perf machine: Introduce find_thread method

There are cases where we want just to find a thread if it exists
already, so provide a method for that.

While doing that start moving 'machine' methods to a separate file.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-8wpzqs9kfupng6xq8hx6lnxa@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
new file mode 100644
index 0000000..9d36d7e
--- /dev/null
+++ b/tools/perf/util/machine.c
@@ -0,0 +1,57 @@
+#include "machine.h"
+#include "map.h"
+#include "thread.h"
+#include <stdbool.h>
+
+static struct thread *__machine__findnew_thread(struct machine *machine, pid_t pid,
+						bool create)
+{
+	struct rb_node **p = &machine->threads.rb_node;
+	struct rb_node *parent = NULL;
+	struct thread *th;
+
+	/*
+	 * Font-end cache - PID lookups come in blocks,
+	 * so most of the time we dont have to look up
+	 * the full rbtree:
+	 */
+	if (machine->last_match && machine->last_match->pid == pid)
+		return machine->last_match;
+
+	while (*p != NULL) {
+		parent = *p;
+		th = rb_entry(parent, struct thread, rb_node);
+
+		if (th->pid == pid) {
+			machine->last_match = th;
+			return th;
+		}
+
+		if (pid < th->pid)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+
+	if (!create)
+		return NULL;
+
+	th = thread__new(pid);
+	if (th != NULL) {
+		rb_link_node(&th->rb_node, parent, p);
+		rb_insert_color(&th->rb_node, &machine->threads);
+		machine->last_match = th;
+	}
+
+	return th;
+}
+
+struct thread *machine__findnew_thread(struct machine *machine, pid_t pid)
+{
+	return __machine__findnew_thread(machine, pid, true);
+}
+
+struct thread *machine__find_thread(struct machine *machine, pid_t pid)
+{
+	return __machine__findnew_thread(machine, pid, false);
+}