feat(snap): add Snap compression option

.changeset/spicy-crabs-draw.md

@@ -0,0 +1,13 @@
+---
+"app-builder-lib": minor
+"builder-util": major
+---
+
+Default to LZO compression for snap packages.
+This greatly improves cold startup performance (https://snapcraft.io/blog/why-lzo-was-chosen-as-the-new-compression-method).
+LZO has already been adopted by most desktop-oriented snaps outside of the Electron realm.
+
+For the rare case where developers prefer a smaller file size (XZ) to vastly improved decompression performance (LZO),
+provide an option to override the default compression method.
+
+Consumers do not need to update their configuration unless they specifically want to stick to XZ compression.

docker/base/Dockerfile

@@ -13,7 +13,7 @@ RUN apt-get -qq update && apt-get -qq dist-upgrade && \
   apt-get -qq install --no-install-recommends \
         qtbase5-dev build-essential autoconf libssl-dev gcc-multilib g++-multilib \
         lzip rpm python libcurl4 git git-lfs ssh unzip libarchive-tools \
-        libxtst6 libsecret-1-dev libopenjp2-tools \
+        libxtst6 libsecret-1-dev libopenjp2-tools liblzo2-2 \
   && \
   # git-lfs
   git lfs install && \

packages/app-builder-lib/scheme.json

@@ -2146,7 +2146,8 @@
               "enum": [
                 "bzip2",
                 "gz",
-                "xz"
+                "xz",
+                "lzo"
               ],
               "type": "string"
             },
@@ -5400,6 +5401,22 @@
             "string"
           ]
         },
+        "compression": {
+          "anyOf": [
+            {
+              "enum": [
+                "xz",
+                "lzo"
+              ],
+              "type": "string"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": "lzo",
+          "description": "Sets the compression type for the snap. Can be xz or lzo. Defaults to lzo when not specified."
+        },
         "useTemplateApp": {
           "description": "Whether to use template snap. Defaults to `true` if `stagePackages` not specified.",
           "type": "boolean"

packages/app-builder-lib/src/options/SnapOptions.ts

@@ -125,6 +125,12 @@ export interface SnapOptions extends CommonLinuxOptions, TargetSpecificOptions {
    * An optional title for the snap, may contain uppercase letters and spaces. Defaults to `productName`. See [snap format documentation](https://snapcraft.io/docs/snap-format).
    */
   readonly title?: string | null
+
+  /**
+   * Sets the compression type for the snap. Can be xz or lzo. Defaults to lzo when not specified.
+   * @default lzo
+   */
+   readonly compression?: "xz" | "lzo" | null
 }
 
 export interface PlugDescriptor {

packages/app-builder-lib/src/options/linuxOptions.ts

@@ -77,7 +77,7 @@ export interface LinuxTargetSpecificOptions extends CommonLinuxOptions, TargetSp
    * The compression type.
    * @default xz
    */
-  readonly compression?: "gz" | "bzip2" | "xz" | null
+  readonly compression?: "gz" | "bzip2" | "xz" | "lzo" | null
 
   readonly icon?: string
 

packages/app-builder-lib/src/targets/snap.ts

@@ -100,6 +100,7 @@ export default class SnapTarget extends Target {
       version: appInfo.version,
       title: options.title || appInfo.productName,
       summary: options.summary || appInfo.productName,
+      compression: options.compression,
       description: this.helper.getDescription(options),
       architectures: [toLinuxArchString(arch, "snap")],
       apps: {
@@ -207,6 +208,10 @@ export default class SnapTarget extends Target {
       }
     }
 
+    if (snap.compression != null) {
+      args.push("--compression", snap.compression)
+    }
+
     if (packager.packagerOptions.effectiveOptionComputed != null && (await packager.packagerOptions.effectiveOptionComputed({ snap, desktopFile, args }))) {
       return
     }
@@ -221,6 +226,7 @@ export default class SnapTarget extends Target {
     if (this.isUseTemplateApp) {
       args.push("--template-url", `electron4:${snapArch}`)
     }
+
     await executeAppBuilder(args)
 
     await packager.info.callArtifactBuildCompleted({

packages/app-builder-lib/templates/snap/snapcraft.yaml

@@ -1,6 +1,7 @@
 base: core18
 grade: stable
 confinement: strict
+compression: lzo
 parts:
   launch-scripts:
     plugin: dump

packages/builder-util/package.json

@@ -18,7 +18,7 @@
     "7zip-bin": "~5.1.1",
     "@types/debug": "^4.1.6",
     "@types/fs-extra": "^9.0.11",
-    "app-builder-bin": "3.7.1",
+    "app-builder-bin": "4.1.0",
     "bluebird-lst": "^1.0.9",
     "builder-util-runtime": "workspace:*",
     "chalk": "^4.1.1",