r341455 - [VFS] Cache the current working directory for the real FS.
Eric Liu via cfe-commits
cfe-commits at lists.llvm.org
Wed Sep 5 02:45:27 PDT 2018
Author: ioeric
Date: Wed Sep 5 02:45:27 2018
New Revision: 341455
URL: http://llvm.org/viewvc/llvm-project?rev=341455&view=rev
Log:
[VFS] Cache the current working directory for the real FS.
Reviewers: sammccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D51641
Modified:
cfe/trunk/lib/Basic/VirtualFileSystem.cpp
Modified: cfe/trunk/lib/Basic/VirtualFileSystem.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/VirtualFileSystem.cpp?rev=341455&r1=341454&r2=341455&view=diff
==============================================================================
--- cfe/trunk/lib/Basic/VirtualFileSystem.cpp (original)
+++ cfe/trunk/lib/Basic/VirtualFileSystem.cpp Wed Sep 5 02:45:27 2018
@@ -49,6 +49,7 @@
#include <limits>
#include <map>
#include <memory>
+#include <mutex>
#include <string>
#include <system_error>
#include <utility>
@@ -244,6 +245,9 @@ public:
std::error_code setCurrentWorkingDirectory(const Twine &Path) override;
std::error_code getRealPath(const Twine &Path,
SmallVectorImpl<char> &Output) const override;
+private:
+ mutable std::mutex CWDMutex;
+ mutable std::string CWDCache;
};
} // namespace
@@ -266,10 +270,14 @@ RealFileSystem::openFileForRead(const Tw
}
llvm::ErrorOr<std::string> RealFileSystem::getCurrentWorkingDirectory() const {
+ std::lock_guard<std::mutex> Lock(CWDMutex);
+ if (!CWDCache.empty())
+ return CWDCache;
SmallString<256> Dir;
if (std::error_code EC = llvm::sys::fs::current_path(Dir))
return EC;
- return Dir.str().str();
+ CWDCache = Dir.str();
+ return CWDCache;
}
std::error_code RealFileSystem::setCurrentWorkingDirectory(const Twine &Path) {
@@ -280,7 +288,13 @@ std::error_code RealFileSystem::setCurre
// difference for example on network filesystems, where symlinks might be
// switched during runtime of the tool. Fixing this depends on having a
// file system abstraction that allows openat() style interactions.
- return llvm::sys::fs::set_current_path(Path);
+ if (auto EC = llvm::sys::fs::set_current_path(Path))
+ return EC;
+
+ // Invalidate cache.
+ std::lock_guard<std::mutex> Lock(CWDMutex);
+ CWDCache.clear();
+ return std::error_code();
}
std::error_code
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