| # Cronet impl (and shared) code |
| |
| This directory contains the so-called Cronet "impl" code, which provides |
| working production implementations of the Cronet API. Currently this includes: |
| |
| - The "native" CronetEngine implementation backed by `//net`, which is what most |
| people refer to as simply "Cronet" and comes with all the bells and whistles. |
| Relevant classes are typically identified by a `Cronet` prefix; |
| - The "fallback" or "Java" lightweight implementation backed by |
| `java.net.HttpURLConnection`. This implementation is much smaller and lacks |
| many features. Relevant classes are typically identified by a `Java` prefix. |
| |
| This directory also contains so-called "shared" code, which is shared between |
| all Cronet packages, *including* the API package. |
| |
| TODO(crbug.com/40947707): these should really be three distinct directories. |
| |
| **IMPORTANT:** in most Cronet release channels (e.g. Google-internal, Maven, |
| AOSP) the API and impl code are expected to always be in sync with each other, |
| i.e. they come from the same build. That is NOT true, however, when loading |
| Cronet from Google Play Services. In that case the app will typically bundle a |
| Cronet API library that is from a different build/version than the Cronet native |
| impl code provided by Google Play Services on a given device. In practice this |
| means that **the API code and native impl code must be backwards and forwards |
| compatible with each other at the Java ABI level**. Note, though, that Google |
| Play Services only provides *native* Cronet - this is not an issue for the |
| fallback implementation. |
