Merge pull request #887 from dfinity/ulan/image-classification-simd

Use Wasm SIMD in the image classification example

Author: ulan

rust/image-classification/Cargo.lock

@@ -3,18 +3,12 @@
 This is an ICP smart contract that accepts an image from the user and runs image classification inference.
 The smart contract consists of two canisters:
 
-- the backend canister embeds the [the Tract ONNX inference engine](https://github.com/sonos/tract) with [the MobileNet v2-7 model](https://github.com/onnx/models/tree/main/validated/vision/classification/mobilenet). It provides a `classify()` endpoint for the frontend code to call.
+- the backend canister embeds the [the Tract ONNX inference engine](https://github.com/sonos/tract) with [the MobileNet v2-7 model](https://github.com/onnx/models/tree/main/validated/vision/classification/mobilenet).
+  It provides `classify()` and `classify_query()` endpoints for the frontend code to call.
+  The former endpoint is used for replicated execution (running on all nodes) whereas the latter runs only on a single node.
 - the frontend canister contains the Web assets such as HTML, JS, CSS that are served to the browser.
 
-Note that currently Wasm execution is not optimized for this workload.
-A single call executes about 24B instructions (~10s).
-
-This is expected to improve in the future with:
-
-- faster deterministic floating-point operations.
-- Wasm SIMD (Single-Instruction Multiple Data).
-
-The ICP mainnet subnets and `dfx` running a replica version older than [463296](https://dashboard.internetcomputer.org/release/463296c0bc82ad5999b70245e5f125c14ba7d090) may fail with an instruction-limit-exceeded error.
+This example uses Wasm SIMD instructions that are available in `dfx` version `0.20.2-beta.0` or newer.
 
 # Dependencies
 
@@ -45,12 +39,18 @@ Install NodeJS dependencies for the frontend:
 npm install
 ```
 
+Install `wasm-opt`:
+
+```
+cargo install wasm-opt
+```
+
 # Build
 
 ```
 dfx start --background
 dfx deploy
 ```
 
-If the deployment is successfull, the it will show the `frontend` URL.
+If the deployment is successful, the it will show the `frontend` URL.
 Open that URL in browser to interact with the smart contract.

rust/image-classification/README.md

@@ -5,11 +5,7 @@
       "package": "backend",
       "type": "custom",
       "wasm": "target/wasm32-wasi/release/backend-ic.wasm",
-      "build": [
-         "cargo build --release --target=wasm32-wasi",
-         "wasi2ic ./target/wasm32-wasi/release/backend.wasm ./target/wasm32-wasi/release/backend-ic.wasm"
-       ]
- 
+      "build": [ "bash build.sh" ]
     },
     "frontend": {
       "dependencies": [

rust/image-classification/dfx.json

@@ -16,6 +16,6 @@ prost = "0.11.0"
 prost-types = "0.11.0"
 image = { version = "0.24", features = ["png"], default-features = false }
 serde = { version = "1.0", features = ["derive"] }
-tract-onnx = { git = "https://github.com/sonos/tract", version = "=0.21.2-pre" }
+tract-onnx = { git = "https://github.com/sonos/tract", rev = "2a2914ac29390cc08963301c9f3d437b52dd321a" }
 ic-stable-structures = "0.6"
 ic-wasi-polyfill = { git = "https://github.com/wasm-forge/ic-wasi-polyfill", version = "0.3.17" }

rust/image-classification/src/backend/Cargo.toml

@@ -14,4 +14,5 @@ type ClassificationResult = variant {
 
 service : {
     "classify": (image: blob) -> (ClassificationResult);
+    "classify_query": (image: blob) -> (ClassificationResult) query;
 }

rust/image-classification/src/backend/backend.did

@@ -1,6 +1,9 @@
-use std::cell::RefCell;
 use candid::{CandidType, Deserialize};
-use ic_stable_structures::{memory_manager::{MemoryId, MemoryManager}, DefaultMemoryImpl};
+use ic_stable_structures::{
+    memory_manager::{MemoryId, MemoryManager},
+    DefaultMemoryImpl,
+};
+use std::cell::RefCell;
 
 mod onnx;
 
@@ -31,7 +34,7 @@ enum ClassificationResult {
     Err(ClassificationError),
 }
 
-#[ic_cdk::update]
+#[ic_cdk::query]
 fn classify(image: Vec<u8>) -> ClassificationResult {
     let result = match onnx::classify(image) {
         Ok(result) => ClassificationResult::Ok(result),
@@ -42,6 +45,17 @@ fn classify(image: Vec<u8>) -> ClassificationResult {
     result
 }
 
+#[ic_cdk::query]
+fn classify_query(image: Vec<u8>) -> ClassificationResult {
+    let result = match onnx::classify(image) {
+        Ok(result) => ClassificationResult::Ok(result),
+        Err(err) => ClassificationResult::Err(ClassificationError {
+            message: err.to_string(),
+        }),
+    };
+    result
+}
+
 #[ic_cdk::init]
 fn init() {
     let wasi_memory = MEMORY_MANAGER.with(|m| m.borrow().get(WASI_MEMORY_ID));

rust/image-classification/src/backend/src/lib.rs

@@ -14,4 +14,5 @@ type ClassificationResult = variant {
 
 service : {
     "classify": (image: blob) -> (ClassificationResult);
+    "classify_query": (image: blob) -> (ClassificationResult) query;
 }

rust/image-classification/src/declarations/backend/backend.did

@@ -8,6 +8,7 @@ export type ClassificationResult = { 'Ok' : Array<Classification> } |
   { 'Err' : ClassificationError };
 export interface _SERVICE {
   'classify' : ActorMethod<[Uint8Array | number[]], ClassificationResult>,
+  'classify_query' : ActorMethod<[Uint8Array | number[]], ClassificationResult>,
 }
 export declare const idlFactory: IDL.InterfaceFactory;
 export declare const init: (args: { IDL: typeof IDL }) => IDL.Type[];

rust/image-classification/src/declarations/backend/backend.did.d.ts

@@ -10,6 +10,11 @@ export const idlFactory = ({ IDL }) => {
   });
   return IDL.Service({
     'classify' : IDL.Func([IDL.Vec(IDL.Nat8)], [ClassificationResult], []),
+    'classify_query' : IDL.Func(
+        [IDL.Vec(IDL.Nat8)],
+        [ClassificationResult],
+        ['query'],
+      ),
   });
 };
 export const init = ({ IDL }) => { return []; };

rust/image-classification/src/declarations/backend/backend.did.js

@@ -47,6 +47,7 @@ textarea {
     flex-flow: row;
     justify-content: left;
     align-items: center;
+    margin-bottom: 20px;
 }
 
 .toggle-switch {
@@ -71,7 +72,6 @@ textarea {
     bottom: 0;
     background-color: #ccc;
     border-radius: 18px;
-    transition: 0.4s;
 }
 
 .slider:before {
@@ -83,7 +83,6 @@ textarea {
     bottom: 1px;
     background-color: white;
     border-radius: 50%;
-    transition: 0.4s;
 }
 
 input:checked+.slider {
@@ -129,15 +128,15 @@ li {
 
 @keyframes astrodance {
     0% {
-        transform: translate(-50%,-50%) rotate(-20deg)
+        transform: translate(-50%, -50%) rotate(-20deg)
     }
 
     50% {
-        transform: translate(-50%,-50%) rotate(10deg)
+        transform: translate(-50%, -50%) rotate(10deg)
     }
 
     to {
-        transform: translate(-50%,-50%) rotate(-20deg)
+        transform: translate(-50%, -50%) rotate(-20deg)
     }
 }
 

rust/image-classification/src/frontend/assets/main.css

@@ -20,6 +20,15 @@ <h1>ICP image classification</h1>
       <input id="file" class="file" name="file" type="file" accept="image/png, image/jpeg" />
       <div id="container">
         <div id="message"></div>
+        <div class="option invisible" id="replicated_option">
+          <label>
+            <div class="toggle-switch">
+              <input type="checkbox" id="replicated">
+              <span class="slider"></span>
+            </div>
+            &nbsp; replicated execution
+          </label>
+        </div>
         <img id="loader" src="loader.svg" class="loader invisible" />
         <button id="classify" class="clean-button invisible" disabled>Go!</button>
       </div>