Added ghiper.c, Jeff Pohlmeyer's example code using the curl_multi_socket()

API with glib2

1 files changed, 462 insertions, 0 deletions

diff --git a/docs/examples/ghiper.c b/docs/examples/ghiper.c
new file mode 100644
index 000000000..7a3ae90c6
--- /dev/null
+++ b/docs/examples/ghiper.c
@@ -0,0 +1,462 @@
+/*****************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * $Id: ghiper.c
+ *
+ * Example application source code using the multi socket interface to
+ * download many files at once.
+ *
+ * Written by Jeff Pohlmeyer
+
+Requires glib-2.x and a (POSIX?) system that has mkfifo().
+
+This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c"
+sample programs, adapted to use glib's g_io_channel in place of libevent.
+
+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.
+
+This is purely a demo app, all retrieved data is simply discarded by the write
+callback.
+
+*/
+
+
+#include <glib.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <curl/curl.h>
+
+
+#define MSG_OUT g_print   /* Change to "g_error" to write to stderr */
+#define SHOW_VERBOSE 0    /* Set to non-zero for libcurl messages */
+#define SHOW_PROGRESS 0   /* Set to non-zero to enable progress callback */
+
+
+
+/* Global information, common to all connections */
+typedef struct _GlobalInfo {
+  CURLM *multi;
+  guint timer_event;
+  int prev_running;
+  int still_running;
+  int requested; /* count: curl_easy_init() */
+  int completed; /* count: curl_easy_cleanup() */
+} 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;
+  GIOChannel *ch;
+  guint ev;
+  GlobalInfo *global;
+} SockInfo;
+
+
+
+
+static void update_timeout(GlobalInfo *g);
+
+
+
+
+/* Die if we get a bad CURLMcode somewhere */
+static 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";
+    }
+    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;
+
+    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;
+          break;
+        }
+      }
+      if (easy) {
+          curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
+          curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
+          MSG_OUT("DONE: %s => (%d) %s\n", eff_url, res, conn->error);
+          curl_multi_remove_handle(g->multi, easy);
+          g_free(conn->url);
+          curl_easy_cleanup(easy);
+          g_free(conn);
+          g->completed++;
+      }
+    } while ( easy );
+    MSG_OUT("Requested: %d Completed:%d\n", g->requested, g->completed);
+  }
+  g->prev_running = g->still_running;
+}
+
+
+
+
+/* Called by glib when our timeout expires */
+static gboolean timer_cb(gpointer data)
+{
+  GlobalInfo *g = (GlobalInfo *)data;
+  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); }
+  return FALSE;
+}
+
+
+
+
+/* Update the event timer after curl_multi library calls */
+static void update_timeout(GlobalInfo *g)
+{
+  long timeout_ms;
+  curl_multi_timeout(g->multi, &timeout_ms);
+  if ( timeout_ms < 0 ) { return; }
+  /* MSG_OUT("update_timeout to %ld ms\n", timeout_ms); */
+  g->timer_event = g_timeout_add(timeout_ms, timer_cb,g);
+}
+
+
+
+/* Called by glib when we get action on a multi socket */
+static gboolean event_cb(GIOChannel *ch, GIOCondition condition, gpointer data)
+{
+  GlobalInfo *g = (GlobalInfo*) data;
+  CURLMcode rc;
+  int fd=g_io_channel_unix_get_fd(ch);
+  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);
+    return TRUE;
+  } else {
+    MSG_OUT("last transfer done, kill timeout\n");
+    if (g->timer_event) { g_source_remove(g->timer_event); }
+    return FALSE;
+  }
+}
+
+
+
+/* Clean up the SockInfo structure */
+static void remsock(SockInfo *f)
+{
+  if (!f) { return; }
+  if (f->ev) { g_source_remove(f->ev); }
+  g_free(f);
+}
+
+
+
+/* Assign information to a SockInfo structure */
+static void setsock(SockInfo*f, curl_socket_t s, CURL*e, int act, GlobalInfo*g)
+{
+  GIOCondition kind =
+     (act&CURL_POLL_IN?G_IO_IN:0)|(act&CURL_POLL_OUT?G_IO_OUT:0);
+
+  f->sockfd = s;
+  f->action = act;
+  f->easy = e;
+  if (f->ev) { g_source_remove(f->ev); }
+  f->ev=g_io_add_watch(f->ch, kind, event_cb,g);
+
+}
+
+
+
+/* Initialize a new SockInfo structure */
+static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
+{
+  SockInfo *fdp = g_malloc0(sizeof(SockInfo));
+
+  fdp->global = g;
+  fdp->ch=g_io_channel_unix_new(s);
+  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" };
+
+  MSG_OUT("socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
+  if (what == CURL_POLL_REMOVE) {
+    MSG_OUT("\n");
+    remsock(fdp);
+  } else {
+    if (!fdp) {
+      MSG_OUT("Adding data: %s%s\n",
+             what&CURL_POLL_IN?"READ":"",
+             what&CURL_POLL_OUT?"WRITE":"" );
+      addsock(s, e, what, g);
+    }
+    else {
+      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 */
+static int prog_cb (void *p, double dltotal, double dlnow, double ult, double uln)
+{
+  ConnInfo *conn = (ConnInfo *)p;
+  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 */
+static void new_conn(char *url, GlobalInfo *g )
+{
+  ConnInfo *conn;
+  CURLMcode rc;
+
+  conn = g_malloc0(sizeof(ConnInfo));
+
+  conn->error[0]='\0';
+
+  conn->easy = curl_easy_init();
+  if (!conn->easy) {
+    MSG_OUT("curl_easy_init() failed, exiting!\n");
+    exit(2);
+  }
+  conn->global = g;
+  conn->url = g_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, SHOW_VERBOSE);
+  curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
+  curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
+  curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, SHOW_PROGRESS?0:1);
+  curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
+  curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
+  curl_easy_setopt(conn->easy, CURLOPT_FOLLOWLOCATION, 1);
+  curl_easy_setopt(conn->easy, CURLOPT_CONNECTTIMEOUT, 30);
+  curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 1);
+  curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 30);
+
+  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);
+  g->requested++;
+  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 by glib whenever data is received from the fifo */
+static gboolean fifo_cb (GIOChannel *ch, GIOCondition condition, gpointer data)
+{
+  #define BUF_SIZE 1024
+  gsize len, tp;
+  gchar *buf, *tmp, *all=NULL;
+  GIOStatus rv;
+
+  do {
+    GError *err=NULL;
+    rv = g_io_channel_read_line (ch,&buf,&len,&tp,&err);
+    if ( buf ) {
+      if (tp) { buf[tp]='\0'; }
+      new_conn(buf,(GlobalInfo*)data);
+      g_free(buf);
+    } else {
+      buf = g_malloc(BUF_SIZE+1);
+      while (TRUE) {
+        buf[BUF_SIZE]='\0';
+        g_io_channel_read_chars(ch,buf,BUF_SIZE,&len,&err);
+        if (len) {
+          buf[len]='\0';
+          if (all) {
+            tmp=all;
+            all=g_strdup_printf("%s%s", tmp, buf);
+            g_free(tmp);
+          } else {
+            all = g_strdup(buf);
+          }
+        } else {
+           break;
+        }
+      }
+      if (all) {
+        new_conn(all,(GlobalInfo*)data);
+        g_free(all);
+      }
+      g_free(buf);
+    }
+    if ( err ) {
+      g_error("fifo_cb: %s", err->message);
+      g_free(err);
+      break;
+    }
+  } while ( (len) && (rv == G_IO_STATUS_NORMAL) );
+  return TRUE;
+}
+
+
+
+
+int init_fifo(void)
+{
+ struct stat st;
+ char *fifo = "hiper.fifo";
+ int socket;
+
+ 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);
+ }
+ MSG_OUT("Now, pipe some URL's into > %s\n", fifo);
+
+ return socket;
+
+}
+
+
+
+
+int main(int argc, char **argv)
+{
+  GlobalInfo *g;
+  CURLMcode rc;
+  GMainLoop*gmain;
+  int fd;
+  GIOChannel* ch;
+  g=g_malloc0(sizeof(GlobalInfo));
+
+  fd=init_fifo();
+  ch=g_io_channel_unix_new(fd);
+  g_io_add_watch(ch,G_IO_IN,fifo_cb,g);
+  gmain=g_main_loop_new(NULL,FALSE);
+  g->multi = curl_multi_init();
+  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);
+  g_main_loop_run(gmain);
+  curl_multi_cleanup(g->multi);
+  return 0;
+}