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Momento/memento-note/lib/ai/services/embedding.service.ts
Antigravity e09ea3a145
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fix: switch embedding dimension from 1536 to 2560 for qwen-embedding-4b
2026-05-12 09:07:55 +00:00

116 lines
3.3 KiB
TypeScript

/**
* Embedding Service
* Generates vector embeddings for semantic search and similarity analysis.
* Stores embeddings as native pgvector(2560) in PostgreSQL.
*/
import { getAIProvider } from '../factory'
import { getSystemConfig } from '@/lib/config'
export interface EmbeddingResult {
embedding: number[]
model: string
dimension: number
}
export class EmbeddingService {
private readonly EMBEDDING_DIMENSION = 2560
async generateEmbedding(text: string): Promise<EmbeddingResult> {
if (!text || text.trim().length === 0) {
throw new Error('Cannot generate embedding for empty text')
}
try {
const config = await getSystemConfig()
const provider = getAIProvider(config)
const embedding = await provider.getEmbeddings(text)
return {
embedding,
model: 'text-embedding-3-small',
dimension: embedding.length
}
} catch (error) {
console.error('Error generating embedding:', error)
throw new Error(`Failed to generate embedding: ${error}`)
}
}
async generateBatchEmbeddings(texts: string[]): Promise<EmbeddingResult[]> {
if (!texts || texts.length === 0) return []
const validTexts = texts.filter(t => t && t.trim().length > 0)
if (validTexts.length === 0) return []
try {
const config = await getSystemConfig()
const provider = getAIProvider(config)
const embeddings = await Promise.all(
validTexts.map(text => provider.getEmbeddings(text))
)
return embeddings.map(embedding => ({
embedding,
model: 'text-embedding-3-small',
dimension: embedding.length
}))
} catch (error) {
console.error('Error generating batch embeddings:', error)
throw error
}
}
/**
* Format a number[] embedding as a pgvector-compatible string literal.
* e.g. [0.1, 0.2, 0.3] → '[0.1,0.2,0.3]'
*/
toVectorString(embedding: number[]): string {
return `[${embedding.join(',')}]`
}
/**
* Parse a pgvector string from the DB back into number[].
* e.g. '[0.1,0.2,0.3]' → [0.1, 0.2, 0.3]
*/
fromVectorString(vec: string): number[] {
if (Array.isArray(vec)) return vec
if (!vec || typeof vec !== 'string') return []
return vec.replace(/^\[/, '').replace(/\]$/, '').split(',').map(Number)
}
/**
* JS cosine similarity — still used by memory-echo pairwise comparisons.
*/
calculateCosineSimilarity(a: number[], b: number[]): number {
if (!a.length || !b.length) return 0
const minLen = Math.min(a.length, b.length)
let dot = 0, mA = 0, mB = 0
for (let i = 0; i < minLen; i++) {
dot += a[i] * b[i]
mA += a[i] * a[i]
mB += b[i] * b[i]
}
mA = Math.sqrt(mA)
mB = Math.sqrt(mB)
if (mA === 0 || mB === 0) return 0
return dot / (mA * mB)
}
/**
* Check if a note needs embedding regeneration.
* Uses a content-content comparison (not embedding-content).
*/
shouldRegenerateEmbedding(
noteContent: string,
_lastEmbeddingContent: string | null,
lastAnalysis: Date | null
): boolean {
if (!lastAnalysis) return true
const daysSinceAnalysis = (Date.now() - lastAnalysis.getTime()) / (1000 * 60 * 60 * 24)
return daysSinceAnalysis > 7
}
}
export const embeddingService = new EmbeddingService()