#else
fd = open(file, O_RDONLY);
fd = open(wsi->filepath, O_RDONLY);
#endif
if (fd < 1) {
p += sprintf(p, "HTTP/1.0 400 Bad\x0d\x0a"
@ -2014,6 +2017,7 @@ int libwebsockets_serve_http_file(struct libwebsocket *wsi, const char *file,
}
fstat(fd, &stat_buf);
wsi->filelen = stat_buf.st_size;
p += sprintf(p, "HTTP/1.0 200 OK\x0d\x0a"
"Server: libwebsockets\x0d\x0a"
"Content-Type: %s\x0d\x0a"
@ -2023,20 +2027,53 @@ int libwebsockets_serve_http_file(struct libwebsocket *wsi, const char *file,
libwebsocket_write(wsi, (unsigned char *)buf, p - buf, LWS_WRITE_HTTP);
n = 1;
while (n > 0) {
n = read(fd, buf, 512);
if (n <= 0)
continue;
libwebsocket_write(wsi, (unsigned char *)buf, n,
LWS_WRITE_HTTP);
}
wsi->filepos = 0;
libwebsocket_callback_on_writable(context, wsi);
wsi->state = WSI_STATE_HTTP_ISSUING_FILE;
close(fd);
return 0;
}
int libwebsockets_serve_http_file_fragment(struct libwebsocket_context *context,
struct libwebsocket *wsi)
{
int fd;
int ret = 0;
char buf[512];
int n;
#ifdef WIN32
fd = open(wsi->filepath, O_RDONLY | _O_BINARY);
#else
fd = open(wsi->filepath, O_RDONLY);
#endif
if (fd < 1)
return -1;
lseek(fd, wsi->filepos, SEEK_SET);
n = read(fd, buf, 512);
if (n > 0) {
libwebsocket_write(wsi, (unsigned char *)buf, n, LWS_WRITE_HTTP);
wsi->filepos += n;
}
if (n < 0)
ret = -1;
if (n < 512 || wsi->filepos == wsi->filelen)
wsi->state = WSI_STATE_HTTP;
else
if (!ret)
libwebsocket_callback_on_writable(context, wsi);
close(fd);
return ret;
}
/**
* libwebsockets_remaining_packet_payload() - Bytes to come before "overall"

8
lib/private-libwebsockets.h
View file

@ -203,6 +203,7 @@ enum lws_websocket_opcodes_07 {
enum lws_connection_states {
WSI_STATE_HTTP,
WSI_STATE_HTTP_ISSUING_FILE,
WSI_STATE_HTTP_HEADERS,
WSI_STATE_DEAD_SOCKET,
WSI_STATE_ESTABLISHED,
@ -245,6 +246,8 @@ enum lws_rx_parse_state {
enum connection_mode {
LWS_CONNMODE_HTTP_SERVING,
LWS_CONNMODE_WS_SERVING,
LWS_CONNMODE_WS_CLIENT,
@ -385,6 +388,11 @@ struct libwebsocket {
int use_ssl;
#endif
/* http send file */
char filepath[PATH_MAX];
unsigned long filepos;
unsigned long filelen;
void *user_space;
};

8
libwebsockets-api-doc.html
View file

@ -411,7 +411,8 @@ packet while not burdening the user code with any protocol knowledge.
<h2>libwebsockets_serve_http_file - Send a file back to the client using http</h2>
<i>int</i>
<b>libwebsockets_serve_http_file</b>
(<i>struct libwebsocket *</i> <b>wsi</b>,
(<i>struct libwebsocket_context *</i> <b>context</b>,
<i>struct libwebsocket *</i> <b>wsi</b>,
<i>const char *</i> <b>file</b>,
<i>const char *</i> <b>content_type</b>)
<h3>Arguments</h3>
@ -638,6 +639,11 @@ That's important because it uses a slot in the
total number of client connections allowed set
by MAX_CLIENTS.
</blockquote>
<h3>LWS_CALLBACK_HTTP_FILE_COMPLETION</h3>
<blockquote>
a file requested to be send down
http link has completed.
</blockquote>
<h3>LWS_CALLBACK_SERVER_WRITEABLE</h3>
<blockquote>
If you call

26
test-server/test-server.c
View file

@ -85,10 +85,10 @@ static int callback_http(struct libwebsocket_context *context,
switch (reason) {
case LWS_CALLBACK_HTTP:
fprintf(stderr, "serving HTTP URI %s\n", (char *)in);
// fprintf(stderr, "serving HTTP URI %s\n", (char *)in);
if (in && strcmp(in, "/favicon.ico") == 0) {
if (libwebsockets_serve_http_file(wsi,
if (libwebsockets_serve_http_file(context, wsi,
LOCAL_RESOURCE_PATH"/favicon.ico", "image/x-icon"))
fprintf(stderr, "Failed to send favicon\n");
break;
@ -96,11 +96,21 @@ static int callback_http(struct libwebsocket_context *context,
/* send the script... when it runs it'll start websockets */
if (libwebsockets_serve_http_file(wsi,
if (libwebsockets_serve_http_file(context, wsi,
LOCAL_RESOURCE_PATH"/test.html", "text/html"))
fprintf(stderr, "Failed to send HTTP file\n");
/* we are done with this http connection */
/*
* notice that the sending of the file completes asynchronously,
* we'll get a LWS_CALLBACK_HTTP_FILE_COMPLETION callback when
* it's done
*/
return 0;
case LWS_CALLBACK_HTTP_FILE_COMPLETION:
// fprintf(stderr, "LWS_CALLBACK_HTTP_FILE_COMPLETION seen\n");
/* kill the connection after we sent one file */
return 1;
/*
@ -116,8 +126,8 @@ static int callback_http(struct libwebsocket_context *context,
libwebsockets_get_peer_addresses((int)(long)user, client_name,
sizeof(client_name), client_ip, sizeof(client_ip));
fprintf(stderr, "Received network connect from %s (%s)\n",
client_name, client_ip);
// fprintf(stderr, "Received network connect from %s (%s)\n",
// client_name, client_ip);
/* if we returned non-zero from here, we kill the connection */
break;
@ -573,6 +583,7 @@ int main(int argc, char **argv)
if (n < 0)
continue;
if (n)
for (n = 0; n < count_pollfds; n++)
if (pollfds[n].revents)
@ -584,13 +595,12 @@ int main(int argc, char **argv)
if (libwebsocket_service_fd(context,
&pollfds[n]) < 0)
goto done;
#else
n = libwebsocket_service(context, 50);
#endif
}
#else
#else /* !LWS_NO_FORK */
/*
* This example shows how to work with the forked websocket service loop