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/erasure-utils_test.go

@@ -0,0 +1,160 @@
+/*
+ * 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 (
+	"bytes"
+	"errors"
+	"io"
+	"testing"
+)
+
+// Test validates the number hash writers returned.
+func TestNewHashWriters(t *testing.T) {
+	diskNum := 8
+	hashWriters := newHashWriters(diskNum, bitRotAlgo)
+	if len(hashWriters) != diskNum {
+		t.Errorf("Expected %d hashWriters, but instead got %d", diskNum, len(hashWriters))
+	}
+
+}
+
+// Tests validate the output of getChunkSize.
+func TestGetChunkSize(t *testing.T) {
+	// Refer to comments on getChunkSize() for details.
+	testCases := []struct {
+		blockSize  int64
+		dataBlocks int
+		// expected result.
+		expectedChunkSize int64
+	}{
+		{
+			10,
+			10,
+			1,
+		},
+		{
+			10,
+			11,
+			1,
+		},
+		{
+			10,
+			9,
+			2,
+		},
+	}
+	// Verify getChunkSize() for the test cases.
+	for i, testCase := range testCases {
+		got := getChunkSize(testCase.blockSize, testCase.dataBlocks)
+		if testCase.expectedChunkSize != got {
+			t.Errorf("Test %d : expected=%d got=%d", i+1, testCase.expectedChunkSize, got)
+		}
+	}
+}
+
+// TestCopyBuffer - Tests validate the result and errors produced when `copyBuffer` is called with sample inputs.
+func TestCopyBuffer(t *testing.T) {
+	// create posix test setup
+	disk, diskPath, err := newPosixTestSetup()
+	if err != nil {
+		t.Fatalf("Unable to create posix test setup, %s", err)
+	}
+	defer removeAll(diskPath)
+
+	volume := "success-vol"
+	// Setup test environment.
+	if err = disk.MakeVol(volume); err != nil {
+		t.Fatalf("Unable to create volume, %s", err)
+	}
+
+	// creating io.Writer for the input to copyBuffer.
+	buffers := []*bytes.Buffer{
+		new(bytes.Buffer),
+		new(bytes.Buffer),
+		new(bytes.Buffer),
+	}
+
+	testFile := "testFile"
+	testContent := []byte("hello, world")
+	err = disk.AppendFile(volume, testFile, testContent)
+	if err != nil {
+		t.Fatalf("AppendFile failed: <ERROR> %s", err)
+	}
+
+	testCases := []struct {
+		writer io.Writer
+		disk   StorageAPI
+		volume string
+		path   string
+		buf    []byte
+
+		expectedResult []byte
+		// flag to indicate whether test case should pass.
+		shouldPass  bool
+		expectedErr error
+	}{
+		// Test case - 1.
+		// case with empty buffer.
+		{nil, nil, "", "", []byte{}, nil, false, errors.New("empty buffer in readBuffer")},
+		// Test case - 2.
+		// Test case with empty volume.
+		{buffers[0], disk, "", "", make([]byte, 5), nil, false, errInvalidArgument},
+		// Test case - 3.
+		// Test case with non existent volume.
+		{buffers[0], disk, "abc", "", make([]byte, 5), nil, false, errVolumeNotFound},
+		// Test case - 4.
+		// Test case with empty filename/path.
+		{buffers[0], disk, volume, "", make([]byte, 5), nil, false, errIsNotRegular},
+		// Test case - 5.
+		// Test case with non existent file name.
+		{buffers[0], disk, volume, "abcd", make([]byte, 5), nil, false, errFileNotFound},
+		// Test case - 6.
+		// Test case where the writer returns EOF.
+		{NewEOFWriter(buffers[0], 3), disk, volume, testFile, make([]byte, 5), nil, false, io.EOF},
+		// Test case - 7.
+		// Test case to produce io.ErrShortWrite, the TruncateWriter returns after writing 3 bytes.
+		{TruncateWriter(buffers[1], 3), disk, volume, testFile, make([]byte, 5), nil, false, io.ErrShortWrite},
+		// Teset case - 8.
+		// Valid case, expected to read till EOF and write the contents into the writer.
+		{buffers[2], disk, volume, testFile, make([]byte, 5), testContent, true, nil},
+	}
+	// iterate over the test cases and call copy Buffer with data.
+	for i, testCase := range testCases {
+		actualErr := copyBuffer(testCase.writer, testCase.disk, testCase.volume, testCase.path, testCase.buf)
+
+		if actualErr != nil && testCase.shouldPass {
+			t.Errorf("Test %d: Expected to pass but failed instead with \"%s\"", i+1, actualErr)
+		}
+
+		if actualErr == nil && !testCase.shouldPass {
+			t.Errorf("Test %d: Expected to fail with error <Error> \"%v\", but instead passed", i+1, testCase.expectedErr)
+		}
+		// Failed as expected, but does it fail for the expected reason.
+		if actualErr != nil && !testCase.shouldPass {
+			if testCase.expectedErr.Error() != actualErr.Error() {
+				t.Errorf("Test %d: Expected Error to be \"%v\", but instead found \"%v\" ", i+1, testCase.expectedErr, actualErr)
+			}
+		}
+		// test passed as expected, asserting the result.
+		if actualErr == nil && testCase.shouldPass {
+			if !bytes.Equal(testCase.expectedResult, buffers[2].Bytes()) {
+				t.Errorf("Test %d: copied buffer differs from the expected one.", i+1)
+			}
+		}
+	}
+}