github.com/m3db/m3@v1.5.0/src/dbnode/storage/lease_verifier.go (about)

     1  // Copyright (c) 2019 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package storage
    22  
    23  import (
    24  	"fmt"
    25  
    26  	"github.com/m3db/m3/src/dbnode/storage/block"
    27  	"github.com/m3db/m3/src/x/ident"
    28  	xtime "github.com/m3db/m3/src/x/time"
    29  )
    30  
    31  type flushStateRetriever interface {
    32  	FlushState(namespace ident.ID, shardID uint32, blockStart xtime.UnixNano) (fileOpState, error)
    33  }
    34  
    35  type leaseVerifier struct {
    36  	flushStateRetriever flushStateRetriever
    37  }
    38  
    39  // NewLeaseVerifier creates a new LeaseVerifier.
    40  func NewLeaseVerifier(retriever flushStateRetriever) *leaseVerifier {
    41  	return &leaseVerifier{
    42  		flushStateRetriever: retriever,
    43  	}
    44  }
    45  
    46  func (v *leaseVerifier) VerifyLease(
    47  	descriptor block.LeaseDescriptor,
    48  	state block.LeaseState,
    49  ) error {
    50  	flushState, err := v.flushStateRetriever.FlushState(
    51  		descriptor.Namespace, uint32(descriptor.Shard), descriptor.BlockStart)
    52  	if err != nil {
    53  		return fmt.Errorf(
    54  			"err retrieving flushState for lease verification, ns: %s, shard: %d, blockStart: %s, err: %v",
    55  			descriptor.Namespace.String(), descriptor.Shard, descriptor.BlockStart.String(), err)
    56  	}
    57  
    58  	if state.Volume != flushState.ColdVersionFlushed {
    59  		// The cold flush version and volume correspond 1:1 so a lease should only
    60  		// be permitted if the requested volume is equal to the highest flushed
    61  		// volume (the current cold flush version).
    62  		//
    63  		// This logic also holds in situations where the cold flush feature is not
    64  		// enabled because even in that case the volume number for the first warm
    65  		// flush should be 0 and the cold version should also be 0.
    66  		return fmt.Errorf(
    67  			"cannot permit lease for ns: %s, shard: %d, blockStart: %s, volume: %d when latest volume is %d",
    68  			descriptor.Namespace.String(), descriptor.Shard, descriptor.BlockStart.String(), state.Volume, flushState.ColdVersionFlushed)
    69  	}
    70  
    71  	return nil
    72  }
    73  
    74  func (v *leaseVerifier) LatestState(descriptor block.LeaseDescriptor) (block.LeaseState, error) {
    75  	flushState, err := v.flushStateRetriever.FlushState(
    76  		descriptor.Namespace, descriptor.Shard, descriptor.BlockStart)
    77  	if err != nil {
    78  		return block.LeaseState{}, fmt.Errorf(
    79  			"err retrieving flushState for LatestState, ns: %s, shard: %d, blockStart: %s, err: %v",
    80  			descriptor.Namespace.String(), descriptor.Shard, descriptor.BlockStart.String(), err)
    81  	}
    82  
    83  	// LeaseVerifier should return ColdVersionFlushed not ColdVersionRetrievable since ColdVersionFlushed
    84  	// represents the latest version that is available on disk while ColdVersion only represents
    85  	// the latest version that is retrievable from the block retriever and SeekerManager.
    86  	return block.LeaseState{Volume: flushState.ColdVersionFlushed}, nil
    87  }