github.com/hasnat/dolt/go@v0.0.0-20210628190320-9eb5d843fbb7/store/nbs/chunk_source_adapter.go (about)

     1  // Copyright 2019 Dolthub, Inc.
     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  package nbs
    16  
    17  type chunkSourceAdapter struct {
    18  	tableReader
    19  	h addr
    20  }
    21  
    22  func (csa chunkSourceAdapter) hash() (addr, error) {
    23  	return csa.h, nil
    24  }
    25  
    26  func newReaderFromIndexData(indexCache *indexCache, idxData []byte, name addr, tra tableReaderAt, blockSize uint64) (cs chunkSource, err error) {
    27  	index, err := parseTableIndex(idxData)
    28  
    29  	if err != nil {
    30  		return nil, err
    31  	}
    32  
    33  	if indexCache != nil {
    34  		indexCache.lockEntry(name)
    35  		defer func() {
    36  			unlockErr := indexCache.unlockEntry(name)
    37  
    38  			if err == nil {
    39  				err = unlockErr
    40  			}
    41  		}()
    42  		indexCache.put(name, index)
    43  	}
    44  
    45  	return &chunkSourceAdapter{newTableReader(index, tra, blockSize), name}, nil
    46  }
    47  
    48  func (csa chunkSourceAdapter) Close() error {
    49  	return csa.tableReader.Close()
    50  }
    51  
    52  func (csa chunkSourceAdapter) Clone() chunkSource {
    53  	return &chunkSourceAdapter{csa.tableReader.Clone(), csa.h}
    54  }