There's no good reason why these can't be code constants.
Especially given that, due to a bug, changes to the
"idle_queue.{min,long}_period" constants were not being passed onto the C++
code!
Here's why: those two prefs were specified as integers in all.js. But we used
AddFloatVarCache() to set up the reading of those prefs. libpref fakes floats
by storing them as strings and then converting them to floats when they are
read.
Which means that AddFloatVarCache() used to fail to get the value from all.js
-- because there's a type mismatch, int vs. string -- and instead use the
fallback default. That value is the same as the one in all.js, which is lucky.
But if someone changed the value in about:config to 100 (an integer), a similar
failure would have occured and the value used by the C++ code wouldn't be
updated!
Also note that idle_queue.max_timer_thread_bound did not have a value in
all.js.
What a mess!
--HG--
extra : rebase_source : 86f8fa905163803eb95007609c029e18c2c4f586
There's no good reason why these should't just be constants. The patch also
appends "MiB" to some of the C++ values to make their meaning clearer.
This patch fixes one outright bug, and one inconsistency.
The bug is due to a prefname mismatch:
- ContentPrefs.cpp and AvailableMemoryTracker.cpp use
"memory.low_virtual_mem_threshold_mb".
- all.js uses "memory.low_virtual_memory_threshold_mb".
Which means that "memory.low_virtual_memory_threshold_mb" showed up in
about:config, but if you changed it nothing would happen because the callback
listened for changes to to "memory.low_virtual_mem_threshold_mb"!
Now for the inconsistency. The above means we actually use a value of 256 for
the virtual memory threshold, even though all.js says 128. But we *do* use a
value of 128 for the commit space threshold, because that's what all.js says
and that prefname is used correctly everywhere. The patch changes the commit
space threshold to 256 for consistency with the virtual memory threshold.
What a mess!
--HG--
extra : rebase_source : d3842c732efa9ab0e90eeb6a4f341aeb289589ed
This was originally added for b2g, where the pref had a different value.
Bug 1398033 enabled it everywhere.
--HG--
extra : rebase_source : c8bb03190cd00d25e6c2ec62a99ed8e911e08197
libpref has callbacks. You can register a callback function against a
particular pref (or pref prefix), and it'll be called when any matching pref
changes.
This is implemented in two layers. The lower layer is the list of CallbackNode
objects, pointed to by gFirstCallback.
The upper layer involves gObserverTable, which is a hash table of ValueObserver
objects. It is used for callbacks registered via
Preferences::RegisterCallback() and Preferences::Add*VarCache(), but not for
observers registered with Preferences::Add{Weak,Strong}Observer(). If multiple
callbacks with identical prefnames, callback functions and MatchKinds occur,
they are commoned up into a single ValueObserver, which is then wrapped by a
single CallbackNode. (The callbacks within a single ValueObserver can have
different void* aClosure args; ValueObserver keeps those in an nsTArray.)
Note also that gObserverTable is very inelegant, with duplication of data
between the keys and the values due it being a
nsRefPtrHashtable<ValueObserverHashKey, ValueObserver> and ValueObserver being
a subclass of ValueObserverHashKey(!)
This extra layer might make sense if there were a lot of commoning up
happening, but there's not. Across all process kinds there is an average of
between 1.2 and 1.7 closures per ValueObserver. The vast majority have 1
closure, and there are a handful that have multiple; the highest number I've
seen is 71.
(Note that this two-layer design probably seemed more natural back when libpref
was spread across multiple files.)
This patch removes the ValueObserver layer. The only tricky part is that there
is a notion of a MatchKind -- ExactMatch or PrefixMatch -- which exists in the
ValueObserverLayer but not in the CallbackNode layer. So the patch moves the
MatchKind into the CallbackNode layer, which is straightforward.
On Linux64 this reduces memory usage by about 40 KiB in the parent process and
about 30 KiB in each content processes.
The performance implications are minor.
- The list of CallbackNodes is a bit longer, so when a pref is changed we must
check more nodes. But we avoid possibly doing prefname matching twice.
- Callback registration is much faster, just a simple list prepend, without any
hash table insertion required.
- Callback unregistration is probably not much different. There is a longer
list to traverse, but no hash table removal.
- Pref lookup is by far the hottest libpref operation, and it's unchanged.
For perf to be genuinely affected would require (a) a *lot* more
almost-duplicate callbacks that would have been commoned up, and (b) frequent
changing of the pref those callbacks are observing. This seems highly unlikely.
MozReview-Commit-ID: 6xo4xmytOf3
--HG--
extra : rebase_source : cf9884a8a40b2cc3b00ab165ae5ab4ec3383f72d
Bug 1345294 introduced nsPrefBranch::{get,set}StringPref(), which allowed the
getting of utf8 strings from prefs, which previously required using
nsISupportsString with {get,set}ComplexValue. That bug also converted most
uses.
This patch finishes the job.
- It removes the nsISupportsString support.
- It converts existing code that relied on the nsISupportsString.
- It removes the lint that was set up to detect such uses of nsISupportsString.
--HG--
extra : rebase_source : fb7af066adfa0491a79fae6282a62b08661553c8
Pref callbacks registered via Preferences::Add*VarCache() are wrapped in a
ValueObserver -- which groups all callback requests that have the same prefname
and callback function -- and the ValueObserver is put into gObserverTable. This
is reasonable.
Observers registered via nsPrefBranch::Add{Weak,Strong}Observer() are wrapped
in a PrefCallback, and the PrefCallback is put into sRootBranch->mObservers.
This is also reasonable.
Pref callbacks registered via Preferences::RegisterCallback() are conceptually
similar to those registered via Preferences::Add*VarCache(). However, they are
implemented by using *both* of the above mechanisms: they are wrapped in a
ValueObserver which is put into gObserverTable, *and* that ValueObserver is then
wrapped in a PrefCallback which is put into sRootBranch->mObservers.
Using both mechanisms isn't necessary, so this patch removes the
PrefCallback/mObservers part. This makes Preferences::RegisterCallback() work
in much the same way as Preferences::Add*VarCache().
Specifically:
- Preferences::RegisterCallback() now calls PREF_RegisterCallback() instead of
Preferences::AddStrongObserver(). This makes it more similar to
RegisterPriorityCallback().
- Preferences::UnregisterCallback() now explicitly calls
PREF_UnregisterCallback() instead of Preferences::RemoveObserver (which
previously happened via ~ValueObserver() when the ValueObserver was removed
from gObserverTable and its refcount dropped to zerod).
MozReview-Commit-ID: 1tEQNeYrBUU
--HG--
extra : rebase_source : 431a42402397a172d562b81b8d46418503bb8dfe
The notable part of this change is Shutdown(). I've made it just null out
sPreferences, contrary to the old comment, which was strange for a couple of
reasons:
- ~Preferences() used to null out sPreference, which is backwards compared to
how this sort of thing normally works.
- In both the before and after cases, as far as I can tell,
Preferences::Shutdown() is called but ~Preferences() is never called;
something keeps the singleton Preferences instance alive until process
termination.
MozReview-Commit-ID: Ab0ui31rVcI
sRootBranch and sDefaultRootBranch have the same lifetime as sPreferences, so
this patch makes them non-static nsCOMPtr<> members of Preferences.
MozReview-Commit-ID: 1TLhh13ZpBI
--HG--
extra : rebase_source : 9419cd205b9a06f7ae82722a6732e3fc2722473b
It's no longer needed, now that legacy extensions aren't supported.
Pieces removed include the following.
- The "load-extension-default" observer notification.
- The code for reading defaults/preferences/*.js from extensions.
- The unit test for this stuff.
- A crash reporter annotation relating to very long prefs set by add-ons.
- All references to "ExtPrefDL".
MozReview-Commit-ID: KMBoYn3uZ3x
--HG--
extra : rebase_source : 4dc8ffd425c6cdf06806409090c4f9d04a64930b
Behaviour is controlled through the media.navigator.video.vp9_preferred preference.
MozReview-Commit-ID: J06ArFYNmTk
--HG--
extra : rebase_source : a25bd4783fde0acf8291ee440745a619d3fa7db8
This patch does the following.
- Reduces nesting and simplifies control flow by handling failure cases
earlier, and makes all three functions have identical structure.
- Avoids unnecessary temporary local variables, including |rv|.
- Removes low-value comments, including some misleading ones (e.g. "This
function will perform conversion...").
- PREF_GetCStringValue() previously did not check HasDefaultValue(), unlike the
other two. It now does.
- PREF_GetCStringValue() now calls SetIsVoid(true) at the start, so that
aValueOut will be Voided on all failure paths.
MozReview-Commit-ID: 2uCSv76Y8eu
--HG--
extra : rebase_source : 9ca9148ad0a5069bdd3e08aec0038216d27ea092
This patch converts it to use Gecko strings instead of C strings, which makes
it much nicer.
MozReview-Commit-ID: KtRp3vaXwN5
--HG--
extra : rebase_source : c6788cbed5c4b932eb5b4119c407aea538cb1799
This was created for B2G and isn't really useful otherwise. It only works on
Linux, and it's behind the memory.system_memory_reporter pref, which is false
by default.
The patch also removes LinuxUtils.{h,cpp}, which is no longer used.
--HG--
extra : rebase_source : b97a018be11a79f83855a73b88020bfa86e60f78
This is needed for local developer builds to enable extended
telemetry recording by default. As a consequence, other subsystems
relying on this prefs will turn on (e.g. experiments, BHR, ...).
MozReview-Commit-ID: W3RarufCdY
--HG--
extra : rebase_source : 8690e969baad1b9191ea3fef9fb7dd6e41e00de7
In Unified Telemetry toolkit.telemetry.enabled controls whether we send base
collection data or extended collection. The difference is mostly in volume, not
in kind (though extended collection has a little stricter testing and monitoring
requirements).
Since the Preferences UI change in Firefox 56, users no longer have the ability
to change toolkit.telemetry.enabled. This is a good thing as for pre-release
users very few disabled extended collection, and even fewer release users
enabled it. This provides uniform collection based on channel which should
eventually net us some efficiencies.
Until then we need to align our use of the toolkit.telemetry.enabled pref with
the UI change that has already shipped. This is accomplished by locking t.t.e
to 'true' on pre-release channels and locking it to 'false' on everything else.
This doesn't apply to Android as it doesn't (yet) use Unified Telemetry. t.t.e
means something rather different there.
MozReview-Commit-ID: EOpWm8b0jWA
This makes the code nicer. In particular, it removes many getter_Copies()
calls. The patch also converts a lot of nsCStrings to nsAutoCString, which will
avoid heap allocation in the common case.
The patch also renames PREF_CopyCharPref() as PREF_GetCStringPref(), because
it's actually getting a string, not a char, and that matches the existing
GetCString() and GetDefaultCString() methods. Correspondingly, it also renames
PREF_SetCharPref() as PREF_SetCStringPref().
The |aPrefName| arguments in nsIPrefBranch.idl remain as |string| because they
almost always involve passing in C string literals, and passing "foo" is much
nicer than passing NS_LITERAL_CSTRING("foo").
It's worth noting that early versions of this patch used |AUTF8String| instead
of |ACString|. But it turns out that libpref stores prefs internally as Latin1.
And |ACString| is compatible with Latin1 but |AUTF8String| isn't, because
non-ASCII Latin1 strings are not valid UTF-8!
MozReview-Commit-ID: D3f7a1Vl1oE
--HG--
extra : rebase_source : e6e4b15d6d210cfd93686f96400281f02bd1d06b
In Unified Telemetry toolkit.telemetry.enabled controls whether we send base
collection data or extended collection. The difference is mostly in volume, not
in kind (though extended collection has a little stricter testing and monitoring
requirements).
Since the Preferences UI change in Firefox 56, users no longer have the ability
to change toolkit.telemetry.enabled. This is a good thing as for pre-release
users very few disabled extended collection, and even fewer release users
enabled it. This provides uniform collection based on channel which should
eventually net us some efficiencies.
Until then we need to align our use of the toolkit.telemetry.enabled pref with
the UI change that has already shipped. This is accomplished by locking t.t.e
to 'true' on pre-release channels and locking it to 'false' on everything else.
This doesn't apply to Android as it doesn't (yet) use Unified Telemetry. t.t.e
means something rather different there.
MozReview-Commit-ID: EOpWm8b0jWA
Because nsCString is nicer than UniqueFreePtr<char>.
The patch also streamlines pref_savePrefs(). And also changes StrEscape() to
always put quotations around the result, because that's needed in both call
sites.
MozReview-Commit-ID: HT7HZz4QiSN
--HG--
extra : rebase_source : 442bb6002e004803a9ecb637239a000f11ec5774
First, the patch removes the return values from PrefTypeFlags::Set*(). They
allow chained calls, but they're barely used and they just make the code harder
to read.
Second, the patch changes pref_SetValue() to not modify and return the pref
flags. It's clearer if the flags changing is done separately. This requires
passing pref_SetValue() the old type instead of the flags.
MozReview-Commit-ID: HZVS2TIlBIY
--HG--
extra : rebase_source : 6638244214cda15ceae5a1930659aed434d8261b
This makes it clear that the stored string values are never modified.
It requires some const_casts to free the strings, but that feels like an ok
trade-off.
MozReview-Commit-ID: JikBT3uwpfq
--HG--
extra : rebase_source : 1720969ba2c1ae245dff91a6d3a85d48fb669ced
There's not much use using |protected| in a |final| class.
MozReview-Commit-ID: IECyfNGZsL5
--HG--
extra : rebase_source : e734b360c18e5e040bea186d5aedf91137711861
It's always gHashTable, and all the other functions in this file work directly
on gHashTable rather than taking a parameter.
MozReview-Commit-ID: BDCEvcMlo8P
--HG--
extra : rebase_source : 8f136c100f2a4f7b2b34cfa884b8cc91c2d80e3a
At present, the "layout.css.stylo-blocklist.blocked_domains" pref is empty. It
is probably meaningless to set "layout.css.stylo-blocklist.enabled" pref to true
by default. We can set "layout.css.stylo-blocklist.enabled" pref to true by the
styloblocklist system add-on once the "layout.css.stylo-blocklist.blocked_domains"
pref is non-empty.
MozReview-Commit-ID: 2B5JnGEafLo
--HG--
extra : rebase_source : 7b694a2cbe70d2d09c1a5c2c2e4c6eec31f39a1e
It's unnecessarily general, because we only ever use
Preferences::DirtyCallback() as the callback.
And because it's no longer a callback, the patch renames DirtyCallback() as
HandleDirty().
MozReview-Commit-ID: Hl50dcxfVQq
--HG--
extra : rebase_source : 5807d2ed650466f85cd7325f2adccdc177ccb4d2
