discover: Make device handler a little more testable

This change moves some of the device-handler code into an #ifdef-ed
section, so we can easily drop the stuff that's not required for
testing.

Although the change is quite large, most of it is moving entire
functions around.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 307 insertions, 280 deletions

diff --git a/discover/device-handler.c b/discover/device-handler.c
index 2396124..8e71310 100644
--- a/discover/device-handler.c
+++ b/discover/device-handler.c
@@ -33,203 +33,169 @@ struct device_handler {
 	struct list		unresolved_boot_options;
 };
 
-static bool resource_is_resolved(struct resource *res)
+void discover_context_add_boot_option(struct discover_context *ctx,
+		struct discover_boot_option *boot_option)
 {
-	return !res || res->resolved;
+	boot_option->source = ctx->parser;
+	list_add_tail(&ctx->boot_options, &boot_option->list);
+	talloc_steal(ctx, boot_option);
 }
 
-/* We only use this in an assert, which will disappear if we're compiling
- * with NDEBUG, so we need the 'used' attribute for these builds */
-static bool __attribute__((used)) boot_option_is_resolved(
-		struct discover_boot_option *opt)
+/**
+ * device_handler_get_device_count - Get the count of current handler devices.
+ */
+
+int device_handler_get_device_count(const struct device_handler *handler)
 {
-	return resource_is_resolved(opt->boot_image) &&
-		resource_is_resolved(opt->initrd) &&
-		resource_is_resolved(opt->icon);
+	return handler->n_devices;
 }
 
-static bool resource_resolve(struct resource *res, struct parser *parser,
-		struct device_handler *handler)
-{
-	if (resource_is_resolved(res))
-		return true;
+/**
+ * device_handler_get_device - Get a handler device by index.
+ */
 
-	parser->resolve_resource(handler, res);
+const struct discover_device *device_handler_get_device(
+	const struct device_handler *handler, unsigned int index)
+{
+	if (index >= handler->n_devices) {
+		assert(0 && "bad index");
+		return NULL;
+	}
 
-	return res->resolved;
+	return handler->devices[index];
 }
 
-static bool boot_option_resolve(struct discover_boot_option *opt,
-		struct device_handler *handler)
+struct discover_boot_option *discover_boot_option_create(
+		struct discover_context *ctx,
+		struct discover_device *device)
 {
-	return resource_resolve(opt->boot_image, opt->source, handler) &&
-		resource_resolve(opt->initrd, opt->source, handler) &&
-		resource_resolve(opt->icon, opt->source, handler);
+	struct discover_boot_option *opt;
+
+	opt = talloc_zero(ctx, struct discover_boot_option);
+	opt->option = talloc_zero(opt, struct boot_option);
+	opt->device = device;
+
+	return opt;
 }
 
-static void boot_option_finalise(struct discover_boot_option *opt)
+static int device_match_path(struct discover_device *dev, const char *path)
 {
-	assert(boot_option_is_resolved(opt));
+	return dev->device_path && !strcmp(dev->device_path, path);
+}
 
-	/* check that the parsers haven't set any of the final data */
-	assert(!opt->option->boot_image_file);
-	assert(!opt->option->initrd_file);
-	assert(!opt->option->icon_file);
-	assert(!opt->option->device_id);
+static int device_match_uuid(struct discover_device *dev, const char *uuid)
+{
+	return dev->uuid && !strcmp(dev->uuid, uuid);
+}
 
-	if (opt->boot_image)
-		opt->option->boot_image_file = opt->boot_image->url->full;
-	if (opt->initrd)
-		opt->option->initrd_file = opt->initrd->url->full;
-	if (opt->icon)
-		opt->option->icon_file = opt->icon->url->full;
+static int device_match_label(struct discover_device *dev, const char *label)
+{
+	return dev->label && !strcmp(dev->label, label);
+}
 
-	opt->option->device_id = opt->device->device->id;
+static int device_match_id(struct discover_device *dev, const char *id)
+{
+	return !strcmp(dev->device->id, id);
 }
 
-static void process_boot_option_queue(struct device_handler *handler)
+static struct discover_device *device_lookup(
+		struct device_handler *device_handler,
+		int (match_fn)(struct discover_device *, const char *),
+		const char *str)
 {
-	struct discover_boot_option *opt, *tmp;
+	struct discover_device *dev;
+	unsigned int i;
 
-	list_for_each_entry_safe(&handler->unresolved_boot_options,
-			opt, tmp, list) {
+	if (!str)
+		return NULL;
 
-		if (!boot_option_resolve(opt, handler))
-			continue;
+	for (i = 0; i < device_handler->n_devices; i++) {
+		dev = device_handler->devices[i];
 
-		list_remove(&opt->list);
-		list_add(&opt->device->boot_options, &opt->list);
-		talloc_steal(opt->device, opt);
-		boot_option_finalise(opt);
-		discover_server_notify_boot_option_add(handler->server,
-							opt->option);
+		if (match_fn(dev, str))
+			return dev;
 	}
+
+	return NULL;
 }
 
-/**
- * context_commit - Commit a temporary discovery context to the handler,
- * and notify the clients about any new options / devices
- */
-static void context_commit(struct device_handler *handler,
-		struct discover_context *ctx)
+struct discover_device *device_lookup_by_name(struct device_handler *handler,
+		const char *name)
 {
-	struct discover_device *dev = ctx->device;
-	struct discover_boot_option *opt, *tmp;
-	unsigned int i, existing_device = 0;
-
-	/* do we already have this device? */
-	for (i = 0; i < handler->n_devices; i++) {
-		if (ctx->device == handler->devices[i]) {
-			existing_device = 1;
-			break;
-		}
-	}
-
-	/* if not already present, add the device to the handler's array */
-	if (!existing_device) {
-		handler->n_devices++;
-		handler->devices = talloc_realloc(handler, handler->devices,
-			struct discover_device *, handler->n_devices);
-		handler->devices[handler->n_devices - 1] = dev;
-		talloc_steal(handler, dev);
+	struct discover_device *dev;
+	char *path;
 
-		discover_server_notify_device_add(handler->server, dev->device);
+	if (strncmp(name, "/dev/", strlen("/dev/")))
+		path = talloc_asprintf(NULL, "/dev/%s", name);
+	else
+		path = talloc_strdup(NULL, name);
 
-		/* this new device might be able to resolve existing boot
-		 * options */
-		process_boot_option_queue(handler);
-	}
+	dev = device_lookup_by_path(handler, path);
 
+	talloc_free(path);
 
-	/* move boot options from the context to the device */
-	list_for_each_entry_safe(&ctx->boot_options, opt, tmp, list) {
-		list_remove(&opt->list);
+	return dev;
+}
 
-		if (boot_option_resolve(opt, handler)) {
-			list_add(&dev->boot_options, &opt->list);
-			talloc_steal(dev, opt);
-			boot_option_finalise(opt);
-			discover_server_notify_boot_option_add(handler->server,
-								opt->option);
-		} else {
-			if (!opt->source->resolve_resource) {
-				pb_log("parser %s gave us an unresolved "
-					"resource (%s), but no way to "
-					"resolve it\n",
-					opt->source->name, opt->option->id);
-				talloc_free(opt);
-			} else {
-				pb_log("boot option %s is unresolved, "
-						"adding to queue\n",
-						opt->option->id);
-				list_add(&handler->unresolved_boot_options,
-						&opt->list);
-				talloc_steal(handler, opt);
-			}
-		}
-	}
+struct discover_device *device_lookup_by_path(
+		struct device_handler *device_handler,
+		const char *path)
+{
+	return device_lookup(device_handler, device_match_path, path);
 }
 
-void discover_context_add_boot_option(struct discover_context *ctx,
-		struct discover_boot_option *boot_option)
+struct discover_device *device_lookup_by_uuid(
+		struct device_handler *device_handler,
+		const char *uuid)
 {
-	boot_option->source = ctx->parser;
-	list_add_tail(&ctx->boot_options, &boot_option->list);
-	talloc_steal(ctx, boot_option);
+	return device_lookup(device_handler, device_match_uuid, uuid);
 }
 
-/**
- * device_handler_remove - Remove a device from the handler device array.
- */
+struct discover_device *device_lookup_by_label(
+		struct device_handler *device_handler,
+		const char *label)
+{
+	return device_lookup(device_handler, device_match_label, label);
+}
 
-static void device_handler_remove(struct device_handler *handler,
-	struct discover_device *device)
+struct discover_device *device_lookup_by_id(
+		struct device_handler *device_handler,
+		const char *id)
 {
-	unsigned int i;
+	return device_lookup(device_handler, device_match_id, id);
+}
 
-	for (i = 0; i < handler->n_devices; i++)
-		if (handler->devices[i] == device)
-			break;
+void device_handler_destroy(struct device_handler *handler)
+{
+	talloc_free(handler);
+}
 
-	if (i == handler->n_devices) {
-		assert(0 && "unknown device");
-		return;
-	}
+#ifdef PETITBOOT_TEST
 
-	handler->n_devices--;
-	memmove(&handler->devices[i], &handler->devices[i + 1],
-		(handler->n_devices - i) * sizeof(handler->devices[0]));
-	handler->devices = talloc_realloc(handler, handler->devices,
-		struct discover_device *, handler->n_devices);
+/* we have a simplified interface for petitboot testing, but still want
+ * to keep struct device_handler opaque. */
+struct device_handler *device_handler_init(
+		struct discover_server *server __attribute__((unused)),
+		int dry_run __attribute__((unused)))
+{
+	struct device_handler *handler;
 
-	discover_server_notify_device_remove(handler->server, device->device);
+	handler = talloc_zero(NULL, struct device_handler);
+	list_init(&handler->unresolved_boot_options);
 
-	talloc_free(device);
+	return handler;
 }
 
-/**
- * device_handler_get_device_count - Get the count of current handler devices.
- */
-
-int device_handler_get_device_count(const struct device_handler *handler)
+void device_handler_add_device(struct device_handler *handler,
+		struct discover_device *dev)
 {
-	return handler->n_devices;
+	handler->n_devices++;
+	handler->devices = talloc_realloc(handler, handler->devices,
+		struct discover_device *, handler->n_devices);
+	handler->devices[handler->n_devices - 1] = dev;
 }
 
-/**
- * device_handler_get_device - Get a handler device by index.
- */
-
-const struct discover_device *device_handler_get_device(
-	const struct device_handler *handler, unsigned int index)
-{
-	if (index >= handler->n_devices) {
-		assert(0 && "bad index");
-		return NULL;
-	}
-
-	return handler->devices[index];
-}
+#else
 
 static int mount_device(struct discover_device *dev)
 {
@@ -307,6 +273,35 @@ static int umount_device(struct discover_device *dev)
 	return 0;
 }
 
+struct device_handler *device_handler_init(struct discover_server *server,
+		int dry_run)
+{
+	struct device_handler *handler;
+
+	handler = talloc(NULL, struct device_handler);
+	handler->devices = NULL;
+	handler->n_devices = 0;
+	handler->server = server;
+	handler->dry_run = dry_run;
+	list_init(&handler->unresolved_boot_options);
+
+	/* set up our mount point base */
+	pb_mkdir_recursive(mount_base());
+
+	parser_init();
+
+	return handler;
+}
+
+static int destroy_device(void *arg)
+{
+	struct discover_device *dev = arg;
+
+	umount_device(dev);
+
+	return 0;
+}
+
 static struct discover_device *find_device(struct device_handler *handler,
 		const char *id)
 {
@@ -322,15 +317,6 @@ static struct discover_device *find_device(struct device_handler *handler,
 	return NULL;
 }
 
-static int destroy_device(void *arg)
-{
-	struct discover_device *dev = arg;
-
-	umount_device(dev);
-
-	return 0;
-}
-
 static struct discover_device *discover_device_create(
 		struct device_handler *handler,
 		struct discover_context *ctx,
@@ -358,19 +344,171 @@ static struct discover_device *discover_device_create(
 	return dev;
 }
 
-struct discover_boot_option *discover_boot_option_create(
-		struct discover_context *ctx,
-		struct discover_device *device)
+/**
+ * device_handler_remove - Remove a device from the handler device array.
+ */
+
+static void device_handler_remove(struct device_handler *handler,
+	struct discover_device *device)
 {
-	struct discover_boot_option *opt;
+	unsigned int i;
 
-	opt = talloc_zero(ctx, struct discover_boot_option);
-	opt->option = talloc_zero(opt, struct boot_option);
-	opt->device = device;
+	for (i = 0; i < handler->n_devices; i++)
+		if (handler->devices[i] == device)
+			break;
 
-	return opt;
+	if (i == handler->n_devices) {
+		assert(0 && "unknown device");
+		return;
+	}
+
+	handler->n_devices--;
+	memmove(&handler->devices[i], &handler->devices[i + 1],
+		(handler->n_devices - i) * sizeof(handler->devices[0]));
+	handler->devices = talloc_realloc(handler, handler->devices,
+		struct discover_device *, handler->n_devices);
+
+	discover_server_notify_device_remove(handler->server, device->device);
+
+	talloc_free(device);
+}
+
+static bool resource_is_resolved(struct resource *res)
+{
+	return !res || res->resolved;
+}
+
+/* We only use this in an assert, which will disappear if we're compiling
+ * with NDEBUG, so we need the 'used' attribute for these builds */
+static bool __attribute__((used)) boot_option_is_resolved(
+		struct discover_boot_option *opt)
+{
+	return resource_is_resolved(opt->boot_image) &&
+		resource_is_resolved(opt->initrd) &&
+		resource_is_resolved(opt->icon);
+}
+
+static bool resource_resolve(struct resource *res, struct parser *parser,
+		struct device_handler *handler)
+{
+	if (resource_is_resolved(res))
+		return true;
+
+	parser->resolve_resource(handler, res);
+
+	return res->resolved;
+}
+
+static bool boot_option_resolve(struct discover_boot_option *opt,
+		struct device_handler *handler)
+{
+	return resource_resolve(opt->boot_image, opt->source, handler) &&
+		resource_resolve(opt->initrd, opt->source, handler) &&
+		resource_resolve(opt->icon, opt->source, handler);
+}
+
+static void boot_option_finalise(struct discover_boot_option *opt)
+{
+	assert(boot_option_is_resolved(opt));
+
+	/* check that the parsers haven't set any of the final data */
+	assert(!opt->option->boot_image_file);
+	assert(!opt->option->initrd_file);
+	assert(!opt->option->icon_file);
+	assert(!opt->option->device_id);
+
+	if (opt->boot_image)
+		opt->option->boot_image_file = opt->boot_image->url->full;
+	if (opt->initrd)
+		opt->option->initrd_file = opt->initrd->url->full;
+	if (opt->icon)
+		opt->option->icon_file = opt->icon->url->full;
+
+	opt->option->device_id = opt->device->device->id;
+}
+
+static void process_boot_option_queue(struct device_handler *handler)
+{
+	struct discover_boot_option *opt, *tmp;
+
+	list_for_each_entry_safe(&handler->unresolved_boot_options,
+			opt, tmp, list) {
+
+		if (!boot_option_resolve(opt, handler))
+			continue;
+
+		list_remove(&opt->list);
+		list_add(&opt->device->boot_options, &opt->list);
+		talloc_steal(opt->device, opt);
+		boot_option_finalise(opt);
+		discover_server_notify_boot_option_add(handler->server,
+							opt->option);
+	}
 }
 
+/**
+ * context_commit - Commit a temporary discovery context to the handler,
+ * and notify the clients about any new options / devices
+ */
+static void context_commit(struct device_handler *handler,
+		struct discover_context *ctx)
+{
+	struct discover_device *dev = ctx->device;
+	struct discover_boot_option *opt, *tmp;
+	unsigned int i, existing_device = 0;
+
+	/* do we already have this device? */
+	for (i = 0; i < handler->n_devices; i++) {
+		if (ctx->device == handler->devices[i]) {
+			existing_device = 1;
+			break;
+		}
+	}
+
+	/* if not already present, add the device to the handler's array */
+	if (!existing_device) {
+		handler->n_devices++;
+		handler->devices = talloc_realloc(handler, handler->devices,
+			struct discover_device *, handler->n_devices);
+		handler->devices[handler->n_devices - 1] = dev;
+		talloc_steal(handler, dev);
+
+		discover_server_notify_device_add(handler->server, dev->device);
+
+		/* this new device might be able to resolve existing boot
+		 * options */
+		process_boot_option_queue(handler);
+	}
+
+
+	/* move boot options from the context to the device */
+	list_for_each_entry_safe(&ctx->boot_options, opt, tmp, list) {
+		list_remove(&opt->list);
+
+		if (boot_option_resolve(opt, handler)) {
+			list_add(&dev->boot_options, &opt->list);
+			talloc_steal(dev, opt);
+			boot_option_finalise(opt);
+			discover_server_notify_boot_option_add(handler->server,
+								opt->option);
+		} else {
+			if (!opt->source->resolve_resource) {
+				pb_log("parser %s gave us an unresolved "
+					"resource (%s), but no way to "
+					"resolve it\n",
+					opt->source->name, opt->option->id);
+				talloc_free(opt);
+			} else {
+				pb_log("boot option %s is unresolved, "
+						"adding to queue\n",
+						opt->option->id);
+				list_add(&handler->unresolved_boot_options,
+						&opt->list);
+				talloc_steal(handler, opt);
+			}
+		}
+	}
+}
 
 static int handle_add_udev_event(struct device_handler *handler,
 		struct event *event)
@@ -552,116 +690,11 @@ int device_handler_event(struct device_handler *handler,
 	return handlers[event->type][event->action](handler, event);
 }
 
-struct device_handler *device_handler_init(struct discover_server *server,
-		int dry_run)
-{
-	struct device_handler *handler;
-
-	handler = talloc(NULL, struct device_handler);
-	handler->devices = NULL;
-	handler->n_devices = 0;
-	handler->server = server;
-	handler->dry_run = dry_run;
-	list_init(&handler->unresolved_boot_options);
-
-	/* set up our mount point base */
-	pb_mkdir_recursive(mount_base());
-
-	parser_init();
-
-	return handler;
-}
-
-void device_handler_destroy(struct device_handler *handler)
-{
-	talloc_free(handler);
-}
-
-static int device_match_path(struct discover_device *dev, const char *path)
-{
-	return dev->device_path && !strcmp(dev->device_path, path);
-}
-
-static int device_match_uuid(struct discover_device *dev, const char *uuid)
-{
-	return dev->uuid && !strcmp(dev->uuid, uuid);
-}
-
-static int device_match_label(struct discover_device *dev, const char *label)
-{
-	return dev->label && !strcmp(dev->label, label);
-}
-
-static int device_match_id(struct discover_device *dev, const char *id)
-{
-	return !strcmp(dev->device->id, id);
-}
-
-static struct discover_device *device_lookup(
-		struct device_handler *device_handler,
-		int (match_fn)(struct discover_device *, const char *),
-		const char *str)
-{
-	struct discover_device *dev;
-	unsigned int i;
-
-	if (!str)
-		return NULL;
-
-	for (i = 0; i < device_handler->n_devices; i++) {
-		dev = device_handler->devices[i];
-
-		if (match_fn(dev, str))
-			return dev;
-	}
-
-	return NULL;
-}
-
-struct discover_device *device_lookup_by_name(struct device_handler *handler,
-		const char *name)
-{
-	struct discover_device *dev;
-	char *path;
-
-	if (strncmp(name, "/dev/", strlen("/dev/")))
-		path = talloc_asprintf(NULL, "/dev/%s", name);
-	else
-		path = talloc_strdup(NULL, name);
-
-	dev = device_lookup_by_path(handler, path);
-
-	talloc_free(path);
-
-	return dev;
-}
-
-struct discover_device *device_lookup_by_path(
-		struct device_handler *device_handler,
-		const char *path)
-{
-	return device_lookup(device_handler, device_match_path, path);
-}
-
-struct discover_device *device_lookup_by_uuid(
-		struct device_handler *device_handler,
-		const char *uuid)
-{
-	return device_lookup(device_handler, device_match_uuid, uuid);
-}
-
-struct discover_device *device_lookup_by_label(
-		struct device_handler *device_handler,
-		const char *label)
+static void boot_status(void *arg, struct boot_status *status)
 {
-	return device_lookup(device_handler, device_match_label, label);
-}
+	struct device_handler *handler = arg;
 
-struct discover_device *device_lookup_by_id(
-		struct device_handler *device_handler,
-		const char *id)
-{
-	return device_lookup(device_handler, device_match_id, id);
+	discover_server_notify_boot_status(handler->server, status);
 }
 
 static struct discover_boot_option *find_boot_option_by_id(
@@ -681,13 +714,6 @@ static struct discover_boot_option *find_boot_option_by_id(
 	return NULL;
 }
 
-static void boot_status(void *arg, struct boot_status *status)
-{
-	struct device_handler *handler = arg;
-
-	discover_server_notify_boot_status(handler->server, status);
-}
-
 void device_handler_boot(struct device_handler *handler,
 		struct boot_command *cmd)
 {
@@ -697,3 +723,4 @@ void device_handler_boot(struct device_handler *handler,
 
 	boot(handler, opt, cmd, handler->dry_run, boot_status, handler);
 }
+#endif