2025-04-19 08:05:49 +09:00

927 lines
33 KiB
JavaScript

window.TINYCHAT_ROOT = "/tinychat-browser/";
const queryParams = new URLSearchParams(window.location.search);
const normalizedParams = Object.fromEntries([...queryParams].map(([key, value]) => [key.toUpperCase(), value.toUpperCase()]));
window.BACKEND = (normalizedParams["BACKEND"] === "WASM") ? "WASM" : "WebGPU";
const isMobileAgent = /Mobi|Android|iPhone|iPad|iPod/i.test(navigator.userAgent);
const hasTouchScreen = 'ontouchstart' in window || navigator.maxTouchPoints > 0;
window.isMobile = isMobileAgent || hasTouchScreen;
if (window.isMobile) document.documentElement.classList.add('mobile'); // prevent annoying auto-zoom when entering prompt on mobile
// MODEL_BASE_URL is where the weights are hosted, WEBGPU_EXPORT is the JS-wrapped WebGPU code exported from tinygrad
window.PC_MODEL_BASE_URL = ".";
window.PC_WEBGPU_EXPORT = './net.js'
window.PC_MAX_CONTEXT = 1024;
window.MOBILE_MODEL_BASE_URL = ".";
window.MOBILE_WEBGPU_EXPORT = './net.js'
window.MOBILE_MAX_CONTEXT = 1024;
const tiktokenReady = (async () => {
const { init, get_encoding, Tiktoken, load } = await import('./tiktoken.js');
window.Tiktoken = Tiktoken;
window.tiktokenInit = init;
window.tiktokenGetEncoding = get_encoding;
window.tiktokenLoad = load;
})();
async function getDevice() {
let adapter;
try {
adapter = await navigator.gpu.requestAdapter();
if (!adapter) {
this.loadingMessage = "Loading WASM (WebGPU not enabled):";
throw new Error("No WebGPU adapter found");
}
} catch(error) {
this.loadingMessage = "Loading WASM (WebGPU not enabled):";
throw error;
}
const requiredLimits = {};
const maxBufferSize = 322122544;
requiredLimits.maxStorageBufferBindingSize = maxBufferSize;
requiredLimits.maxBufferSize = maxBufferSize;
requiredLimits.maxComputeInvocationsPerWorkgroup = 512; // may need to vary based on what the WEBGPU backend produces
try {
return await adapter.requestDevice({ requiredLimits });
} catch(error) {
this.loadingMessage = "Loading WASM (WebGPU error):";
throw error;
}
};
// copied from examples/webgpu/stable_diffusion/index.html
function initDb() {
return new Promise((resolve, reject) => {
let db;
const request = indexedDB.open('tinydb', 1);
request.onerror = (event) => {
console.error('Database error:', event.target.error);
resolve(null);
};
request.onsuccess = (event) => {
db = event.target.result;
console.log("Db initialized.");
resolve(db);
};
request.onupgradeneeded = (event) => {
db = event.target.result;
if (!db.objectStoreNames.contains('tensors')) {
db.createObjectStore('tensors', { keyPath: 'id' });
}
};
});
}
// copied from examples/webgpu/stable_diffusion/index.html
function readTensorFromDb(db, id) {
return new Promise((resolve, reject) => {
if (db == null) {
resolve(null);
}
const transaction = db.transaction(['tensors'], 'readonly');
const store = transaction.objectStore('tensors');
const request = store.get(id);
transaction.onabort = (event) => {
console.log("Transaction error while reading tensor: " + event.target.error);
resolve(null);
};
request.onsuccess = (event) => {
const result = event.target.result;
if (result) {
resolve(result);
} else {
resolve(null);
}
};
request.onerror = (event) => {
console.error('Tensor retrieve failed: ', event.target.error);
resolve(null);
};
});
}
function getAllKeysFromDb(db) {
return new Promise((resolve, reject) => {
if (db == null) {resolve([]);}
const transaction = db.transaction(['tensors'], 'readonly');
const store = transaction.objectStore('tensors');
const request = store.getAllKeys();
transaction.onabort = (event) => {
console.log("Transaction error while reading IndexedDB keys: " + event.target.error);
resolve([]);
};
request.onsuccess = function (event) {resolve(event.target.result);};
request.onerror = (event) => {
console.error('Retrieval of IndexedDB keys failed: ', event.target.error);
resolve([]);
};
});
}
// modified from examples/webgpu/stable_diffusion/index.html
function saveTensorToDb(db, id, tensor) {
return readTensorFromDb(db, id).then((result) => {
if (!result) {
new Promise((resolve, reject) => {
if (db == null) {
resolve(null);
}
const transaction = db.transaction(['tensors'], 'readwrite');
const store = transaction.objectStore('tensors');
const request = store.put({ id: id, content: tensor });
transaction.onabort = (event) => {
console.log("Transaction error while saving tensor: " + event.target.error);
resolve(null);
};
request.onsuccess = () => {
console.log('Tensor saved successfully.');
resolve();
};
request.onerror = (event) => {
console.error('Tensor save failed:', event.target.error);
resolve(null);
};
});
} else {
return null;
}
}).catch(()=> null);
}
function deleteTensorFromDb(db, id) {
return new Promise((resolve, reject) => {
if (db == null) {
console.error("Database is not initialized.");
resolve(null);
return;
}
const transaction = db.transaction(['tensors'], 'readwrite');
const store = transaction.objectStore('tensors');
const request = store.delete(id);
transaction.oncomplete = () => {
console.log(`Tensor with ID '${id}' deleted successfully.`);
resolve();
};
transaction.onerror = (event) => {
console.error("Transaction error while deleting tensor:", event.target.error);
resolve(null);
};
request.onerror = (event) => {
console.error('Tensor deletion failed:', event.target.error);
resolve(null);
};
request.onsuccess = () => {
console.log(`Delete request for tensor with ID '${id}' succeeded.`);
};
});
}
function makeProgress(total) {
let acc = 0;
const ret = function progress(amount, message) {
if (amount >= 0) { // allow updating message only
acc += amount;
const percentage = total ? Math.trunc((acc / total) * 100) : 0;
document.querySelector('.progress').style.width = `${percentage}%`;
document.getElementById('progress-percentage').textContent = `${percentage}%`;
}
if (message) {
this.loadingMessage = message;
document.getElementById('loading-message').textContent = this.loadingMessage;
}
}.bind(this);
ret.total = total;
return ret;
}
function sendMessageToWorker(worker, message) {
return new Promise((resolve, reject) => {
const onMessage = (event) => {
resolve(event.data);
worker.removeEventListener('message', onMessage);
worker.removeEventListener('error', onError);
};
const onError = (error) => {
reject(error);
worker.removeEventListener('message', onMessage);
worker.removeEventListener('error', onError);
};
worker.addEventListener('message', onMessage);
worker.addEventListener('error', onError);
if (message.header === "token") worker.postMessage(message.data);
else if (message.header === "load_state_dict") {
if (message.data === "done") worker.postMessage(message.data);
else worker.postMessage(message.data, message.data.map(file => file.bytes.buffer));
}
else if (message.header === "init") worker.postMessage("init");
});
}
async function load_state_dict (data, device, progress) {
let state_dict = data.metadata.state_dict;
let completed = 0;
// modified from examples/webgpu/stable_diffusion/index.html getProgressDlForPart
const loadPart = async (part) => {
const response = await fetch(part);
const res = new Response(new ReadableStream({
async start(controller) {
const reader = response.body.getReader();
for (;;) {
const { done, value } = await reader.read();
if (done) break;
progress(value.byteLength);
controller.enqueue(value);
}
controller.close();
},
}));
return res.arrayBuffer();
};
let db = await initDb();
const getPart = async(filename, hash) => {
let part = await readTensorFromDb(db, hash);
if (part) {
console.log(`Cache hit: ${filename}, hash: ${hash}`);
progress(part.content.byteLength);
return Promise.resolve(part.content);
} else {
console.log(`Cache miss: ${filename}, hash: ${hash}`);
return loadPart(`${window.MODEL_BASE_URL}/${filename}`);
}
}
const correctHashes = data.metadata.files.map(file => file.hash)
// delete unused cached buffers to free disk space -- if we update weights, user will otherwise have obsolete cached buffers
const dbKeys = await getAllKeysFromDb(db);
const correctHashesSet = new Set(correctHashes);
const notInCorrectHashes = dbKeys.filter(key => !correctHashesSet.has(key));
// await these right before starting to save new stuff
const deletionPromises = notInCorrectHashes.map(async (hash) => deleteTensorFromDb(db, hash));
// instantiates empty weight buffers on WebGPU, attaches buffers to state_dict
let model;
if (window.BACKEND === "WebGPU") {
//model = await transformer().setup(device, state_dict, progress);
model = await transformer.setupNet(device, state_dict);
progress(0.15 * progress.total);
}
else if (window.BACKEND === "WASM") {
progress(0.02 * progress.total);
model = new Worker(`./worker.js?version=${Date.now()}`);
await sendMessageToWorker(model, {header: "init"});
progress(0.02 * progress.total);
progress(0.11 * progress.total);
}
const downloaded = [];
const triggerChainDownload = async (toDownload) => {
const numDownloaders = window.isMobile ? 4 : toDownload.length; // TODO: dynamically base this on DL file size? current assumption is 16 MiB chunks
const chainDownload = async() => {
const file = toDownload.shift();
loadPart(`${window.MODEL_BASE_URL}/${file.name}`) // triggers download
.then(async (arraybuf) => {
downloaded.push({ ...file, bytes: new Uint8Array(arraybuf)});
// pause downloads if further processing is a bottleneck
while (toDownload.length && downloaded.length >= numDownloaders) await new Promise(resolve => setTimeout(resolve, 5));
if (toDownload.length && downloaded.length < numDownloaders) chainDownload(); // start next download
})
}
for (let i=0; i<numDownloaders; i++) if (toDownload.length) chainDownload();
}
const loadFileToStateDict = async(file) => {
if (window.BACKEND === "WebGPU") {
for (const part of file.parts) {
if (part.empty) continue;
part.bytes = (part.size === file.bytes.length) ? file.bytes : file.bytes.slice(part.file_start_pos, part.file_start_pos + part.size);
device.queue.writeBuffer(state_dict[part.key].bytes, part.target_start_pos, part.bytes); // improves stability over mappedAtCreation writing
part.bytes = null;
}
}
else if (window.BACKEND === "WASM") {
await sendMessageToWorker(model, {header: "load_state_dict", data: [file]});
}
file.bytes = null;
}
if (window.BACKEND === "WebGPU") { // contiguous loading not needed for WebGPU stability
const files = data.tensor_file_groups.flatMap(obj => obj.files);
data.tensor_file_groups = [{contiguous: false, files: files}];
}
for (const group of data.tensor_file_groups) {
const contiguous = group.contiguous;
const files = group.files;
const tensor_file_indices = files.map(file => file.index);
const contiguousFiles = [];
const fileHashes = new Set(files.map(file => file.hash));
const cachedFileHashes = new Set(dbKeys.filter(key => fileHashes.has(key)));
const cachedFiles = files.filter(file => cachedFileHashes.has(file.hash));
const toDownload = files.filter(file => !cachedFileHashes.has(file.hash));
triggerChainDownload(toDownload);
const loadDelay = 5;
await Promise.all(deletionPromises);
while (completed < files.length) {
const start = performance.now();
// prioritize files from downloaded queue, so we can continue downloading more files
if (downloaded.length) {
const file = downloaded.shift();
await saveTensorToDb(db, file.hash, file.bytes); // for wasm, must await to prevent race between indexedDB and transfer to worker
if (!contiguous) await loadFileToStateDict(file);
else contiguousFiles.push(file);
completed += 1;
}
else if (!downloaded.length && cachedFiles.length) {
const file = cachedFiles.shift();
file.bytes = await getPart(file.name, file.hash); // reads data from IndexedDB
if (!contiguous) await loadFileToStateDict(file);
else contiguousFiles.push(file);
completed += 1;
}
const end = performance.now();
const elapsed = end - start;
if (elapsed < loadDelay) await new Promise(resolve => setTimeout(resolve, loadDelay - elapsed));
}
if (contiguous) {
const orderMap = tensor_file_indices.reduce((acc, id, index) => {acc[id] = index; return acc;}, {});
contiguousFiles.sort((a, b) => orderMap[a.index] - orderMap[b.index]); // glue files together in the right order
await sendMessageToWorker(model, {header: "load_state_dict", data: contiguousFiles});
}
completed = 0;
}
// initialize empty kv_caches, which were part of exported model's state_dict, but which we didn't want to package/download
if (window.BACKEND === "WASM") {
for (const [k, v] of Object.entries(state_dict).filter(([_, v]) => v.empty === true)) {
v.parts[0].file_start_pos = 0;
const file = { parts: v.parts, size: v.size, bytes: new Uint8Array(v.size).fill(0) };
await loadFileToStateDict(file);
}
}
return model;
};
document.addEventListener("alpine:init", () => {
Alpine.data("state", () => ({
// loadingMessage updates the user on page load progress, including weights download and decompression
// if loadingMessage is not '', then prompt box will be hidden: this is default behavior on page load
placeholderText: "Generating...",
loadingMessage: `Loading ${window.BACKEND} model:`,
// model
nets: {},
tokenizer: null,
max_context: 1024,
lastSeenToks: [],
progress: null,
async init() {
var device = null;
var webgpuErrorMessage = null;
if (window.BACKEND === "WebGPU") {
try {
device = await getDevice.call(this);
console.log("WebGPU device initialized");
} catch (error) {
window.BACKEND = "WASM";
console.log(`error: ${error}\nFailed to launch WebGPU. Loading WASM model instead...`); // return;
webgpuErrorMessage = this.loadingMessage;
}
}
window.MODEL_BASE_URL = (window.BACKEND === "WebGPU" && !window.isMobile) ? window.PC_MODEL_BASE_URL : window.MOBILE_MODEL_BASE_URL;
this.max_context = (window.BACKEND === "WebGPU" && !window.isMobile) ? window.PC_MAX_CONTEXT : window.MOBILE_MAX_CONTEXT;
const kernelsReady = (async () => {
if (window.BACKEND === "WASM") {var exports = await import(`./net_clang.js?version=${Date.now()}`);}
else if (window.BACKEND === "WebGPU" && !window.isMobile) {var exports = await import(`${PC_WEBGPU_EXPORT}?version=${Date.now()}`);}
else if (window.BACKEND === "WebGPU" && window.isMobile) {var exports = await import(`${MOBILE_WEBGPU_EXPORT}?version=${Date.now()}`);}
self.transformer = exports.default;
})();
const response = await fetch(`${window.MODEL_BASE_URL}/net_metadata.json`);
// TODO: cache metadata (and everything else, including tokenizer)
// TODO: use service worker to reload page when offline
const data = await response.json();
data.metadata.files = data.metadata.files.map((file, index) => ({...file, index}));
const state_dict = data.metadata.state_dict;
/*
- allocating memory to WASM on mobile has longstanding issues: https://github.com/WebAssembly/design/issues/1397
- the below pattern, while yielding a succesfully-functioning model when it doesn't crash, causes regular crashes on iOS Safari (iphone 15 iOS 18.3):
- call WASM malloc (to fit all tensors, or one per tensor) for all tensors up front, then load tensor byte chunks into the buffers in random order
- the below pattern has been stable on iOS Safari (iphone 15 iOS 18.3):
- call only one WASM malloc at a time before filling the allocated bytes, as small as possible (malloc up to 256 MiB has been tested)
- fill the malloc'd memory in linear order from start to end (what has been tested is calling wasm.HEAPU8.set on 16 MiB chunks from start to end)
- use ALLOW_MEMORY_GROWTH=1 in wasm compilation, minimize initial memory
- additional considerations affecting loading design, for WASM:
- it seems that copying bytes into wasm memory cannot be zero-copy without sharedarraybuffer, which isn't currently used due to increased hosting complexity
- non-zero copies create memory pressure, which is not reliably capped because of lack of control over garbage collection
- to minimize peak memory pressure if GC is delayed, we process (i.e. download + copy into WASM) large tensors (> 16 MiB) one at a time, in descending size order
*/
data.tensor_file_groups = []; // see above: for WASM, limit processing of multi-file Tensors to one at a time, in descending order based on Tensor size
const unsplit_tensors = [];
const sortedEntries = Object.entries(state_dict).sort(([, objA], [, objB]) => objB.size - objA.size);
let totalSize = 0;
const seen = new Set();
for (const [k,v] of sortedEntries) {
const files_in_tensor = [];
for (const part of v.parts) {
part.key = k;
if (part.empty) state_dict[k].empty = true; // assumes no other parts of this weight exist and are non-empty
else {
const file = data.metadata.files[part.file];
if (!seen.has(file.index)) {
seen.add(file.index);
files_in_tensor.push(file);
}
totalSize += part.size;
part.dtype = v.dtype;
if (!data.metadata.files[part.file].parts) data.metadata.files[part.file].parts = [];
data.metadata.files[part.file].size ??= 0;
data.metadata.files[part.file].size += part.size;
data.metadata.files[part.file].parts.push(part);
}
}
if (files_in_tensor.length > 1) data.tensor_file_groups.push({contiguous: true, files: files_in_tensor}); // [tensorN_file0, tensorN_file1, ...]
else if (files_in_tensor.length > 0) unsplit_tensors.push(files_in_tensor[0]);
}
data.tensor_file_groups.push({contiguous: false, files: unsplit_tensors});
data.totalSize = totalSize;
totalSize = totalSize / 0.8; // give space in progress bar for initializing model bufs, and tokenizer
this.progress = makeProgress.call(this, totalSize); // creates closure with totalSize
try {
this.progress(0.01 * totalSize, "Loading tokenizer:");
const wasmResponse = await fetch(`${window.MODEL_BASE_URL}/tiktoken_bg.wasm`);
this.progress(0.01 * totalSize);
const wasmBytes = await wasmResponse.arrayBuffer();
await tiktokenReady;
await window.tiktokenInit((imports) => WebAssembly.instantiate(wasmBytes, imports));
this.progress(0.01 * totalSize);
this.tokenizer = await createTokenizer(`${window.MODEL_BASE_URL}/llama3-2.tiktoken`);
const tokenizer_works = (new TextDecoder().decode(this.tokenizer.decode(this.tokenizer.encode("hello world"))) === "hello world");
console.log("tokenizer works:", tokenizer_works)
this.progress(0.01 * totalSize);
} catch (error) {this.progress(-1, `Error launching tokenizer: ${error}`); console.log(error); return;}
try {
const loadModelMessage = (webgpuErrorMessage) ? webgpuErrorMessage : `Loading ${window.BACKEND} model:`
this.progress(0, loadModelMessage);
await kernelsReady;
const model = await load_state_dict(data, device, this.progress);
if (window.BACKEND === "WebGPU") {
this.nets = {"transformer": model};
}
else if (window.BACKEND === "WASM") {
const msg = await sendMessageToWorker(model, {header: "load_state_dict", data: "done"});
this.nets = {"transformer": async (tok, start_pos) => sendMessageToWorker(model, {header: "token", data: [tok, start_pos]})};
}
this.progress(0.01 * totalSize, `Launching ${window.BACKEND} model:`);
this.loadingMessage = ""; // Triggers removal of loading bar, display of prompt box
} catch (error) {this.progress(-1, `Error launching model: ${error}`); console.log(error); return;}
},
// current state
cstate: {
time: null,
messages: [],
},
// historical state
histories: JSON.parse(localStorage.getItem("histories")) || [],
home: 0,
generating: false,
maxContextReached: false,
cancelGeneration: false,
endpoint: `${window.location.origin}/v1`,
// performance tracking
time_till_first: 0,
tokens_per_second: 0,
total_tokens: 0,
max_context: 0,
removeHistory(cstate) {
const index = this.histories.findIndex((state) => {
return state.time === cstate.time;
});
if (index !== -1) {
this.histories.splice(index, 1);
localStorage.setItem("histories", JSON.stringify(this.histories));
}
},
async handleSend() {
const el = document.getElementById("input-form");
const value = el.value.trim();
if (!value) return;
if (this.generating) return;
this.maxContextReached = false;
this.placeholderText = "Generating...";
this.generating = true;
this.cancelGeneration = false;
if (this.home === 0) this.home = 1;
// ensure that going back in history will go back to home
window.history.pushState({}, "", window.TINYCHAT_ROOT || "/");
// add message to list
this.cstate.messages.push({ role: "user", content: value });
// clear textarea
el.value = "";
el.style.height = "auto";
el.style.height = el.scrollHeight + "px";
// reset performance tracking
const prefill_start = Date.now();
let start_time = 0;
let tokens = 0;
this.tokens_per_second = 0;
let gottenFirstChunk = false;
try {
for await (
const chunk of this.openaiChatCompletion(this.cstate.messages)
) {
if (!gottenFirstChunk) {
this.cstate.messages.push({ role: "assistant", content: "" });
gottenFirstChunk = true;
}
// add chunk to the last message
// TODO: handle localStorage overflow
// possible example: this.cstate.messages[...] was undefined when trying to prompt within an old cstate (chat session)
this.cstate.messages[this.cstate.messages.length - 1].content += chunk;
// calculate performance tracking
tokens += 1;
this.total_tokens += 1;
if (start_time === 0) {
start_time = Date.now();
this.time_till_first = start_time - prefill_start;
} else {
const diff = Date.now() - start_time;
if (diff > 0) {
this.tokens_per_second = tokens / (diff / 1000);
}
}
this.checkMaxContext(this.total_tokens);
if (this.cancelGeneration) break;
}
} finally {
// update the state in histories or add it if it doesn't exist
const index = this.histories.findIndex((cstate) => {
return cstate.time === this.cstate.time;
});
this.cstate.time = Date.now();
if (index !== -1) {
// update the time
this.histories[index] = this.cstate;
} else {
this.histories.push(this.cstate);
}
// update in local storage
localStorage.setItem("histories", JSON.stringify(this.histories));
if (!this.maxContextReached) this.generating = false;
if (this.cancelGeneration && !this.maxContextReached) this.cstate = { time: null, messages: [] };
}
},
async handleEnter(event) {
// if shift is not pressed
if (!event.shiftKey) {
event.preventDefault();
await this.handleSend();
}
},
updateTotalTokens(messages) {
try {
let toks = [this.tokenizer.bos_id];
messages.forEach((message) => {
if (!message.role || !message.content) {
throw new Error("Each message must have a 'role' and 'content' property.");
}
toks = toks.concat(this.tokenizer.encodeMessage(message.role, message.content));
if (messages.length > 0 && messages[messages.length - 1].role === "user") {
toks = toks.concat(this.tokenizer.encodeRole("assistant"));
}
this.total_tokens = toks.length;
});
} catch (error) {
console.error("Error updating total tokens:", error);
}
},
checkMaxContext(num_tokens) {
if (num_tokens >= this.max_context) {
this.cancelGeneration = true;
this.maxContextReached = true;
this.placeholderText = `Max context reached: ${this.max_context} tokens`;
}
},
async *openaiChatCompletion(messages) {
let tokens = [this.tokenizer.bos_id];
for (const message of messages) {
tokens = tokens.concat(this.tokenizer.encodeMessage(message.role, message.content));
}
tokens = tokens.concat(this.tokenizer.encodeRole("assistant"));
this.checkMaxContext(tokens.length); // don't waste time prefilling if we know we're over the token limit
let startPos = 0
const prefillToks = tokens.slice(0, -1);
// Skip the largest possible sequence of tokens already represented at the beginning of the model's kv caches
for (let i=0; i <= prefillToks.length; i++) {
startPos = i;
if (i == prefillToks.length) break;
if (i == this.lastSeenToks.length) break;
if (prefillToks[i] !== this.lastSeenToks[i]) break;
}
//this.lastSeenToks = prefillToks;
//prefillToks = prefillToks.slice(startPos);
const unprocessedPrefillToks = prefillToks.slice(startPos);
this.lastSeenToks = prefillToks.slice(0, startPos);
this.progress = makeProgress(unprocessedPrefillToks.length);
this.loadingMessage = (window.BACKEND === "WebGPU") ? "Reading input:" : "Loading (enable WebGPU for speed):";
this.progress(0, this.loadingMessage);
for (const tok of unprocessedPrefillToks) {
if (this.cancelGeneration) {this.loadingMessage=""; return;}
if (window.BACKEND === "WebGPU") {await this.nets["transformer"](new Int32Array([tok]), new Int32Array([startPos]));}
else {await this.nets["transformer"](tok, startPos);}
this.lastSeenToks.push(tok)
startPos += 1;
this.progress(1);
}
this.loadingMessage = ""; // hides progress bar
let lastTok = tokens[tokens.length - 1];
while (true) {
if (window.BACKEND === "WebGPU") {var tok = await this.nets["transformer"](new Int32Array([lastTok]), new Int32Array([startPos])); tok = tok[0][0];}
else {var tok = await this.nets["transformer"](lastTok, startPos);}
this.lastSeenToks.push(lastTok); // lets us skip prefilling with these tokens at the next prompt in this chain
startPos += 1;
lastTok = tok;
if (this.tokenizer.stop_tokens.has(lastTok)) break;
yield new TextDecoder().decode(this.tokenizer.decode([lastTok]));
}
},
}));
});
const { markedHighlight } = globalThis.markedHighlight;
marked.use(markedHighlight({
langPrefix: "hljs language-",
highlight(code, lang, _info) {
const language = hljs.getLanguage(lang) ? lang : "plaintext";
return hljs.highlight(code, { language }).value;
},
}));
// **** eventsource-parser ****
class EventSourceParserStream extends TransformStream {
constructor() {
let parser;
super({
start(controller) {
parser = createParser((event) => {
if (event.type === "event") {
controller.enqueue(event);
}
});
},
transform(chunk) {
parser.feed(chunk);
},
});
}
}
function createParser(onParse) {
let isFirstChunk;
let buffer;
let startingPosition;
let startingFieldLength;
let eventId;
let eventName;
let data;
reset();
return {
feed,
reset,
};
function reset() {
isFirstChunk = true;
buffer = "";
startingPosition = 0;
startingFieldLength = -1;
eventId = void 0;
eventName = void 0;
data = "";
}
function feed(chunk) {
buffer = buffer ? buffer + chunk : chunk;
if (isFirstChunk && hasBom(buffer)) {
buffer = buffer.slice(BOM.length);
}
isFirstChunk = false;
const length = buffer.length;
let position = 0;
let discardTrailingNewline = false;
while (position < length) {
if (discardTrailingNewline) {
if (buffer[position] === "\n") {
++position;
}
discardTrailingNewline = false;
}
let lineLength = -1;
let fieldLength = startingFieldLength;
let character;
for (
let index = startingPosition;
lineLength < 0 && index < length;
++index
) {
character = buffer[index];
if (character === ":" && fieldLength < 0) {
fieldLength = index - position;
} else if (character === "\r") {
discardTrailingNewline = true;
lineLength = index - position;
} else if (character === "\n") {
lineLength = index - position;
}
}
if (lineLength < 0) {
startingPosition = length - position;
startingFieldLength = fieldLength;
break;
} else {
startingPosition = 0;
startingFieldLength = -1;
}
parseEventStreamLine(buffer, position, fieldLength, lineLength);
position += lineLength + 1;
}
if (position === length) {
buffer = "";
} else if (position > 0) {
buffer = buffer.slice(position);
}
}
function parseEventStreamLine(lineBuffer, index, fieldLength, lineLength) {
if (lineLength === 0) {
if (data.length > 0) {
onParse({
type: "event",
id: eventId,
event: eventName || void 0,
data: data.slice(0, -1),
// remove trailing newline
});
data = "";
eventId = void 0;
}
eventName = void 0;
return;
}
const noValue = fieldLength < 0;
const field = lineBuffer.slice(
index,
index + (noValue ? lineLength : fieldLength),
);
let step = 0;
if (noValue) {
step = lineLength;
} else if (lineBuffer[index + fieldLength + 1] === " ") {
step = fieldLength + 2;
} else {
step = fieldLength + 1;
}
const position = index + step;
const valueLength = lineLength - step;
const value = lineBuffer.slice(position, position + valueLength).toString();
if (field === "data") {
data += value ? "".concat(value, "\n") : "\n";
} else if (field === "event") {
eventName = value;
} else if (field === "id" && !value.includes("\0")) {
eventId = value;
} else if (field === "retry") {
const retry = parseInt(value, 10);
if (!Number.isNaN(retry)) {
onParse({
type: "reconnect-interval",
value: retry,
});
}
}
}
}
const BOM = [239, 187, 191];
function hasBom(buffer) {
return BOM.every((charCode, index) => buffer.charCodeAt(index) === charCode);
}
const PAT_STR = "(?i:'s|'t|'re|'ve|'m|'ll|'d)|[^\r\n\\p{L}\\p{N}]?\\p{L}+|\\p{N}{1,3}| ?[^\\s\\p{L}\\p{N}]+[\\r\\n]*|\\s*[\\r\\n]+|\\s+(?!\\S)|\\s+";
async function createTokenizer(bpeUrl) {
const num_base_tokens = 128000;
const special_tokens = {
"<|begin_of_text|>": 128000,
"<|end_of_text|>": 128001,
"<|start_header_id|>": 128006,
"<|end_header_id|>": 128007,
"<|eot_id|>": 128009
};
const model = await window.tiktokenLoad({
"load_tiktoken_bpe": bpeUrl,
"special_tokens": special_tokens,
"pat_str": PAT_STR
});
const tokenizer = new window.Tiktoken(model.bpe_ranks, model.special_tokens, model.pat_str)
return {
get bos_id() {
return special_tokens["<|begin_of_text|>"];
},
get stop_tokens() {
return new Set([
special_tokens["<|end_of_text|>"],
special_tokens["<|eot_id|>"],
]);
},
decode(toks) {
const filtered = toks.filter((t) => t < num_base_tokens);
return tokenizer.decode(filtered);
},
encode(text, allow_special = false) {
const allowedSpecial = allow_special ? "all" : new Set();
const disallowedSpecial = new Set();
return tokenizer.encode(text, allowedSpecial, disallowedSpecial);
},
encodeRole(role) {
const tokens = [];
tokens.push(special_tokens["<|start_header_id|>"]);
tokens.push(...this.encode(role));
tokens.push(special_tokens["<|end_header_id|>"]);
tokens.push(...this.encode("\n\n"));
return tokens;
},
encodeMessage(role, content) {
const roleTokens = this.encodeRole(role);
const contentTokens = this.encode(content.trim());
return [...roleTokens, ...contentTokens, special_tokens["<|eot_id|>"]];
},
};
}