This commit is introducing breaking changes.
For clients, everything is managed in a new class called
YoutubeJavaScriptPlayerManager:
- caching JavaScript base player code and its extracted code (functions and
variables);
- getting player signature timestamp;
- getting deobfuscated signatures of streaming URLs;
- getting streaming URLs with a throttling parameter deobfuscated, if
applicable.
The class delegates the extraction parts to external package-private classes:
- YoutubeJavaScriptExtractor, to extract and download YouTube's JavaScript base
player code: it always already present before and has been edited to mainly
remove the previous caching system and made it package-private;
- YoutubeSignatureUtils, for player signature timestamp and signature
deobfuscation function of streaming URLs, added in a recent commit;
- YoutubeThrottlingParameterUtils, which was originally
YoutubeThrottlingDecrypter, for throttling parameter of streaming URLs
deobfuscation function and checking whether this parameter is in a streaming
URL.
YoutubeJavaScriptPlayerManager caches and then runs the extracted code if it
has been executed successfully. The cache system of throttling parameters
deobfuscated values has been kept, its size can be get using the
getThrottlingParametersCacheSize method and can be cleared independently using
the clearThrottlingParametersCache method.
If an exception occurs during the extraction or the parsing of a function
property which is not related to JavaScript base player code fetching, it is
stored until caches are cleared, making subsequent failing extraction calls of
the requested function or property faster and consuming less resources, as the
result should be the same until the base player code changes.
All caches can be reset using the clearAllCaches method of
YoutubeJavaScriptPlayerManager.
Classes using JavaScript base player code and utilities directly (in the code
and its tests) have been also updated in this commit.
7de3753a81