- eliminate iterators from PackedList since they were unused, had
lower performance than direct access and added unneeded complexity.
- eliminate auto-vivify for the PackedList '[] operator.
The set() method provides any required auto-vivification and
removing this ability from the '[]' operator allows for a lower
when accessing the values. Replaced the previous cascade of iterators
with simpler reference class.
PackedBoolList:
- (temporarily) eliminate logic and addition operators since
these contained partially unclear semantics.
- the new test() method tests the value of a single bit position and
returns a bool without any ambiguity caused by the return type
(like the get() method), nor the const/non-const access (like
operator[] has). The name corresponds to what std::bitset uses.
- more consistent use of PackedBoolList test(), set(), unset() methods
for fewer operation and clearer code. Eg,
if (list.test(index)) ... | if (list[index]) ...
if (!list.test(index)) ... | if (list[index] == 0u) ...
list.set(index); | list[index] = 1u;
list.unset(index); | list[index] = 0u;
- deleted the operator=(const labelUList&) and replaced with a setMany()
method for more clarity about the intended operation and to avoid any
potential inadvertent behaviour.
- The bitSet class replaces the old PackedBoolList class.
The redesign provides better block-wise access and reduced method
calls. This helps both in cases where the bitSet may be relatively
sparse, and in cases where advantage of contiguous operations can be
made. This makes it easier to work with a bitSet as top-level object.
In addition to the previously available count() method to determine
if a bitSet is being used, now have simpler queries:
- all() - true if all bits in the addressable range are empty
- any() - true if any bits are set at all.
- none() - true if no bits are set.
These are faster than count() and allow early termination.
The new test() method tests the value of a single bit position and
returns a bool without any ambiguity caused by the return type
(like the get() method), nor the const/non-const access (like
operator[] has). The name corresponds to what std::bitset uses.
The new find_first(), find_last(), find_next() methods provide a faster
means of searching for bits that are set.
This can be especially useful when using a bitSet to control an
conditional:
OLD (with macro):
forAll(selected, celli)
{
if (selected[celli])
{
sumVol += mesh_.cellVolumes()[celli];
}
}
NEW (with const_iterator):
for (const label celli : selected)
{
sumVol += mesh_.cellVolumes()[celli];
}
or manually
for
(
label celli = selected.find_first();
celli != -1;
celli = selected.find_next()
)
{
sumVol += mesh_.cellVolumes()[celli];
}
- When marking up contiguous parts of a bitset, an interval can be
represented more efficiently as a labelRange of start/size.
For example,
OLD:
if (isA<processorPolyPatch>(pp))
{
forAll(pp, i)
{
ignoreFaces.set(i);
}
}
NEW:
if (isA<processorPolyPatch>(pp))
{
ignoreFaces.set(pp.range());
}
This change requires that the de-reference operator '()' returns a
const-reference to the object stored irrespective of the const-ness of
object stored and the new member function 'ref()' is provided to return
an non-const reference to stored object which throws a fatal error if the
stored object is const.
In order to smooth the transition to this new safer 'tmp' the now
deprecated and unsafe non-const de-reference operator '()' is still
provided by default but may be switched-off with the compilation switch
'CONST_TMP'.
The main OpenFOAM library has already been upgraded and '-DCONST_TMP'
option specified in the 'options' file to switch to the new 'tmp'
behavior. The rest of OpenFOAM-dev will be upgraded over the following
few weeks.
Henry G. Weller
CFD Direct
