Files
doris/be/src/exec/local_file_reader.cpp
2017-08-11 17:51:21 +08:00

91 lines
2.7 KiB
C++

// Copyright (c) 2017, Baidu.com, Inc. All Rights Reserved
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you 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.
#include "exec/local_file_reader.h"
namespace palo {
LocalFileReader::LocalFileReader(const std::string& path, int64_t start_offset)
: _path(path), _start_offset(start_offset), _eof(false), _fp(nullptr) {
}
LocalFileReader::~LocalFileReader() {
close();
}
Status LocalFileReader::open() {
_fp = fopen(_path.c_str(), "r");
if (_fp == nullptr) {
char err_buf[64];
std::stringstream ss;
ss << "Open file failed. path=" << _path
<< ", error=" << strerror_r(errno, err_buf, 64);
return Status(ss.str());
}
if (_start_offset != 0) {
int res = fseek(_fp, _start_offset, SEEK_SET);
if (res != 0) {
char err_buf[64];
std::stringstream ss;
ss << "Seek to start_offset failed. offset=" << _start_offset
<< ", error=" << strerror_r(errno, err_buf, 64);
return Status(ss.str());
}
}
return Status::OK;
}
Status LocalFileReader::read(uint8_t* buf, size_t* buf_len, bool* eof) {
if (_eof) {
*buf_len = 0;
*eof = true;
return Status::OK;
}
size_t read_len = fread(buf, 1, *buf_len, _fp);
if (read_len < *buf_len) {
if (ferror(_fp)) {
char err_buf[64];
std::stringstream ss;
ss << "Read file failed. path=" << _path
<< ", error=" << strerror_r(errno, err_buf, 64);
return Status(ss.str());
} else if (feof(_fp)) {
*buf_len = read_len;
_eof = true;
if (*buf_len == 0) {
*eof = true;
}
} else {
return Status("Unknown read failed.");
}
}
return Status::OK;
}
void LocalFileReader::close() {
if (_fp != nullptr) {
fclose(_fp);
_fp = nullptr;
}
}
}