110e286aa8d39fb51a21412850265d9dae74613eeChris Lattner//===--- FileSystemStatCache.h - Caching for 'stat' calls -------*- C++ -*-===// 210e286aa8d39fb51a21412850265d9dae74613eeChris Lattner// 310e286aa8d39fb51a21412850265d9dae74613eeChris Lattner// The LLVM Compiler Infrastructure 410e286aa8d39fb51a21412850265d9dae74613eeChris Lattner// 510e286aa8d39fb51a21412850265d9dae74613eeChris Lattner// This file is distributed under the University of Illinois Open Source 610e286aa8d39fb51a21412850265d9dae74613eeChris Lattner// License. See LICENSE.TXT for details. 710e286aa8d39fb51a21412850265d9dae74613eeChris Lattner// 810e286aa8d39fb51a21412850265d9dae74613eeChris Lattner//===----------------------------------------------------------------------===// 92f7f5b1f5ff023cb8c4008ae53a12b09e3ea2622James Dennett/// 102f7f5b1f5ff023cb8c4008ae53a12b09e3ea2622James Dennett/// \file 112f7f5b1f5ff023cb8c4008ae53a12b09e3ea2622James Dennett/// \brief Defines the FileSystemStatCache interface. 122f7f5b1f5ff023cb8c4008ae53a12b09e3ea2622James Dennett/// 1310e286aa8d39fb51a21412850265d9dae74613eeChris Lattner//===----------------------------------------------------------------------===// 1410e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 1510e286aa8d39fb51a21412850265d9dae74613eeChris Lattner#ifndef LLVM_CLANG_FILESYSTEMSTATCACHE_H 1610e286aa8d39fb51a21412850265d9dae74613eeChris Lattner#define LLVM_CLANG_FILESYSTEMSTATCACHE_H 1710e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 186f42b62b6194f53bcbc349f5d17388e1936535d7Dylan Noblesmith#include "clang/Basic/LLVM.h" 1910e286aa8d39fb51a21412850265d9dae74613eeChris Lattner#include "llvm/ADT/OwningPtr.h" 2010e286aa8d39fb51a21412850265d9dae74613eeChris Lattner#include "llvm/ADT/StringMap.h" 2110e286aa8d39fb51a21412850265d9dae74613eeChris Lattner#include <sys/types.h> 2210e286aa8d39fb51a21412850265d9dae74613eeChris Lattner#include <sys/stat.h> 2310e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 2410e286aa8d39fb51a21412850265d9dae74613eeChris Lattnernamespace clang { 2510e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 2610e286aa8d39fb51a21412850265d9dae74613eeChris Lattner/// \brief Abstract interface for introducing a FileManager cache for 'stat' 2710e286aa8d39fb51a21412850265d9dae74613eeChris Lattner/// system calls, which is used by precompiled and pretokenized headers to 2810e286aa8d39fb51a21412850265d9dae74613eeChris Lattner/// improve performance. 2910e286aa8d39fb51a21412850265d9dae74613eeChris Lattnerclass FileSystemStatCache { 3099ba9e3bd70671f3441fb974895f226a83ce0e66David Blaikie virtual void anchor(); 3110e286aa8d39fb51a21412850265d9dae74613eeChris Lattnerprotected: 326f42b62b6194f53bcbc349f5d17388e1936535d7Dylan Noblesmith OwningPtr<FileSystemStatCache> NextStatCache; 3310e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 3410e286aa8d39fb51a21412850265d9dae74613eeChris Lattnerpublic: 3510e286aa8d39fb51a21412850265d9dae74613eeChris Lattner virtual ~FileSystemStatCache() {} 3610e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 3710e286aa8d39fb51a21412850265d9dae74613eeChris Lattner enum LookupResult { 3849fdccb4595862828aa5cadc1497d466a8031ddaDmitri Gribenko CacheExists, ///< We know the file exists and its cached stat data. 3949fdccb4595862828aa5cadc1497d466a8031ddaDmitri Gribenko CacheMissing ///< We know that the file doesn't exist. 4010e286aa8d39fb51a21412850265d9dae74613eeChris Lattner }; 4111aa4b03b054cb9d3c201bba5632241145865e29Chris Lattner 42af50aab0c317462129d73ae8000c6394c718598dJames Dennett /// \brief Get the 'stat' information for the specified path, using the cache 43af50aab0c317462129d73ae8000c6394c718598dJames Dennett /// to accelerate it if possible. 44af50aab0c317462129d73ae8000c6394c718598dJames Dennett /// 45af50aab0c317462129d73ae8000c6394c718598dJames Dennett /// \returns \c true if the path does not exist or \c false if it exists. 46898a061f69e1145bf89a987c08203132b9922a3cChris Lattner /// 47898a061f69e1145bf89a987c08203132b9922a3cChris Lattner /// If FileDescriptor is non-null, then this lookup should only return success 48898a061f69e1145bf89a987c08203132b9922a3cChris Lattner /// for files (not directories). If it is null this lookup should only return 49898a061f69e1145bf89a987c08203132b9922a3cChris Lattner /// success for directories (not files). On a successful file lookup, the 50898a061f69e1145bf89a987c08203132b9922a3cChris Lattner /// implementation can optionally fill in FileDescriptor with a valid 51898a061f69e1145bf89a987c08203132b9922a3cChris Lattner /// descriptor and the client guarantees that it will close it. 52898a061f69e1145bf89a987c08203132b9922a3cChris Lattner static bool get(const char *Path, struct stat &StatBuf, int *FileDescriptor, 53898a061f69e1145bf89a987c08203132b9922a3cChris Lattner FileSystemStatCache *Cache); 54898a061f69e1145bf89a987c08203132b9922a3cChris Lattner 5510e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 5610e286aa8d39fb51a21412850265d9dae74613eeChris Lattner /// \brief Sets the next stat call cache in the chain of stat caches. 5710e286aa8d39fb51a21412850265d9dae74613eeChris Lattner /// Takes ownership of the given stat cache. 5810e286aa8d39fb51a21412850265d9dae74613eeChris Lattner void setNextStatCache(FileSystemStatCache *Cache) { 5910e286aa8d39fb51a21412850265d9dae74613eeChris Lattner NextStatCache.reset(Cache); 6010e286aa8d39fb51a21412850265d9dae74613eeChris Lattner } 6110e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 6210e286aa8d39fb51a21412850265d9dae74613eeChris Lattner /// \brief Retrieve the next stat call cache in the chain. 6310e286aa8d39fb51a21412850265d9dae74613eeChris Lattner FileSystemStatCache *getNextStatCache() { return NextStatCache.get(); } 6410e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 6510e286aa8d39fb51a21412850265d9dae74613eeChris Lattner /// \brief Retrieve the next stat call cache in the chain, transferring 6610e286aa8d39fb51a21412850265d9dae74613eeChris Lattner /// ownership of this cache (and, transitively, all of the remaining caches) 6710e286aa8d39fb51a21412850265d9dae74613eeChris Lattner /// to the caller. 6810e286aa8d39fb51a21412850265d9dae74613eeChris Lattner FileSystemStatCache *takeNextStatCache() { return NextStatCache.take(); } 6910e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 7010e286aa8d39fb51a21412850265d9dae74613eeChris Lattnerprotected: 71898a061f69e1145bf89a987c08203132b9922a3cChris Lattner virtual LookupResult getStat(const char *Path, struct stat &StatBuf, 72898a061f69e1145bf89a987c08203132b9922a3cChris Lattner int *FileDescriptor) = 0; 7311aa4b03b054cb9d3c201bba5632241145865e29Chris Lattner 74898a061f69e1145bf89a987c08203132b9922a3cChris Lattner LookupResult statChained(const char *Path, struct stat &StatBuf, 75898a061f69e1145bf89a987c08203132b9922a3cChris Lattner int *FileDescriptor) { 7610e286aa8d39fb51a21412850265d9dae74613eeChris Lattner if (FileSystemStatCache *Next = getNextStatCache()) 77898a061f69e1145bf89a987c08203132b9922a3cChris Lattner return Next->getStat(Path, StatBuf, FileDescriptor); 7810e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 79d6f611198089b78e32d3a15fe8bc986204aee1aaChris Lattner // If we hit the end of the list of stat caches to try, just compute and 80d6f611198089b78e32d3a15fe8bc986204aee1aaChris Lattner // return it without a cache. 81898a061f69e1145bf89a987c08203132b9922a3cChris Lattner return get(Path, StatBuf, FileDescriptor, 0) ? CacheMissing : CacheExists; 8210e286aa8d39fb51a21412850265d9dae74613eeChris Lattner } 8310e286aa8d39fb51a21412850265d9dae74613eeChris Lattner}; 8410e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 8510e286aa8d39fb51a21412850265d9dae74613eeChris Lattner/// \brief A stat "cache" that can be used by FileManager to keep 8610e286aa8d39fb51a21412850265d9dae74613eeChris Lattner/// track of the results of stat() calls that occur throughout the 8710e286aa8d39fb51a21412850265d9dae74613eeChris Lattner/// execution of the front end. 8810e286aa8d39fb51a21412850265d9dae74613eeChris Lattnerclass MemorizeStatCalls : public FileSystemStatCache { 8910e286aa8d39fb51a21412850265d9dae74613eeChris Lattnerpublic: 9074e976ba4b0d407bb798ea26476f618e256fc8c7Chris Lattner /// \brief The set of stat() calls that have been seen. 9174e976ba4b0d407bb798ea26476f618e256fc8c7Chris Lattner llvm::StringMap<struct stat, llvm::BumpPtrAllocator> StatCalls; 9210e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 9374e976ba4b0d407bb798ea26476f618e256fc8c7Chris Lattner typedef llvm::StringMap<struct stat, llvm::BumpPtrAllocator>::const_iterator 9410e286aa8d39fb51a21412850265d9dae74613eeChris Lattner iterator; 9510e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 9610e286aa8d39fb51a21412850265d9dae74613eeChris Lattner iterator begin() const { return StatCalls.begin(); } 9710e286aa8d39fb51a21412850265d9dae74613eeChris Lattner iterator end() const { return StatCalls.end(); } 9810e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 99898a061f69e1145bf89a987c08203132b9922a3cChris Lattner virtual LookupResult getStat(const char *Path, struct stat &StatBuf, 100898a061f69e1145bf89a987c08203132b9922a3cChris Lattner int *FileDescriptor); 10110e286aa8d39fb51a21412850265d9dae74613eeChris Lattner}; 10210e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 10310e286aa8d39fb51a21412850265d9dae74613eeChris Lattner} // end namespace clang 10410e286aa8d39fb51a21412850265d9dae74613eeChris Lattner 10510e286aa8d39fb51a21412850265d9dae74613eeChris Lattner#endif 106