pie 0.2.0

Pie: A Programmable LLM Serving System
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
use crate::instance::InstanceState;
use crate::api::core::Queue;
use crate::model::request::{ForwardPassRequest, ForwardPassResponse, Request};
use crate::model::resource::{EMBED_TYPE_ID, KV_PAGE_TYPE_ID, ResourceId};
use crate::model::submit_request;
use anyhow::{Result, bail};
use std::collections::HashMap;
use std::iter;
use std::mem::take;
use tokio::sync::oneshot;
use wasmtime::component::Resource;
use wasmtime_wasi::WasiView;
use wasmtime_wasi::async_trait;
use wasmtime_wasi::p2::{DynPollable, Pollable, subscribe};
use crate::api::inferlet;

#[derive(Debug)]
pub struct ForwardPass {
    pub queue: Queue,
    input_tokens: Vec<u32>,
    input_token_positions: Vec<u32>,
    input_embed_ptrs: Vec<u32>,
    input_embed_positions: Vec<u32>,
    pub adapter: Option<u32>,
    pub adapter_seed: Option<i64>,
    mask: Vec<Vec<u32>>,
    kv_page_ptrs: Vec<u32>,
    kv_page_last_len: u32,
    output_token_indices: Vec<u32>,
    output_token_samplers: Vec<HashMap<String, rmpv::Value>>,
    output_embed_ptrs: Vec<u32>,
    output_embed_indices: Vec<u32>,
}

#[derive(Debug)]
pub struct ForwardPassResult {
    pub receiver: oneshot::Receiver<ForwardPassResponse>,
    pub distributions: Vec<(Vec<u32>, Vec<f32>)>,
    pub tokens: Vec<u32>,
    pub done: bool,
}

enum Sampler {
    Distribution = 0,
    Multinomial = 1,
    TopP = 2,
    TopK = 3,
    MinP = 4,
    TopKTopP = 5,
}

#[async_trait]
impl Pollable for ForwardPassResult {
    async fn ready(&mut self) {
        if self.done {
            return;
        }

        if let Ok(res) = (&mut self.receiver).await {
            self.distributions = res.dists;
            self.tokens = res.tokens;
        }

        self.done = true;
    }
}

impl inferlet::core::forward::Host for InstanceState {
    async fn create_forward_pass(
        &mut self,
        queue: Resource<Queue>,
    ) -> Result<Resource<ForwardPass>> {
        let queue = self.ctx().table.get(&queue)?.clone();

        let pass = ForwardPass {
            queue,
            input_tokens: vec![],
            input_token_positions: vec![],
            input_embed_ptrs: vec![],
            input_embed_positions: vec![],
            adapter: None,
            adapter_seed: None,
            mask: vec![],
            kv_page_ptrs: vec![],
            kv_page_last_len: 0,
            output_token_indices: vec![],
            output_token_samplers: vec![],
            output_embed_ptrs: vec![],
            output_embed_indices: vec![],
        };
        Ok(self.ctx().table.push(pass)?)
    }

    async fn attention_mask(
        &mut self,
        pass: Resource<ForwardPass>,
        mask: Vec<Vec<u32>>,
    ) -> Result<()> {
        let pass = self.ctx().table.get_mut(&pass)?;
        pass.mask = mask;
        Ok(())
    }

    async fn kv_cache(
        &mut self,
        pass: Resource<ForwardPass>,
        mut kv_page_ptrs: Vec<ResourceId>,
        kv_page_last_len: u32,
    ) -> Result<()> {
        let svc_id = self.ctx().table.get(&pass)?.queue.service_id;

        kv_page_ptrs.iter_mut().try_for_each(|kv_page_ptr| {
            *kv_page_ptr = self.translate_resource_ptr(svc_id, KV_PAGE_TYPE_ID, *kv_page_ptr)?;
            Ok::<_, anyhow::Error>(())
        })?;

        let pass = self.ctx().table.get_mut(&pass)?;
        pass.kv_page_ptrs = kv_page_ptrs;
        pass.kv_page_last_len = kv_page_last_len;
        Ok(())
    }

    async fn input_embeddings(
        &mut self,
        pass: Resource<ForwardPass>,
        mut emb_ptrs: Vec<ResourceId>,
        positions: Vec<u32>,
    ) -> Result<()> {
        let svc_id = self.ctx().table.get(&pass)?.queue.service_id;

        emb_ptrs.iter_mut().try_for_each(|emb_ptr| {
            *emb_ptr = self.translate_resource_ptr(svc_id, EMBED_TYPE_ID, *emb_ptr)?;
            Ok::<_, anyhow::Error>(())
        })?;

        let pass = self.ctx().table.get_mut(&pass)?;

        if pass.input_tokens.len() + emb_ptrs.len() > pass.queue.info.max_batch_tokens {
            bail!(
                "max batch tokens exceeded, input tokens: {}, max tokens: {}",
                emb_ptrs.len(),
                pass.queue.info.max_batch_tokens
            );
        }

        pass.input_embed_ptrs.extend(emb_ptrs);
        pass.input_embed_positions.extend(positions);
        Ok(())
    }

    async fn input_tokens(
        &mut self,
        pass: Resource<ForwardPass>,
        input_tokens: Vec<u32>,
        positions: Vec<u32>,
    ) -> Result<()> {
        let pass = self.ctx().table.get_mut(&pass)?;

        if pass.input_tokens.len() + input_tokens.len() > pass.queue.info.max_batch_tokens {
            println!(
                "max batch tokens exceeded, input tokens: {}, max tokens: {}",
                input_tokens.len(),
                pass.queue.info.max_batch_tokens
            );
            bail!(
                "max batch tokens exceeded, input tokens: {}, max tokens: {}",
                input_tokens.len(),
                pass.queue.info.max_batch_tokens
            );
        }

        // check if token ids are in the vocab range
        let num_vocabs = pass.queue.info.tokenizer.num_vocab() as u32;
        for &token in input_tokens.iter() {
            if token >= num_vocabs {
                println!("token id {} is out of range", token);
                bail!("token id {} is out of range", token);
            }
        }

        pass.input_tokens.extend(input_tokens);
        pass.input_token_positions.extend(positions);
        Ok(())
    }

    async fn output_embeddings(
        &mut self,
        pass: Resource<ForwardPass>,
        mut emb_ptrs: Vec<ResourceId>,
        indices: Vec<u32>,
    ) -> Result<()> {
        let svc_id = self.ctx().table.get(&pass)?.queue.service_id;
        emb_ptrs.iter_mut().try_for_each(|emb_ptr| {
            *emb_ptr = self.translate_resource_ptr(svc_id, EMBED_TYPE_ID, *emb_ptr)?;
            Ok::<_, anyhow::Error>(())
        })?;

        let pass = self.ctx().table.get_mut(&pass)?;
        pass.output_embed_ptrs.extend(emb_ptrs);
        pass.output_embed_indices.extend(indices);
        Ok(())
    }

    async fn output_distributions(
        &mut self,
        pass: Resource<ForwardPass>,
        indices: Vec<u32>,
        temperature: f32,
        top_k: Option<u32>,
    ) -> Result<()> {
        let mut sampler = HashMap::new();
        sampler.insert(
            "sampler".to_string(),
            rmpv::Value::from(Sampler::Distribution as u32),
        );
        sampler.insert("temperature".to_string(), rmpv::Value::from(temperature));
        sampler.insert("top_k".to_string(), rmpv::Value::from(top_k.unwrap_or(32)));

        let pass = self.ctx().table.get_mut(&pass)?;
        pass.output_token_samplers
            .extend(iter::repeat(sampler.clone()).take(indices.len()));
        pass.output_token_indices.extend(indices);
        Ok(())
    }

    async fn output_tokens(
        &mut self,
        pass: Resource<ForwardPass>,
        indices: Vec<u32>,
        temperature: f32,
    ) -> Result<()> {
        let mut sampler = HashMap::new();

        sampler.insert(
            "sampler".to_string(),
            rmpv::Value::from(Sampler::Multinomial as u32),
        );
        sampler.insert("temperature".to_string(), rmpv::Value::from(temperature));

        let samplers = iter::repeat(sampler.clone())
            .take(indices.len())
            .collect::<Vec<_>>();

        let pass = self.ctx().table.get_mut(&pass)?;
        pass.output_token_indices.extend(indices);
        pass.output_token_samplers.extend(samplers);
        Ok(())
    }

    async fn output_tokens_top_k(
        &mut self,
        pass: Resource<ForwardPass>,
        indices: Vec<u32>,
        temperature: f32,
        top_k: u32,
    ) -> Result<()> {
        let mut sampler = HashMap::new();

        sampler.insert(
            "sampler".to_string(),
            rmpv::Value::from(Sampler::TopK as u32),
        );
        sampler.insert("temperature".to_string(), rmpv::Value::from(temperature));
        sampler.insert("top_k".to_string(), rmpv::Value::from(top_k));

        let pass = self.ctx().table.get_mut(&pass)?;
        pass.output_token_samplers
            .extend(iter::repeat(sampler.clone()).take(indices.len()));
        pass.output_token_indices.extend(indices);

        Ok(())
    }

    async fn output_tokens_top_p(
        &mut self,
        pass: Resource<ForwardPass>,
        indices: Vec<u32>,
        temperature: f32,
        top_p: f32,
    ) -> Result<()> {
        let mut sampler = HashMap::new();

        sampler.insert(
            "sampler".to_string(),
            rmpv::Value::from(Sampler::TopP as u32),
        );
        sampler.insert("temperature".to_string(), rmpv::Value::from(temperature));
        sampler.insert("top_p".to_string(), rmpv::Value::from(top_p));

        let pass = self.ctx().table.get_mut(&pass)?;
        pass.output_token_samplers
            .extend(iter::repeat(sampler.clone()).take(indices.len()));
        pass.output_token_indices.extend(indices);

        Ok(())
    }

    async fn output_tokens_min_p(
        &mut self,
        pass: Resource<ForwardPass>,
        indices: Vec<u32>,
        temperature: f32,
        min_p: f32,
    ) -> Result<()> {
        let mut sampler = HashMap::new();

        sampler.insert(
            "sampler".to_string(),
            rmpv::Value::from(Sampler::MinP as u32),
        );
        sampler.insert("temperature".to_string(), rmpv::Value::from(temperature));
        sampler.insert("min_p".to_string(), rmpv::Value::from(min_p));

        let pass = self.ctx().table.get_mut(&pass)?;
        pass.output_token_samplers
            .extend(iter::repeat(sampler.clone()).take(indices.len()));
        pass.output_token_indices.extend(indices);

        Ok(())
    }

    async fn output_tokens_top_k_top_p(
        &mut self,
        pass: Resource<ForwardPass>,
        indices: Vec<u32>,
        temperature: f32,
        top_k: u32,
        top_p: f32,
    ) -> Result<()> {
        let mut sampler = HashMap::new();

        sampler.insert(
            "sampler".to_string(),
            rmpv::Value::from(Sampler::TopKTopP as u32),
        );
        sampler.insert("temperature".to_string(), rmpv::Value::from(temperature));
        sampler.insert("top_k".to_string(), rmpv::Value::from(top_k));
        sampler.insert("top_p".to_string(), rmpv::Value::from(top_p));

        let pass = self.ctx().table.get_mut(&pass)?;
        pass.output_token_samplers
            .extend(iter::repeat(sampler.clone()).take(indices.len()));
        pass.output_token_indices.extend(indices);

        Ok(())
    }
}

impl inferlet::core::forward::HostForwardPass for InstanceState {
    async fn execute(
        &mut self,
        this: Resource<ForwardPass>,
    ) -> Result<Option<Resource<ForwardPassResult>>> {
        // 1) Check whether we need output (immutable borrow)
        let returns_output = {
            let pass = self.ctx().table.get(&this)?;
            !pass.output_token_indices.is_empty()
        };

        // 2) Build the request by MOVING data out of the pass (mutable borrow)
        let (request, svc_id, queue_id, priority) = {
            let pass = self.ctx().table.get_mut(&this)?;

            let svc_id = pass.queue.service_id;
            let queue_id = pass.queue.uid;
            let priority = pass.queue.priority;

            let request = ForwardPassRequest {
                input_tokens: take(&mut pass.input_tokens),
                input_token_positions: take(&mut pass.input_token_positions),
                input_embed_ptrs: take(&mut pass.input_embed_ptrs),
                input_embed_positions: take(&mut pass.input_embed_positions),
                adapter: pass.adapter,
                adapter_seed: pass.adapter_seed,
                mask: take(&mut pass.mask),
                kv_page_ptrs: take(&mut pass.kv_page_ptrs),
                kv_page_last_len: pass.kv_page_last_len,
                output_token_indices: take(&mut pass.output_token_indices),
                output_token_samplers: take(&mut pass.output_token_samplers),
                output_embed_ptrs: take(&mut pass.output_embed_ptrs),
                output_embed_indices: take(&mut pass.output_embed_indices),
            };

            (request, svc_id, queue_id, priority)
        };

        if returns_output {
            let (tx, rx) = oneshot::channel();

            let req = Request::ForwardPass(request, Some(tx));

            submit_request(svc_id, queue_id, priority, req)?;

            let res = ForwardPassResult {
                receiver: rx,
                distributions: vec![],
                tokens: vec![],
                done: false,
            };

            Ok(Some(self.ctx().table.push(res)?))
        } else {
            let req = Request::ForwardPass(request, None);

            submit_request(svc_id, queue_id, priority, req)?;

            Ok(None)
        }
    }
    async fn drop(&mut self, this: Resource<ForwardPass>) -> Result<()> {
        self.ctx().table.delete(this)?;
        Ok(())
    }
}

impl inferlet::core::forward::HostForwardPassResult for InstanceState {
    async fn pollable(
        &mut self,
        this: Resource<ForwardPassResult>,
    ) -> Result<Resource<DynPollable>> {
        subscribe(self.ctx().table, this)
    }

    async fn get_distributions(
        &mut self,
        this: Resource<ForwardPassResult>,
    ) -> Result<Option<Vec<(Vec<u32>, Vec<f32>)>>> {
        let result = self.ctx().table.get_mut(&this)?;

        if result.done {
            Ok(Some(take(&mut result.distributions)))
        } else {
            Ok(None)
        }
    }

    async fn get_tokens(&mut self, this: Resource<ForwardPassResult>) -> Result<Option<Vec<u32>>> {
        let result = self.ctx().table.get_mut(&this)?;

        if result.done {
            Ok(Some(take(&mut result.tokens)))
        } else {
            Ok(None)
        }
    }

    async fn drop(&mut self, this: Resource<ForwardPassResult>) -> Result<()> {
        self.ctx().table.delete(this)?;
        Ok(())
    }
}