Simple single-threaded file store service

Intended for storing function source code.

src/controller/fileStore.go

@@ -0,0 +1,98 @@
+/*
+Copyright 2016 The Fission Authors.
+
+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 controller
+
+import (
+	"io/ioutil"
+	"log"
+	"path"
+)
+
+type requestType int
+
+const (
+	READ requestType = iota
+	WRITE
+)
+
+type (
+	fileStore struct {
+		root           string // abs path of root of filestore
+		requestChannel chan fileStoreRequest
+	}
+
+	fileStoreRequest struct {
+		requestType
+		fileName        string // relative path
+		fileContents    []byte
+		responseChannel chan fileStoreResponse
+	}
+
+	fileStoreResponse struct {
+		error
+		fileContents []byte
+	}
+)
+
+func makeFileStore(path string) *fileStore {
+	fileStore := &fileStore{
+		root:           path,
+		requestChannel: make(chan fileStoreRequest),
+	}
+	go fileStore.fileStoreService()
+	return fileStore
+}
+
+func (fs *fileStore) fileStoreService() {
+	for {
+		req := <-fs.requestChannel
+		response := &fileStoreResponse{}
+
+		switch req.requestType {
+		case READ:
+			response.fileContents, response.error = ioutil.ReadFile(path.Join(fs.root, req.fileName))
+		case WRITE:
+			response.error = ioutil.WriteFile(path.Join(fs.root, req.fileName), req.fileContents, 0600)
+		default:
+			log.Panic("bad request")
+		}
+		req.responseChannel <- *response
+	}
+}
+
+func (fs *fileStore) read(fileName string) ([]byte, error) {
+	req := &fileStoreRequest{
+		requestType:     READ,
+		fileName:        fileName,
+		responseChannel: make(chan fileStoreResponse),
+	}
+	fs.requestChannel <- *req
+	response := <-req.responseChannel
+	return response.fileContents, response.error
+}
+
+func (fs *fileStore) write(fileName string, contents []byte) error {
+	req := &fileStoreRequest{
+		requestType:     WRITE,
+		fileName:        fileName,
+		fileContents:    contents,
+		responseChannel: make(chan fileStoreResponse),
+	}
+	fs.requestChannel <- *req
+	response := <-req.responseChannel
+	return response.error
+}

src/controller/fileStore_test.go

@@ -0,0 +1,58 @@
+/*
+Copyright 2016 The Fission Authors.
+
+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 controller
+
+import (
+	"io/ioutil"
+	"log"
+	"os"
+	"testing"
+)
+
+func TestFileStore(t *testing.T) {
+	// tmp dir
+	dir, err := ioutil.TempDir("", "testFileStore")
+	if err != nil {
+		t.Fatalf("error creating temp dir: %v", err)
+	}
+	defer os.RemoveAll(dir)
+	log.Printf("temp dir at %v", dir)
+
+	// file store
+	fs := makeFileStore(dir)
+
+	_, err = fs.read("nonexistent")
+	if err == nil {
+		t.Fatalf("expected an error")
+	}
+
+	path := "foo"
+	contents := []byte("bar")
+	err = fs.write(path, contents)
+	if err != nil {
+		t.Fatalf("error: %v", err)
+	}
+
+	observedContents, err := fs.read(path)
+	if err != nil {
+		t.Fatalf("error: %v", err)
+	}
+
+	if string(observedContents) != string(contents) {
+		t.Fatalf("contents don't match")
+	}
+}