Related issues:
- https://github.com/uBlockOrigin/uBlock-issues/issues/761
- https://github.com/uBlockOrigin/uBlock-issues/issues/528
The previous bidi-trie code could only hold filters which
are plain pattern, i.e. no wildcard characters, and which
had no origin option (`domain=`), right and/or left anchor,
and no `csp=` option.
Example of filters that could be moved into a bidi-trie
data structure:
&ad_box_
/w/d/capu.php?z=$script,third-party
||liveonlinetv247.com/images/muvixx-150x50-watch-now-in-hd-play-btn.gif
Examples of filters that could NOT be moved to a bidi-trie:
-adap.$domain=~l-adap.org
/tsc.php?*&ses=
||ibsrv.net/*forumsponsor$domain=[...]
@@||imgspice.com/jquery.cookie.js|$script
||view.atdmt.com^*/iview/$third-party
||postimg.cc/image/$csp=[...]
Ideally the filters above should be able to be moved to a
bidi-trie since they are basically plain patterns, or at
least partially moved to a bidi-trie when there is only a
single wildcard (i.e. made of two plain patterns).
Also, there were two distinct bidi-tries in which
plain-pattern filters can be moved to: one for patterns
without hostname anchoring and another one for patterns
with hostname-anchoring. This was required because the
hostname-anchored patterns have an extra condition which
is outside the bidi-trie knowledge.
This commit expands the number of filters which can be
stored in the bidi-trie, and also remove the need to
use two distinct bidi-tries.
- Added ability to associate a pattern with an integer
in the bidi-trie [1].
- The bidi-trie match code passes this externally
provided integer when calling an externally
provided method used for testing extra conditions
that may be present for a plain pattern found to
be matching in the bidi-trie.
- Decomposed existing filters into smaller logical units:
- FilterPlainLeftAnchored =>
FilterPatternPlain +
FilterAnchorLeft
- FilterPlainRightAnchored =>
FilterPatternPlain +
FilterAnchorRight
- FilterExactMatch =>
FilterPatternPlain +
FilterAnchorLeft +
FilterAnchorRight
- FilterPlainHnAnchored =>
FilterPatternPlain +
FilterAnchorHn
- FilterWildcard1 =>
FilterPatternPlain + [
FilterPatternLeft or
FilterPatternRight
]
- FilterWildcard1HnAnchored =>
FilterPatternPlain + [
FilterPatternLeft or
FilterPatternRight
] +
FilterAnchorHn
- FilterGenericHnAnchored =>
FilterPatternGeneric +
FilterAnchorHn
- FilterGenericHnAndRightAnchored =>
FilterPatternGeneric +
FilterAnchorRight +
FilterAnchorHn
- FilterOriginMixedSet =>
FilterOriginMissSet +
FilterOriginHitSet
- Instances of FilterOrigin[...], FilterDataHolder
can also be added to a composite filter to
represent `domain=` and `csp=` options.
- Added a new filter class, FilterComposite, for
filters which are a combination of two or more
logical units. A FilterComposite instance is a
match when *all* filters composing it are a
match.
Since filters are now encoded into combination of
smaller units, it becomes possible to extract the
FilterPatternPlain component and store it in the
bidi-trie, and use the integer as a handle for the
remaining extra conditions, if any.
Since a single pattern in the bidi-trie may be a
component for different filters, the associated
integer points to a sequence of extra conditions,
and a match occurs as soon as one of the extra
conditions (which may itself be a sequence of
conditions) is fulfilled.
Decomposing filters which are currently single
instance into sequences of smaller logical filters
means increasing the storage and CPU overhead when
evaluating such filters. The CPU overhead is
compensated by the fact that more filters can now
moved into the bidi-trie, where the first match is
efficiently evaluated. The extra conditions have to
be evaluated if and only if there is a match in the
bidi-trie.
The storage overhead is compensated by the
bidi-trie's intrinsic nature of merging similar
patterns.
Furthermore, the storage overhead is reduced by no
longer using JavaScript array to store collection
of filters (which is what FilterComposite is):
the same technique used in [2] is imported to store
sequences of filters.
A sequence of filters is a sequence of integer pairs
where the first integer is an index to an actual
filter instance stored in a global array of filters
(`filterUnits`), while the second integer is an index
to the next pair in the sequence -- which means all
sequences of filters are encoded in one single array
of integers (`filterSequences` => Uint32Array). As
a result, a sequence of filters can be represented by
one single integer -- an index to the first pair --
regardless of the number of filters in the sequence.
This representation is further leveraged to replace
the use of JavaScript array in FilterBucket [3],
which used a JavaScript array to store collection
of filters. Doing so means there is no more need for
FilterPair [4], which purpose was to be a lightweight
representation when there was only two filters in a
collection.
As a result of the above changes, the map of `token`
(integer) => filter instance (object) used to
associate tokens to filters or collections of filters
is replaced with a more efficient map of `token`
(integer) to filter unit index (integer) to lookup a
filter object from the global `filterUnits` array.
Another consequence of using one single global
array to store all filter instances means we can reuse
existing instances when a logical filter instance is
parameter-less, which is the case for FilterAnchorLeft,
FilterAnchorRight, FilterAnchorHn, the index to these
single instances is reused where needed.
`urlTokenizer` now stores the character codes of the
scanned URL into a bidi-trie buffer, for reuse when
string matching methods are called.
New method: `tokenHistogram()`, used to generate
histograms of occurrences of token extracted from URLs
in built-in benchmark. The top results of the "miss"
histogram are used as "bad tokens", i.e. tokens to
avoid if possible when compiling filter lists.
All plain pattern strings are now stored in the
bidi-trie memory buffer, regardless of whether they
will be used in the trie proper or not.
Three methods have been added to the bidi-trie to test
stored string against the URL which is also stored in
then bidi-trie.
FilterParser is now instanciated on demand and
released when no longer used.
***
[1] 135a45a878/src/js/strie.js (L120)
[2] e94024d350
[3] 135a45a878/src/js/static-net-filtering.js (L1630)
[4] 135a45a878/src/js/static-net-filtering.js (L1566)
This commits make it so that `csp=` filters
are now stored in the same data structures as
all other static network filters rather than
being stored in a separate one.
This internal change is motivated by the wish
to bring session filters to the static network
filtering engine, as has already been done for
the static extended filtering engine in the
following commit:
59c9a34d34
This works only for platforms supporting the return of
Promise by network listeners, i.e. only Firefox at this
point.
When filter lists are reloaded[1], there is a small
time window in which some network requests which should
have normally been blocked are not being blocked
because the static network filtering engine may not
have yet loaded all the filters in memory
This is now addressed by suspending the network request
handler when filter lists are reloaded -- again, this
works only on supported platforms.
[1] Examples: when a filter list update session
completes; when user filters change, when
adding/removing filter lists.
Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/610
The service worker-related issue affects both
Chromium/Firefox: the type of resources fetched
from a service worker are uniformly set to
`xmlhttprequest`, hence losing a key piece of
information for the purpose of accurate content
filtering.
The motivations for the re-arrangement:
- Reducing the number of entry points:
matchStringExactString() has been removed and
matchString() is simply reused with a modifier parameter
to enable matching variants.
- Presumption that most matches, if any, occur early with
the left-most tokens in a URL. This gives a very small
marginal performance gain as per built-in benchmark.
Relocate workaround to the code responsible to compute filtering context, such
that the workaround will also be applied in other code paths, for example also
for webRequest.onHeadersReceived.
The value of `suspendTabsUntilReady` was disregarded in Firefox and
uBO defaulted to always defer tab loading until it was ready.
This commit allows to disable the deferring of tab loading in
Firefox. The new valid values for `suspendTabsUntilReady` are:
- `unset`: leave it to the platform to pick the optimal
behavior (default)
- `no`: do no suspend tab loading at launch time
- `yes`: suspend tab loading at launch time
Performance-related work: the logger data has been decoupled
from the DOM -- inspired from CodeMirror's way of efficiently
handling large amout of text data.
This decoupling now makes the logger highly efficient CPU- and
memory-wise, and open the way to more possibilities.
Ability to configure some aspect of the logger behavior and
visuals:
- The hard-coded limit of 5000 entries has been
removed and is now replaced with a variety of
user-configurable settings to enforce the discarding of
logger entries.
- Some columns in the logger output can now be hidden.
The filter list look-up feature has been merged into the
existing overlay dialog used to create URL rules or static
filters, as an entry in a new "Details" pane.
Other issues addressed during refactoring:
- https://github.com/uBlockOrigin/uBlock-issues/issues/280
- https://github.com/gorhill/uBlock/issues/1999
The minimum version supported on Firefox has been bumped
up to 55.0.
<https://github.com/gorhill/uBlock/issues/3436>: a new per-site switch
has been added, no-scripting, which purpose is to wholly disable/enable
javascript for a given site. This new switch has precedence over all
other ways javascript can be disabled, including precedence over dynamic
filtering rules.
The popup panel will report the number of script resources which have
been seen by uBO for the current page. There is a minor inaccuracy to
be fixed regarding the count, and which fix requires to extend request
journaling.
<https://github.com/gorhill/uBlock/issues/308>: the `noscript` tags will
now be respected when the new no-scripting switch is in effect on a given
site.
A default setting has been added to the _Settings_ pane to
disable/enable globally the new no-script switch, such that one can
work in default-deny mode regarding javascript execution.
<https://github.com/uBlockOrigin/uBlock-issues/issues/155>: a new
hidden setting, `requestJournalProcessPeriod`, has been added to
allow controlling the delay before uBO internally process it's
network request journal queue. Default to 1000 (milliseconds).
