cmArchiveWrite: Consolidate multiple ways to set thread count

Merge use of SetFilterOption() into more abstract thread count
in cmArchiveWrite constructor.

libarchive defaulting of threads for threads == 0 seems to be
configuration dependent. Preemptively default thread count via
std::thread::hardware_concurrency().

Also allow negative values for the thread count in which case
the detected hardware concurrency is also used but the given
absolute thread count is used as an upper limit.

1 files changed, 1 insertions, 1 deletions

diff --git a/Source/CPack/cmCPackArchiveGenerator.h b/Source/CPack/cmCPackArchiveGenerator.h
index 5b40013..8a9bbc6 100644
--- a/Source/CPack/cmCPackArchiveGenerator.h
+++ b/Source/CPack/cmCPackArchiveGenerator.h
@@ -85,7 +85,7 @@ private:
     return this->OutputExtension.c_str();
   }
 
-  bool SetArchiveOptions(cmArchiveWrite* archive);
+  int GetThreadCount() const;
 
 private:
   cmArchiveWrite::Compress Compress;