Add blocking OCR pipeline for the Rust engine

litellm-rust/src/pipeline.rs

@@ -0,0 +1,78 @@
+//! Pure orchestration of an OCR call using blocking HTTP. No PyO3.
+//!
+//! Builds url + headers + body via the pure transforms, POSTs, and parses the
+//! response. The async path used by the HTTP server reuses the same transforms.
+
+use serde_json::Value;
+
+use crate::error::OcrError;
+use crate::llms::base_llm::ocr::transformation::{BaseOcrConfig, Headers, OcrRequest, OcrResponse};
+use crate::llms::mistral::ocr::transformation::MistralOcrConfig;
+
+/// A prepared OCR call: (url, headers, request body).
+pub type PreparedCall = (String, Headers, Value);
+
+/// Build (url, headers, body) for an OCR request using the pure transforms.
+///
+/// Shared by the blocking (Python) and async (server) code paths so both go
+/// through exactly the same transform logic.
+pub fn build_call(config: &dyn BaseOcrConfig, req: &OcrRequest) -> Result<PreparedCall, OcrError> {
+    let headers = config
+        .validate_environment(&req.model, req.api_key.as_deref(), &|key| {
+            std::env::var(key).ok()
+        })
+        .map_err(OcrError::Auth)?;
+
+    let url = config.get_complete_url(req.api_base.as_deref(), &req.model);
+
+    let filtered = config.map_ocr_params(&req.optional_params, &req.model);
+    let body = config
+        .transform_ocr_request(&req.model, &req.document, &filtered)
+        .map_err(OcrError::Transform)?;
+
+    Ok((url, headers, body))
+}
+
+/// Parse an upstream response body into the standard `OcrResponse`.
+pub fn parse_response(
+    config: &dyn BaseOcrConfig,
+    model: &str,
+    response_json: &Value,
+) -> Result<OcrResponse, OcrError> {
+    config
+        .transform_ocr_response(model, response_json)
+        .map_err(OcrError::Parse)
+}
+
+/// Perform a blocking Mistral OCR call end to end.
+///
+/// Used by the Python extension (called synchronously from Python).
+pub fn ocr_blocking(req: OcrRequest) -> Result<OcrResponse, OcrError> {
+    let config = MistralOcrConfig::new();
+    let (url, headers, body) = build_call(&config, &req)?;
+
+    let client = reqwest::blocking::Client::new();
+    let mut builder = client.post(&url).json(&body);
+    for (k, v) in &headers {
+        builder = builder.header(k, v);
+    }
+
+    let resp = builder
+        .send()
+        .map_err(|e| OcrError::Network(e.to_string()))?;
+
+    let status = resp.status();
+    let text = resp.text().map_err(|e| OcrError::Network(e.to_string()))?;
+
+    if !status.is_success() {
+        return Err(OcrError::Http {
+            status: status.as_u16(),
+            body: text,
+        });
+    }
+
+    let response_json: Value =
+        serde_json::from_str(&text).map_err(|e| OcrError::Parse(e.to_string()))?;
+
+    parse_response(&config, &req.model, &response_json)
+}