The code to migrate from the toolkit.telemetry.enabledPreRelease pref to
toolkit.telemetry.enabled was added to Firefox 31 in bug 986582. It should be
safe to remove now.
MozReview-Commit-ID: JBkn20bUQXx
Preferences::SetPreference() is used when setting prefs in the content process
from dom::Pref values that are passed from the parent process. Currently we
use the high-level Set*InAnyProcess() methods to do this -- basically the same
code path as sets done via the API -- but this has several problems.
- It is subtly broken. If the content process already has a pref of type T with
a default value and then we get a SetPreference() call that tries to change
it to type U, it will erroneously fail. In practice this never(?) happens,
but it shows that things aren't arranged very well.
- SetPreference() also looks up the hashtable twice to get the same pref if
both a default value and a user value are present in the dom::Pref.
- This happens in content processes, while all other pref set operations occur
in the parent process. This is the main reason we have the Set*InAnyProcess()
functions.
In short, the setting of prefs via IPC is quite different to the setting of
prefs via other means -- because it happens in content processes, and it's more
of a clobber that can set both values at once -- and so should be handled
differently.
The solution is to make Preferences::SetPreference() use lower-level operations
to do the update. It now does the hash table lookup/add itself, and then calls
the new Pref::FromDomPref() method. That method then possibly calls the new
PrefValue::FromDomPrefValue() method for both kinds of value, and overwrites
them as necessary. SetValueFromDom() is no longer used and the patch removes it.
MozReview-Commit-ID: 2Rg8VMOc0Cl
The nice thing about this is that the memory management of the strings
(moz_xstrdup() and free()) is now entirely within PrefValue.
MozReview-Commit-ID: KJjnURpmgfE
It's something of an obfuscation, and it forces together various bool values
that don't necessarily have to be together (and won't be together after future
refactorings).
The patch also reorders some function arguments for consistency: PrefType, then
PrefValueKind, then PrefValue.
MozReview-Commit-ID: KNY0Pxo0Nxf
Although it is a subclass of PLDHashEntryHdr, it's the main representation of a
pref, so the name should reflect that.
MozReview-Commit-ID: 5qJNQtjbFmH
As is done in pref_SavePrefs().
The confusion here is because a Vector can fill 100% of its capacity, but a
hash table cannot go past 75% of its capacity.
MozReview-Commit-ID: 5JMbmtrxMGN
It represents a pref, so `Pref` is a better name. Within Preferences.cpp the
patch uses domPref/aDomPref to distinguish it from PrefHashEntry values.
MozReview-Commit-ID: HXTl0GX4BtO
This factors out some common code from SetValue(), making it easier to read.
The patch also improves the comments in SetValue().
MozReview-Commit-ID: 60JnBlIS1q6
Currently, you can create a pref that only has a user value, and then later
give it a default value with a different type. The entire pref is then recorded
as having this second type. This causes problems later when interpreting the
user value.
This patch makes SetValue() fail if it tries to set a default value whose type
differs from an existing user value. It also expands an existing test to cover
this case and some similar ones.
MozReview-Commit-ID: 89tvISQ7RNT
This requires adding an aPriority argument (defaulting to false) to
Preferences::RegisterCallback(). And RegisterVarCacheCallback() is no longer
necessary.
MozReview-Commit-ID: BMDk3HuaQVV
We can move the setting into ReplaceValue() and ClearValue(), and then those
methods aren't needed any more.
The patch also removes some getter calls within PrefHashEntry by directly using
field names.
MozReview-Commit-ID: 42EAx1Kh9Et
There's an "XXX" comment suggesting a possible leak when string user values are
cleared. Turns out a lot of the time there won't be a leak, because the string
pointer isn't overwritten and ClearEntry() frees the string when the pref is
destroyed. However, if the user value is subsequently overwritten with a
different string, there will be a leak. Also, even in the non-leak case, we
currently hold onto the string for longer than necessary.
This patch introduces ClearUserValue() -- which frees the string when
appropriate -- and uses it in all the places where values are cleared.
MozReview-Commit-ID: ARuWUNzPTfy
Specifically:
- rename it as NotifyCallbacks();
- remove the return value, because it is always NS_OK;
- some minor naming and declaration clean-ups.
MozReview-Commit-ID: GcH81owPLsp
This moves part of pref_savePrefs() into PrefHashEntry.
This requires moving StrEscape() higher up to avoid a forward declaration.
Note that clang-format insists on indenting an unrelated comment, I don't know
why.
MozReview-Commit-ID: 7gww3r7t9y4
And invert its sense, renaming as Equals(), because that is easier to think
about.
The patch also reorders some conditions so that
HasDefaultValue()/HasUserValue() is tested before Equals(). This isn't strictly
necessary, but it reads better.
MozReview-Commit-ID: JeGrevDwqKz
