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0029302: Foundation Classes, NCollection - optimize iteration of indexed maps

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NCollection_IndexedMap and NCollection_IndexedDataMap
now access Key by Index number without computing Hash code.
IndexedMapNode::myNext2 and IndexedDataMapNode::myNext2 fields
have been removed, so that indexed map now may utilize less memory.

TCollection::NextPrimeForMap() has been extended upto 2038431745
(almost full signed 32-bit integer range),
and NCollection_BaseMap::mySaturated property has been removed.

NCollection_IndexedDataMap::RemoveFromIndex(), FindKey(), FindFromIndex(),
ChangeFromIndex() - removed duplicating checks for out of range input.
This commit is contained in:
kgv
2017-11-08 15:25:51 +03:00
committed by bugmaster
parent f88457e638
commit 510cb85241
5 changed files with 225 additions and 379 deletions
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63
src/TCollection/TCollection.cxx
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@@ -14,9 +14,10 @@
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.
#include <TCollection.hxx>
#include <Standard_OutOfRange.hxx>
// The array of prime numbers used as consequtive steps for
// size of array of buckets in the map.
// The prime numbers are used for array size with the hope that this will
@@ -27,27 +28,47 @@
// memory overhead in that case is only ~15% as compared with total size of
// all auxiliary data structures (each map node takes ~24 bytes),
// and this proves to pay off in performance (see OCC13189).
#define NB_PRIMES 12
static const Standard_Integer Primes[NB_PRIMES+1] = {
101,
1009,
2003,
5003,
10007,
20011,
37003,
57037,
65003,
100019,
209953, // The following are Pierpont primes taken from Wikipedia [List of prime numbers]
472393,
995329
};
#define THE_NB_PRIMES 24
static const Standard_Integer THE_TCollection_Primes[THE_NB_PRIMES] =
{
101,
1009,
2003,
5003,
10007,
20011,
37003,
57037,
65003,
100019,
209953, // The following are Pierpont primes [List of prime numbers]
472393,
995329,
2359297,
4478977,
9437185,
17915905,
35831809,
71663617,
150994945,
301989889,
573308929,
1019215873,
2038431745
};
// =======================================================================
// function : NextPrimeForMap
// purpose :
// =======================================================================
Standard_Integer TCollection::NextPrimeForMap(const Standard_Integer N)
{
Standard_Integer i;
for (i = 0; i < NB_PRIMES; i++)
if (Primes[i] > N) break;
return Primes[i];
for (Standard_Integer aPrimeIter = 0; aPrimeIter < THE_NB_PRIMES; ++aPrimeIter)
{
if (THE_TCollection_Primes[aPrimeIter] > N)
{
return THE_TCollection_Primes[aPrimeIter];
}
}
throw Standard_OutOfRange ("TCollection::NextPrimeForMap() - requested too big size");
}