Add compatibility mode for missing require key

Traces with metadata version 1 don't use per-thread information, so we
cannot read the 'require' key. All models will be enabled for old traces
(which will cause performance problems).

include/ovni.h.in

@@ -18,7 +18,7 @@ extern "C" {
 #include <string.h>
 #include <sys/types.h>
 
-#define OVNI_METADATA_VERSION 1
+#define OVNI_METADATA_VERSION 2
 
 #define OVNI_TRACEDIR "ovni"
 #define OVNI_MAX_HOSTNAME 512

src/emu/model.c

@@ -7,6 +7,7 @@
 #include "version.h"
 #include "emu.h"
 #include "thread.h"
+#include "proc.h"
 
 void
 model_init(struct model *model)
@@ -180,6 +181,23 @@ model_version_probe(struct model_spec *spec, struct emu *emu)
 	/* Find a stream with an model name key */
 	struct system *sys = &emu->system;
 	for (struct thread *t = sys->threads; t; t = t->gnext) {
+		/* If there is not metadata, it may be a stream created with
+		 * older libovni, so ensure the proc metadata version. */
+		if (t->meta == NULL) {
+			/* Version 1 doesn't have thread metadata, so we enable
+			 * all models. */
+			if (t->proc->metadata_version == 1) {
+				warn("found old metadata (version 1), enabling model %s",
+						spec->name);
+				enable = 1;
+				break;
+			}
+
+			/* Otherwise is an error */
+			err("missing metadata for thread %s with version > 1", t->id);
+			return -1;
+		}
+
 		/* The ovni.require key is mandatory */
 		JSON_Object *require = json_object_dotget_object(t->meta, "ovni.require");
 		if (require == NULL) {

src/emu/proc.c

@@ -110,6 +110,14 @@ proc_load_metadata(struct proc *proc, JSON_Object *meta)
 		return -1;
 	}
 
+	JSON_Value *version_val = json_object_get_value(meta, "version");
+	if (version_val == NULL) {
+		err("missing attribute 'version' in metadata");
+		return -1;
+	}
+
+	proc->metadata_version = (int) json_number(version_val);
+
 	JSON_Value *appid_val = json_object_get_value(meta, "app_id");
 	if (appid_val == NULL) {
 		err("missing attribute 'app_id' in metadata");

src/emu/proc.h

@@ -19,6 +19,7 @@ struct proc {
 	int is_init;
 
 	int metadata_loaded;
+	int metadata_version;
 	int pid;
 	int index;
 	int appid;

src/emu/system.c

@@ -50,6 +50,8 @@ create_thread(struct proc *proc, const char *tracedir, const char *relpath)
 		return NULL;
 	}
 
+	/* Old version 1 doesn't have thread metadata */
+	if (proc->metadata_version > 1) {
 		/* Build metadata path */
 		char mpath[PATH_MAX];
 		if (snprintf(mpath, PATH_MAX, "%s/%s/thread.%d.json",
@@ -62,6 +64,7 @@ create_thread(struct proc *proc, const char *tracedir, const char *relpath)
 			err("cannot load metadata from %s", mpath);
 			return NULL;
 		}
+	}
 
 	if (proc_add_thread(proc, thread) != 0) {
 		err("failed to add thread to proc");

src/emu/thread.c

@@ -153,7 +153,7 @@ thread_init_end(struct thread *th)
 	}
 
 	if (th->meta == NULL) {
-		err("missing metadata for thread %s", th->id);
+		err("missing thread metadata for %s", th->id);
 		return -1;
 	}
 
@@ -448,6 +448,11 @@ thread_migrate_cpu(struct thread *th, struct cpu *cpu)
 int
 thread_load_metadata(struct thread *thread, JSON_Object *meta)
 {
+	if (meta == NULL) {
+		err("metadata is null");
+		return -1;
+	}
+
 	if (thread->meta != NULL) {
 		err("thread %s already loaded metadata", thread->id);
 		return -1;