fix(embedding): improve dimension detection performance and reliability

- Add dimension detection flags to prevent redundant API calls for custom models
- Replace fragile magic number logic with explicit boolean flags for OAPI detection
- Make environment variable check case-insensitive for better user experience
- Fix setModel method to properly reset detection flags for unknown models
- Update test imports to fix TypeScript compilation errors

Performance improvements:
- Dimension detection now happens only once per model/instance
- Eliminates unnecessary API calls for known and already-detected models
- Concurrent embed calls no longer trigger duplicate dimension detection

Reliability improvements:
- OAPI dimension detection no longer relies on magic number comparison
- Case-insensitive environment variable parsing (true/TRUE/True all work)
- Proper state management for model changes via setModel()

Author: MapleEve

packages/core/src/embedding/openai-embedding.test.ts

@@ -1,4 +1,4 @@
-import { OpenAI } from 'openai';
+import OpenAI from 'openai';
 import { OpenAIEmbedding } from './openai-embedding';
 import type { EmbeddingVector } from './base-embedding';
 
@@ -12,7 +12,7 @@ jest.mock('openai', () => {
   }));
 });
 
-const MockOpenAI = OpenAI as jest.Mock;
+const MockOpenAI = OpenAI as unknown as jest.Mock;
 
 describe('OpenAIEmbedding OAPI Forwarding', () => {
   const originalEnv = process.env;

packages/core/src/embedding/openai-embedding.ts

@@ -12,17 +12,18 @@ export class OpenAIEmbedding extends Embedding {
     private client: OpenAI;
     private config: OpenAIEmbeddingConfig;
     private dimension: number = 1536; // Default dimension for text-embedding-3-small
+    private dimensionDetected: boolean = false; // Track if dimension has been detected
     protected maxTokens: number = 8192; // Maximum tokens for OpenAI embedding models
     private isOllamaViaOAPI: boolean = false; // Whether using Ollama model via OAPI
+    private isOllamaDimensionDetected: boolean = false; // Track if OAPI dimension has been detected
 
     constructor(config: OpenAIEmbeddingConfig) {
         super();
         this.config = config;
 
         // Check environment variable for Ollama via OAPI
         this.isOllamaViaOAPI = config.useOllamaModel || 
-                              process.env.OPENAI_CUSTOM_BASE_USING_OLLAMA_MODEL === 'true' ||
-                              process.env.OPENAI_CUSTOM_BASE_USING_OLLAMA_MODEL === 'True';
+                              (process.env.OPENAI_CUSTOM_BASE_USING_OLLAMA_MODEL || '').toLowerCase() === 'true';
 
         // Auto-correct baseURL if needed
         const correctedBaseURL = this.correctBaseURL(config.baseURL);
@@ -36,6 +37,13 @@ export class OpenAIEmbedding extends Embedding {
             console.log(`[OpenAI] Configured for Ollama model ${config.model} via OAPI forwarding`);
             // Reset dimension since Ollama models have different dimensions
             this.dimension = 768; // Common Ollama embedding dimension
+        } else {
+            // Set dimension detection flag for known models
+            const knownModels = OpenAIEmbedding.getSupportedModels();
+            if (knownModels[config.model]) {
+                this.dimension = knownModels[config.model].dimension;
+                this.dimensionDetected = true;
+            }
         }
     }
 
@@ -143,8 +151,10 @@ export class OpenAIEmbedding extends Embedding {
         const knownModels = OpenAIEmbedding.getSupportedModels();
         if (knownModels[model] && this.dimension !== knownModels[model].dimension) {
             this.dimension = knownModels[model].dimension;
-        } else if (!knownModels[model]) {
+            this.dimensionDetected = true;
+        } else if (!knownModels[model] && !this.dimensionDetected) {
             this.dimension = await this.detectDimension();
+            this.dimensionDetected = true;
         }
 
         try {
@@ -179,9 +189,10 @@ export class OpenAIEmbedding extends Embedding {
         const processedText = this.preprocessText(text);
         const model = this.config.model;
 
-        // Detect dimension if using default OpenAI dimension
-        if (this.dimension === 1536) {
+        // Detect dimension if not already detected for Ollama
+        if (!this.isOllamaDimensionDetected) {
             this.dimension = await this.detectOllamaDimensionViaOAPI('test', model);
+            this.isOllamaDimensionDetected = true;
         }
 
         try {
@@ -218,8 +229,10 @@ export class OpenAIEmbedding extends Embedding {
         const knownModels = OpenAIEmbedding.getSupportedModels();
         if (knownModels[model] && this.dimension !== knownModels[model].dimension) {
             this.dimension = knownModels[model].dimension;
-        } else if (!knownModels[model]) {
+            this.dimensionDetected = true;
+        } else if (!knownModels[model] && !this.dimensionDetected) {
             this.dimension = await this.detectDimension();
+            this.dimensionDetected = true;
         }
 
         try {
@@ -255,9 +268,10 @@ export class OpenAIEmbedding extends Embedding {
         const processedTexts = this.preprocessTexts(texts);
         const model = this.config.model;
 
-        // Detect dimension if using default OpenAI dimension
-        if (this.dimension === 1536) {
+        // Detect dimension if not already detected for Ollama
+        if (!this.isOllamaDimensionDetected) {
             this.dimension = await this.detectOllamaDimensionViaOAPI('test', model);
+            this.isOllamaDimensionDetected = true;
         }
 
         try {
@@ -299,8 +313,15 @@ export class OpenAIEmbedding extends Embedding {
         const knownModels = OpenAIEmbedding.getSupportedModels();
         if (knownModels[model]) {
             this.dimension = knownModels[model].dimension;
+            this.dimensionDetected = true;
         } else {
+            // Reset detection flags for unknown models
+            this.dimensionDetected = false;
+            if (this.isOllamaViaOAPI) {
+                this.isOllamaDimensionDetected = false;
+            }
             this.dimension = await this.detectDimension();
+            this.dimensionDetected = true;
         }
     }