Coverage for src/dataknobs_data/backends/sqlite_mixins.py: 25%

1"""SQLite-specific mixins for vector support and other functionality.""" 

2 

3from __future__ import annotations 

4 

5import json 

6import logging 

7 

8import numpy as np 

9 

10from typing import TYPE_CHECKING 

11from ..fields import VectorField 

12from ..vector.types import DistanceMetric 

13 

14if TYPE_CHECKING: 

15 from ..records import Record 

16 

17 

18logger = logging.getLogger(__name__) 

19 

20 

21class SQLiteVectorSupport: 

22 """Vector support for SQLite using JSON storage and Python-based similarity.""" 

23 

24 def __init__(self): 

25 """Initialize vector support tracking.""" 

26 self._vector_dimensions = {} 

27 self._vector_fields = {} 

28 

29 def _has_vector_fields(self, record: Record) -> bool: 

30 """Check if record has vector fields. 

31  

32 Args: 

33 record: Record to check 

34  

35 Returns: 

36 True if record has vector fields 

37 """ 

38 return any(isinstance(field, VectorField) 

39 for field in record.fields.values()) 

40 

41 def _extract_vector_dimensions(self, record: Record) -> dict[str, int]: 

42 """Extract dimensions from vector fields in a record. 

43  

44 Args: 

45 record: Record containing potential vector fields 

46  

47 Returns: 

48 Dictionary mapping field names to dimensions 

49 """ 

50 dimensions = {} 

51 for name, field in record.fields.items(): 

52 if isinstance(field, VectorField): 

53 if field.value is not None: 

54 if isinstance(field.value, np.ndarray): 

55 dimensions[name] = field.value.shape[0] 

56 elif isinstance(field.value, list): 

57 dimensions[name] = len(field.value) 

58 elif field.dimensions: 

59 dimensions[name] = field.dimensions 

60 return dimensions 

61 

62 def _update_vector_dimensions(self, record: Record) -> None: 

63 """Update tracked vector dimensions from a record. 

64  

65 Args: 

66 record: Record containing vector fields 

67 """ 

68 dimensions = self._extract_vector_dimensions(record) 

69 self._vector_dimensions.update(dimensions) 

70 

71 # Track which fields are vectors 

72 for name, field in record.fields.items(): 

73 if isinstance(field, VectorField): 

74 self._vector_fields[name] = { 

75 "dimensions": dimensions.get(name), 

76 "source_field": field.source_field, 

77 "model_name": field.model_name, 

78 "model_version": field.model_version, 

79 } 

80 

81 def _serialize_vector(self, vector: np.ndarray | list) -> str: 

82 """Serialize a vector to JSON string for storage. 

83  

84 Args: 

85 vector: Vector as numpy array or list 

86  

87 Returns: 

88 JSON string representation 

89 """ 

90 if isinstance(vector, np.ndarray): 

91 vector = vector.tolist() 

92 return json.dumps(vector) 

93 

94 def _deserialize_vector(self, vector_str: str) -> np.ndarray | None: 

95 """Deserialize a vector from JSON string. 

96  

97 Args: 

98 vector_str: JSON string representation 

99  

100 Returns: 

101 Numpy array 

102 """ 

103 if not vector_str: 

104 return None 

105 try: 

106 vector_list = json.loads(vector_str) 

107 return np.array(vector_list, dtype=np.float32) 

108 except (json.JSONDecodeError, TypeError, ValueError): 

109 return None 

110 

111 def _compute_similarity( 

112 self, 

113 vec1: np.ndarray | None, 

114 vec2: np.ndarray | None, 

115 metric: DistanceMetric = DistanceMetric.COSINE 

116 ) -> float: 

117 """Compute similarity between two vectors. 

118  

119 Args: 

120 vec1: First vector 

121 vec2: Second vector 

122 metric: Distance metric to use 

123  

124 Returns: 

125 Similarity score (higher is more similar) 

126 """ 

127 if vec1 is None or vec2 is None: 

128 return 0.0 

129 

130 # Ensure vectors are numpy arrays 

131 if not isinstance(vec1, np.ndarray): 

132 vec1 = np.array(vec1, dtype=np.float32) # type: ignore[unreachable] 

133 if not isinstance(vec2, np.ndarray): 

134 vec2 = np.array(vec2, dtype=np.float32) # type: ignore[unreachable] 

135 

136 # Check dimensions match 

137 if vec1.shape != vec2.shape: 

138 raise ValueError(f"Vector dimensions don't match: {vec1.shape} vs {vec2.shape}") 

139 

140 if metric == DistanceMetric.COSINE: 

141 # Cosine similarity 

142 norm1 = np.linalg.norm(vec1) 

143 norm2 = np.linalg.norm(vec2) 

144 if norm1 == 0 or norm2 == 0: 

145 return 0.0 

146 return float(np.dot(vec1, vec2) / (norm1 * norm2)) 

147 

148 elif metric == DistanceMetric.EUCLIDEAN: 

149 # Convert Euclidean distance to similarity (inverse) 

150 distance = float(np.linalg.norm(vec1 - vec2)) 

151 return 1.0 / (1.0 + distance) 

152 

153 elif metric == DistanceMetric.DOT_PRODUCT: 

154 # Dot product similarity 

155 return float(np.dot(vec1, vec2)) 

156 

157 else: 

158 raise ValueError(f"Unsupported metric: {metric}") 

159