github.com/minio/minio-go/v6@v6.0.57/examples/s3/listobjects-N.go (about)

     1  // +build ignore
     2  
     3  /*
     4   * MinIO Go Library for Amazon S3 Compatible Cloud Storage
     5   * Copyright 2015-2017 MinIO, Inc.
     6   *
     7   * Licensed under the Apache License, Version 2.0 (the "License");
     8   * you may not use this file except in compliance with the License.
     9   * You may obtain a copy of the License at
    10   *
    11   *     http://www.apache.org/licenses/LICENSE-2.0
    12   *
    13   * Unless required by applicable law or agreed to in writing, software
    14   * distributed under the License is distributed on an "AS IS" BASIS,
    15   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    16   * See the License for the specific language governing permissions and
    17   * limitations under the License.
    18   */
    19  
    20  package main
    21  
    22  import (
    23  	"fmt"
    24  
    25  	"github.com/minio/minio-go/v6"
    26  )
    27  
    28  func main() {
    29  	// Note: YOUR-ACCESSKEYID, YOUR-SECRETACCESSKEY, my-bucketname and my-prefixname
    30  	// are dummy values, please replace them with original values.
    31  
    32  	// Requests are always secure (HTTPS) by default. Set secure=false to enable insecure (HTTP) access.
    33  	// This boolean value is the last argument for New().
    34  
    35  	// New returns an Amazon S3 compatible client object. API compatibility (v2 or v4) is automatically
    36  	// determined based on the Endpoint value.
    37  	s3Client, err := minio.New("s3.amazonaws.com", "YOUR-ACCESSKEYID", "YOUR-SECRETACCESSKEY", true)
    38  	if err != nil {
    39  		fmt.Println(err)
    40  		return
    41  	}
    42  
    43  	// List 'N' number of objects from a bucket-name with a matching prefix.
    44  	listObjectsN := func(bucket, prefix string, recursive bool, N int) (objsInfo []minio.ObjectInfo, err error) {
    45  		// Create a done channel to control 'ListObjects' go routine.
    46  		doneCh := make(chan struct{}, 1)
    47  
    48  		// Free the channel upon return.
    49  		defer close(doneCh)
    50  
    51  		i := 1
    52  		for object := range s3Client.ListObjects(bucket, prefix, recursive, doneCh) {
    53  			if object.Err != nil {
    54  				return nil, object.Err
    55  			}
    56  			i++
    57  			// Verify if we have printed N objects.
    58  			if i == N {
    59  				// Indicate ListObjects go-routine to exit and stop
    60  				// feeding the objectInfo channel.
    61  				doneCh <- struct{}{}
    62  			}
    63  			objsInfo = append(objsInfo, object)
    64  		}
    65  		return objsInfo, nil
    66  	}
    67  
    68  	// List recursively first 100 entries for prefix 'my-prefixname'.
    69  	recursive := true
    70  	objsInfo, err := listObjectsN("my-bucketname", "my-prefixname", recursive, 100)
    71  	if err != nil {
    72  		fmt.Println(err)
    73  	}
    74  
    75  	// Print all the entries.
    76  	fmt.Println(objsInfo)
    77  }