Adding object table (#1)

* code for maintaining the object table

* Makefile fix

* Clone git submodules.

* directory -> object_table

* Fix Makefile and remove unnecessary files.

* Fix formatting.

* make code more generic

test/db_tests.c

@@ -0,0 +1,69 @@
+#include "greatest.h"
+
+#include <assert.h>
+
+#include "event_loop.h"
+#include "state/db.h"
+#include "state/object_table.h"
+#include "state/redis.h"
+
+SUITE(db_tests);
+
+int lookup_successful = 0;
+const char *manager_addr = "127.0.0.1";
+int manager_port = 12345;
+char received_addr[16] = {0};
+char received_port[6] = {0};
+
+void test_callback(void *userdata);
+
+void test_callback(void *userdata) {
+  char *reply = userdata;
+  lookup_successful = 1;
+  if (!reply ||
+      sscanf(reply, "%15[0-9.]:%5[0-9]", received_addr, received_port) != 2) {
+    assert(0);
+  }
+  free(reply);
+}
+
+TEST object_table_lookup_test(void) {
+  event_loop loop;
+  event_loop_init(&loop);
+  db_conn conn;
+  db_connect("127.0.0.1", 6379, "plasma_manager", manager_addr, manager_port,
+             &conn);
+  int64_t index = db_attach(&conn, &loop, 0);
+  unique_id id = {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}};
+  object_table_add(&conn, id);
+  object_table_lookup(&conn, id, test_callback);
+  while (!lookup_successful) {
+    int num_ready = event_loop_poll(&loop);
+    if (num_ready < 0) {
+      exit(-1);
+    }
+    for (int i = 0; i < event_loop_size(&loop); ++i) {
+      struct pollfd *waiting = event_loop_get(&loop, i);
+      if (waiting->revents == 0)
+        continue;
+      if (i == index) {
+        db_event(&conn);
+      }
+    }
+  }
+  ASSERT_STR_EQ(&received_addr[0], manager_addr);
+  ASSERT_EQ(atoi(received_port), manager_port);
+  PASS();
+}
+
+SUITE(db_tests) {
+  RUN_TEST(object_table_lookup_test);
+}
+
+GREATEST_MAIN_DEFS();
+
+int main(int argc, char **argv) {
+  GREATEST_MAIN_BEGIN();
+  RUN_SUITE(db_tests);
+  GREATEST_MAIN_END();
+}