github.com/cs3org/reva/v2@v2.27.7/pkg/storage/utils/downloader/downloader.go (about)

     1  // Copyright 2018-2021 CERN
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain 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,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  //
    15  // In applying this license, CERN does not waive the privileges and immunities
    16  // granted to it by virtue of its status as an Intergovernmental Organization
    17  // or submit itself to any jurisdiction.
    18  
    19  package downloader
    20  
    21  import (
    22  	"context"
    23  	"fmt"
    24  	"io"
    25  	"net/http"
    26  
    27  	gateway "github.com/cs3org/go-cs3apis/cs3/gateway/v1beta1"
    28  	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
    29  	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
    30  	"github.com/cs3org/reva/v2/internal/http/services/datagateway"
    31  	"github.com/cs3org/reva/v2/pkg/errtypes"
    32  	"github.com/cs3org/reva/v2/pkg/rgrpc/todo/pool"
    33  	"github.com/cs3org/reva/v2/pkg/rhttp"
    34  )
    35  
    36  // Downloader is the interface implemented by the objects that are able to
    37  // download a path into a destination Writer
    38  type Downloader interface {
    39  	Download(context.Context, *provider.ResourceId, io.Writer) error
    40  }
    41  
    42  type revaDownloader struct {
    43  	gatewaySelector pool.Selectable[gateway.GatewayAPIClient]
    44  	httpClient      *http.Client
    45  }
    46  
    47  // NewDownloader creates a Downloader from the reva gateway
    48  func NewDownloader(gatewaySelector pool.Selectable[gateway.GatewayAPIClient], options ...rhttp.Option) Downloader {
    49  	return &revaDownloader{
    50  		gatewaySelector: gatewaySelector,
    51  		httpClient:      rhttp.GetHTTPClient(options...),
    52  	}
    53  }
    54  
    55  func getDownloadProtocol(protocols []*gateway.FileDownloadProtocol, prot string) (*gateway.FileDownloadProtocol, error) {
    56  	for _, p := range protocols {
    57  		if p.Protocol == prot {
    58  			return p, nil
    59  		}
    60  	}
    61  	return nil, errtypes.InternalError(fmt.Sprintf("protocol %s not supported for downloading", prot))
    62  }
    63  
    64  // Download downloads a resource given the path to the dst Writer
    65  func (r *revaDownloader) Download(ctx context.Context, id *provider.ResourceId, dst io.Writer) error {
    66  	gatewayClient, err := r.gatewaySelector.Next()
    67  	if err != nil {
    68  		return err
    69  	}
    70  	downResp, err := gatewayClient.InitiateFileDownload(ctx, &provider.InitiateFileDownloadRequest{
    71  		Ref: &provider.Reference{
    72  			ResourceId: id,
    73  			Path:       ".",
    74  		},
    75  	})
    76  
    77  	switch {
    78  	case err != nil:
    79  		return err
    80  	case downResp.Status.Code != rpc.Code_CODE_OK:
    81  		return errtypes.InternalError(downResp.Status.Message)
    82  	}
    83  
    84  	p, err := getDownloadProtocol(downResp.Protocols, "simple")
    85  	if err != nil {
    86  		p, err = getDownloadProtocol(downResp.Protocols, "spaces")
    87  		if err != nil {
    88  			return err
    89  		}
    90  	}
    91  
    92  	httpReq, err := rhttp.NewRequest(ctx, http.MethodGet, p.DownloadEndpoint, nil)
    93  	if err != nil {
    94  		return err
    95  	}
    96  	httpReq.Header.Set(datagateway.TokenTransportHeader, p.Token)
    97  
    98  	httpRes, err := r.httpClient.Do(httpReq)
    99  	if err != nil {
   100  		return err
   101  	}
   102  	defer httpRes.Body.Close()
   103  
   104  	if err := errtypes.NewErrtypeFromHTTPStatusCode(httpRes.StatusCode, id.String()); err != nil {
   105  		return err
   106  	}
   107  
   108  	_, err = io.Copy(dst, httpRes.Body)
   109  	return err
   110  }