From 21340f24bafbee6707783255fb9693bb2118a032 Mon Sep 17 00:00:00 2001
From: OlivierDehaene <olivier@huggingface.co>
Date: Mon, 27 Feb 2023 14:56:58 +0100
Subject: [PATCH] feat(router): add legacy route for api-inference support
 (#88)

---
 router/src/lib.rs    | 26 +++++++++++++++++++++++---
 router/src/server.rs | 28 ++++++++++++++++++++++++----
 2 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/router/src/lib.rs b/router/src/lib.rs
index 1f23bfd3..d7cfa4c7 100644
--- a/router/src/lib.rs
+++ b/router/src/lib.rs
@@ -47,7 +47,7 @@ pub(crate) struct GenerateParameters {
     #[schema(exclusive_minimum = 0, exclusive_maximum = 512, default = "20")]
     pub max_new_tokens: u32,
     #[serde(default)]
-    #[schema(inline, max_items = 4, example = json!(["photographer"]))]
+    #[schema(inline, max_items = 4, example = json ! (["photographer"]))]
     pub stop: Vec<String>,
     #[serde(default)]
     #[schema(default = "true")]
@@ -86,13 +86,33 @@ pub(crate) struct GenerateRequest {
     pub parameters: GenerateParameters,
 }
 
+#[derive(Clone, Debug, Deserialize, ToSchema)]
+pub(crate) struct CompatGenerateRequest {
+    #[schema(example = "My name is Olivier and I")]
+    pub inputs: String,
+    #[serde(default = "default_parameters")]
+    pub parameters: GenerateParameters,
+    #[serde(default)]
+    #[allow(dead_code)]
+    pub stream: bool,
+}
+
+impl From<CompatGenerateRequest> for GenerateRequest {
+    fn from(req: CompatGenerateRequest) -> Self {
+        Self {
+            inputs: req.inputs,
+            parameters: req.parameters,
+        }
+    }
+}
+
 #[derive(Debug, Serialize, ToSchema)]
 pub struct PrefillToken {
     #[schema(example = 0)]
     id: u32,
     #[schema(example = "test")]
     text: String,
-    #[schema(nullable = true, example = -0.34)]
+    #[schema(nullable = true, example = - 0.34)]
     logprob: f32,
 }
 
@@ -102,7 +122,7 @@ pub struct Token {
     id: u32,
     #[schema(example = "test")]
     text: String,
-    #[schema(nullable = true, example = -0.34)]
+    #[schema(nullable = true, example = - 0.34)]
     logprob: f32,
     #[schema(example = "false")]
     special: bool,
diff --git a/router/src/server.rs b/router/src/server.rs
index de96e397..83b0297e 100644
--- a/router/src/server.rs
+++ b/router/src/server.rs
@@ -1,8 +1,9 @@
 /// HTTP Server logic
 use crate::infer::{InferError, InferStreamResponse};
 use crate::{
-    Details, ErrorResponse, FinishReason, GenerateParameters, GenerateRequest, GenerateResponse,
-    Infer, PrefillToken, StreamDetails, StreamResponse, Token, Validation,
+    CompatGenerateRequest, Details, ErrorResponse, FinishReason, GenerateParameters,
+    GenerateRequest, GenerateResponse, Infer, PrefillToken, StreamDetails, StreamResponse, Token,
+    Validation,
 };
 use axum::extract::Extension;
 use axum::http::{HeaderMap, Method, StatusCode};
@@ -25,6 +26,25 @@ use tracing::{info_span, instrument, Instrument};
 use utoipa::OpenApi;
 use utoipa_swagger_ui::SwaggerUi;
 
+/// Compatibility route with api-inference and AzureML
+#[instrument(skip(infer))]
+async fn compat_generate(
+    infer: Extension<Infer>,
+    req: Json<CompatGenerateRequest>,
+) -> Result<impl IntoResponse, (StatusCode, Json<ErrorResponse>)> {
+    // switch on stream
+    let req = req.0;
+    if req.stream {
+        Ok(generate_stream(infer, Json(req.into()))
+            .await
+            .into_response())
+    } else {
+        let (headers, generation) = generate(infer, Json(req.into())).await?;
+        // wrap generation inside a Vec to match api-inference
+        Ok((headers, Json(vec![generation.0])).into_response())
+    }
+}
+
 /// Health check method
 #[instrument(skip(infer))]
 async fn health(infer: Extension<Infer>) -> Result<(), (StatusCode, Json<ErrorResponse>)> {
@@ -84,7 +104,7 @@ async fn health(infer: Extension<Infer>) -> Result<(), (StatusCode, Json<ErrorRe
 async fn generate(
     infer: Extension<Infer>,
     req: Json<GenerateRequest>,
-) -> Result<impl IntoResponse, (StatusCode, Json<ErrorResponse>)> {
+) -> Result<(HeaderMap, Json<GenerateResponse>), (StatusCode, Json<ErrorResponse>)> {
     let span = tracing::Span::current();
     let start_time = Instant::now();
 
@@ -404,7 +424,7 @@ pub async fn run(
     // Create router
     let app = Router::new()
         .merge(SwaggerUi::new("/docs").url("/api-doc/openapi.json", ApiDoc::openapi()))
-        .route("/", post(generate))
+        .route("/", post(compat_generate))
         .route("/generate", post(generate))
         .route("/generate_stream", post(generate_stream))
         .route("/", get(health))