hiperfifo.c by Jeff Pohlmeyer

docs/examples/Makefile.am

@@ -11,7 +11,8 @@ EXTRA_DIST = README curlgtk.c sepheaders.c simple.c postit2.c		\
  multi-post.c fopen.c simplepost.c makefile.dj curlx.c https.c		\
  multi-debugcallback.c fileupload.c getinfo.c ftp3rdparty.c debug.c	\
  anyauthput.c htmltitle.cc htmltidy.c opensslthreadlock.c		\
- cookie_interface.c cacertinmem.c synctime.c sampleconv.c ftpuploadresume.c
+ cookie_interface.c cacertinmem.c synctime.c sampleconv.c ftpuploadresume.c \
+ 10-at-a-time.c hiperfifo.c
 
 all:
 	@echo "done"

docs/examples/README

@@ -26,9 +26,9 @@ want you do reorganize them like:
   $ `curl-config --cc` -o example example.c `curl-config --cflags --libs`
 
 *PLEASE* do not use the curl.haxx.se site as a test target for your libcurl
-applications/experiments. Even if the examples in this directory use that site
+applications/experiments. Even if some of the examples use that site as a URL
-as an example URL at some places, it doesn't mean that the URLs work or that
+at some places, it doesn't mean that the URLs work or that we expect you to
-we expect you to actually torture our web site with your tests! Thanks.
+actually torture our web site with your tests!  Thanks.
 
 EXAMPLES
 
@@ -43,9 +43,11 @@ fopen.c        - fopen() layer that supports opening URLs and files
 ftp3rdparty.c  - FTP 3rd party transfer
 ftpget.c       - simple getting a file from FTP
 ftpgetresp.c   - get the response strings from the FTP server
-ftpupload.c    - upload a file to a FTP server
+ftpupload.c    - upload a file to an FTP server
+ftpuploadresume.c - resume an upload to an FTP server
 getinfo.c      - get the Content-Type from the recent transfer
 getinmemory.c  - download a file to memory only
+hiperfifo.c    - downloads all URLs written to the fifo
 htmltitle.cc   - download a HTML file and extract the <title> tag from a HTML
                  page using libxml
 http-post.c    - HTTP POST
@@ -61,8 +63,12 @@ opensslthreadlock.c - show how to do locking when using OpenSSL multi-threaded
 persistant.c   - request two URLs with a persistant connection
 post-callback.c - send a HTTP POST using a callback
 postit2.c      - send a HTTP multipart formpost
+sampleconv.c   - showing how a program on a non-ASCII platform would invoke
+                 callbacks to do its own codeset conversions instead of using
+                 the built-in iconv functions in libcurl
 sepheaders.c   - download headers to a separate file
 simple.c       - the most simple download a URL source
 simplepost.c   - HTTP POST
 simplessl.c    - HTTPS example with certificates many options set
 synctime.c     - Sync local time by extracing date from remote HTTP servers
+10-at-a-time.c - Download many files simultaneously, 10 at a time.

docs/examples/hiperfifo.c

@@ -0,0 +1,412 @@
+/*****************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * $Id$
+ *
+ * Example application source code using the multi socket interface to
+ * download many files at once.
+ *
+ * Written by Jeff Pohlmeyer
+
+Requires libevent and a (POSIX?) system that has mkfifo().
+
+This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c"
+sample programs.
+
+When running, the program creates the named pipe "hiper.fifo"
+
+Whenever there is input into the fifo, the program reads the input as a list
+of URL's and creates some new easy handles to fetch each URL via the
+curl_multi "hiper" API.
+
+
+Thus, you can try a single URL:
+  % echo http://www.yahoo.com > hiper.fifo
+
+Or a whole bunch of them:
+  % cat my-url-list > hiper.fifo
+
+The fifo buffer is handled almost instantly, so you can even add more URL's
+while the previous requests are still being downloaded.
+
+Note:
+  For the sake of simplicity, URL length is limited to 1023 char's !
+
+This is purely a demo app, all retrieved data is simply discarded by the write
+callback.
+
+*/
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/poll.h>
+#include <curl/curl.h>
+#include <event.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+
+#define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */
+
+
+/* Global information, common to all connections */
+typedef struct _GlobalInfo {
+  struct event fifo_event;
+  struct event timer_event;
+  CURLM *multi;
+  int prev_running;
+  int still_running;
+  FILE* input;
+} GlobalInfo;
+
+
+/* Information associated with a specific easy handle */
+typedef struct _ConnInfo {
+  CURL *easy;
+  char *url;
+  GlobalInfo *global;
+  char error[CURL_ERROR_SIZE];
+} ConnInfo;
+
+
+/* Information associated with a specific socket */
+typedef struct _SockInfo {
+  curl_socket_t sockfd;
+  CURL *easy;
+  int action;
+  long timeout;
+  struct event ev;
+  int evset;
+  GlobalInfo *global;
+} SockInfo;
+
+
+
+/* Update the event timer after curl_multi library calls */
+static void update_timeout(GlobalInfo *g)
+{
+  long timeout_ms;
+  struct timeval timeout;
+
+  curl_multi_timeout(g->multi, &timeout_ms);
+  timeout.tv_sec = timeout_ms/1000;
+  timeout.tv_usec = (timeout_ms%1000)*1000;
+  evtimer_add(&g->timer_event, &timeout);
+}
+
+
+
+/* Die if we get a bad CURLMcode somewhere */
+void mcode_or_die(char *where, CURLMcode code) {
+  if ( CURLM_OK != code ) {
+    char *s;
+    switch (code) {
+      case     CURLM_CALL_MULTI_PERFORM: s="CURLM_CALL_MULTI_PERFORM"; break;
+      case     CURLM_OK:                 s="CURLM_OK";                 break;
+      case     CURLM_BAD_HANDLE:         s="CURLM_BAD_HANDLE";         break;
+      case     CURLM_BAD_EASY_HANDLE:    s="CURLM_BAD_EASY_HANDLE";    break;
+      case     CURLM_OUT_OF_MEMORY:      s="CURLM_OUT_OF_MEMORY";      break;
+      case     CURLM_INTERNAL_ERROR:     s="CURLM_INTERNAL_ERROR";     break;
+      case     CURLM_BAD_SOCKET:         s="CURLM_BAD_SOCKET";         break;
+      case     CURLM_UNKNOWN_OPTION:     s="CURLM_UNKNOWN_OPTION";     break;
+      case     CURLM_LAST:               s="CURLM_LAST";               break;
+      default: s="CURLM_unknown";
+    }
+    fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
+    exit(code);
+  }
+}
+
+
+
+/* Check for completed transfers, and remove their easy handles */
+static void check_run_count(GlobalInfo *g)
+{
+  if (g->prev_running > g->still_running) {
+    char *eff_url=NULL;
+    CURLMsg *msg;
+    int msgs_left;
+    ConnInfo *conn=NULL;
+    CURL*easy;
+    CURLcode res;
+
+    fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running);
+    /*
+      I am still uncertain whether it is safe to remove an easy handle
+      from inside the curl_multi_info_read loop, so here I will search
+      for completed transfers in the inner "while" loop, and then remove
+      them in the outer "do-while" loop...
+   */
+    do {
+      easy=NULL;
+      while ((msg = curl_multi_info_read(g->multi, &msgs_left))) {
+        if (msg->msg == CURLMSG_DONE) {
+          easy=msg->easy_handle;
+          res=msg->data.result;
+        }
+      }
+      if (easy) {
+          curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
+          curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
+          fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error);
+          curl_multi_remove_handle(g->multi, easy);
+          free(conn->url);
+          curl_easy_cleanup(easy);
+          free(conn);
+      }
+    } while ( easy );
+  }
+  g->prev_running = g->still_running;
+}
+
+
+
+/* Called by libevent when we get action on a multi socket */
+static void event_cb(int fd, short kind, void *userp)
+{
+  GlobalInfo *g = (GlobalInfo*) userp;
+  CURLMcode rc;
+
+  do {
+    rc = curl_multi_socket(g->multi, fd, &g->still_running);
+  } while (rc == CURLM_CALL_MULTI_PERFORM);
+  mcode_or_die("event_cb: curl_multi_socket", rc);
+  check_run_count(g);
+  if(g->still_running) {
+    update_timeout(g);
+  } else {
+    fprintf(MSG_OUT, "last transfer done, kill timeout\n");
+    if (evtimer_pending(&g->timer_event, NULL)) {
+      evtimer_del(&g->timer_event);
+    }
+  }
+}
+
+
+
+/* Called by libevent when our timeout expires */
+static void timer_cb(int fd, short kind, void *userp)
+{
+  (void)fd;
+  (void)kind;
+  GlobalInfo *g = (GlobalInfo *)userp;
+  CURLMcode rc;
+
+  do {
+    rc = curl_multi_socket(g->multi, CURL_SOCKET_TIMEOUT, &g->still_running);
+  } while (rc == CURLM_CALL_MULTI_PERFORM);
+  mcode_or_die("timer_cb: curl_multi_socket", rc);
+  check_run_count(g);
+  if ( g->still_running ) { update_timeout(g); }
+}
+
+
+
+/* Clean up the SockInfo structure */
+static void remsock(SockInfo *f)
+{
+  if (!f) { return; }
+  if (f->evset) { event_del(&f->ev); }
+  free(f);
+}
+
+
+
+/* Assign information to a SockInfo structure */
+static void setsock(SockInfo*f, curl_socket_t s, CURL*e, int act, GlobalInfo*g)
+{
+  int kind =
+     (act&CURL_POLL_IN?EV_READ:0)|(act&CURL_POLL_OUT?EV_WRITE:0)|EV_PERSIST;
+
+  f->sockfd = s;
+  f->action = act;
+  f->easy = e;
+  if (f->evset) { event_del(&f->ev); }
+  event_set( &f->ev, f->sockfd, kind, event_cb, g);
+  f->evset=1;
+  event_add(&f->ev, NULL);
+}
+
+
+
+/* Initialize a new SockInfo structure */
+static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g) {
+  SockInfo *fdp = calloc(sizeof(SockInfo), 1);
+
+  fdp->global = g;
+  setsock(fdp, s, easy, action, g);
+  curl_multi_assign(g->multi, s, fdp);
+}
+
+
+
+/* CURLMOPT_SOCKETFUNCTION */
+static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
+{
+  GlobalInfo *g = (GlobalInfo*) cbp;
+  SockInfo *fdp = (SockInfo*) sockp;
+  char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE" };
+
+  fprintf(MSG_OUT,
+          "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
+  if (what == CURL_POLL_REMOVE) {
+    fprintf(MSG_OUT, "\n");
+    remsock(fdp);
+  } else {
+    if (!fdp) {
+      fprintf(MSG_OUT, "Adding data: %s%s\n",
+             what&CURL_POLL_IN?"READ":"",
+             what&CURL_POLL_OUT?"WRITE":"" );
+      addsock(s, e, what, g);
+    }
+    else {
+      fprintf(MSG_OUT,
+        "Changing action from %d to %d\n", fdp->action, what);
+      setsock(fdp, s, e, what, g);
+    }
+  }
+  return 0;
+}
+
+
+
+/* CURLOPT_WRITEFUNCTION */
+static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data)
+{
+  size_t realsize = size * nmemb;
+  ConnInfo *conn = (ConnInfo*) data;
+  (void)ptr;
+  (void)conn;
+  return realsize;
+}
+
+
+/* CURLOPT_PROGRESSFUNCTION */
+int prog_cb (void *p, double dltotal, double dlnow, double ult, double uln)
+{
+  ConnInfo *conn = (ConnInfo *)p;
+  fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal);
+  return 0;
+}
+
+
+/* Create a new easy handle, and add it to the global curl_multi */
+void new_conn(char *url, GlobalInfo *g ) {
+  ConnInfo *conn;
+  CURLMcode rc;
+
+  conn = calloc(1, sizeof(ConnInfo));
+  memset(conn, 0, sizeof(ConnInfo));
+  conn->error[0]='\0';
+
+  conn->easy = curl_easy_init();
+  if (!conn->easy) {
+    fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
+    exit(2);
+  }
+  conn->global = g;
+  conn->url = strdup(url);
+  curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
+  curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
+  curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, &conn);
+  curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 0);
+  curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
+  curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
+  curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 0);
+  curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
+  curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
+  fprintf(MSG_OUT,
+          "Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url);
+  rc =curl_multi_add_handle(g->multi, conn->easy);
+  mcode_or_die("new_conn: curl_multi_add_handle", rc);
+  do {
+    rc = curl_multi_socket_all(g->multi, &g->still_running);
+  } while (CURLM_CALL_MULTI_PERFORM == rc);
+  mcode_or_die("new_conn: curl_multi_socket_all", rc);
+  check_run_count(g);
+}
+
+
+
+/* This gets called whenever data is received from the fifo */
+void fifo_cb(int fd, short event, void *arg) {
+  char s[1024];
+  long int rv=0;
+  int n=0;
+  GlobalInfo *g = (GlobalInfo *)arg;
+
+  do {
+    s[0]='\0';
+    rv=fscanf(g->input, "%1023s%n", s, &n);
+    s[n]='\0';
+    if ( n && s[0] ) {
+      new_conn(s,arg);  /* if we read a URL, go get it! */
+    } else break;
+  } while ( rv != EOF);
+}
+
+
+
+/* Create a named pipe and tell libevent to monitor it */
+int init_fifo (GlobalInfo *g) {
+  struct stat st;
+  char *fifo = "hiper.fifo";
+  int socket;
+
+  fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
+  if (lstat (fifo, &st) == 0) {
+    if ((st.st_mode & S_IFMT) == S_IFREG) {
+      errno = EEXIST;
+      perror("lstat");
+      exit (1);
+    }
+  }
+  unlink(fifo);
+  if (mkfifo (fifo, 0600) == -1) {
+    perror("mkfifo");
+    exit (1);
+  }
+  socket = open(fifo, O_RDWR | O_NONBLOCK, 0);
+  if (socket == -1) {
+     perror("open");
+     exit (1);
+  }
+  g->input = fdopen(socket, "r");
+
+  fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo);
+  event_set(&g->fifo_event, socket, EV_READ | EV_PERSIST, fifo_cb, g);
+  event_add(&g->fifo_event, NULL);
+  return (0);
+}
+
+
+
+int main(int argc, char **argv)
+{
+  GlobalInfo g;
+  CURLMcode rc;
+
+  memset(&g, 0, sizeof(GlobalInfo));
+  event_init();
+  init_fifo(&g);
+  g.multi = curl_multi_init();
+  evtimer_set(&g.timer_event, timer_cb, &g);
+  curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
+  curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
+  do {
+    rc = curl_multi_socket_all(g.multi, &g.still_running);
+  } while (CURLM_CALL_MULTI_PERFORM == rc);
+  update_timeout(&g);
+  event_dispatch();
+  curl_multi_cleanup(g.multi);
+  return 0;
+}