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authorDaniel Stenberg <daniel@haxx.se>2015-06-02 11:04:00 +0200
committerDaniel Stenberg <daniel@haxx.se>2015-06-24 23:44:42 +0200
commitbf445b6e12f0a01959edbb3ca6fb548837289718 (patch)
tree166a514f9801c8d72c1979b7175aa10ac50b3136 /docs
parenta3a55d80ecc7cb44239b774a6a1d37adc6bf2fc8 (diff)
http2-serverpush.c: example code
Diffstat (limited to 'docs')
-rw-r--r--docs/examples/Makefile.inc2
-rw-r--r--docs/examples/http2-serverpush.c313
2 files changed, 314 insertions, 1 deletions
diff --git a/docs/examples/Makefile.inc b/docs/examples/Makefile.inc
index 4b0c28ff4..b2161300b 100644
--- a/docs/examples/Makefile.inc
+++ b/docs/examples/Makefile.inc
@@ -32,7 +32,7 @@ check_PROGRAMS = 10-at-a-time anyauthput cookie_interface debug fileupload \
imap-list imap-lsub imap-fetch imap-store imap-append imap-examine \
imap-search imap-create imap-delete imap-copy imap-noop imap-ssl \
imap-tls imap-multi url2file sftpget ftpsget postinmemory http2-download \
- http2-upload
+ http2-upload http2-serverpush
# These examples require external dependencies that may not be commonly
# available on POSIX systems, so don't bother attempting to compile them here.
diff --git a/docs/examples/http2-serverpush.c b/docs/examples/http2-serverpush.c
new file mode 100644
index 000000000..cc5bf3037
--- /dev/null
+++ b/docs/examples/http2-serverpush.c
@@ -0,0 +1,313 @@
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+#include <stdio.h>
+#include <stdlib.h>
+
+/* somewhat unix-specific */
+#include <sys/time.h>
+#include <unistd.h>
+
+/* curl stuff */
+#include <curl/curl.h>
+
+#ifndef CURLPIPE_MULTIPLEX
+#error "too old libcurl, can't do HTTP/2 server push!"
+#endif
+
+static
+void dump(const char *text, unsigned char *ptr, size_t size,
+ char nohex)
+{
+ size_t i;
+ size_t c;
+
+ unsigned int width=0x10;
+
+ if(nohex)
+ /* without the hex output, we can fit more on screen */
+ width = 0x40;
+
+ fprintf(stderr, "%s, %ld bytes (0x%lx)\n",
+ text, (long)size, (long)size);
+
+ for(i=0; i<size; i+= width) {
+
+ fprintf(stderr, "%4.4lx: ", (long)i);
+
+ if(!nohex) {
+ /* hex not disabled, show it */
+ for(c = 0; c < width; c++)
+ if(i+c < size)
+ fprintf(stderr, "%02x ", ptr[i+c]);
+ else
+ fputs(" ", stderr);
+ }
+
+ for(c = 0; (c < width) && (i+c < size); c++) {
+ /* check for 0D0A; if found, skip past and start a new line of output */
+ if (nohex && (i+c+1 < size) && ptr[i+c]==0x0D && ptr[i+c+1]==0x0A) {
+ i+=(c+2-width);
+ break;
+ }
+ fprintf(stderr, "%c",
+ (ptr[i+c]>=0x20) && (ptr[i+c]<0x80)?ptr[i+c]:'.');
+ /* check again for 0D0A, to avoid an extra \n if it's at width */
+ if (nohex && (i+c+2 < size) && ptr[i+c+1]==0x0D && ptr[i+c+2]==0x0A) {
+ i+=(c+3-width);
+ break;
+ }
+ }
+ fputc('\n', stderr); /* newline */
+ }
+}
+
+static
+int my_trace(CURL *handle, curl_infotype type,
+ char *data, size_t size,
+ void *userp)
+{
+ const char *text;
+ (void)handle; /* prevent compiler warning */
+ (void)userp;
+ switch (type) {
+ case CURLINFO_TEXT:
+ fprintf(stderr, "== Info: %s", data);
+ default: /* in case a new one is introduced to shock us */
+ return 0;
+
+ case CURLINFO_HEADER_OUT:
+ text = "=> Send header";
+ break;
+ case CURLINFO_DATA_OUT:
+ text = "=> Send data";
+ break;
+ case CURLINFO_SSL_DATA_OUT:
+ text = "=> Send SSL data";
+ break;
+ case CURLINFO_HEADER_IN:
+ text = "<= Recv header";
+ break;
+ case CURLINFO_DATA_IN:
+ text = "<= Recv data";
+ break;
+ case CURLINFO_SSL_DATA_IN:
+ text = "<= Recv SSL data";
+ break;
+ }
+
+ dump(text, (unsigned char *)data, size, 1);
+ return 0;
+}
+
+static void setup(CURL *hnd)
+{
+ FILE *out = fopen("dl", "wb");
+
+ /* write to this file */
+ curl_easy_setopt(hnd, CURLOPT_WRITEDATA, out);
+
+ /* set the same URL */
+ curl_easy_setopt(hnd, CURLOPT_URL, "https://localhost:8443/index.html");
+
+ /* send it verbose for max debuggaility */
+ curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
+ curl_easy_setopt(hnd, CURLOPT_DEBUGFUNCTION, my_trace);
+
+ /* HTTP/2 please */
+ curl_easy_setopt(hnd, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
+
+ /* we use a self-signed test server, skip verification during debugging */
+ curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYPEER, 0L);
+ curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYHOST, 0L);
+
+#if (CURLPIPE_MULTIPLEX > 0)
+ /* wait for pipe connection to confirm */
+ curl_easy_setopt(hnd, CURLOPT_PIPEWAIT, 1L);
+#endif
+
+}
+
+/* called when there's an incoming push */
+static int server_push_callback(CURL *parent,
+ CURL *easy,
+ size_t num_headers,
+ struct curl_pushheaders *headers,
+ void *userp)
+{
+ char *headp;
+ size_t i;
+ int *transfers = (int *)userp;
+ char filename[128];
+ FILE *out;
+ static unsigned int count = 0;
+
+ (void)parent; /* we have no use for this */
+
+ sprintf(filename, "push%u", count++);
+
+ /* here's a new stream, save it in a new file for each new push */
+ out = fopen(filename, "wb");
+
+ /* write to this file */
+ curl_easy_setopt(easy, CURLOPT_WRITEDATA, out);
+
+ fprintf(stderr, "**** push callback approves stream %u, got %d headers!\n",
+ count, (int)num_headers);
+
+ for(i=0; i<num_headers; i++) {
+ headp = curl_pushheader_bynum(headers, i);
+ fprintf(stderr, "**** header %u: %s\n", (int)i, headp);
+ }
+
+ headp = curl_pushheader_byname(headers, ":path");
+ if(headp) {
+ fprintf(stderr, "**** The PATH is %s\n", headp /* skip :path + colon */ );
+ }
+
+ (*transfers)++; /* one more */
+ return CURL_PUSH_OK;
+}
+
+
+/*
+ * Download a file over HTTP/2, take care of server push.
+ */
+int main(void)
+{
+ CURL *easy;
+ CURLM *multi_handle;
+ int still_running; /* keep number of running handles */
+ int transfers=1; /* we start with one */
+ struct CURLMsg *m;
+
+ /* init a multi stack */
+ multi_handle = curl_multi_init();
+
+ easy = curl_easy_init();
+
+ /* set options */
+ setup(easy);
+
+ /* add the easy transfer */
+ curl_multi_add_handle(multi_handle, easy);
+
+ curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
+ curl_multi_setopt(multi_handle, CURLMOPT_PUSHFUNCTION, server_push_callback);
+ curl_multi_setopt(multi_handle, CURLMOPT_PUSHDATA, &transfers);
+
+ /* we start some action by calling perform right away */
+ curl_multi_perform(multi_handle, &still_running);
+
+ do {
+ struct timeval timeout;
+ int rc; /* select() return code */
+ CURLMcode mc; /* curl_multi_fdset() return code */
+
+ fd_set fdread;
+ fd_set fdwrite;
+ fd_set fdexcep;
+ int maxfd = -1;
+
+ long curl_timeo = -1;
+
+ FD_ZERO(&fdread);
+ FD_ZERO(&fdwrite);
+ FD_ZERO(&fdexcep);
+
+ /* set a suitable timeout to play around with */
+ timeout.tv_sec = 1;
+ timeout.tv_usec = 0;
+
+ curl_multi_timeout(multi_handle, &curl_timeo);
+ if(curl_timeo >= 0) {
+ timeout.tv_sec = curl_timeo / 1000;
+ if(timeout.tv_sec > 1)
+ timeout.tv_sec = 1;
+ else
+ timeout.tv_usec = (curl_timeo % 1000) * 1000;
+ }
+
+ /* get file descriptors from the transfers */
+ mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
+
+ if(mc != CURLM_OK) {
+ fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
+ break;
+ }
+
+ /* On success the value of maxfd is guaranteed to be >= -1. We call
+ select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
+ no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
+ to sleep 100ms, which is the minimum suggested value in the
+ curl_multi_fdset() doc. */
+
+ if(maxfd == -1) {
+#ifdef _WIN32
+ Sleep(100);
+ rc = 0;
+#else
+ /* Portable sleep for platforms other than Windows. */
+ struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
+ rc = select(0, NULL, NULL, NULL, &wait);
+#endif
+ }
+ else {
+ /* Note that on some platforms 'timeout' may be modified by select().
+ If you need access to the original value save a copy beforehand. */
+ rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);
+ }
+
+ switch(rc) {
+ case -1:
+ /* select error */
+ break;
+ case 0:
+ default:
+ /* timeout or readable/writable sockets */
+ curl_multi_perform(multi_handle, &still_running);
+ break;
+ }
+
+ /*
+ * A little caution when doing server push is that libcurl itself has
+ * created and added one or more easy handles but we need to clean them up
+ * when we are done.
+ */
+
+ do {
+ int msgq = 0;;
+ m = curl_multi_info_read(multi_handle, &msgq);
+ if(m && (m->msg == CURLMSG_DONE)) {
+ CURL *e = m->easy_handle;
+ transfers--;
+ curl_multi_remove_handle(multi_handle, e);
+ curl_easy_cleanup(e);
+ }
+ } while(m);
+
+ } while(transfers); /* as long as we have transfers going */
+
+ curl_multi_cleanup(multi_handle);
+
+
+ return 0;
+}