[llvm-commits] CVS: llvm/include/Support/SlowOperationInformer.h

[Chris Lattner]

Changes in directory llvm/include/Support:

SlowOperationInformer.h added (r1.1)

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Log message:

New class, useful for command-line interactive programs.


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Diffs of the changes:  (+56 -0)

Index: llvm/include/Support/SlowOperationInformer.h
diff -c /dev/null llvm/include/Support/SlowOperationInformer.h:1.1
*** /dev/null	Tue Dec 30 23:40:12 2003
--- llvm/include/Support/SlowOperationInformer.h	Tue Dec 30 23:40:02 2003
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*** 0 ****
--- 1,56 ----
+ //===- SlowOperationInformer.h - Keep the user informed ---------*- C++ -*-===//
+ // 
+ //                     The LLVM Compiler Infrastructure
+ //
+ // This file was developed by the LLVM research group and is distributed under
+ // the University of Illinois Open Source License. See LICENSE.TXT for details.
+ // 
+ //===----------------------------------------------------------------------===//
+ //
+ // This file defines a simple object which can be used to let the user know what
+ // is going on when a slow operation is happening,l and gives them the ability
+ // to cancel it.  Potentially slow operations can stack allocate one of these
+ // objects, and periodically call the "progress" method to update the progress
+ // bar.  If the operation takes more than 3 seconds to complete, the progress
+ // bar is automatically shown and updated every second.  As such, the slow
+ // operation should not print stuff to the screen, and should not be confused if
+ // an extra line appears on the screen (ie, the cursor should be at the start of
+ // the line).
+ //
+ // If the user presses CTRL-C during the operation, the next invocation of the
+ // progress method with throw an std::string object indicating that the
+ // operation was cancelled.  As such, client code must be exception safe around
+ // the progress method.
+ //
+ // Because SlowOperationInformers fiddle around with signals, they cannot be
+ // nested.  The SIGINT signal handler is restored after the
+ // SlowOperationInformer is destroyed, but the SIGALRM handlers is set back to
+ // the default.
+ //
+ //===----------------------------------------------------------------------===//
+ 
+ #ifndef SUPPORT_SLOW_OPERATION_INFORMER_H
+ #define SUPPORT_SLOW_OPERATION_INFORMER_H
+ 
+ #include <string>
+ 
+ namespace llvm {
+   class SlowOperationInformer {
+     std::string OperationName;
+     unsigned LastPrintAmount;
+     
+     SlowOperationInformer(const SlowOperationInformer&);   // DO NOT IMPLEMENT
+     void operator=(const SlowOperationInformer&);          // DO NOT IMPLEMENT
+   public:
+     SlowOperationInformer(const std::string &Name);
+     ~SlowOperationInformer();
+     
+     /// progress - Clients should periodically call this method when they are in
+     /// an exception-safe state.  The Amount variable should indicate how far
+     /// along the operation is, given in 1/10ths of a percent (in other words,
+     /// Amount should range from 0 to 1000).
+     void progress(unsigned Amount);
+   };
+ } // end namespace llvm
+ 
+ #endif /* SLOW_OPERATION_INFORMER_H */