anything-llm/server/utils/AiProviders/deepseek/index.js
Timothy Carambat d1ca16f7f8
Add tokenizer improvments via Singleton class and estimation ()
* Add tokenizer improvments via Singleton class
linting

* dev build

* Estimation fallback when string exceeds a fixed byte size

* Add notice to tiktoken on backend
2025-01-30 17:55:03 -08:00

309 lines
9.9 KiB
JavaScript

const { NativeEmbedder } = require("../../EmbeddingEngines/native");
const {
LLMPerformanceMonitor,
} = require("../../helpers/chat/LLMPerformanceMonitor");
const { v4: uuidv4 } = require("uuid");
const { MODEL_MAP } = require("../modelMap");
const {
writeResponseChunk,
clientAbortedHandler,
} = require("../../helpers/chat/responses");
class DeepSeekLLM {
constructor(embedder = null, modelPreference = null) {
if (!process.env.DEEPSEEK_API_KEY)
throw new Error("No DeepSeek API key was set.");
const { OpenAI: OpenAIApi } = require("openai");
this.openai = new OpenAIApi({
apiKey: process.env.DEEPSEEK_API_KEY,
baseURL: "https://api.deepseek.com/v1",
});
this.model =
modelPreference || process.env.DEEPSEEK_MODEL_PREF || "deepseek-chat";
this.limits = {
history: this.promptWindowLimit() * 0.15,
system: this.promptWindowLimit() * 0.15,
user: this.promptWindowLimit() * 0.7,
};
this.embedder = embedder ?? new NativeEmbedder();
this.defaultTemp = 0.7;
this.log("Initialized with model:", this.model);
}
log(text, ...args) {
console.log(`\x1b[36m[${this.constructor.name}]\x1b[0m ${text}`, ...args);
}
#appendContext(contextTexts = []) {
if (!contextTexts || !contextTexts.length) return "";
return (
"\nContext:\n" +
contextTexts
.map((text, i) => {
return `[CONTEXT ${i}]:\n${text}\n[END CONTEXT ${i}]\n\n`;
})
.join("")
);
}
streamingEnabled() {
return "streamGetChatCompletion" in this;
}
static promptWindowLimit(modelName) {
return MODEL_MAP.deepseek[modelName] ?? 8192;
}
promptWindowLimit() {
return MODEL_MAP.deepseek[this.model] ?? 8192;
}
async isValidChatCompletionModel(modelName = "") {
const models = await this.openai.models.list().catch(() => ({ data: [] }));
return models.data.some((model) => model.id === modelName);
}
constructPrompt({
systemPrompt = "",
contextTexts = [],
chatHistory = [],
userPrompt = "",
}) {
const prompt = {
role: "system",
content: `${systemPrompt}${this.#appendContext(contextTexts)}`,
};
return [prompt, ...chatHistory, { role: "user", content: userPrompt }];
}
/**
* Parses and prepends reasoning from the response and returns the full text response.
* @param {Object} response
* @returns {string}
*/
#parseReasoningFromResponse({ message }) {
let textResponse = message?.content;
if (
!!message?.reasoning_content &&
message.reasoning_content.trim().length > 0
)
textResponse = `<think>${message.reasoning_content}</think>${textResponse}`;
return textResponse;
}
async getChatCompletion(messages = null, { temperature = 0.7 }) {
if (!(await this.isValidChatCompletionModel(this.model)))
throw new Error(
`DeepSeek chat: ${this.model} is not valid for chat completion!`
);
const result = await LLMPerformanceMonitor.measureAsyncFunction(
this.openai.chat.completions
.create({
model: this.model,
messages,
temperature,
})
.catch((e) => {
throw new Error(e.message);
})
);
if (
!result?.output?.hasOwnProperty("choices") ||
result?.output?.choices?.length === 0
)
throw new Error(
`Invalid response body returned from DeepSeek: ${JSON.stringify(result.output)}`
);
return {
textResponse: this.#parseReasoningFromResponse(result.output.choices[0]),
metrics: {
prompt_tokens: result.output.usage.prompt_tokens || 0,
completion_tokens: result.output.usage.completion_tokens || 0,
total_tokens: result.output.usage.total_tokens || 0,
outputTps: result.output.usage.completion_tokens / result.duration,
duration: result.duration,
},
};
}
async streamGetChatCompletion(messages = null, { temperature = 0.7 }) {
if (!(await this.isValidChatCompletionModel(this.model)))
throw new Error(
`DeepSeek chat: ${this.model} is not valid for chat completion!`
);
const measuredStreamRequest = await LLMPerformanceMonitor.measureStream(
this.openai.chat.completions.create({
model: this.model,
stream: true,
messages,
temperature,
}),
messages,
false
);
return measuredStreamRequest;
}
// TODO: This is a copy of the generic handleStream function in responses.js
// to specifically handle the DeepSeek reasoning model `reasoning_content` field.
// When or if ever possible, we should refactor this to be in the generic function.
handleStream(response, stream, responseProps) {
const { uuid = uuidv4(), sources = [] } = responseProps;
let hasUsageMetrics = false;
let usage = {
completion_tokens: 0,
};
return new Promise(async (resolve) => {
let fullText = "";
let reasoningText = "";
// Establish listener to early-abort a streaming response
// in case things go sideways or the user does not like the response.
// We preserve the generated text but continue as if chat was completed
// to preserve previously generated content.
const handleAbort = () => {
stream?.endMeasurement(usage);
clientAbortedHandler(resolve, fullText);
};
response.on("close", handleAbort);
try {
for await (const chunk of stream) {
const message = chunk?.choices?.[0];
const token = message?.delta?.content;
const reasoningToken = message?.delta?.reasoning_content;
if (
chunk.hasOwnProperty("usage") && // exists
!!chunk.usage && // is not null
Object.values(chunk.usage).length > 0 // has values
) {
if (chunk.usage.hasOwnProperty("prompt_tokens")) {
usage.prompt_tokens = Number(chunk.usage.prompt_tokens);
}
if (chunk.usage.hasOwnProperty("completion_tokens")) {
hasUsageMetrics = true; // to stop estimating counter
usage.completion_tokens = Number(chunk.usage.completion_tokens);
}
}
// Reasoning models will always return the reasoning text before the token text.
if (reasoningToken) {
// If the reasoning text is empty (''), we need to initialize it
// and send the first chunk of reasoning text.
if (reasoningText.length === 0) {
writeResponseChunk(response, {
uuid,
sources: [],
type: "textResponseChunk",
textResponse: `<think>${reasoningToken}`,
close: false,
error: false,
});
reasoningText += `<think>${reasoningToken}`;
continue;
} else {
writeResponseChunk(response, {
uuid,
sources: [],
type: "textResponseChunk",
textResponse: reasoningToken,
close: false,
error: false,
});
reasoningText += reasoningToken;
}
}
// If the reasoning text is not empty, but the reasoning token is empty
// and the token text is not empty we need to close the reasoning text and begin sending the token text.
if (!!reasoningText && !reasoningToken && token) {
writeResponseChunk(response, {
uuid,
sources: [],
type: "textResponseChunk",
textResponse: `</think>`,
close: false,
error: false,
});
fullText += `${reasoningText}</think>`;
reasoningText = "";
}
if (token) {
fullText += token;
// If we never saw a usage metric, we can estimate them by number of completion chunks
if (!hasUsageMetrics) usage.completion_tokens++;
writeResponseChunk(response, {
uuid,
sources: [],
type: "textResponseChunk",
textResponse: token,
close: false,
error: false,
});
}
// LocalAi returns '' and others return null on chunks - the last chunk is not "" or null.
// Either way, the key `finish_reason` must be present to determine ending chunk.
if (
message?.hasOwnProperty("finish_reason") && // Got valid message and it is an object with finish_reason
message.finish_reason !== "" &&
message.finish_reason !== null
) {
writeResponseChunk(response, {
uuid,
sources,
type: "textResponseChunk",
textResponse: "",
close: true,
error: false,
});
response.removeListener("close", handleAbort);
stream?.endMeasurement(usage);
resolve(fullText);
break; // Break streaming when a valid finish_reason is first encountered
}
}
} catch (e) {
console.log(`\x1b[43m\x1b[34m[STREAMING ERROR]\x1b[0m ${e.message}`);
writeResponseChunk(response, {
uuid,
type: "abort",
textResponse: null,
sources: [],
close: true,
error: e.message,
});
stream?.endMeasurement(usage);
resolve(fullText); // Return what we currently have - if anything.
}
});
}
async embedTextInput(textInput) {
return await this.embedder.embedTextInput(textInput);
}
async embedChunks(textChunks = []) {
return await this.embedder.embedChunks(textChunks);
}
async compressMessages(promptArgs = {}, rawHistory = []) {
const { messageArrayCompressor } = require("../../helpers/chat");
const messageArray = this.constructPrompt(promptArgs);
return await messageArrayCompressor(this, messageArray, rawHistory);
}
}
module.exports = {
DeepSeekLLM,
};