1 files changed, 49 insertions, 0 deletions
diff --git a/clang/lib/Serialization/InMemoryModuleCache.cpp b/clang/lib/Serialization/InMemoryModuleCache.cpp
new file mode 100644
index 00000000000..130ece01504
--- /dev/null
+++ b/clang/lib/Serialization/InMemoryModuleCache.cpp
@@ -0,0 +1,49 @@
+//===- InMemoryModuleCache.cpp - Cache for loaded memory buffers ----------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Serialization/InMemoryModuleCache.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+using namespace clang;
+
+llvm::MemoryBuffer &
+InMemoryModuleCache::addBuffer(llvm::StringRef Filename,
+                               std::unique_ptr<llvm::MemoryBuffer> Buffer) {
+  auto Insertion = PCMs.insert({Filename, PCM{std::move(Buffer), NextIndex++}});
+  assert(Insertion.second && "Already has a buffer");
+  return *Insertion.first->second.Buffer;
+}
+
+llvm::MemoryBuffer *
+InMemoryModuleCache::lookupBuffer(llvm::StringRef Filename) {
+  auto I = PCMs.find(Filename);
+  if (I == PCMs.end())
+    return nullptr;
+  return I->second.Buffer.get();
+}
+
+bool InMemoryModuleCache::isBufferFinal(llvm::StringRef Filename) {
+  auto I = PCMs.find(Filename);
+  if (I == PCMs.end())
+    return false;
+  return I->second.Index < FirstRemovableIndex;
+}
+
+bool InMemoryModuleCache::tryToRemoveBuffer(llvm::StringRef Filename) {
+  auto I = PCMs.find(Filename);
+  assert(I != PCMs.end() && "No buffer to remove...");
+  if (I->second.Index < FirstRemovableIndex)
+    return true;
+
+  PCMs.erase(I);
+  return false;
+}
+
+void InMemoryModuleCache::finalizeCurrentBuffers() {
+  FirstRemovableIndex = NextIndex;
+}