StringBeginsWith (resp. StringEndsWith) takes a defaulted
nsStringComparator object for doing comparisons. The flexibility this
affords is great, but the cost is not: nsStringComparator has virtual
methods, so initializing that defaulted object (at every callsite)
requires a temporary object whose vtable must be initialized.
Since the overwhemingly common case is to use the default comparator
anyway, we should not use defaulted arguments and instead provide the
default comparator/user-provided comparator cases as separate overloads.
This change eliminates the virtual call for the majority of callsites
and reduces codesize as well.
The patch changes all uses of SizeOfIncludingThisMustBeUnshared() to
SizeOfIncludingThisIfUnshared(). This incurs the (tiny) cost of an unnecessary
IsReadonly() check for guaranteed-unshared strings, but avoids the possible
assertion failures that would occur when MustBeUnshared() was used incorrectly
on shared strings, which is an easy mistake to make.
The patch removes 455 occurrences of FAIL_ON_WARNINGS from moz.build files, and
adds 78 instances of ALLOW_COMPILER_WARNINGS. About half of those 78 are in
code we control and which should be removable with a little effort.
They are kept around for the sake of the standalone glue, which is used
for e.g. webapprt, which doesn't have direct access to jemalloc, and thus
still needs a wrapper to go through the xpcom function list and get to
jemalloc from there.
We have better, C++-ier ways of doing compile-time assertions now. Fold in the
nsTSubstring.cpp change in passing, since mccr8 suggested it in his review.
This patch handles most of the call sites for these allocations except
for a few where I added TODO comments with some information. Handling
those places may require reworking lots of code, so I prefer to not do
that here.
ReplaceSubstring() is an O(n*m) algorithm (n being the length of the
string and m being the number of occurrences of aTarget) because we have
to move the remainder of the string, search it again and potentially
memmove most of it again as we find more matches. This patch rewrites
that function to make it O(n+m).
Note that we currently don't build TestStrings.cpp, so the test case in
this patch is not run automatically, but the test case has been verified
to pass separately by moving the test function into Gecko and calling it
during startup and stepping through it in the debugger.
--HG--
extra : rebase_source : b020e17c1973330b0dbbd6bf956c073cfdcb775e
ReplaceSubstring() is an O(n*m) algorithm (n being the length of the
string and m being the number of occurrences of aTarget) because we have
to move the remainder of the string, search it again and potentially
memmove most of it again as we find more matches. This patch rewrites
that function to make it O(n+m).
Note that we currently don't build TestStrings.cpp, so the test case in
this patch is not run automatically, but the test case has been verified
to pass separately by moving the test function into Gecko and calling it
during startup and stepping through it in the debugger.
ReplaceSubstring() is an O(n*m) algorithm (n being the length of the
string and m being the number of occurrences of aTarget) because we have
to move the remainder of the string, search it again and potentially
memmove most of it again as we find more matches. This patch rewrites
that function to make it O(n+m).
Note that we currently don't build TestStrings.cpp, so the test case in
this patch is not run automatically, but the test case has been verified
to pass separately by moving the test function into Gecko and calling it
during startup and stepping through it in the debugger.
--HG--
extra : rebase_source : 0330c130520802392b92bd094dde85f57cfe6420
