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// Copyright 2011 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef NINJA_DISK_INTERFACE_H_
#define NINJA_DISK_INTERFACE_H_
#include <map>
#include <string>
using namespace std;
#include "timestamp.h"
/// Interface for reading files from disk. See DiskInterface for details.
/// This base offers the minimum interface needed just to read files.
struct FileReader {
virtual ~FileReader() {}
/// Result of ReadFile.
enum Status {
Okay,
NotFound,
OtherError
};
/// Read and store in given string. On success, return Okay.
/// On error, return another Status and fill |err|.
virtual Status ReadFile(const string& path, string* contents,
string* err) = 0;
};
/// Interface for accessing the disk.
///
/// Abstract so it can be mocked out for tests. The real implementation
/// is RealDiskInterface.
struct DiskInterface: public FileReader {
/// stat() a file, returning the mtime, or 0 if missing and -1 on
/// other errors.
virtual TimeStamp Stat(const string& path, string* err) const = 0;
/// Create a directory, returning false on failure.
virtual bool MakeDir(const string& path) = 0;
/// Create a file, with the specified name and contents
/// Returns true on success, false on failure
virtual bool WriteFile(const string& path, const string& contents) = 0;
/// Remove the file named @a path. It behaves like 'rm -f path' so no errors
/// are reported if it does not exists.
/// @returns 0 if the file has been removed,
/// 1 if the file does not exist, and
/// -1 if an error occurs.
virtual int RemoveFile(const string& path) = 0;
/// Create all the parent directories for path; like mkdir -p
/// `basename path`.
bool MakeDirs(const string& path);
};
/// Implementation of DiskInterface that actually hits the disk.
struct RealDiskInterface : public DiskInterface {
RealDiskInterface()
#ifdef _WIN32
: use_cache_(false)
#endif
{}
virtual ~RealDiskInterface() {}
virtual TimeStamp Stat(const string& path, string* err) const;
virtual bool MakeDir(const string& path);
virtual bool WriteFile(const string& path, const string& contents);
virtual Status ReadFile(const string& path, string* contents, string* err);
virtual int RemoveFile(const string& path);
/// Whether stat information can be cached. Only has an effect on Windows.
void AllowStatCache(bool allow);
private:
#ifdef _WIN32
/// Whether stat information can be cached.
bool use_cache_;
typedef map<string, TimeStamp> DirCache;
// TODO: Neither a map nor a hashmap seems ideal here. If the statcache
// works out, come up with a better data structure.
typedef map<string, DirCache> Cache;
mutable Cache cache_;
#endif
};
#endif // NINJA_DISK_INTERFACE_H_