From 252914599ad73e01ca8d0a89ef8d8d391d072858 Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Wed, 2 May 2018 08:33:49 +0200
Subject: [PATCH] ENH: bitSet::find_first_not() method (issue #751)
- find the position of the first bit off - symmetrical with find_first()
---
applications/test/bitSet2/Test-bitSet2.C | 72 +++++++---
src/OpenFOAM/containers/Bits/bitSet/bitSet.H | 17 ++-
src/OpenFOAM/containers/Bits/bitSet/bitSetI.H | 125 ++++++++++++------
3 files changed, 156 insertions(+), 58 deletions(-)
diff --git a/applications/test/bitSet2/Test-bitSet2.C b/applications/test/bitSet2/Test-bitSet2.C
index 9c62bd7e7a..b76048b01d 100644
--- a/applications/test/bitSet2/Test-bitSet2.C
+++ b/applications/test/bitSet2/Test-bitSet2.C
@@ -40,12 +40,19 @@ Description
using namespace Foam;
-inline Ostream& report
-(
- const bitSet& bitset,
- bool showBits = false,
- bool debugOutput = false
-)
+
+inline Ostream& extent(const bitSet& bitset)
+{
+ Info<< "first: " << bitset.find_first()
+ << " last: " << bitset.find_last()
+ << " first_not: " << bitset.find_first_not()
+ << endl;
+
+ return Info;
+}
+
+
+inline Ostream& info(const bitSet& bitset)
{
Info<< "size=" << bitset.size() << "/" << bitset.capacity()
<< " count=" << bitset.count()
@@ -54,17 +61,11 @@ inline Ostream& report
<< " any:" << bitset.any()
<< " none:" << bitset.none() << nl;
- Info<< "values: " << flatOutput(bitset) << nl;
- if (showBits)
- {
- bitset.printBits(Info, debugOutput) << nl;
- }
-
return Info;
}
-inline Ostream& report(const UList<bool>& bools)
+inline Ostream& info(const UList<bool>& bools)
{
Info<< "size=" << bools.size()
<< " count=" << BitOps::count(bools)
@@ -77,6 +78,31 @@ inline Ostream& report(const UList<bool>& bools)
}
+inline Ostream& report
+(
+ const bitSet& bitset,
+ bool showBits = false,
+ bool debugOutput = false
+)
+{
+ info(bitset);
+
+ Info<< "values: " << flatOutput(bitset) << nl;
+ if (showBits)
+ {
+ bitset.printBits(Info, debugOutput) << nl;
+ }
+
+ return Info;
+}
+
+
+inline Ostream& report(const UList<bool>& bools)
+{
+ return info(bools);
+}
+
+
template<class UIntType>
std::string toString(UIntType value, char off='.', char on='1')
{
@@ -153,10 +179,7 @@ int main(int argc, char *argv[])
compare(list1, "...................1..1..1..1..1");
report(list1, true);
-
-
- Info<< "first: " << list1.find_first()
- << " last: " << list1.find_last() << endl;
+ extent(list1);
Info<< "iterate through:";
for (const label idx : list1)
@@ -172,6 +195,21 @@ int main(int argc, char *argv[])
Info<< "\nflipped bit pattern\n";
report(list2, true);
+ extent(list2);
+
+ Info<< "\nsparse set\n";
+ {
+ bitSet sparse(1000);
+ sparse.set(300);
+
+ info(sparse);
+ extent(sparse);
+
+ sparse.set(0);
+
+ info(sparse);
+ extent(sparse);
+ }
// set every other on
forAll(list2, i)
diff --git a/src/OpenFOAM/containers/Bits/bitSet/bitSet.H b/src/OpenFOAM/containers/Bits/bitSet/bitSet.H
index 32b104df2c..8f2cfae003 100644
--- a/src/OpenFOAM/containers/Bits/bitSet/bitSet.H
+++ b/src/OpenFOAM/containers/Bits/bitSet/bitSet.H
@@ -65,6 +65,15 @@ class bitSet
:
public PackedList<1>
{
+private:
+
+ // Private Member Functions
+
+ //- Find the first block with a '0' bit
+ // \return block number or -1 if the set is empty or all bits are on.
+ inline label first_not_block() const;
+
+
protected:
// Protected Member Functions
@@ -203,12 +212,18 @@ public:
// \note Method name compatibility with std::bitset
inline bool test(const label pos) const;
- //- Locate the first bit set.
+ //- Locate the first bit that is set.
// \return the location or -1 if there are no bits set.
//
// \note Method name compatibility with boost::dynamic_bitset
inline label find_first() const;
+ //- Locate the first bit that is unset.
+ // \return the location or -1 if the set is empty or all bits are on.
+ //
+ // \note Provided for symmetry with find_first()
+ inline label find_first_not() const;
+
//- Locate the last bit set.
// \return the location or -1 if there are no bits set.
//
diff --git a/src/OpenFOAM/containers/Bits/bitSet/bitSetI.H b/src/OpenFOAM/containers/Bits/bitSet/bitSetI.H
index 0ab1bb59ab..413aa87c33 100644
--- a/src/OpenFOAM/containers/Bits/bitSet/bitSetI.H
+++ b/src/OpenFOAM/containers/Bits/bitSet/bitSetI.H
@@ -23,6 +23,53 @@ License
\*---------------------------------------------------------------------------*/
+// * * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * //
+
+inline Foam::label Foam::bitSet::first_not_block() const
+{
+ if (empty())
+ {
+ return -1;
+ }
+
+ // Use complement to change 0 <-> 1 and check if any 1's now appear
+
+ const label nblocks = num_blocks(size());
+
+ // Extra bits in the final block?
+ const unsigned int off = size() % elem_per_block;
+
+ if (!off)
+ {
+ for (label blocki=0; blocki < nblocks; ++blocki)
+ {
+ if (~(blocks_[blocki]))
+ {
+ return blocki;
+ }
+ }
+ }
+ else
+ {
+ for (label blocki=0; blocki < nblocks-1; ++blocki)
+ {
+ if (~(blocks_[blocki]))
+ {
+ return blocki;
+ }
+ }
+
+ // The final block needs masking
+ if (~(blocks_[nblocks-1]) & mask_lower(off))
+ {
+ return nblocks-1;
+ }
+ }
+
+ return -1;
+}
+
+
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
inline constexpr Foam::bitSet::bitSet() noexcept
@@ -257,6 +304,38 @@ inline Foam::label Foam::bitSet::find_first() const
}
+inline Foam::label Foam::bitSet::find_first_not() const
+{
+ const label blocki = first_not_block();
+
+ if (blocki >= 0)
+ {
+ label pos = (blocki * elem_per_block);
+
+ // Detect first '0' bit by checking the complement.
+
+ // No special masking for the final block, that was already checked
+ // in the first_not_block() call.
+
+ for
+ (
+ unsigned int blockval = ~(blocks_[blocki]);
+ blockval;
+ blockval >>= 1u
+ )
+ {
+ if (blockval & 1u)
+ {
+ return pos;
+ }
+ ++pos;
+ }
+ }
+
+ return -1;
+}
+
+
inline Foam::label Foam::bitSet::find_last() const
{
// Process block-wise, detecting any '1' bits
@@ -339,44 +418,7 @@ inline Foam::label Foam::bitSet::find_next(label pos) const
inline bool Foam::bitSet::all() const
{
- if (empty())
- {
- return true;
- }
-
- // Use complement to change 0 <-> 1 and check if any 1's now appear
-
- const label nblocks = num_blocks(size());
-
- // Extra bits in the final block?
- const unsigned int off = size() % elem_per_block;
-
- if (!off)
- {
- for (label blocki=0; blocki < nblocks; ++blocki)
- {
- if (~(blocks_[blocki]))
- {
- return false;
- }
- }
- }
- else
- {
- for (label blocki=0; blocki < nblocks-1; ++blocki)
- {
- if (~(blocks_[blocki]))
- {
- return false;
- }
- }
-
- // Verify the final block, with masking
-
- return (!(~blocks_[nblocks-1] & mask_lower(off)));
- }
-
- return true;
+ return -1 == first_not_block();
}
@@ -388,7 +430,10 @@ inline bool Foam::bitSet::any() const
for (label blocki=0; blocki < nblocks; ++blocki)
{
- if (blocks_[blocki]) return true;
+ if (blocks_[blocki])
+ {
+ return true;
+ }
}
}
@@ -421,7 +466,7 @@ inline unsigned int Foam::bitSet::count(const bool on) const
if (!on)
{
- // Return the number of bits that are off.
+ // Return the number of bits that are OFF.
return (unsigned(size()) - total);
}
--
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