From: ageay <ageay>
Date: Fri, 4 May 2012 09:12:53 +0000 (+0000)
Subject: Fast DataArrayInt hash code computation
X-Git-Tag: V6_5_0~9
X-Git-Url: http://git.salome-platform.org/gitweb/?a=commitdiff_plain;h=01a1fc3ee32b6afe5b19725daacb58c5937c10b6;p=tools%2Fmedcoupling.git

Fast DataArrayInt hash code computation
---

diff --git a/src/MEDCoupling/MEDCouplingMemArray.cxx b/src/MEDCoupling/MEDCouplingMemArray.cxx
index 4a3022687..76a475b4e 100644
--- a/src/MEDCoupling/MEDCouplingMemArray.cxx
+++ b/src/MEDCoupling/MEDCouplingMemArray.cxx
@@ -2909,6 +2909,24 @@ int DataArrayInt::intValue() const throw(INTERP_KERNEL::Exception)
     throw INTERP_KERNEL::Exception("DataArrayInt::intValue : DataArrayInt instance is not allocated !");
 }
 
+/*!
+ * This method expects that \b this is well allocated. If not an INTERP_KERNEL::Exception will be thrown. This method is useful for a quick comparison of many instances of DataArrayInt.
+ */
+int DataArrayInt::getHashCode() const throw(INTERP_KERNEL::Exception)
+{
+  checkAllocated();
+  int nbOfElems=getNbOfElems();
+  int ret=nbOfElems*65536;
+  int delta=3;
+  if(nbOfElems>48)
+    delta=nbOfElems/8;
+  int ret0=0;
+  const int *pt=begin();
+  for(int i=0;i<nbOfElems;i+=delta)
+    ret0+=pt[i] & 0x1FFF;
+  return ret+ret0;
+}
+
 /*!
  * This method should be called on an allocated DataArrayInt instance. If not an exception will be throw !
  * This method checks the number of tupes. If it is equal to 0, it returns true, if not false is returned.
diff --git a/src/MEDCoupling/MEDCouplingMemArray.hxx b/src/MEDCoupling/MEDCouplingMemArray.hxx
index a70555ddf..5dafbf608 100644
--- a/src/MEDCoupling/MEDCouplingMemArray.hxx
+++ b/src/MEDCoupling/MEDCouplingMemArray.hxx
@@ -322,6 +322,7 @@ namespace ParaMEDMEM
     MEDCOUPLING_EXPORT void checkAllocated() const throw(INTERP_KERNEL::Exception);
     MEDCOUPLING_EXPORT void setInfoAndChangeNbOfCompo(const std::vector<std::string>& info) throw(INTERP_KERNEL::Exception);
     MEDCOUPLING_EXPORT int intValue() const throw(INTERP_KERNEL::Exception);
+    MEDCOUPLING_EXPORT int getHashCode() const throw(INTERP_KERNEL::Exception);
     MEDCOUPLING_EXPORT bool empty() const throw(INTERP_KERNEL::Exception);
     MEDCOUPLING_EXPORT DataArrayInt *deepCpy() const;
     MEDCOUPLING_EXPORT DataArrayInt *performCpy(bool deepCpy) const;