Brotli compression

package.json

@@ -24,13 +24,15 @@
   },
   "dependencies": {
     "archiver": "^5.2.0",
+    "brotli": "^1.3.2",
     "commander": "^7.0.0",
     "crypto-random-string": "^3.3.0",
     "execa": "^4.1.0",
     "fs-extra": "^9.1.0"
   },
   "devDependencies": {
     "@types/archiver": "^5.1.0",
+    "@types/brotli": "^1.3.0",
     "@types/fs-extra": "^9.0.7",
     "@types/jest": "^26.0.20",
     "@types/node": "^14.14.26",

src/index.ts

@@ -1,29 +1,36 @@
 #!/usr/bin/env node
 
+import stream from "stream";
 import process from "process";
 import path from "path";
 import os from "os";
 import fs from "fs-extra";
 import execa from "execa";
 import archiver from "archiver";
+import brotli from "brotli";
 import cryptoRandomString from "crypto-random-string";
 import commander from "commander";
 
 export default async function caxa({
   directory,
   command,
   output,
+  format,
 }: {
   directory: string;
   command: string[];
   output: string;
+  format: string;
 }): Promise<void> {
   if (
     !(await fs.pathExists(directory)) ||
     !(await fs.lstat(directory)).isDirectory()
   )
     throw new Error(`The path to package isn’t a directory: ‘${directory}’.`);
 
+  if (["gzip", "brotli"].indexOf(format) === -1)
+    throw new Error(`Format must be ‘gzip’ or ‘brotli’.`);
+
   const identifier = path.join(
     path.basename(path.basename(output, ".app"), ".exe"),
     cryptoRandomString({ length: 10, type: "alphanumeric" }).toLowerCase()
@@ -87,17 +94,34 @@ export default async function caxa({
       ),
       output
     );
-    const archive = archiver("tar", { gzip: true });
-    const archiveStream = fs.createWriteStream(output, { flags: "a" });
+
+    const rawData: any[] = [];
+    const rawStream = new stream.Writable({
+      write: (chunk, _, done) => {
+        rawData.push(chunk);
+        done();
+      },
+    });
+
+    const archive = archiver("tar", { gzip: format === "gzip" });
+    const archiveStream = (format === "gzip") ? fs.createWriteStream(output, { flags: "a" }) : rawStream;
+
     archive.pipe(archiveStream);
     archive.directory(appDirectory, false);
-    await archive.finalize();
+
     // FIXME: Use ‘stream/promises’ when Node.js 16 lands, because then an LTS version will have the feature: await stream.finished(archiveStream);
-    await new Promise((resolve, reject) => {
+    let finishPromise = new Promise((resolve, reject) => {
       archiveStream.on("finish", resolve);
       archiveStream.on("error", reject);
     });
-    await fs.appendFile(output, "\n" + JSON.stringify({ identifier, command }));
+
+    await archive.finalize();
+    await finishPromise;
+
+    if (format === "brotli")
+      await fs.appendFile(output, brotli.compress(Buffer.concat(rawData)));
+
+    await fs.appendFile(output, "\n" + JSON.stringify({ identifier, command, format }));
   }
 }
 
@@ -116,6 +140,7 @@ if (require.main === module)
         "-o, --output <output>",
         "The path at which to produce the executable. Overwrites existing files/folders. On Windows must end in ‘.exe’. On macOS may end in ‘.app’ to generate a macOS Application Bundle."
       )
+      .option("-f, --format <format>", "The compression format to use, either ‘gzip’ (default) or ‘brotli’. Brotli takes several minutes to compress, but generates an output executable at least 6MB smaller.", "gzip")
       .version(require("../package.json").version)
       .addHelpText(
         "after",
@@ -137,13 +162,15 @@ Examples:
           directory,
           command,
           output,
+          format,
         }: {
           directory: string;
           command: string[];
           output: string;
+          format: string;
         }) => {
           try {
-            await caxa({ directory, command, output });
+            await caxa({ directory, command, output, format });
           } catch (error) {
             console.error(error.message);
             process.exit(1);

stubs/go.mod

@@ -0,0 +1,5 @@
+module github.com/leafac/caxa/stubs
+
+go 1.16
+
+require github.com/google/brotli/go/cbrotli v0.0.0-20210127140805-63be8a994019

stubs/go.sum

@@ -0,0 +1,2 @@
+github.com/google/brotli/go/cbrotli v0.0.0-20210127140805-63be8a994019 h1:XYW4NntIMcMzsu+XjMKziKuSgthVc/nSnDrFu/iJuzA=
+github.com/google/brotli/go/cbrotli v0.0.0-20210127140805-63be8a994019/go.mod h1:nOPhAkwVliJdNTkj3gXpljmWhjc4wCaVqbMJcPKWP4s=

stubs/stub.go

@@ -16,6 +16,7 @@ import (
 	"regexp"
 	"strings"
 	"time"
+	"github.com/google/brotli/go/cbrotli"
 )
 
 func main() {
@@ -38,12 +39,15 @@ func main() {
 	var footer struct {
 		Identifier string   `json:"identifier"`
 		Command    []string `json:"command"`
+		Format     string   `json:"format"`
 	}
 	if err := json.Unmarshal(footerString, &footer); err != nil {
 		log.Fatalf("caxa stub: Failed to parse JSON in footer: %v", err)
 	}
 
 	appDirectory := path.Join(os.TempDir(), "caxa", footer.Identifier)
+	log.Printf("caxa stub: appDirectory: %v", appDirectory)
+
 	appDirectoryFileInfo, err := os.Stat(appDirectory)
 	if err != nil && !errors.Is(err, os.ErrNotExist) {
 		log.Fatalf("caxa stub: Failed to find information about caxa directory: %v", err)
@@ -63,7 +67,18 @@ func main() {
 		}
 		archive := executable[archiveIndex+len(archiveSeparator) : footerIndex]
 
-		if err := Untar(bytes.NewReader(archive), appDirectory); err != nil {
+		var reader io.Reader;
+
+		if footer.Format == "brotli" {
+			reader = cbrotli.NewReader(bytes.NewReader(archive))
+		} else {
+			reader, err = gzip.NewReader(bytes.NewReader(archive))
+			if err != nil {
+				log.Fatalf("requires gzip compressed body: %v", err)
+			}
+		}
+
+		if err := Untar(reader, appDirectory); err != nil {
 			log.Fatalf("caxa stub: Failed to uncompress archive: %v", err)
 		}
 	}
@@ -131,11 +146,7 @@ func untar(r io.Reader, dir string) (err error) {
 	// 		log.Printf("error extracting tarball into %s after %d files, %d dirs, %v: %v", dir, nFiles, len(madeDir), td, err)
 	// 	}
 	// }()
-	zr, err := gzip.NewReader(r)
-	if err != nil {
-		return fmt.Errorf("requires gzip-compressed body: %v", err)
-	}
-	tr := tar.NewReader(zr)
+	tr := tar.NewReader(r)
 	loggedChtimesError := false
 	for {
 		f, err := tr.Next()

tsconfig.json

@@ -12,5 +12,6 @@
     "sourceMap": true,
 
     "strict": true
-  }
+  },
+  "exclude": ["examples"]
 }