Add schedule.if_absent for clients that re-register periodic tasks.

schedule restarts a re-registered task's countdown, if_absent keeps the existing entry.

test/rpc/test_command_scheduler.cc

@@ -0,0 +1,65 @@
+#include "config.h"
+
+#include "test/rpc/test_command_scheduler.h"
+
+#include <chrono>
+
+#include "rpc/command_scheduler.h"
+#include "rpc/command_scheduler_item.h"
+#include "torrent/object.h"
+
+CPPUNIT_TEST_SUITE_REGISTRATION(TestCommandScheduler);
+
+namespace {
+
+const torrent::Object test_command = torrent::Object(std::string("print=scheduled"));
+
+std::chrono::microseconds
+time_scheduled(rpc::CommandScheduler& scheduler, const std::string& key) {
+  auto itr = scheduler.find(key);
+
+  CPPUNIT_ASSERT(itr != scheduler.end());
+
+  return (*itr)->time_scheduled();
+}
+
+}
+
+void
+TestCommandScheduler::setUp() {
+  TestFixtureWithMainThread::setUp();
+
+  m_main_thread->test_set_cached_time(std::chrono::seconds(0));
+}
+
+void
+TestCommandScheduler::tearDown() {
+  TestFixtureWithMainThread::tearDown();
+}
+
+void
+TestCommandScheduler::test_parse_rearms_existing_key() {
+  rpc::CommandScheduler scheduler;
+
+  scheduler.parse("key", "3600", "3600", test_command);
+
+  auto first = time_scheduled(scheduler, "key");
+
+  m_main_thread->test_add_cached_time(std::chrono::seconds(600));
+  scheduler.parse("key", "3600", "3600", test_command);
+
+  CPPUNIT_ASSERT_EQUAL(size_t{1}, scheduler.size());
+  CPPUNIT_ASSERT(time_scheduled(scheduler, "key") == first + std::chrono::seconds(600));
+}
+
+void
+TestCommandScheduler::test_find_locates_a_scheduled_key() {
+  rpc::CommandScheduler scheduler;
+
+  CPPUNIT_ASSERT(scheduler.find("key") == scheduler.end());
+
+  scheduler.parse("key", "3600", "3600", test_command);
+
+  CPPUNIT_ASSERT(scheduler.find("key") != scheduler.end());
+  CPPUNIT_ASSERT(scheduler.find("other") == scheduler.end());
+}