github.com/hasnat/dolt/go@v0.0.0-20210628190320-9eb5d843fbb7/libraries/doltcore/remotestorage/noop_chunk_cache.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 remotestorage
    16  
    17  import (
    18  	"github.com/dolthub/dolt/go/store/hash"
    19  	"github.com/dolthub/dolt/go/store/nbs"
    20  )
    21  
    22  // noopChunkCache is a ChunkCache implementation that stores nothing
    23  // ever.  Using a noopChunkCache with a remotestore.DoltChunkStore
    24  // will cause the DoltChunkStore to behave incorrectly when _writing_
    25  // dolt repositories; this should only be used for read-only use
    26  // cases.
    27  var noopChunkCache = &noopChunkCacheImpl{}
    28  
    29  type noopChunkCacheImpl struct {
    30  }
    31  
    32  func (*noopChunkCacheImpl) Put(chnks []nbs.CompressedChunk) {
    33  }
    34  
    35  func (*noopChunkCacheImpl) Get(hashes hash.HashSet) map[hash.Hash]nbs.CompressedChunk {
    36  	return make(map[hash.Hash]nbs.CompressedChunk)
    37  }
    38  
    39  func (*noopChunkCacheImpl) Has(hashes hash.HashSet) (absent hash.HashSet) {
    40  	return hashes
    41  }
    42  
    43  func (*noopChunkCacheImpl) PutChunk(ch nbs.CompressedChunk) bool {
    44  	return true
    45  }
    46  
    47  func (*noopChunkCacheImpl) GetAndClearChunksToFlush() map[hash.Hash]nbs.CompressedChunk {
    48  	panic("noopChunkCache does not support GetAndClearChunksToFlush().")
    49  }