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/*
* Copyright (C) 2016 The Android Open Source Project
*
* 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 FILE_READER_H_
#define FILE_READER_H_
#include <string>
#include <vector>
namespace profiler {
// Class to read file and perform related tokenize util functions.
class FileReader {
public:
// Real whole file and split it into lines.
static bool Read(const std::string &file_path,
std::vector<std::string> *lines);
// Reads whole file from beginning, and put output in a single string content.
// Returns true on success.
// The ownership of |content| is not transferred.
// TODO(b/29111072): Provide an option to read the entire file in a single
// access. Multiple reads may cause consistency issues, especially for virtual
// files such as /proc.stat in Android/Linux.
static bool Read(const std::string &file_path, std::string *content);
// Returns true if the needed token is found, false otherwise. Tokens are
// separated by whitespace in given line. token_index does not indicate the
// character index but indicates the whitespace separated token index.
// For example, we are looking for the second token from line
// "Today is Thursday.", the second token "is" exists. But if we specify
// 4 as the token_index, the needed token is not found.
static bool FindTokenPosition(const std::string &line, const int token_index,
size_t *token_start);
// Returns true if line contains a substring that is the same as token, and
// the substring is at given whitespace-separated index token_index.
static bool CompareToken(const std::string &line, const std::string &token,
const int token_index);
private:
// Single system call buffer size.
// TODO: Make the buffer size configurable in a constructor.
static const short kBufferSize_ = 4096;
};
} // namespace profiler
#endif // FILE_READER_H_
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