From: Rusty Russell <rusty@rustcorp.com.au>
Date: Sat, 22 Jan 2011 03:40:51 +0000 (+1030)
Subject: lca2011: oserver_restore.
X-Git-Url: http://git.ozlabs.org/?a=commitdiff_plain;h=33b799969447a818cd99749aa937a59c88e4f83f;p=ccan-lca-2011.git

lca2011: oserver_restore.
---

diff --git a/ccan/oserver/_info b/ccan/oserver/_info
index 9107e66..7d05837 100644
--- a/ccan/oserver/_info
+++ b/ccan/oserver/_info
@@ -52,6 +52,7 @@ int main(int argc, char *argv[])
 		printf("ccan/array_size\n");
 		printf("ccan/tevent\n");
 		printf("ccan/cdump\n");
+		printf("ccan/grab_file\n");
 		return 0;
 	}
 
diff --git a/ccan/oserver/oserver.c b/ccan/oserver/oserver.c
index 8a5fdce..b65fe6b 100644
--- a/ccan/oserver/oserver.c
+++ b/ccan/oserver/oserver.c
@@ -5,6 +5,7 @@
 #include <ccan/opt/opt.h>
 #include <ccan/tevent/tevent.h>
 #include <ccan/array_size/array_size.h>
+#include <ccan/grab_file/grab_file.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
@@ -306,6 +307,53 @@ static void dump(struct tevent_context *ev,
 	talloc_free(str);
 }
 
+static bool load_file(struct oserver *oserver, const char *file)
+{
+	char *str;
+
+	if (!file)
+		return false;
+
+	str = grab_file(oserver, file, NULL);
+	if (!str)
+		return false;
+
+	if (!cdump_unbundle(oserver, cdump_struct_oserver, oserver, str)) {
+		talloc_free(str);
+		return false;
+	}
+	talloc_free(str);
+	return true;
+}
+
+static void complete_server(struct tevent_context *ev,
+			    struct oserver *oserver, const char *dumpfile)
+{
+	/* Re-set this even if restored from file, in case it changed. */
+	oserver->dumpfile = dumpfile;
+	if (oserver->dumpfile)
+		tevent_add_signal(ev, oserver, SIGHUP, SA_RESTART,
+				  dump, oserver);
+
+	/* Don't kill us if client dies. */
+	signal(SIGPIPE, SIG_IGN);
+
+	/* Show talloc tree on SIGUSR1. */
+	tevent_add_signal(ev, oserver, SIGUSR1, SA_RESTART,
+			  talloc_dump, oserver);
+}
+
+struct oserver *oserver_restore(struct tevent_context *ev, const char *dumpfile)
+{
+	struct oserver *oserver = talloc(ev, struct oserver);
+	if (!load_file(oserver, dumpfile)) {
+		talloc_free(oserver);
+		return NULL;
+	}
+	complete_server(ev, oserver, dumpfile);
+	return oserver;
+}
+
 struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port,
 			      const char *dumpfile)
 {
@@ -350,18 +398,6 @@ struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port,
 		return NULL;
 	}
 
-	oserver->dumpfile = dumpfile;
-	if (oserver->dumpfile) {
-		tevent_add_signal(ev, oserver, SIGHUP, SA_RESTART,
-				  dump, oserver);
-	}
-
-	/* Don't kill us if client dies. */
-	signal(SIGPIPE, SIG_IGN);
-
-	/* Show talloc tree on SIGUSR1. */
-	tevent_add_signal(ev, oserver, SIGUSR1, SA_RESTART,
-			  talloc_dump, oserver);
-
+	complete_server(ev, oserver, dumpfile);
 	return oserver;
 }
diff --git a/ccan/oserver/oserver.h b/ccan/oserver/oserver.h
index 3342ba8..06a89b2 100644
--- a/ccan/oserver/oserver.h
+++ b/ccan/oserver/oserver.h
@@ -4,13 +4,12 @@
 #include <ccan/tevent/tevent.h>
 
 /**
- * oserver_setup - set up an oserver
+ * oserver_restore - restore an oserver from dump
  * @ev: tevent context to use.
- * @port: port to use (usually OSERVER_PORT)
- * @dumpfile: file to save state to on SIGHUP (if non-NULL).
+ * @dumpfile: file to with saved state.
  *
- * Opens a socket and binds it to @port, then sets it up to listen
- * for connections.  talloc_free() the pointer returned to shut it down
+ * Tries to restore an oserver from the dump file.  Returns NULL on failure.
+ * talloc_free() the pointer returned to shut it down
  * (its parent is the tevent_context).
  *
  * Example:
@@ -18,10 +17,31 @@
  *	struct tevent_context *ev;
  *
  *	ev = tevent_context_init(NULL);
- *	oserver = oserver_setup(ev, OSERVER_PORT, "oserver.dump");
- *	if (!oserver)
- *		err(1, "Failed to set up server");
+ *	oserver = oserver_restore(ev, "oserver.dump");
+ *	if (oserver)
+ *		printf("Restored oserver!");
+ */
+struct oserver *oserver_restore(struct tevent_context *ev,
+				const char *dumpfile);
+
+
+/**
+ * oserver_setup - set up an oserver
+ * @ev: tevent context to use.
+ * @port: port to use (usually OSERVER_PORT)
+ * @dumpfile: file to save state to on SIGHUP (if non-NULL).
  *
+ * Opens a socket and binds it to @port, then sets it up to listen
+ * for connections.  talloc_free() the pointer returned to shut it down
+ * (its parent is the tevent_context).
+ *
+ * Example:
+ *	...
+ *	else {
+ *		oserver = oserver_setup(ev, OSERVER_PORT, "oserver.dump");
+ *		if (!oserver)
+ *			err(1, "Failed to set up server");
+ *	}
  *	while (tevent_loop_wait(ev) == 0);
  *	err(1, "Event loop failed");
  */