1 files changed, 37 insertions, 33 deletions

diff --git a/lib/Support/CachePruning.cpp b/lib/Support/CachePruning.cpp
index 60d0964f2764..3e97c991f504 100644
--- a/lib/Support/CachePruning.cpp
+++ b/lib/Support/CachePruning.cpp
@@ -113,6 +113,10 @@ llvm::parseCachePruningPolicy(StringRef PolicyStr) {
         return make_error<StringError>("'" + Value + "' not an integer",
                                        inconvertibleErrorCode());
       Policy.MaxSizeBytes = Size * Mult;
+    } else if (Key == "cache_size_files") {
+      if (Value.getAsInteger(0, Policy.MaxSizeFiles))
+        return make_error<StringError>("'" + Value + "' not an integer",
+                                       inconvertibleErrorCode());
     } else {
       return make_error<StringError>("Unknown key: '" + Key + "'",
                                      inconvertibleErrorCode());
@@ -141,7 +145,7 @@ bool llvm::pruneCache(StringRef Path, CachePruningPolicy Policy) {
 
   if (Policy.Expiration == seconds(0) &&
       Policy.MaxSizePercentageOfAvailableSpace == 0 &&
-      Policy.MaxSizeBytes == 0) {
+      Policy.MaxSizeBytes == 0 && Policy.MaxSizeFiles == 0) {
     DEBUG(dbgs() << "No pruning settings set, exit early\n");
     // Nothing will be pruned, early exit
     return false;
@@ -161,7 +165,7 @@ bool llvm::pruneCache(StringRef Path, CachePruningPolicy Policy) {
       return false;
     }
   } else {
-    if (Policy.Interval == seconds(0)) {
+    if (Policy.Interval != seconds(0)) {
       // Check whether the time stamp is older than our pruning interval.
       // If not, do nothing.
       const auto TimeStampModTime = FileStatus.getLastModificationTime();
@@ -179,22 +183,9 @@ bool llvm::pruneCache(StringRef Path, CachePruningPolicy Policy) {
     writeTimestampFile(TimestampFile);
   }
 
-  bool ShouldComputeSize =
-      (Policy.MaxSizePercentageOfAvailableSpace > 0 || Policy.MaxSizeBytes > 0);
-
-  // Keep track of space
+  // Keep track of space. Needs to be kept ordered by size for determinism.
   std::set<std::pair<uint64_t, std::string>> FileSizes;
   uint64_t TotalSize = 0;
-  // Helper to add a path to the set of files to consider for size-based
-  // pruning, sorted by size.
-  auto AddToFileListForSizePruning =
-      [&](StringRef Path) {
-        if (!ShouldComputeSize)
-          return;
-        TotalSize += FileStatus.getSize();
-        FileSizes.insert(
-            std::make_pair(FileStatus.getSize(), std::string(Path)));
-      };
 
   // Walk the entire directory cache, looking for unused files.
   std::error_code EC;
@@ -212,15 +203,16 @@ bool llvm::pruneCache(StringRef Path, CachePruningPolicy Policy) {
 
     // Look at this file. If we can't stat it, there's nothing interesting
     // there.
-    if (sys::fs::status(File->path(), FileStatus)) {
+    ErrorOr<sys::fs::basic_file_status> StatusOrErr = File->status();
+    if (!StatusOrErr) {
       DEBUG(dbgs() << "Ignore " << File->path() << " (can't stat)\n");
       continue;
     }
 
     // If the file hasn't been used recently enough, delete it
-    const auto FileAccessTime = FileStatus.getLastAccessedTime();
+    const auto FileAccessTime = StatusOrErr->getLastAccessedTime();
     auto FileAge = CurrentTime - FileAccessTime;
-    if (FileAge > Policy.Expiration) {
+    if (Policy.Expiration != seconds(0) && FileAge > Policy.Expiration) {
       DEBUG(dbgs() << "Remove " << File->path() << " ("
                    << duration_cast<seconds>(FileAge).count() << "s old)\n");
       sys::fs::remove(File->path());
@@ -228,11 +220,32 @@ bool llvm::pruneCache(StringRef Path, CachePruningPolicy Policy) {
     }
 
     // Leave it here for now, but add it to the list of size-based pruning.
-    AddToFileListForSizePruning(File->path());
+    TotalSize += StatusOrErr->getSize();
+    FileSizes.insert({StatusOrErr->getSize(), std::string(File->path())});
   }
 
+  auto FileAndSize = FileSizes.rbegin();
+  size_t NumFiles = FileSizes.size();
+
+  auto RemoveCacheFile = [&]() {
+    // Remove the file.
+    sys::fs::remove(FileAndSize->second);
+    // Update size
+    TotalSize -= FileAndSize->first;
+    NumFiles--;
+    DEBUG(dbgs() << " - Remove " << FileAndSize->second << " (size "
+                 << FileAndSize->first << "), new occupancy is " << TotalSize
+                 << "%\n");
+    ++FileAndSize;
+  };
+
+  // Prune for number of files.
+  if (Policy.MaxSizeFiles)
+    while (NumFiles > Policy.MaxSizeFiles)
+      RemoveCacheFile();
+
   // Prune for size now if needed
-  if (ShouldComputeSize) {
+  if (Policy.MaxSizePercentageOfAvailableSpace > 0 || Policy.MaxSizeBytes > 0) {
     auto ErrOrSpaceInfo = sys::fs::disk_space(Path);
     if (!ErrOrSpaceInfo) {
       report_fatal_error("Can't get available size");
@@ -252,18 +265,9 @@ bool llvm::pruneCache(StringRef Path, CachePruningPolicy Policy) {
                  << "% target is: " << Policy.MaxSizePercentageOfAvailableSpace
                  << "%, " << Policy.MaxSizeBytes << " bytes\n");
 
-    auto FileAndSize = FileSizes.rbegin();
-    // Remove the oldest accessed files first, till we get below the threshold
-    while (TotalSize > TotalSizeTarget && FileAndSize != FileSizes.rend()) {
-      // Remove the file.
-      sys::fs::remove(FileAndSize->second);
-      // Update size
-      TotalSize -= FileAndSize->first;
-      DEBUG(dbgs() << " - Remove " << FileAndSize->second << " (size "
-                   << FileAndSize->first << "), new occupancy is " << TotalSize
-                   << "%\n");
-      ++FileAndSize;
-    }
+    // Remove the oldest accessed files first, till we get below the threshold.
+    while (TotalSize > TotalSizeTarget && FileAndSize != FileSizes.rend())
+      RemoveCacheFile();
   }
   return true;
 }