API and documentation enhancements (#1)

Comprehensive update to the buildinfo package

* Added LoadAsync function so that build information can be loaded
  from a separate goroutine.

* Documentation improvements.

* Github action integration.

* Create README.md

* Added code example.

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,71 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ main ]
+  schedule:
+    - cron: '26 2 * * 4'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

.github/workflows/test.yml

@@ -0,0 +1,14 @@
+name: test
+
+on: [push]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    container:
+      image: qqiao/dev-env:latest
+      options: --user root
+
+    steps:
+      - uses: actions/checkout@v2
+      - run: go test -v ./...

README.md

@@ -0,0 +1,14 @@
+# buildinfo
+
+Buildinfo is a library that provides an easy solution to embed build information into any applications.
+
+### Installation
+
+The `buildinfo` package is a go module, so simply using:
+
+    go get github.com/qqiao/buildinfo
+
+in your application's go module should make it available.
+
+### Usage
+Please refer to [source code documentation](https://pkg.go.dev/github.com/qqiao/buildinfo) for usage examples.

buildinfo.go

@@ -25,13 +25,39 @@ type BuildInfo struct {
 	Revision  string `json:"revision"`
 }
 
-// Load loads the build info from the given path.
-func Load(path string) (BuildInfo, error) {
+// Load loads the build information from the given path.
+func Load(path string) (*BuildInfo, error) {
 	var buildInfo BuildInfo
 	file, err := ioutil.ReadFile(path)
 	if err != nil {
-		return buildInfo, err
+		return nil, err
 	}
 
-	return buildInfo, json.Unmarshal(file, &buildInfo)
+	if err := json.Unmarshal(file, &buildInfo); err != nil {
+		return nil, err
+	}
+
+	return &buildInfo, nil
+}
+
+// LoadAsync loads the build information from the given path.
+//
+// This function internally invokes the Load funtion in a separate goroutine.
+// This allows the slow file I/O and JSON unmarshalling to be parallelized.
+func LoadAsync(path string) (<-chan *BuildInfo, <-chan error) {
+	out := make(chan *BuildInfo)
+	errs := make(chan error)
+
+	go func() {
+		defer close(out)
+		defer close(errs)
+
+		if buildInfo, err := Load(path); err != nil {
+			errs <- err
+		} else {
+			out <- buildInfo
+		}
+	}()
+
+	return out, errs
 }

buildinfo_test.go

@@ -0,0 +1,73 @@
+// Copyright 2017 Qian Qiao
+//
+// 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 buildinfo_test
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+
+	"github.com/qqiao/buildinfo"
+)
+
+var expected = &buildinfo.BuildInfo{
+	BuildTime: 1648396360413459000,
+	Revision:  "e594b8e",
+}
+
+func ExampleLoad() {
+	buildInfo, err := buildinfo.Load("./test_data.json")
+	if err != nil {
+		// Handle the loading error
+	} else {
+		// Use/store the buildInfo
+		fmt.Println(buildInfo.Revision)
+	}
+}
+
+func ExampleLoadAsync() {
+	buildInfoCh, errCh := buildinfo.LoadAsync("./test_data.json")
+
+	select {
+	case <-errCh:
+		// Handle the loading error
+	case buildInfo := <-buildInfoCh:
+		// Use/store the buildInfo
+		fmt.Println(buildInfo.Revision)
+	}
+}
+
+func TestLoad(t *testing.T) {
+	if got, err := buildinfo.Load("./test_data.json"); err != nil {
+		t.Errorf("Error loading test data: %v", err)
+	} else {
+		if !reflect.DeepEqual(expected, got) {
+			t.Errorf("Expected: %v\nGot: %v", expected, got)
+		}
+	}
+}
+
+func TestLoadAsync(t *testing.T) {
+	gotCh, errCh := buildinfo.LoadAsync("./test_data.json")
+
+	select {
+	case err := <-errCh:
+		t.Errorf("Error loading test data: %v", err)
+	case got := <-gotCh:
+		if !reflect.DeepEqual(expected, got) {
+			t.Errorf("Expected: %v\nGot: %v", expected, got)
+		}
+	}
+}

doc.go

@@ -0,0 +1,21 @@
+// Copyright 2022 Qian Qiao
+//
+// 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 buildinfo contains helper functions to help embed build information
+into an application.
+
+*/
+package buildinfo

test_data.json

@@ -0,0 +1,4 @@
+{
+  "buildTime" : 1648396360413459000,
+  "revision" : "e594b8e"
+}