/// <summary> /// Computes the existence of a path when not cached. For graph file systems the existence state of all paths /// is statically known, so non-existent is returned here as not finding a cached path means it does not appear /// in graph file system. /// </summary> private Possible <PathExistence> ComputeAndAddCacheRealFileSystemExistence(AbsolutePath path, FileSystemViewMode mode, bool?isReadOnly = default) { Contract.Requires(mode == FileSystemViewMode.Real); // Optimization. Check if the path can be determined to not exist based on a parent path without // checking file system if (m_inferNonExistenceBasedOnParentPathInRealFileSystem && TryInferNonExistenceBasedOnParentPathInRealFileSystem(path, out var trackedParentPath, out var intermediateParentPath) && TrackRealFileSystemAbsentChildPath(trackedParentPath, descendantPath: path)) { return(PathExistence.Nonexistent); } // TODO: Some kind of strategy to trigger enumerating directories with commonly probed members // TODO: Perhaps probabilistically enumerate based on hash of path and some counter var possibleExistence = LocalDiskFileSystem.TryProbeAndTrackPathForExistence(path.Expand(PathTable), isReadOnly); Counters.IncrementCounter(FileSystemViewCounters.RealFileSystemDiskProbes); if (possibleExistence.Succeeded) { GetOrAddExistence(path, mode, possibleExistence.Result); } return(possibleExistence); }
private bool TrackRealFileSystemAbsentChildPath(AbsolutePath trackedParentPath, AbsolutePath descendantPath) { var path = descendantPath; while (path.IsValid && path != trackedParentPath) { GetOrAddExistence(path, FileSystemViewMode.Real, PathExistence.Nonexistent); path = path.GetParent(PathTable); } return(LocalDiskFileSystem.TrackAbsentPath(trackedParentPath, descendantPath)); }
/// <summary> /// Queries the existence and members of a directory in the specified file system mode /// </summary> public Possible <PathExistence> TryEnumerateDirectory(AbsolutePath path, FileSystemViewMode mode, Action <string, AbsolutePath, PathExistence> handleEntry, bool cachePathExistence = true) { FileSystemEntry entry; PathExistence existence; if (PathExistenceCache.TryGetValue(path, out entry) && entry.TryGetExistence(mode, out existence)) { if (existence == PathExistence.Nonexistent) { return(existence); } if (existence == PathExistence.ExistsAsFile) { bool isDirectorySymlinkOrJunction = false; if (entry.HasFlag(FileSystemEntryFlags.CheckedIsDirectorySymlink)) { isDirectorySymlinkOrJunction = entry.HasFlag(FileSystemEntryFlags.IsDirectorySymlink); } else { isDirectorySymlinkOrJunction = FileUtilities.IsDirectorySymlinkOrJunction(path.ToString(PathTable)); PathExistenceCache.AddOrUpdate(path, false, (key, data) => { throw Contract.AssertFailure("Entry should already be added for path"); }, (key, data, oldValue) => oldValue.SetFlag( FileSystemEntryFlags.CheckedIsDirectorySymlink | (isDirectorySymlinkOrJunction ? FileSystemEntryFlags.IsDirectorySymlink : FileSystemEntryFlags.None))); } if (!isDirectorySymlinkOrJunction) { return(existence); } } // For graph file systems, directory members can be determined by overlaying path table with existence state in-memory // For real file system, this same is true if the directory has already been enumerated if (mode != FileSystemViewMode.Real || ((entry.Flags & FileSystemEntryFlags.IsRealFileSystemEnumerated) != 0)) { foreach (var childPathValue in PathTable.EnumerateImmediateChildren(path.Value)) { var childPath = new AbsolutePath(childPathValue); PathExistence childExistence; if (TryGetKnownPathExistence(childPath, mode, out childExistence) && childExistence != PathExistence.Nonexistent) { var entryName = childPath.GetName(PathTable).ToString(PathTable.StringTable); handleEntry(entryName, childPath, childExistence); } } return(existence); } } if (mode == FileSystemViewMode.Real) { var handleDirectoryEntry = new Action <string, FileAttributes>((entryName, entryAttributes) => { // Reparse points are always treated as files. Otherwise, honor the directory attribute to determine // existence var childExistence = (entryAttributes & FileAttributes.ReparsePoint) != 0 ? PathExistence.ExistsAsFile : (entryAttributes & FileAttributes.Directory) != 0 ? PathExistence.ExistsAsDirectory : PathExistence.ExistsAsFile; var childPath = path.Combine(PathTable, entryName); childExistence = GetOrAddExistence(childPath, mode, childExistence, updateParents: false); // NOTE: Because we are caching file system state in memory, it is possible that the existence state of // files does not match the state from the file system. if (childExistence != PathExistence.Nonexistent) { handleEntry(entryName, childPath, childExistence); } }); Counters.IncrementCounter(FileSystemViewCounters.RealFileSystemEnumerations); if (cachePathExistence) { Possible <PathExistence> possibleExistence; using (Counters.StartStopwatch(FileSystemViewCounters.RealFileSystemEnumerationsDuration)) { possibleExistence = LocalDiskFileSystem.TryEnumerateDirectoryAndTrackMembership( path, handleDirectoryEntry, // This method is called during observed input processing. Currently, we simply include all entries. // TODO: In the future, we may want to restrict it based on pip's untracked scopes/paths. shouldIncludeEntry: null /* include all entries */); } if (possibleExistence.Succeeded) { existence = GetOrAddExistence(path, mode, possibleExistence.Result); PathExistenceCache.AddOrUpdate(path, false, (key, data) => { throw Contract.AssertFailure("Entry should already be added for path"); }, (key, data, oldValue) => oldValue.SetFlag(FileSystemEntryFlags.IsRealFileSystemEnumerated)); return(existence); } return(possibleExistence); } using (Counters.StartStopwatch(FileSystemViewCounters.RealFileSystemEnumerationsDuration)) { var possibleFingerprintResult = DirectoryMembershipTrackingFingerprinter.ComputeFingerprint( path.Expand(PathTable).ExpandedPath, handleEntry: handleDirectoryEntry); return(possibleFingerprintResult.Succeeded ? new Possible <PathExistence>(possibleFingerprintResult.Result.PathExistence) : new Possible <PathExistence>(possibleFingerprintResult.Failure)); } } else if (ExistsInGraphFileSystem(PipGraph.TryGetLatestFileArtifactForPath(path), mode)) { return(PathExistence.ExistsAsFile); } return(PathExistence.Nonexistent); }
/// <summary> /// Queries the existence and members of a directory in the specified file system mode /// </summary> public Possible <PathExistence> TryEnumerateDirectory(AbsolutePath path, FileSystemViewMode mode, Action <string, AbsolutePath, PathExistence> handleEntry, bool cachePathExistence = true) { FileSystemEntry entry; PathExistence existence; if (PathExistenceCache.TryGetValue(path, out entry) && entry.TryGetExistence(mode, out existence)) { if (existence != PathExistence.ExistsAsDirectory) { return(existence); } // For graph file systems, directory members can be determined by overlaying path table with existence state in-memory // For real file system, this same is true if the directory has already been enumerated if (mode != FileSystemViewMode.Real || ((entry.Flags & FileSystemEntryFlags.IsRealFileSystemEnumerated) != 0)) { foreach (var childPathValue in PathTable.EnumerateImmediateChildren(path.Value)) { var childPath = new AbsolutePath(childPathValue); PathExistence childExistence; if (TryGetKnownPathExistence(childPath, mode, out childExistence) && childExistence != PathExistence.Nonexistent) { var entryName = childPath.GetName(PathTable).ToString(PathTable.StringTable); handleEntry(entryName, childPath, childExistence); } } return(existence); } } if (mode == FileSystemViewMode.Real) { var handleDirectoryEntry = new Action <string, FileAttributes>((entryName, entryAttributes) => { var childExistence = (entryAttributes & FileAttributes.Directory) != 0 ? PathExistence.ExistsAsDirectory : PathExistence.ExistsAsFile; var childPath = path.Combine(PathTable, entryName); childExistence = GetOrAddExistence(childPath, mode, childExistence, updateParents: false); // NOTE: Because we are caching file system state in memory, it is possible that the existence state of // files does not match the state from the file system. if (childExistence != PathExistence.Nonexistent) { handleEntry(entryName, childPath, childExistence); } }); Counters.IncrementCounter(FileSystemViewCounters.RealFileSystemEnumerations); if (cachePathExistence) { Possible <PathExistence> possibleExistence; using (Counters.StartStopwatch(FileSystemViewCounters.RealFileSystemEnumerationsDuration)) { possibleExistence = LocalDiskFileSystem.TryEnumerateDirectoryAndTrackMembership(path, handleDirectoryEntry); } if (possibleExistence.Succeeded) { existence = GetOrAddExistence(path, mode, possibleExistence.Result); PathExistenceCache.AddOrUpdate(path, false, (key, data) => { throw Contract.AssertFailure("Entry should already be added for path"); }, (key, data, oldValue) => oldValue.SetFlag(FileSystemEntryFlags.IsRealFileSystemEnumerated)); return(existence); } return(possibleExistence); } using (Counters.StartStopwatch(FileSystemViewCounters.RealFileSystemEnumerationsDuration)) { var possibleFingerprintResult = DirectoryMembershipTrackingFingerprinter.ComputeFingerprint( path.Expand(PathTable).ExpandedPath, handleEntry: handleDirectoryEntry); return(possibleFingerprintResult.Succeeded ? new Possible <PathExistence>(possibleFingerprintResult.Result.PathExistence) : new Possible <PathExistence>(possibleFingerprintResult.Failure)); } } else if (ExistsInGraphFileSystem(PipGraph.TryGetLatestFileArtifactForPath(path), mode)) { return(PathExistence.ExistsAsFile); } return(PathExistence.Nonexistent); }