Updates to remove Mutex

.gitignore

@@ -1 +1,2 @@
-hacker_news
+hacker_news
+.DS_Store

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.20 AS builder
+FROM golang:1.22 AS builder
 
 WORKDIR /app
 
@@ -17,4 +17,4 @@ WORKDIR /
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
 COPY --from=builder /hacker_news /hacker_news
 
-ENTRYPOINT ["/hacker_news"]
+ENTRYPOINT ["/hacker_news"]

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2021 Anthony Scotti
+Copyright (c) 2024 Anthony Scotti
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -18,4 +18,4 @@ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
+SOFTWARE.

README.md

@@ -2,13 +2,14 @@
 
 A command line tool that shows the top stories from [Hacker News](https://news.ycombinator.com/) using the [Hacker News API from Firebase](https://github.com/HackerNews/API).
 
-This is a port of an dotnet version, [hn-top](https://github.com/amscotti/hn-top) which I used to learn about Go and understand how to keep the order of the stories when using Goroutines with help of Mutex and WaitGroup.
+This is a port of an dotnet version, [hn-top](https://github.com/amscotti/hn-top) which I used to learn about Go and understand how to keep the order of the stories when using Goroutines.
 
 ![hacker_news Output](hacker_news.png)
 
 ## Building and Running
 
 ### With Go
+
 To build and run the application, follow these steps:
 
 1. Clone the repository.
@@ -17,6 +18,7 @@ To build and run the application, follow these steps:
 4. Run the binary with `./hacker_news`.
 
 ### With Docker
+
 To build and run the application with Docker, follow these steps:
 
 1. Clone the repository.
@@ -25,17 +27,19 @@ To build and run the application with Docker, follow these steps:
 4. Run the Docker container with `docker run hacker_news`.
 
 ### With pre-built Docker image from [ghcr.io](https://github.com/amscotti/hacker_news/pkgs/container/hacker_news)
+
 To download and run the pre-built Docker image, follow these steps:
 
 1. Install Docker.
 2. Run the command `docker run ghcr.io/amscotti/hacker_news:main`.
 
 ### Command Line Arguments
+
 The following command line arguments are available:
 
 ```
 Usage of ./hacker_news:
   -n int
-        Specify the number of top stories to display (default: 5). (default 5)
+        Specify the number of top stories to display. (default: 30)
   -u    Include the source URLs of the stories in the output.
-```
+```

go.mod

@@ -1,17 +1,17 @@
 module github.com/amscotti/hacker_news
 
-go 1.20
+go 1.22
 
-require github.com/charmbracelet/lipgloss v0.7.1
+require github.com/charmbracelet/lipgloss v0.10.0
 
 require (
 	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
 	github.com/lucasb-eyer/go-colorful v1.2.0 // indirect
-	github.com/mattn/go-isatty v0.0.17 // indirect
-	github.com/mattn/go-runewidth v0.0.14 // indirect
+	github.com/mattn/go-isatty v0.0.19 // indirect
+	github.com/mattn/go-runewidth v0.0.15 // indirect
 	github.com/muesli/reflow v0.3.0 // indirect
-	github.com/muesli/termenv v0.15.1 // indirect
-	github.com/rivo/uniseg v0.2.0 // indirect
+	github.com/muesli/termenv v0.15.2 // indirect
+	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/valyala/fastjson v1.6.4
-	golang.org/x/sys v0.6.0 // indirect
+	golang.org/x/sys v0.12.0 // indirect
 )

go.sum

@@ -1,23 +1,24 @@
 github.com/aymanbagabas/go-osc52/v2 v2.0.1 h1:HwpRHbFMcZLEVr42D4p7XBqjyuxQH5SMiErDT4WkJ2k=
 github.com/aymanbagabas/go-osc52/v2 v2.0.1/go.mod h1:uYgXzlJ7ZpABp8OJ+exZzJJhRNQ2ASbcXHWsFqH8hp8=
-github.com/charmbracelet/lipgloss v0.7.1 h1:17WMwi7N1b1rVWOjMT+rCh7sQkvDU75B2hbZpc5Kc1E=
-github.com/charmbracelet/lipgloss v0.7.1/go.mod h1:yG0k3giv8Qj8edTCbbg6AlQ5e8KNWpFujkNawKNhE2c=
+github.com/charmbracelet/lipgloss v0.10.0 h1:KWeXFSexGcfahHX+54URiZGkBFazf70JNMtwg/AFW3s=
+github.com/charmbracelet/lipgloss v0.10.0/go.mod h1:Wig9DSfvANsxqkRsqj6x87irdy123SR4dOXlKa91ciE=
 github.com/lucasb-eyer/go-colorful v1.2.0 h1:1nnpGOrhyZZuNyfu1QjKiUICQ74+3FNCN69Aj6K7nkY=
 github.com/lucasb-eyer/go-colorful v1.2.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
-github.com/mattn/go-isatty v0.0.17 h1:BTarxUcIeDqL27Mc+vyvdWYSL28zpIhv3RoTdsLMPng=
-github.com/mattn/go-isatty v0.0.17/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA=
+github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-runewidth v0.0.12/go.mod h1:RAqKPSqVFrSLVXbA8x7dzmKdmGzieGRCM46jaSJTDAk=
-github.com/mattn/go-runewidth v0.0.14 h1:+xnbZSEeDbOIg5/mE6JF0w6n9duR1l3/WmbinWVwUuU=
-github.com/mattn/go-runewidth v0.0.14/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
+github.com/mattn/go-runewidth v0.0.15 h1:UNAjwbU9l54TA3KzvqLGxwWjHmMgBUVhBiTjelZgg3U=
+github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/muesli/reflow v0.3.0 h1:IFsN6K9NfGtjeggFP+68I4chLZV2yIKsXJFNZ+eWh6s=
 github.com/muesli/reflow v0.3.0/go.mod h1:pbwTDkVPibjO2kyvBQRBxTWEEGDGq0FlB1BIKtnHY/8=
-github.com/muesli/termenv v0.15.1 h1:UzuTb/+hhlBugQz28rpzey4ZuKcZ03MeKsoG7IJZIxs=
-github.com/muesli/termenv v0.15.1/go.mod h1:HeAQPTzpfs016yGtA4g00CsdYnVLJvxsS4ANqrZs2sQ=
+github.com/muesli/termenv v0.15.2 h1:GohcuySI0QmI3wN8Ok9PtKGkgkFIk7y6Vpb5PvrY+Wo=
+github.com/muesli/termenv v0.15.2/go.mod h1:Epx+iuz8sNs7mNKhxzH4fWXGNpZwUaJKRS1noLXviQ8=
 github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
-github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
+github.com/rivo/uniseg v0.4.7/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
 github.com/valyala/fastjson v1.6.4 h1:uAUNq9Z6ymTgGhcm0UynUAB6tlbakBrz6CQFax3BXVQ=
 github.com/valyala/fastjson v1.6.4/go.mod h1:CLCAqky6SMuOcxStkYQvblddUtoRxhYMGLrsQns1aXY=
-golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.6.0 h1:MVltZSvRTcU2ljQOhs94SXPftV6DCNnZViHeQps87pQ=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
+golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

hackernews/api.go

@@ -16,19 +16,29 @@ const (
 	ITEM_URL_BASE = "https://hacker-news.firebaseio.com/v0/item"
 )
 
-func createClient() *http.Client {
-	transport := &http.Transport{
-		MaxIdleConns:    100,
-		IdleConnTimeout: 30 * time.Second,
-	}
-	return &http.Client{
-		Transport: transport,
-		Timeout:   time.Duration(10 * time.Second),
-	}
+type StoryIdPair struct {
+	PlacementId int
+	StoryId     int
+}
+
+var clientPool = sync.Pool{
+	New: func() interface{} {
+		transport := &http.Transport{
+			MaxIdleConns:        100,
+			MaxIdleConnsPerHost: 100,
+			IdleConnTimeout:     30 * time.Second,
+		}
+		return &http.Client{
+			Transport: transport,
+			Timeout:   time.Duration(10 * time.Second),
+		}
+	},
 }
 
 func fetchJSON(url string) (*fastjson.Value, error) {
-	client := createClient()
+	client := clientPool.Get().(*http.Client)
+	defer clientPool.Put(client)
+
 	resp, err := client.Get(url)
 	if err != nil {
 		return nil, fmt.Errorf("failed to fetch %s: %w", url, err)
@@ -48,36 +58,36 @@ func fetchJSON(url string) (*fastjson.Value, error) {
 	return value, nil
 }
 
-func downloadStory(id int, wg *sync.WaitGroup, m *sync.Mutex, stories map[int]Story) {
-	defer wg.Done()
-
-	url := fmt.Sprintf("%s/%d.json", ITEM_URL_BASE, id)
-
-	value, err := fetchJSON(url)
-	if err != nil {
-		log.Printf("Error fetching story with id %d: %v", id, err)
-		return
+func downloadStory(storyIdChan <-chan StoryIdPair, storyChan chan<- Story) {
+	for storyId := range storyIdChan {
+		url := fmt.Sprintf("%s/%d.json", ITEM_URL_BASE, storyId.StoryId)
+
+		value, err := fetchJSON(url)
+		if err != nil {
+			log.Printf("Error fetching story with id %d: %v", storyId.StoryId, err)
+			storyChan <- Story{}
+			return
+		}
+
+		story := Story{
+			Index:       storyId.PlacementId,
+			Title:       string(value.GetStringBytes("title")),
+			By:          string(value.GetStringBytes("by")),
+			Descendants: int(value.GetInt("descendants")),
+			Id:          int(value.GetInt("id")),
+			Score:       int(value.GetInt("score")),
+			Time:        int(value.GetInt("time")),
+			Type:        string(value.GetStringBytes("type")),
+			URL:         string(value.GetStringBytes("url")),
+		}
+
+		kids := value.GetArray("kids")
+		for i := range kids {
+			story.Kids = append(story.Kids, int(kids[i].GetInt()))
+		}
+
+		storyChan <- story
 	}
-
-	story := Story{
-		Title:       string(value.GetStringBytes("title")),
-		By:          string(value.GetStringBytes("by")),
-		Descendants: int(value.GetInt("descendants")),
-		Id:          int(value.GetInt("id")),
-		Score:       int(value.GetInt("score")),
-		Time:        int(value.GetInt("time")),
-		Type:        string(value.GetStringBytes("type")),
-		URL:         string(value.GetStringBytes("url")),
-	}
-
-	kids := value.GetArray("kids")
-	for i := range kids {
-		story.Kids = append(story.Kids, int(kids[i].GetInt()))
-	}
-
-	m.Lock()
-	stories[id] = story
-	m.Unlock()
 }
 
 func FetchTopStories(number int, showSourceUrls bool) {
@@ -87,32 +97,33 @@ func FetchTopStories(number int, showSourceUrls bool) {
 		return
 	}
 
-	var ids []int
 	valueArray := value.GetArray()
-	for i := 0; i < len(valueArray); i++ {
-		id := int(valueArray[i].GetInt())
-		ids = append(ids, id)
-	}
+	count := min(len(valueArray), number)
 
-	if len(ids) > number {
-		ids = ids[:number]
-	}
+	stories := make([]Story, count)
 
-	storyDetails := make(map[int]Story)
+	storyIdChan := make(chan StoryIdPair, count)
+	storyChan := make(chan Story, count)
 
-	var m sync.Mutex
-	var wg sync.WaitGroup
+	for range count {
+		go downloadStory(storyIdChan, storyChan)
+	}
 
-	wg.Add(len(ids))
+	go func() {
+		for index, id := range valueArray[:number] {
+			storyIdChan <- StoryIdPair{PlacementId: index, StoryId: id.GetInt()}
+		}
+		close(storyIdChan)
+	}()
 
-	for _, id := range ids {
-		go downloadStory(id, &wg, &m, storyDetails)
+	for range count {
+		story := <-storyChan
+		stories[story.Index] = story
 	}
 
-	wg.Wait()
+	close(storyChan)
 
-	for _, id := range ids {
-		story := storyDetails[id]
+	for _, story := range stories {
 		fmt.Print(story.PrintStyling(showSourceUrls))
 	}
 }

hackernews/models.go

@@ -11,6 +11,7 @@ const (
 )
 
 type Story struct {
+	Index       int
 	Title       string
 	By          string
 	Descendants int

main.go

@@ -12,7 +12,7 @@ func main() {
 	var number int
 	var showSourceUrls bool
 
-	flag.IntVar(&number, "n", 5, "Specify the number of top stories to display (default: 5).")
+	flag.IntVar(&number, "n", 30, "Specify the number of top stories to display.")
 	flag.BoolVar(&showSourceUrls, "u", false, "Include the source URLs of the stories in the output.")
 	flag.Parse()