diff options
Diffstat (limited to 'lib/Support/CachePruning.cpp')
| -rw-r--r-- | lib/Support/CachePruning.cpp | 97 |
1 files changed, 87 insertions, 10 deletions
diff --git a/lib/Support/CachePruning.cpp b/lib/Support/CachePruning.cpp index 3831625962ca..aca123639565 100644 --- a/lib/Support/CachePruning.cpp +++ b/lib/Support/CachePruning.cpp @@ -15,6 +15,7 @@ #include "llvm/Support/Debug.h" #include "llvm/Support/Errc.h" +#include "llvm/Support/Error.h" #include "llvm/Support/FileSystem.h" #include "llvm/Support/Path.h" #include "llvm/Support/raw_ostream.h" @@ -33,8 +34,75 @@ static void writeTimestampFile(StringRef TimestampFile) { raw_fd_ostream Out(TimestampFile.str(), EC, sys::fs::F_None); } +static Expected<std::chrono::seconds> parseDuration(StringRef Duration) { + if (Duration.empty()) + return make_error<StringError>("Duration must not be empty", + inconvertibleErrorCode()); + + StringRef NumStr = Duration.slice(0, Duration.size()-1); + uint64_t Num; + if (NumStr.getAsInteger(0, Num)) + return make_error<StringError>("'" + NumStr + "' not an integer", + inconvertibleErrorCode()); + + switch (Duration.back()) { + case 's': + return std::chrono::seconds(Num); + case 'm': + return std::chrono::minutes(Num); + case 'h': + return std::chrono::hours(Num); + default: + return make_error<StringError>("'" + Duration + + "' must end with one of 's', 'm' or 'h'", + inconvertibleErrorCode()); + } +} + +Expected<CachePruningPolicy> +llvm::parseCachePruningPolicy(StringRef PolicyStr) { + CachePruningPolicy Policy; + std::pair<StringRef, StringRef> P = {"", PolicyStr}; + while (!P.second.empty()) { + P = P.second.split(':'); + + StringRef Key, Value; + std::tie(Key, Value) = P.first.split('='); + if (Key == "prune_interval") { + auto DurationOrErr = parseDuration(Value); + if (!DurationOrErr) + return DurationOrErr.takeError(); + Policy.Interval = *DurationOrErr; + } else if (Key == "prune_after") { + auto DurationOrErr = parseDuration(Value); + if (!DurationOrErr) + return DurationOrErr.takeError(); + Policy.Expiration = *DurationOrErr; + } else if (Key == "cache_size") { + if (Value.back() != '%') + return make_error<StringError>("'" + Value + "' must be a percentage", + inconvertibleErrorCode()); + StringRef SizeStr = Value.slice(0, Value.size() - 1); + uint64_t Size; + if (SizeStr.getAsInteger(0, Size)) + return make_error<StringError>("'" + SizeStr + "' not an integer", + inconvertibleErrorCode()); + if (Size > 100) + return make_error<StringError>("'" + SizeStr + + "' must be between 0 and 100", + inconvertibleErrorCode()); + Policy.PercentageOfAvailableSpace = Size; + } else { + return make_error<StringError>("Unknown key: '" + Key + "'", + inconvertibleErrorCode()); + } + } + + return Policy; +} + /// Prune the cache of files that haven't been accessed in a long time. -bool CachePruning::prune() { +bool llvm::pruneCache(StringRef Path, CachePruningPolicy Policy) { using namespace std::chrono; if (Path.empty()) @@ -47,7 +115,11 @@ bool CachePruning::prune() { if (!isPathDir) return false; - if (Expiration == seconds(0) && PercentageOfAvailableSpace == 0) { + Policy.PercentageOfAvailableSpace = + std::min(Policy.PercentageOfAvailableSpace, 100u); + + if (Policy.Expiration == seconds(0) && + Policy.PercentageOfAvailableSpace == 0) { DEBUG(dbgs() << "No pruning settings set, exit early\n"); // Nothing will be pruned, early exit return false; @@ -67,12 +139,12 @@ bool CachePruning::prune() { return false; } } else { - if (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(); auto TimeStampAge = CurrentTime - TimeStampModTime; - if (TimeStampAge <= Interval) { + if (TimeStampAge <= Policy.Interval) { DEBUG(dbgs() << "Timestamp file too recent (" << duration_cast<seconds>(TimeStampAge).count() << "s old), do not prune.\n"); @@ -85,7 +157,7 @@ bool CachePruning::prune() { writeTimestampFile(TimestampFile); } - bool ShouldComputeSize = (PercentageOfAvailableSpace > 0); + bool ShouldComputeSize = (Policy.PercentageOfAvailableSpace > 0); // Keep track of space std::set<std::pair<uint64_t, std::string>> FileSizes; @@ -108,8 +180,11 @@ bool CachePruning::prune() { // Walk all of the files within this directory. for (sys::fs::directory_iterator File(CachePathNative, EC), FileEnd; File != FileEnd && !EC; File.increment(EC)) { - // Do not touch the timestamp. - if (File->path() == TimestampFile) + // Ignore any files not beginning with the string "llvmcache-". This + // includes the timestamp file as well as any files created by the user. + // This acts as a safeguard against data loss if the user specifies the + // wrong directory as their cache directory. + if (!sys::path::filename(File->path()).startswith("llvmcache-")) continue; // Look at this file. If we can't stat it, there's nothing interesting @@ -122,7 +197,7 @@ bool CachePruning::prune() { // If the file hasn't been used recently enough, delete it const auto FileAccessTime = FileStatus.getLastAccessedTime(); auto FileAge = CurrentTime - FileAccessTime; - if (FileAge > Expiration) { + if (FileAge > Policy.Expiration) { DEBUG(dbgs() << "Remove " << File->path() << " (" << duration_cast<seconds>(FileAge).count() << "s old)\n"); sys::fs::remove(File->path()); @@ -143,9 +218,11 @@ bool CachePruning::prune() { auto AvailableSpace = TotalSize + SpaceInfo.free; auto FileAndSize = FileSizes.rbegin(); DEBUG(dbgs() << "Occupancy: " << ((100 * TotalSize) / AvailableSpace) - << "% target is: " << PercentageOfAvailableSpace << "\n"); + << "% target is: " << Policy.PercentageOfAvailableSpace + << "\n"); // Remove the oldest accessed files first, till we get below the threshold - while (((100 * TotalSize) / AvailableSpace) > PercentageOfAvailableSpace && + while (((100 * TotalSize) / AvailableSpace) > + Policy.PercentageOfAvailableSpace && FileAndSize != FileSizes.rend()) { // Remove the file. sys::fs::remove(FileAndSize->second); |