Builtin scriptlets are no longer parsed as text-based resources,
they are imported as JS functions, and `toString()` is used to
obtain text-based representation of a scriptlet.
Scriptlet parameters are now passed as function call arguments
rather than by replacing text-based occurrences of `{{i}}`. The
arguments are always string values (see below for exception).
Support for argument as Object has been added. This opens the
door to have scriptlets using named arguments rather than
positional arguments, and hence easier to extend functionality
of existing scriptlets. Example:
example.com##+js(scriplet, { "prop": "adblock", "value": false, "log": true })
Compatibility with user-provided scriptlets has been preserved.
User-provided scriptlets can benefit some of the changes:
Use the form `function(..){..}` instead of `(function(..){..})();`
in order to received scriptlet arguments as part of function call
-- instead of using `{{i}}`.
If using the form `function(..){..}`, you can choose to receive
an Object as argument -- just be sure that your scriptlet's
parameter is valid JSON notation.
This commit is a rewrite of the static filtering parser into a
tree-based data structure, for easier maintenance and better
abstraction of parsed filters.
This simplifies greatly syntax coloring of filters and also
simplify extending filter syntax.
The minimum version of Chromium-based browsers has been raised
to version 73 because of usage of String.matchAll().
The motivation is to address the higher peak memory usage at launch
time with 3rd-gen HNTrie when a selfie was present.
The selfie generation prior to this change was to collect all
filtering data into a single data structure, and then to serialize
that whole structure at once into storage (using JSON.stringify).
However, HNTrie serialization requires that a large UintArray32 be
converted into a plain JS array, which itslef would be indirectly
converted into a JSON string. This was the main reason why peak
memory usage would be higher at launch from selfie, since the JSON
string would need to be wholly unserialized into JS objects, which
themselves would need to be converted into more specialized data
structures (like that Uint32Array one).
The solution to lower peak memory usage at launch is to refactor
selfie generation to allow a more piecemeal approach: each filtering
component is given the ability to serialize itself rather than to be
forced to be embedded in the master selfie. With this approach, the
HNTrie buffer can now serialize to its own storage by converting the
buffer data directly into a string which can be directly sent to
storage. This avoiding expensive intermediate steps such as
converting into a JS array and then to a JSON string.
As part of the refactoring, there was also opportunistic code
upgrade to ES6 and Promise (eventually all of uBO's code will be
proper ES6).
Additionally, the polyfill to bring getBytesInUse() to Firefox has
been revisited to replace the rather expensive previous
implementation with an implementation with virtually no overhead.
Raymond Hill