通过Android App Bundle（AAB）从Google Play商店获取更新时，是否仅下载本地版本与最新版本间的变更内容？
Great question—let’s unpack this clearly, since it’s easy to mix up build-time optimizations and delivery-time updates.
核心结论
Yes, when distributing updates via Android App Bundle (AAB) through Google Play, users do not download the full app package every time. Instead, Google Play delivers only the changes between the user’s installed version and the latest release, leveraging AAB’s modular design.
详细拆解
First, let’s separate two related but distinct concepts:
- Incremental Build: This is a local development optimization—your build tool (like Gradle) only recompiles parts of your code that have changed since the last build, speeding up your workflow.
- Incremental App Delivery: This is the Google Play distribution mechanism that AAB enables, which is what you’re asking about.
Here’s how the AAB-based incremental update works:
- Modular Split APK Generation: When you upload an AAB to Google Play, the store splits it into multiple optimized split APKs tailored to different device configurations (e.g., CPU architecture, screen density, language packs, feature modules).
- Smart Update Calculation: When a user checks for updates, Google Play compares the split APKs already installed on their device with the latest version’s split APKs:
- If a split APK (like a language pack or feature module) hasn’t changed at all, it’s not downloaded again.
- For split APKs that have changed, Google Play uses delta updates—it calculates the byte-level difference between the old and new split, and only sends that difference (not the entire split file).
- Edge Cases: There are rare scenarios where a full optimized package might be delivered (e.g., if the user’s installed version is extremely outdated, making delta updates inefficient), but this is the exception, not the rule.
为什么AAB是关键？
AAB’s modular structure is what makes this efficient. Unlike a single monolithic APK, where even a tiny change would require downloading the entire file, AAB lets Google Play target only the specific modules or resources that have been updated.
内容的提问来源于stack exchange，提问作者angdroid
