server: Move all the top level files into cmd folder. (#2490)

This change brings a change which was done for the 'mc'
package to allow for clean repo and have a cleaner
github drop in experience.

cmd/tree-walk-pool_test.go

@@ -0,0 +1,103 @@
+/*
+ * Minio Cloud Storage, (C) 2016 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cmd
+
+import (
+	"testing"
+	"time"
+)
+
+// Test if tree walker go-routine is removed from the pool after timeout
+// and that is available in the pool before the timeout.
+func TestTreeWalkPoolBasic(t *testing.T) {
+	// Create a treeWalkPool
+	tw := newTreeWalkPool(1 * time.Second)
+
+	// Create sample params
+	params := listParams{
+		bucket: "test-bucket",
+	}
+
+	// Add a treeWalk to the pool
+	resultCh := make(chan treeWalkResult)
+	endWalkCh := make(chan struct{})
+	tw.Set(params, resultCh, endWalkCh)
+
+	// Wait for treeWalkPool timeout to happen
+	<-time.After(2 * time.Second)
+	if c1, _ := tw.Release(params); c1 != nil {
+		t.Error("treeWalk go-routine must have been freed")
+	}
+
+	// Add the treeWalk back to the pool
+	tw.Set(params, resultCh, endWalkCh)
+
+	// Release the treeWalk before timeout
+	select {
+	case <-time.After(1 * time.Second):
+		break
+	default:
+		if c1, _ := tw.Release(params); c1 == nil {
+			t.Error("treeWalk go-routine got freed before timeout")
+		}
+	}
+}
+
+// Test if multiple tree walkers for the same listParams are managed as expected by the pool.
+func TestManyWalksSameParam(t *testing.T) {
+	// Create a treeWalkPool.
+	tw := newTreeWalkPool(5 * time.Second)
+
+	// Create sample params.
+	params := listParams{
+		bucket: "test-bucket",
+	}
+
+	select {
+	// This timeout is an upper-bound. This is started
+	// before the first treeWalk go-routine's timeout period starts.
+	case <-time.After(5 * time.Second):
+		break
+	default:
+		// Create many treeWalk go-routines for the same params.
+		for i := 0; i < 10; i++ {
+			resultCh := make(chan treeWalkResult)
+			endWalkCh := make(chan struct{})
+			tw.Set(params, resultCh, endWalkCh)
+		}
+
+		tw.lock.Lock()
+		if walks, ok := tw.pool[params]; ok {
+			if len(walks) != 10 {
+				t.Error("There aren't as many walks as were Set")
+			}
+		}
+		tw.lock.Unlock()
+		for i := 0; i < 10; i++ {
+			tw.lock.Lock()
+			if walks, ok := tw.pool[params]; ok {
+				// Before ith Release we should have 10-i treeWalk go-routines.
+				if 10-i != len(walks) {
+					t.Error("There aren't as many walks as were Set")
+				}
+			}
+			tw.lock.Unlock()
+			tw.Release(params)
+		}
+	}
+
+}