[llvm-commits] CVS: llvm/include/llvm/ADT/StringMap.h

[Chris Lattner]

Changes in directory llvm/include/llvm/ADT:

StringMap.h updated: 1.11 -> 1.12
---
Log message:

add new ShouldRehash method to factor out common code.  Fix the dtor to not
delete tombstones.


---
Diffs of the changes:  (+14 -12)

 StringMap.h |   26 ++++++++++++++------------
 1 files changed, 14 insertions(+), 12 deletions(-)


Index: llvm/include/llvm/ADT/StringMap.h
diff -u llvm/include/llvm/ADT/StringMap.h:1.11 llvm/include/llvm/ADT/StringMap.h:1.12
--- llvm/include/llvm/ADT/StringMap.h:1.11	Sun Feb 11 15:07:36 2007
+++ llvm/include/llvm/ADT/StringMap.h	Sun Feb 11 15:46:36 2007
@@ -58,6 +58,16 @@
   StringMapImpl(unsigned InitSize, unsigned ItemSize);
   void RehashTable();
   
+  /// ShouldRehash - Return true if the table should be rehashed after a new
+  /// element was recently inserted.
+  bool ShouldRehash() const {
+    // If the hash table is now more than 3/4 full, or if fewer than 1/8 of
+    // the buckets are empty (meaning that many are filled with tombstones),
+    // grow the table.
+    return NumItems*4 > NumBuckets*3 ||
+           NumBuckets-(NumItems+NumTombstones) < NumBuckets/8;
+  }
+  
   /// LookupBucketFor - Look up the bucket that the specified string should end
   /// up in.  If it already exists as a key in the map, the Item pointer for the
   /// specified bucket will be non-null.  Otherwise, it will be null.  In either
@@ -218,11 +228,7 @@
     Bucket.Item = KeyValue;
     ++NumItems;
     
-    // If the hash table is now more than 3/4 full, or if fewer than 1/8 of
-    // the buckets are empty (meaning that many are filled with tombstones),
-    // grow the table.
-    if (NumItems*4 > NumBuckets*3 ||
-        NumBuckets-(NumItems+NumTombstones) < NumBuckets/8)
+    if (ShouldRehash())
       RehashTable();
     return true;
   }
@@ -247,11 +253,7 @@
     // filled in by LookupBucketFor.
     Bucket.Item = NewItem;
     
-    // If the hash table is now more than 3/4 full, or if fewer than 1/8 of
-    // the buckets are empty (meaning that many are filled with tombstones),
-    // grow the table.
-    if (NumItems*4 > NumBuckets*3 ||
-        NumBuckets-(NumItems+NumTombstones) < NumBuckets/8)
+    if (ShouldRehash())
       RehashTable();
     return *NewItem;
   }
@@ -264,8 +266,8 @@
   
   ~StringMap() {
     for (ItemBucket *I = TheTable, *E = TheTable+NumBuckets; I != E; ++I) {
-      if (MapEntryTy *Id = static_cast<MapEntryTy*>(I->Item))
-        Id->Destroy(Allocator);
+      if (I->Item && I->Item != getTombstoneVal())
+        static_cast<MapEntryTy*>(I->Item)->Destroy(Allocator);
     }
     delete [] TheTable;
   }