github.com/weaviate/weaviate@v1.24.6/adapters/repos/db/lsmkv/cursor_segment_collection.go (about)

     1  //                           _       _
     2  // __      _____  __ ___   ___  __ _| |_ ___
     3  // \ \ /\ / / _ \/ _` \ \ / / |/ _` | __/ _ \
     4  //  \ V  V /  __/ (_| |\ V /| | (_| | ||  __/
     5  //   \_/\_/ \___|\__,_| \_/ |_|\__,_|\__\___|
     6  //
     7  //  Copyright © 2016 - 2024 Weaviate B.V. All rights reserved.
     8  //
     9  //  CONTACT: hello@weaviate.io
    10  //
    11  
    12  package lsmkv
    13  
    14  import (
    15  	"github.com/weaviate/weaviate/entities/lsmkv"
    16  )
    17  
    18  type segmentCursorCollection struct {
    19  	segment    *segment
    20  	nextOffset uint64
    21  }
    22  
    23  func (s *segment) newCollectionCursor() *segmentCursorCollection {
    24  	return &segmentCursorCollection{
    25  		segment: s,
    26  	}
    27  }
    28  
    29  func (sg *SegmentGroup) newCollectionCursors() ([]innerCursorCollection, func()) {
    30  	sg.maintenanceLock.RLock()
    31  	out := make([]innerCursorCollection, len(sg.segments))
    32  
    33  	for i, segment := range sg.segments {
    34  		out[i] = segment.newCollectionCursor()
    35  	}
    36  
    37  	return out, sg.maintenanceLock.RUnlock
    38  }
    39  
    40  func (s *segmentCursorCollection) seek(key []byte) ([]byte, []value, error) {
    41  	node, err := s.segment.index.Seek(key)
    42  	if err != nil {
    43  		return nil, nil, err
    44  	}
    45  
    46  	parsed, err := s.parseCollectionNode(nodeOffset{node.Start, node.End})
    47  	// make sure to set the next offset before checking the error. The error
    48  	// could be 'entities.Deleted' which would require that the offset is still advanced
    49  	// for the next cycle
    50  	s.nextOffset = node.End
    51  	if err != nil {
    52  		return parsed.primaryKey, nil, err
    53  	}
    54  
    55  	return parsed.primaryKey, parsed.values, nil
    56  }
    57  
    58  func (s *segmentCursorCollection) next() ([]byte, []value, error) {
    59  	if s.nextOffset >= s.segment.dataEndPos {
    60  		return nil, nil, lsmkv.NotFound
    61  	}
    62  
    63  	parsed, err := s.parseCollectionNode(nodeOffset{start: s.nextOffset})
    64  	// make sure to set the next offset before checking the error. The error
    65  	// could be 'entities.Deleted' which would require that the offset is still advanced
    66  	// for the next cycle
    67  	s.nextOffset = s.nextOffset + uint64(parsed.offset)
    68  	if err != nil {
    69  		return parsed.primaryKey, nil, err
    70  	}
    71  
    72  	return parsed.primaryKey, parsed.values, nil
    73  }
    74  
    75  func (s *segmentCursorCollection) first() ([]byte, []value, error) {
    76  	s.nextOffset = s.segment.dataStartPos
    77  
    78  	parsed, err := s.parseCollectionNode(nodeOffset{start: s.nextOffset})
    79  	// make sure to set the next offset before checking the error. The error
    80  	// could be 'entities.Deleted' which would require that the offset is still advanced
    81  	// for the next cycle
    82  	s.nextOffset = s.nextOffset + uint64(parsed.offset)
    83  	if err != nil {
    84  		return parsed.primaryKey, nil, err
    85  	}
    86  
    87  	return parsed.primaryKey, parsed.values, nil
    88  }
    89  
    90  func (s *segmentCursorCollection) parseCollectionNode(offset nodeOffset) (segmentCollectionNode, error) {
    91  	r, err := s.segment.newNodeReader(offset)
    92  	if err != nil {
    93  		return segmentCollectionNode{}, err
    94  	}
    95  
    96  	return ParseCollectionNode(r)
    97  }