Force recovery to use entire log by leaving an oldest living transaction that is older than

any transaction that commits or aborts.  Delete code that truncated the log to force the same
behavior.


git-svn-id: file:///svn/toku/tokudb@16233 c7de825b-a66e-492c-adef-691d508d4ae1

src/tests/recover-lsn-filter.c

@@ -18,6 +18,12 @@ static void run_test (void) {
     r = db_env_create(&env, 0);                                                         CKERR(r);
     r = env->open(env, ENVDIR, envflags, S_IRWXU+S_IRWXG+S_IRWXO);                      CKERR(r);
 
+    // create a txn that never closes, forcing recovery to run from the beginning of the log
+    {
+        DB_TXN *oldest_living_txn;
+        r = env->txn_begin(env, NULL, &oldest_living_txn, 0);                                         CKERR(r);
+    }
+
     DB *db;
     r = db_create(&db, env, 0);                                                         CKERR(r);
     r = db->open(db, NULL, namea, NULL, DB_BTREE, DB_AUTO_COMMIT|DB_CREATE, 0666);      CKERR(r);
@@ -48,24 +54,13 @@ static void run_test (void) {
     abort();
 }
 
-static int my_truncate(const char *fname, toku_off_t offset) {
-    int fd = open(fname, O_RDWR + O_BINARY);
-    if (fd == -1) return errno;
-    int r = ftruncate(fd, offset);
-    close(fd);
-    return r;
-}
 
 static void run_recover (void) {
     DB_ENV *env;
     int r;
 
-    // strip the end_checkpoint from the log.  this will force recovery to run the over
-    // the entire log.
-    // TODO need an API to do this
-    toku_struct_stat s;
-    r = toku_stat(ENVDIR "/log000000000000.tokulog", &s);                               CKERR(r);
-    r = my_truncate(ENVDIR "/log000000000000.tokulog", s.st_size - 0x25);               CKERR(r);
+    // Recovery starts from oldest_living_txn, which is older than any inserts done in run_test,
+    // so recovery always runs over the entire log.
 
     // run recovery
     r = db_env_create(&env, 0);                                                         CKERR(r);