data_source.go

Documentation: gopkg.in/ini.v1

     1  // Copyright 2019 Unknwon
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License"): you may
     4  // not use this file except in compliance with the License. You may obtain
     5  // a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    11  // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
    12  // License for the specific language governing permissions and limitations
    13  // under the License.
    14  
    15  package ini
    16  
    17  import (
    18  	"bytes"
    19  	"fmt"
    20  	"io"
    21  	"io/ioutil"
    22  	"os"
    23  )
    24  
    25  var (
    26  	_ dataSource = (*sourceFile)(nil)
    27  	_ dataSource = (*sourceData)(nil)
    28  	_ dataSource = (*sourceReadCloser)(nil)
    29  )
    30  
    31  // dataSource is an interface that returns object which can be read and closed.
    32  type dataSource interface {
    33  	ReadCloser() (io.ReadCloser, error)
    34  }
    35  
    36  // sourceFile represents an object that contains content on the local file system.
    37  type sourceFile struct {
    38  	name string
    39  }
    40  
    41  func (s sourceFile) ReadCloser() (_ io.ReadCloser, err error) {
    42  	return os.Open(s.name)
    43  }
    44  
    45  // sourceData represents an object that contains content in memory.
    46  type sourceData struct {
    47  	data []byte
    48  }
    49  
    50  func (s *sourceData) ReadCloser() (io.ReadCloser, error) {
    51  	return ioutil.NopCloser(bytes.NewReader(s.data)), nil
    52  }
    53  
    54  // sourceReadCloser represents an input stream with Close method.
    55  type sourceReadCloser struct {
    56  	reader io.ReadCloser
    57  }
    58  
    59  func (s *sourceReadCloser) ReadCloser() (io.ReadCloser, error) {
    60  	return s.reader, nil
    61  }
    62  
    63  func parseDataSource(source interface{}) (dataSource, error) {
    64  	switch s := source.(type) {
    65  	case string:
    66  		return sourceFile{s}, nil
    67  	case []byte:
    68  		return &sourceData{s}, nil
    69  	case io.ReadCloser:
    70  		return &sourceReadCloser{s}, nil
    71  	case io.Reader:
    72  		return &sourceReadCloser{ioutil.NopCloser(s)}, nil
    73  	default:
    74  		return nil, fmt.Errorf("error parsing data source: unknown type %q", s)
    75  	}
    76  }
    77
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