Re-organize the wasm examples (#231)

* Move the whisper example.

* More renaming.

* Add llama2 as a new wasm example.

* Live generation.

* More of the llama wasm example.

* Formatting.
This commit is contained in:
Laurent Mazare
2023-07-24 12:36:02 +01:00
committed by GitHub
parent 550a13a547
commit 5a26cba733
22 changed files with 988 additions and 18 deletions

View File

@ -0,0 +1,353 @@
use crate::model::{Cache, Config, Llama};
use byteorder::{LittleEndian, ReadBytesExt};
use candle::{DType, Device, IndexOp, Result, Shape, Tensor, D};
use candle_nn::VarBuilder;
use rand::{distributions::Distribution, SeedableRng};
use serde::{Deserialize, Serialize};
use wasm_bindgen::prelude::*;
use yew_agent::{HandlerId, Public, WorkerLink};
#[wasm_bindgen]
extern "C" {
// Use `js_namespace` here to bind `console.log(..)` instead of just
// `log(..)`
#[wasm_bindgen(js_namespace = console)]
pub fn log(s: &str);
}
#[macro_export]
macro_rules! console_log {
// Note that this is using the `log` function imported above during
// `bare_bones`
($($t:tt)*) => ($crate::worker::log(&format_args!($($t)*).to_string()))
}
// Communication to the worker happens through bincode, the model weights and configs are fetched
// on the main thread and transfered via the following structure.
#[derive(Serialize, Deserialize)]
pub struct ModelData {
pub tokenizer: Vec<u8>,
pub model: Vec<u8>,
}
fn read_i32<R: std::io::Read>(r: &mut R) -> Result<i32> {
let mut buf = [0u8; 4];
r.read_exact(&mut buf)?;
Ok(i32::from_le_bytes(buf))
}
fn read_tensor<R: std::io::Read, S: Into<Shape>>(
r: &mut R,
shape: S,
dev: &Device,
) -> Result<Tensor> {
let shape = shape.into();
let mut data_t = vec![0f32; shape.elem_count()];
r.read_f32_into::<LittleEndian>(&mut data_t)?;
let tensor = Tensor::from_vec(data_t, shape, dev)?;
Ok(tensor)
}
struct Tokenizer {
tokens: Vec<String>,
}
impl Tokenizer {
fn from_reader<R: std::io::Read>(r: &mut R, c: &Config) -> Result<Self> {
let mut tokens = Vec::with_capacity(c.vocab_size);
for _token_index in 0..c.vocab_size {
let token_len = read_i32(r)?;
let mut token = vec![0u8; token_len as usize];
r.read_exact(&mut token)?;
tokens.push(String::from_utf8_lossy(&token).into_owned())
}
Ok(Self { tokens })
}
}
struct Model {
cache: Cache,
config: Config,
llama: Llama,
tokenizer: Tokenizer,
}
pub struct LogitsProcessor {
rng: rand::rngs::StdRng,
temperature: Option<f64>,
}
impl LogitsProcessor {
pub fn new(seed: u64, temperature: Option<f64>) -> Self {
Self {
rng: rand::rngs::StdRng::seed_from_u64(seed),
temperature,
}
}
pub fn sample(&mut self, logits: &Tensor) -> Result<u32> {
let logits = logits.to_dtype(DType::F32)?;
let next_token = if let Some(temperature) = self.temperature {
let prs = (&logits / temperature)?.softmax(D::Minus1)?;
let prs: Vec<f32> = prs.to_vec1()?;
let distr =
rand::distributions::WeightedIndex::new(prs).map_err(candle::Error::wrap)?;
distr.sample(&mut self.rng) as u32
} else {
let logits_v: Vec<f32> = logits.to_vec1()?;
logits_v
.iter()
.enumerate()
.max_by(|(_, u), (_, v)| u.total_cmp(v))
.map(|(i, _)| i as u32)
.unwrap()
};
Ok(next_token)
}
}
impl Model {
fn run(&self, link: &WorkerLink<Worker>, id: HandlerId) -> Result<()> {
let dev = Device::Cpu;
let mut logits_processor = LogitsProcessor::new(299792458, None);
let mut index_pos = 0;
let mut tokens = vec![1u32];
for index in 0..self.config.seq_len - 10 {
let context_size = if self.cache.use_kv_cache && index > 0 {
1
} else {
tokens.len()
};
let ctxt = &tokens[tokens.len().saturating_sub(context_size)..];
let input = Tensor::new(ctxt, &dev)?.unsqueeze(0)?;
let logits = self.llama.forward(&input, index_pos)?;
let logits = logits.squeeze(0)?;
index_pos += ctxt.len();
let next_token = logits_processor.sample(&logits)?;
tokens.push(next_token);
let token = self.tokenizer.tokens[next_token as usize].clone();
link.respond(id, Ok(WorkerOutput::Generated(token)));
}
Ok(())
}
}
impl Config {
fn from_reader<R: std::io::Read>(r: &mut R) -> Result<Self> {
let dim = read_i32(r)? as usize;
let hidden_dim = read_i32(r)? as usize;
let n_layers = read_i32(r)? as usize;
let n_heads = read_i32(r)? as usize;
let n_kv_heads = read_i32(r)? as usize;
let vocab_size = read_i32(r)? as usize;
let seq_len = read_i32(r)? as usize;
Ok(Self {
dim,
hidden_dim,
n_layers,
n_heads,
n_kv_heads,
vocab_size,
seq_len,
norm_eps: 1e-5,
})
}
pub fn head_size(&self) -> usize {
self.dim / self.n_heads
}
}
struct TransformerWeights {
// token embedding table
token_embedding_table: Tensor, // (vocab_size, dim)
// weights for rmsnorms
rms_att_weight: Tensor, // (layer, dim) rmsnorm weights
rms_ffn_weight: Tensor, // (layer, dim)
// weights for matmuls
wq: Tensor, // (layer, dim, dim)
wk: Tensor, // (layer, dim, dim)
wv: Tensor, // (layer, dim, dim)
wo: Tensor, // (layer, dim, dim)
// weights for ffn
w1: Tensor, // (layer, hidden_dim, dim)
w2: Tensor, // (layer, dim, hidden_dim)
w3: Tensor, // (layer, hidden_dim, dim)
// final rmsnorm
rms_final_weight: Tensor, // (dim,)
// freq_cis for RoPE relatively positional embeddings
freq_cis_real: Tensor, // (seq_len, head_size/2)
freq_cis_imag: Tensor, // (seq_len, head_size/2)
}
impl TransformerWeights {
fn from_reader<R: std::io::Read>(r: &mut R, c: &Config, dev: &Device) -> Result<Self> {
let token_embedding_table = read_tensor(r, (c.vocab_size, c.dim), dev)?;
let rms_att_weight = read_tensor(r, (c.n_layers, c.dim), dev)?;
let wq = read_tensor(r, (c.n_layers, c.dim, c.dim), dev)?;
let wk = read_tensor(r, (c.n_layers, c.dim, c.dim), dev)?;
let wv = read_tensor(r, (c.n_layers, c.dim, c.dim), dev)?;
let wo = read_tensor(r, (c.n_layers, c.dim, c.dim), dev)?;
let rms_ffn_weight = read_tensor(r, (c.n_layers, c.dim), dev)?;
let w1 = read_tensor(r, (c.n_layers, c.hidden_dim, c.dim), dev)?;
let w2 = read_tensor(r, (c.n_layers, c.dim, c.hidden_dim), dev)?;
let w3 = read_tensor(r, (c.n_layers, c.hidden_dim, c.dim), dev)?;
let rms_final_weight = read_tensor(r, c.dim, dev)?;
let head_size = c.head_size();
let freq_cis_real = read_tensor(r, (c.seq_len, head_size / 2), dev)?;
let freq_cis_imag = read_tensor(r, (c.seq_len, head_size / 2), dev)?;
Ok(Self {
token_embedding_table,
rms_att_weight,
wq,
wk,
wv,
wo,
rms_ffn_weight,
w1,
w2,
w3,
rms_final_weight,
freq_cis_real,
freq_cis_imag,
})
}
fn var_builder(&self, cfg: &Config, device: &Device) -> Result<VarBuilder> {
let mut ws = std::collections::HashMap::new();
let mut insert = |name: &str, t: Tensor| {
ws.insert(name.to_string(), t);
};
insert("rot.freq_cis_real", self.freq_cis_real.clone());
insert("rot.freq_cis_imag", self.freq_cis_imag.clone());
insert(
"model.embed_tokens.weight",
self.token_embedding_table.clone(),
);
insert("lm_head.weight", self.token_embedding_table.clone());
insert("model.norm.weight", self.rms_final_weight.clone());
for layer in 0..cfg.n_layers {
ws.insert(
format!("model.layers.{layer}.self_attn.q_proj.weight"),
self.wq.i(layer)?,
);
ws.insert(
format!("model.layers.{layer}.self_attn.k_proj.weight"),
self.wk.i(layer)?,
);
ws.insert(
format!("model.layers.{layer}.self_attn.v_proj.weight"),
self.wv.i(layer)?,
);
ws.insert(
format!("model.layers.{layer}.self_attn.o_proj.weight"),
self.wo.i(layer)?,
);
ws.insert(
format!("model.layers.{layer}.mlp.gate_proj.weight"),
self.w1.i(layer)?,
);
ws.insert(
format!("model.layers.{layer}.mlp.down_proj.weight"),
self.w2.i(layer)?,
);
ws.insert(
format!("model.layers.{layer}.mlp.up_proj.weight"),
self.w3.i(layer)?,
);
ws.insert(
format!("model.layers.{layer}.input_layernorm.weight"),
self.rms_att_weight.i(layer)?,
);
ws.insert(
format!("model.layers.{layer}.post_attention_layernorm.weight"),
self.rms_ffn_weight.i(layer)?,
);
}
let vb = VarBuilder::from_tensors(ws, DType::F32, device);
Ok(vb)
}
}
impl Model {
fn load(md: ModelData) -> Result<Self> {
let dev = Device::Cpu;
let mut model = std::io::Cursor::new(md.model);
let config = Config::from_reader(&mut model)?;
let weights = TransformerWeights::from_reader(&mut model, &config, &dev)?;
let vb = weights.var_builder(&config, &dev)?;
let cache = Cache::new(true, &config, vb.pp("rot"))?;
let llama = Llama::load(vb, &cache, &config)?;
let mut tokenizer = std::io::Cursor::new(md.tokenizer);
let tokenizer = Tokenizer::from_reader(&mut tokenizer, &config)?;
Ok(Self {
cache,
config,
llama,
tokenizer,
})
}
}
pub struct Worker {
link: WorkerLink<Self>,
model: Option<Model>,
}
#[derive(Serialize, Deserialize)]
pub enum WorkerInput {
ModelData(ModelData),
Run,
}
#[derive(Serialize, Deserialize)]
pub enum WorkerOutput {
Generated(String),
GenerationDone(std::result::Result<(), String>),
WeightsLoaded,
}
impl yew_agent::Worker for Worker {
type Input = WorkerInput;
type Message = ();
type Output = std::result::Result<WorkerOutput, String>;
type Reach = Public<Self>;
fn create(link: WorkerLink<Self>) -> Self {
Self { link, model: None }
}
fn update(&mut self, _msg: Self::Message) {
// no messaging
}
fn handle_input(&mut self, msg: Self::Input, id: HandlerId) {
let output = match msg {
WorkerInput::ModelData(md) => match Model::load(md) {
Ok(model) => {
self.model = Some(model);
Ok(WorkerOutput::WeightsLoaded)
}
Err(err) => Err(format!("model creation error {err:?}")),
},
WorkerInput::Run => match &self.model {
None => Err("model has not been set yet".to_string()),
Some(model) => {
let result = model.run(&self.link, id).map_err(|e| e.to_string());
Ok(WorkerOutput::GenerationDone(result))
}
},
};
self.link.respond(id, output);
}
fn name_of_resource() -> &'static str {
"worker.js"
}
fn resource_path_is_relative() -> bool {
true
}
}