Files
agentic-pd-hybrid/third_party/sglang/sgl-model-gateway/src/routers/grpc/harmony/streaming.rs

1218 lines
52 KiB
Rust

//! Harmony streaming response processor
use std::{
collections::{hash_map::Entry::Vacant, HashMap},
io,
sync::Arc,
time::Instant,
};
use axum::{body::Body, http::StatusCode, response::Response};
use bytes::Bytes;
use http::header::{HeaderValue, CONTENT_TYPE};
use serde_json::json;
use smg_grpc_client::sglang_proto::generate_complete::MatchedStop::{
MatchedStopStr, MatchedTokenId,
};
use tokio::sync::mpsc;
use tokio_stream::wrappers::UnboundedReceiverStream;
use tracing::{debug, error};
use super::{
processor::ResponsesIterationResult, types::HarmonyChannelDelta, HarmonyParserAdapter,
};
use crate::{
observability::metrics::{metrics_labels, Metrics, StreamingMetricsParams},
protocols::{
chat::{
ChatCompletionRequest, ChatCompletionStreamResponse, ChatMessageDelta, ChatStreamChoice,
},
common::{CompletionTokensDetails, FunctionCallDelta, ToolCall, ToolCallDelta, Usage},
responses::{
OutputTokensDetails, ResponseStatus, ResponseUsage, ResponsesResponse, ResponsesUsage,
},
},
routers::grpc::{
common::responses::streaming::{OutputItemType, ResponseStreamEventEmitter},
context,
proto_wrapper::{ProtoResponseVariant, ProtoStream},
},
};
/// Mode for tool call event emission
#[derive(Debug, Clone, Copy)]
enum ToolCallMode {
/// MCP tool calls (emit .in_progress and .completed events)
Mcp,
/// Function tool calls (no status events, only arguments streaming)
Function,
}
impl ToolCallMode {
/// Get the output item type for this mode
fn output_item_type(&self) -> OutputItemType {
match self {
Self::Mcp => OutputItemType::McpCall,
Self::Function => OutputItemType::FunctionCall,
}
}
/// Get the type string for JSON output
fn type_str(&self) -> &'static str {
match self {
Self::Mcp => "mcp_call",
Self::Function => "function_call",
}
}
/// Whether this mode emits status events (.in_progress, .completed)
fn emits_status_events(&self) -> bool {
matches!(self, Self::Mcp)
}
/// Emit arguments delta event
fn emit_arguments_delta(
&self,
emitter: &mut ResponseStreamEventEmitter,
output_index: usize,
item_id: &str,
delta: &str,
) -> serde_json::Value {
match self {
Self::Mcp => emitter.emit_mcp_call_arguments_delta(output_index, item_id, delta),
Self::Function => {
emitter.emit_function_call_arguments_delta(output_index, item_id, delta)
}
}
}
/// Emit arguments done event
fn emit_arguments_done(
&self,
emitter: &mut ResponseStreamEventEmitter,
output_index: usize,
item_id: &str,
arguments: &str,
) -> serde_json::Value {
match self {
Self::Mcp => emitter.emit_mcp_call_arguments_done(output_index, item_id, arguments),
Self::Function => {
emitter.emit_function_call_arguments_done(output_index, item_id, arguments)
}
}
}
}
/// Processor for streaming Harmony responses
///
/// Returns an SSE stream that parses Harmony tokens incrementally and
/// emits ChatCompletionChunk events for streaming responses.
pub(crate) struct HarmonyStreamingProcessor;
impl HarmonyStreamingProcessor {
/// Create a new Harmony streaming processor
pub fn new() -> Self {
Self
}
/// Process a streaming Harmony Chat Completion response
///
/// Returns an SSE response with streaming token updates.
///
/// Note: Caller should attach load guards to the returned response using
/// `WorkerLoadGuard::attach_to_response()` for proper RAII lifecycle management.
pub fn process_streaming_chat_response(
self: Arc<Self>,
execution_result: context::ExecutionResult,
chat_request: Arc<ChatCompletionRequest>,
dispatch: context::DispatchMetadata,
) -> Response {
// Create SSE channel
let (tx, rx) = mpsc::unbounded_channel::<Result<Bytes, io::Error>>();
// Spawn background task based on execution mode
match execution_result {
context::ExecutionResult::Single { stream } => {
tokio::spawn(async move {
let result =
Self::process_single_stream(stream, dispatch, chat_request, &tx).await;
if let Err(e) = result {
error!("Harmony streaming error: {}", e);
let error_chunk = format!(
"data: {}\n\n",
json!({
"error": {
"message": e,
"type": "internal_error"
}
})
);
let _ = tx.send(Ok(Bytes::from(error_chunk)));
}
let _ = tx.send(Ok(Bytes::from("data: [DONE]\n\n")));
});
}
context::ExecutionResult::Dual { prefill, decode } => {
tokio::spawn(async move {
let result =
Self::process_dual_stream(prefill, *decode, dispatch, chat_request, &tx)
.await;
if let Err(e) = result {
error!("Harmony dual streaming error: {}", e);
let error_chunk = format!(
"data: {}\n\n",
json!({
"error": {
"message": e,
"type": "internal_error"
}
})
);
let _ = tx.send(Ok(Bytes::from(error_chunk)));
}
let _ = tx.send(Ok(Bytes::from("data: [DONE]\n\n")));
});
}
context::ExecutionResult::Embedding { .. } => {
error!("Harmony streaming not supported for embeddings");
let error_chunk = format!(
"data: {}\n\n",
json!({
"error": {
"message": "Embeddings not supported in Harmony streaming",
"type": "invalid_request_error"
}
})
);
let _ = tx.send(Ok(Bytes::from(error_chunk)));
}
}
// Return SSE response
Self::build_sse_response(rx)
}
/// Process streaming chunks from a single stream
async fn process_single_stream(
mut grpc_stream: ProtoStream,
dispatch: context::DispatchMetadata,
original_request: Arc<ChatCompletionRequest>,
tx: &mpsc::UnboundedSender<Result<Bytes, io::Error>>,
) -> Result<(), String> {
// Timing for metrics
let start_time = Instant::now();
let mut first_token_time: Option<Instant> = None;
// Per-index state management (for n>1 support)
let mut parsers: HashMap<u32, HarmonyParserAdapter> = HashMap::new();
let mut is_firsts: HashMap<u32, bool> = HashMap::new();
let mut finish_reasons: HashMap<u32, Option<String>> = HashMap::new();
let mut matched_stops: HashMap<u32, Option<serde_json::Value>> = HashMap::new();
let mut prompt_tokens: HashMap<u32, u32> = HashMap::new();
let mut completion_tokens: HashMap<u32, u32> = HashMap::new();
let stream_options = &original_request.stream_options;
// Process stream
while let Some(result) = grpc_stream.next().await {
let response = result.map_err(|e| format!("Stream error: {}", e))?;
match response.into_response() {
ProtoResponseVariant::Chunk(chunk_wrapper) => {
let chunk = chunk_wrapper.as_sglang();
let index = chunk.index;
// Track first token time for TTFT metric
if first_token_time.is_none() {
first_token_time = Some(Instant::now());
}
// Initialize parser for this index if needed
if let Vacant(e) = parsers.entry(index) {
e.insert(
HarmonyParserAdapter::new()
.map_err(|e| format!("Failed to create parser: {}", e))?,
);
is_firsts.insert(index, true);
}
// Track token counts
*completion_tokens.entry(index).or_insert(0) += 1;
// Parse chunk via Harmony parser
let parser = parsers
.get_mut(&index)
.ok_or("Parser not found for index")?;
let delta_result = parser
.parse_chunk(&chunk.token_ids)
.map_err(|e| format!("Parse error: {}", e))?;
// Emit SSE event if there's a delta
if let Some(delta) = delta_result {
let is_first = is_firsts.get(&index).copied().unwrap_or(false);
Self::emit_chunk_delta(
&delta,
index,
is_first,
&dispatch,
&original_request,
tx,
)?;
if is_first {
is_firsts.insert(index, false);
}
}
}
ProtoResponseVariant::Complete(complete_wrapper) => {
let complete = complete_wrapper.as_sglang();
let index = complete.index;
// Store final metadata
finish_reasons.insert(index, Some(complete.finish_reason.clone()));
matched_stops.insert(
index,
complete.matched_stop.as_ref().map(|m| match m {
MatchedTokenId(id) => {
json!(id)
}
MatchedStopStr(s) => {
json!(s)
}
}),
);
prompt_tokens.insert(index, complete.prompt_tokens as u32);
*completion_tokens.entry(index).or_insert(0) =
complete.completion_tokens as u32;
// Finalize parser and emit final chunk
if let Some(parser) = parsers.get_mut(&index) {
let matched_stop = matched_stops.get(&index).and_then(|m| m.clone());
let final_output = parser
.finalize(complete.finish_reason.clone(), matched_stop.clone())
.map_err(|e| format!("Finalize error: {}", e))?;
Self::emit_final_chunk(
index,
&final_output.finish_reason,
final_output.matched_stop.as_ref(),
&dispatch,
&original_request,
tx,
)?;
}
}
ProtoResponseVariant::Error(error_wrapper) => {
return Err(format!("Server error: {}", error_wrapper.message()));
}
ProtoResponseVariant::None => {}
}
}
// Compute totals once for both usage chunk and metrics
let total_prompt: u32 = prompt_tokens.values().sum();
let total_completion: u32 = completion_tokens.values().sum();
// Emit final usage if requested
if let Some(true) = stream_options.as_ref().and_then(|so| so.include_usage) {
Self::emit_usage_chunk(
total_prompt,
total_completion,
&dispatch,
&original_request,
tx,
)?;
}
// Mark stream as completed successfully to prevent abort on drop
grpc_stream.mark_completed();
// Record streaming metrics
Metrics::record_streaming_metrics(StreamingMetricsParams {
router_type: metrics_labels::ROUTER_GRPC,
backend_type: metrics_labels::BACKEND_HARMONY,
model_id: &original_request.model,
endpoint: metrics_labels::ENDPOINT_CHAT,
ttft: first_token_time.map(|t| t.duration_since(start_time)),
generation_duration: start_time.elapsed(),
input_tokens: Some(total_prompt as u64),
output_tokens: total_completion as u64,
});
Ok(())
}
/// Process streaming chunks from dual streams (prefill + decode)
async fn process_dual_stream(
mut prefill_stream: ProtoStream,
mut decode_stream: ProtoStream,
dispatch: context::DispatchMetadata,
original_request: Arc<ChatCompletionRequest>,
tx: &mpsc::UnboundedSender<Result<Bytes, io::Error>>,
) -> Result<(), String> {
// Timing for metrics
let start_time = Instant::now();
let mut first_token_time: Option<Instant> = None;
// Phase 1: Process prefill stream (collect metadata)
let mut prompt_tokens: HashMap<u32, u32> = HashMap::new();
while let Some(result) = prefill_stream.next().await {
let response = result.map_err(|e| format!("Prefill stream error: {}", e))?;
if let ProtoResponseVariant::Complete(complete_wrapper) = response.into_response() {
let complete = complete_wrapper.as_sglang();
prompt_tokens.insert(complete.index, complete.prompt_tokens as u32);
}
}
// Phase 2: Process decode stream (same as single stream)
let mut parsers: HashMap<u32, HarmonyParserAdapter> = HashMap::new();
let mut is_firsts: HashMap<u32, bool> = HashMap::new();
let mut finish_reasons: HashMap<u32, Option<String>> = HashMap::new();
let mut matched_stops: HashMap<u32, Option<serde_json::Value>> = HashMap::new();
let mut completion_tokens: HashMap<u32, u32> = HashMap::new();
let stream_options = &original_request.stream_options;
while let Some(result) = decode_stream.next().await {
let response = result.map_err(|e| format!("Decode stream error: {}", e))?;
match response.into_response() {
ProtoResponseVariant::Chunk(chunk_wrapper) => {
let chunk = chunk_wrapper.as_sglang();
let index = chunk.index;
// Track first token time for TTFT metric
if first_token_time.is_none() {
first_token_time = Some(Instant::now());
}
// Initialize parser for this index if needed
if let Vacant(e) = parsers.entry(index) {
e.insert(
HarmonyParserAdapter::new()
.map_err(|e| format!("Failed to create parser: {}", e))?,
);
is_firsts.insert(index, true);
}
*completion_tokens.entry(index).or_insert(0) += 1;
let parser = parsers
.get_mut(&index)
.ok_or("Parser not found for index")?;
let delta_result = parser
.parse_chunk(&chunk.token_ids)
.map_err(|e| format!("Parse error: {}", e))?;
if let Some(delta) = delta_result {
let is_first = is_firsts.get(&index).copied().unwrap_or(false);
Self::emit_chunk_delta(
&delta,
index,
is_first,
&dispatch,
&original_request,
tx,
)?;
if is_first {
is_firsts.insert(index, false);
}
}
}
ProtoResponseVariant::Complete(complete_wrapper) => {
let complete = complete_wrapper.as_sglang();
let index = complete.index;
finish_reasons.insert(index, Some(complete.finish_reason.clone()));
matched_stops.insert(
index,
complete.matched_stop.as_ref().map(|m| match m {
MatchedTokenId(id) => {
json!(id)
}
MatchedStopStr(s) => {
json!(s)
}
}),
);
*completion_tokens.entry(index).or_insert(0) =
complete.completion_tokens as u32;
if let Some(parser) = parsers.get_mut(&index) {
let matched_stop = matched_stops.get(&index).and_then(|m| m.clone());
let final_output = parser
.finalize(complete.finish_reason.clone(), matched_stop.clone())
.map_err(|e| format!("Finalize error: {}", e))?;
Self::emit_final_chunk(
index,
&final_output.finish_reason,
final_output.matched_stop.as_ref(),
&dispatch,
&original_request,
tx,
)?;
}
}
ProtoResponseVariant::Error(error_wrapper) => {
return Err(format!("Server error: {}", error_wrapper.message()));
}
ProtoResponseVariant::None => {}
}
}
decode_stream.mark_completed();
// Mark prefill stream as completed AFTER decode completes successfully
// This ensures that if client disconnects during decode, BOTH streams send abort
prefill_stream.mark_completed();
// Compute totals once for both usage chunk and metrics
let total_prompt: u32 = prompt_tokens.values().sum();
let total_completion: u32 = completion_tokens.values().sum();
// Emit final usage if requested
if let Some(true) = stream_options.as_ref().and_then(|so| so.include_usage) {
Self::emit_usage_chunk(
total_prompt,
total_completion,
&dispatch,
&original_request,
tx,
)?;
}
// Record streaming metrics
Metrics::record_streaming_metrics(StreamingMetricsParams {
router_type: metrics_labels::ROUTER_GRPC,
backend_type: metrics_labels::BACKEND_HARMONY,
model_id: &original_request.model,
endpoint: metrics_labels::ENDPOINT_CHAT,
ttft: first_token_time.map(|t| t.duration_since(start_time)),
generation_duration: start_time.elapsed(),
input_tokens: Some(total_prompt as u64),
output_tokens: total_completion as u64,
});
Ok(())
}
/// Emit a chunk delta from Harmony channels
fn emit_chunk_delta(
delta: &HarmonyChannelDelta,
index: u32,
is_first: bool,
dispatch: &context::DispatchMetadata,
original_request: &ChatCompletionRequest,
tx: &mpsc::UnboundedSender<Result<Bytes, io::Error>>,
) -> Result<(), String> {
// On first chunk, emit role announcement separately
if is_first {
let role_chunk = ChatCompletionStreamResponse::builder(
&dispatch.request_id,
&original_request.model,
)
.created(dispatch.created)
.add_choice_role(index, "assistant")
.maybe_system_fingerprint(dispatch.weight_version.as_deref())
.build();
let chunk_json = serde_json::to_string(&role_chunk)
.map_err(|e| format!("JSON serialization error: {}", e))?;
let sse_data = format!("data: {}\n\n", chunk_json);
tx.send(Ok(Bytes::from(sse_data)))
.map_err(|_| "Failed to send role chunk".to_string())?;
}
// Emit content delta (role is always None for content chunks)
let chat_delta = ChatMessageDelta {
role: None,
content: delta.final_delta.clone(),
tool_calls: delta.commentary_delta.as_ref().map(|tc_delta| {
vec![ToolCallDelta {
index: tc_delta.index as u32,
id: tc_delta.id.clone(),
tool_type: tc_delta.id.as_ref().map(|_| "function".to_string()),
function: tc_delta.function.as_ref().map(|f| FunctionCallDelta {
name: f.name.clone(),
arguments: f.arguments.clone(),
}),
}]
}),
reasoning_content: delta.analysis_delta.clone(),
};
// Build and emit chunk
let chunk =
ChatCompletionStreamResponse::builder(&dispatch.request_id, &original_request.model)
.created(dispatch.created)
.add_choice(ChatStreamChoice {
index,
delta: chat_delta,
logprobs: None,
finish_reason: None,
matched_stop: None,
})
.maybe_system_fingerprint(dispatch.weight_version.as_deref())
.build();
let chunk_json = serde_json::to_string(&chunk)
.map_err(|e| format!("JSON serialization error: {}", e))?;
let sse_data = format!("data: {}\n\n", chunk_json);
tx.send(Ok(Bytes::from(sse_data)))
.map_err(|_| "Failed to send chunk".to_string())?;
Ok(())
}
/// Emit final chunk with finish_reason
fn emit_final_chunk(
index: u32,
finish_reason: &str,
matched_stop: Option<&serde_json::Value>,
dispatch: &context::DispatchMetadata,
original_request: &ChatCompletionRequest,
tx: &mpsc::UnboundedSender<Result<Bytes, io::Error>>,
) -> Result<(), String> {
let chunk =
ChatCompletionStreamResponse::builder(&dispatch.request_id, &original_request.model)
.created(dispatch.created)
.add_choice_finish_reason(index, finish_reason, matched_stop.cloned())
.maybe_system_fingerprint(dispatch.weight_version.as_deref())
.build();
let chunk_json = serde_json::to_string(&chunk)
.map_err(|e| format!("JSON serialization error: {}", e))?;
let sse_data = format!("data: {}\n\n", chunk_json);
tx.send(Ok(Bytes::from(sse_data)))
.map_err(|_| "Failed to send final chunk".to_string())?;
Ok(())
}
/// Emit usage chunk at the end
fn emit_usage_chunk(
prompt_tokens: u32,
completion_tokens: u32,
dispatch: &context::DispatchMetadata,
original_request: &ChatCompletionRequest,
tx: &mpsc::UnboundedSender<Result<Bytes, io::Error>>,
) -> Result<(), String> {
let usage_chunk =
ChatCompletionStreamResponse::builder(&dispatch.request_id, &original_request.model)
.created(dispatch.created)
.usage(Usage {
prompt_tokens,
completion_tokens,
total_tokens: prompt_tokens + completion_tokens,
completion_tokens_details: None,
})
.maybe_system_fingerprint(dispatch.weight_version.as_deref())
.build();
let chunk_json = serde_json::to_string(&usage_chunk)
.map_err(|e| format!("JSON serialization error: {}", e))?;
let sse_data = format!("data: {}\n\n", chunk_json);
tx.send(Ok(Bytes::from(sse_data)))
.map_err(|_| "Failed to send usage chunk".to_string())?;
Ok(())
}
/// Process streaming chunks for Responses API iteration
///
/// Emits correct event types based on tool names: mcp_call.* for MCP tools, function_call.* for function tools.
/// Pass empty HashSet for function-only tools, full MCP tool names for MCP-only, or subset for mixed.
pub async fn process_responses_iteration_stream(
execution_result: context::ExecutionResult,
emitter: &mut ResponseStreamEventEmitter,
tx: &mpsc::UnboundedSender<Result<Bytes, io::Error>>,
mcp_tool_names: &std::collections::HashSet<String>,
) -> Result<ResponsesIterationResult, String> {
match execution_result {
context::ExecutionResult::Single { stream } => {
debug!("Processing Responses API single stream mode");
Self::process_responses_single_stream_mixed(stream, emitter, tx, mcp_tool_names)
.await
}
context::ExecutionResult::Dual { prefill, decode } => {
debug!("Processing Responses API dual stream mode");
Self::process_responses_dual_stream_mixed(
prefill,
*decode,
emitter,
tx,
mcp_tool_names,
)
.await
}
context::ExecutionResult::Embedding { .. } => {
Err("Embeddings not supported in Responses API streaming".to_string())
}
}
}
/// Process streaming chunks from a single stream
async fn process_responses_single_stream_mixed(
grpc_stream: ProtoStream,
emitter: &mut ResponseStreamEventEmitter,
tx: &mpsc::UnboundedSender<Result<Bytes, io::Error>>,
mcp_tool_names: &std::collections::HashSet<String>,
) -> Result<ResponsesIterationResult, String> {
Self::process_decode_stream_with_tool_lookup(grpc_stream, emitter, tx, Some(mcp_tool_names))
.await
}
/// Process streaming chunks from dual streams
async fn process_responses_dual_stream_mixed(
mut prefill_stream: ProtoStream,
decode_stream: ProtoStream,
emitter: &mut ResponseStreamEventEmitter,
tx: &mpsc::UnboundedSender<Result<Bytes, io::Error>>,
mcp_tool_names: &std::collections::HashSet<String>,
) -> Result<ResponsesIterationResult, String> {
// Phase 1: Process prefill stream (collect metadata, no output)
while let Some(result) = prefill_stream.next().await {
let _response = result.map_err(|e| format!("Prefill stream error: {}", e))?;
}
// Phase 2: Process decode stream with per-tool mode detection
let result = Self::process_decode_stream_with_tool_lookup(
decode_stream,
emitter,
tx,
Some(mcp_tool_names),
)
.await;
// Mark prefill stream as completed AFTER decode completes successfully
// This ensures that if client disconnects during decode, BOTH streams send abort
prefill_stream.mark_completed();
result
}
/// Decode stream processing with optional per-tool mode lookup
///
/// If mcp_tool_names is Some, determines mode per-tool by checking tool name.
/// If mcp_tool_names is None, uses default MCP mode for all tools.
async fn process_decode_stream_with_tool_lookup(
mut decode_stream: ProtoStream,
emitter: &mut ResponseStreamEventEmitter,
tx: &mpsc::UnboundedSender<Result<Bytes, io::Error>>,
mcp_tool_names: Option<&std::collections::HashSet<String>>,
) -> Result<ResponsesIterationResult, String> {
// Initialize Harmony parser for this iteration
let mut parser =
HarmonyParserAdapter::new().map_err(|e| format!("Failed to create parser: {}", e))?;
// State tracking for channels
let mut has_analysis = false;
let mut accumulated_final_text = String::new();
let mut accumulated_tool_calls: Option<Vec<ToolCall>> = None;
// Track which items we've started
let mut has_emitted_reasoning = false;
let mut message_output_index: Option<usize> = None;
let mut message_item_id: Option<String> = None;
let mut has_emitted_content_part_added = false;
// Tool call tracking (call_index -> (output_index, item_id, mode))
// Mode is determined per-tool when mcp_tool_names is provided
let mut tool_call_tracking: HashMap<usize, (usize, String, ToolCallMode)> = HashMap::new();
// Metadata from Complete message
let mut finish_reason = String::from("stop");
let mut matched_stop: Option<serde_json::Value> = None;
let mut prompt_tokens: u32 = 0;
let mut completion_tokens: u32 = 0;
let mut reasoning_token_count: u32 = 0;
// Process stream
let mut chunk_count = 0;
while let Some(result) = decode_stream.next().await {
chunk_count += 1;
let response = result.map_err(|e| format!("Decode stream error: {}", e))?;
match response.into_response() {
ProtoResponseVariant::Chunk(chunk_wrapper) => {
let chunk = chunk_wrapper.as_sglang();
// Parse chunk via Harmony parser
let delta_result = parser
.parse_chunk(&chunk.token_ids)
.map_err(|e| format!("Parse error: {}", e))?;
// Emit SSE events if there's a delta
if let Some(delta) = delta_result {
// Analysis channel → Reasoning item (wrapper events only, emitted once)
if let Some(_analysis_text) = &delta.analysis_delta {
if !has_emitted_reasoning {
// Emit reasoning item (added + done in one call)
// Note: reasoning_content will be provided at finalize
emitter
.emit_reasoning_item(tx, None)
.map_err(|e| format!("Failed to emit reasoning item: {}", e))?;
has_emitted_reasoning = true;
has_analysis = true;
}
}
// Final channel → Message item (WITH text streaming)
if let Some(final_delta) = &delta.final_delta {
if !final_delta.is_empty() {
// Allocate message item if needed
if message_output_index.is_none() {
let (output_index, item_id) =
emitter.allocate_output_index(OutputItemType::Message);
message_output_index = Some(output_index);
message_item_id = Some(item_id.clone());
// Build message item structure
let item = json!({
"id": item_id,
"type": "message",
"role": "assistant",
"content": []
});
// Emit output_item.added
let event = emitter.emit_output_item_added(output_index, &item);
emitter.send_event_best_effort(&event, tx);
}
let output_index = message_output_index.unwrap();
let item_id = message_item_id.as_ref().unwrap();
let content_index = 0; // Single content part
// Emit content_part.added before first delta
if !has_emitted_content_part_added {
let event = emitter.emit_content_part_added(
output_index,
item_id,
content_index,
);
emitter.send_event_best_effort(&event, tx);
has_emitted_content_part_added = true;
}
// Emit text delta
let event = emitter.emit_text_delta(
final_delta,
output_index,
item_id,
content_index,
);
emitter.send_event_best_effort(&event, tx);
accumulated_final_text.push_str(final_delta);
}
}
// Commentary channel → Tool call streaming
if let Some(tc_delta) = &delta.commentary_delta {
let call_index = tc_delta.index;
// Check if this is a new tool call (has id and name)
if let Some(call_id) = &tc_delta.id {
// Get tool name first to determine mode
let tool_name = tc_delta
.function
.as_ref()
.and_then(|f| f.name.as_ref())
.map(|n| n.as_str())
.unwrap_or("");
// Determine mode for this specific tool call
let tool_mode = if let Some(mcp_names) = mcp_tool_names {
// Mixed mode: check if tool is MCP
if mcp_names.contains(tool_name) {
ToolCallMode::Mcp
} else {
ToolCallMode::Function
}
} else {
// Single mode: use MCP (legacy behavior)
ToolCallMode::Mcp
};
// NEW TOOL CALL: Allocate output item
let (output_index, item_id) =
emitter.allocate_output_index(tool_mode.output_item_type());
// Store tracking info with mode
tool_call_tracking
.insert(call_index, (output_index, item_id.clone(), tool_mode));
// Emit output_item.added wrapper event
let mut item = json!({
"id": item_id,
"type": tool_mode.type_str(),
"name": tool_name,
"call_id": call_id,
"arguments": "",
"status": "in_progress"
});
// Add server_label for MCP calls
if tool_mode.emits_status_events() {
if let Some(ref server_label) = emitter.mcp_server_label {
item["server_label"] = json!(server_label);
}
}
let event = emitter.emit_output_item_added(output_index, &item);
emitter.send_event_best_effort(&event, tx);
// Emit status event if mode supports it (MCP only)
if tool_mode.emits_status_events() {
let event =
emitter.emit_mcp_call_in_progress(output_index, &item_id);
emitter.send_event_best_effort(&event, tx);
}
// If we have function name, emit initial arguments delta
if let Some(func) = &tc_delta.function {
if func.name.is_some() {
let event = tool_mode.emit_arguments_delta(
emitter,
output_index,
&item_id,
"",
);
emitter.send_event_best_effort(&event, tx);
}
}
} else {
// CONTINUING TOOL CALL: Emit arguments delta
if let Some((output_index, item_id, tool_mode)) =
tool_call_tracking.get(&call_index)
{
if let Some(args) = tc_delta
.function
.as_ref()
.and_then(|f| f.arguments.as_ref())
.filter(|a| !a.is_empty())
{
let event = tool_mode.emit_arguments_delta(
emitter,
*output_index,
item_id,
args,
);
emitter.send_event_best_effort(&event, tx);
}
}
}
}
}
}
ProtoResponseVariant::Complete(complete_wrapper) => {
let complete = complete_wrapper.as_sglang();
// Store final metadata
finish_reason = complete.finish_reason.clone();
matched_stop = complete.matched_stop.as_ref().map(|m| match m {
MatchedTokenId(id) => {
json!(id)
}
MatchedStopStr(s) => {
json!(s)
}
});
prompt_tokens = complete.prompt_tokens as u32;
completion_tokens = complete.completion_tokens as u32;
// Finalize parser and get complete output
let final_output = parser
.finalize(finish_reason.clone(), matched_stop.clone())
.map_err(|e| format!("Finalize error: {}", e))?;
// Store finalized tool calls and reasoning token count
accumulated_tool_calls = final_output.commentary.clone();
reasoning_token_count = final_output.reasoning_token_count;
// Complete all tool calls if we have commentary
if let Some(ref tool_calls) = accumulated_tool_calls {
for (call_idx, tool_call) in tool_calls.iter().enumerate() {
if let Some((output_index, item_id, tool_mode)) =
tool_call_tracking.get(&call_idx)
{
let tool_name = &tool_call.function.name;
// Emit arguments done with final arguments
let args_str =
tool_call.function.arguments.as_deref().unwrap_or("");
let event = tool_mode.emit_arguments_done(
emitter,
*output_index,
item_id,
args_str,
);
emitter.send_event_best_effort(&event, tx);
// Emit status event if mode supports it (MCP only)
if tool_mode.emits_status_events() {
let event =
emitter.emit_mcp_call_completed(*output_index, item_id);
emitter.send_event_best_effort(&event, tx);
}
// Emit output_item.done wrapper event
let mut item = json!({
"id": item_id,
"type": tool_mode.type_str(),
"name": tool_name,
"call_id": &tool_call.id,
"arguments": args_str,
"status": "completed"
});
// Add server_label for MCP calls
if tool_mode.emits_status_events() {
// MCP mode - include server_label
if let Some(ref server_label) = emitter.mcp_server_label {
item["server_label"] = json!(server_label);
}
}
let event = emitter.emit_output_item_done(*output_index, &item);
// Mark output item as completed before sending
emitter.complete_output_item(*output_index);
emitter.send_event_best_effort(&event, tx);
}
}
}
// Close message item if we opened one
if let Some(output_index) = message_output_index {
let item_id = message_item_id.as_ref().unwrap();
let content_index = 0;
// Emit text_done
let event = emitter.emit_text_done(output_index, item_id, content_index);
emitter.send_event_best_effort(&event, tx);
// Emit content_part.done
let event =
emitter.emit_content_part_done(output_index, item_id, content_index);
emitter.send_event_best_effort(&event, tx);
// Emit output_item.done
let item = json!({
"id": item_id,
"type": "message",
"role": "assistant",
"content": [{
"type": "text",
"text": accumulated_final_text.clone()
}]
});
let event = emitter.emit_output_item_done(output_index, &item);
// Mark as completed before sending (so it's included in final output even if send fails)
emitter.complete_output_item(output_index);
emitter.send_event_best_effort(&event, tx);
}
}
ProtoResponseVariant::Error(error_wrapper) => {
return Err(format!("Server error: {}", error_wrapper.message()));
}
ProtoResponseVariant::None => {}
}
}
debug!(
"Stream loop ended. Total chunks received: {}, has_analysis: {}, tool_calls: {}, final_text_len: {}",
chunk_count,
has_analysis,
accumulated_tool_calls.as_ref().map(|tc| tc.len()).unwrap_or(0),
accumulated_final_text.len()
);
// Extract tool calls from completed messages or incomplete commentary
if chunk_count > 0 && accumulated_tool_calls.is_none() {
let messages = parser.get_messages();
// Try extracting from completed messages first
let (analysis_opt, commentary_opt, final_text_extracted) =
HarmonyParserAdapter::parse_messages(&messages);
accumulated_tool_calls = commentary_opt.clone();
// If no tool calls found, check for incomplete commentary in parser state
if accumulated_tool_calls.is_none() {
accumulated_tool_calls = parser.extract_incomplete_commentary();
}
debug!(
"Tool call extraction: completed_msgs={}, tool_calls={}, has_analysis={}, final_text_len={}",
messages.len(),
accumulated_tool_calls.as_ref().map(|tc| tc.len()).unwrap_or(0),
analysis_opt.is_some(),
final_text_extracted.len()
);
// Complete any pending tool calls with data from completed messages
if let Some(ref tool_calls) = accumulated_tool_calls {
for (call_idx, tool_call) in tool_calls.iter().enumerate() {
if let Some((output_index, item_id, tool_mode)) =
tool_call_tracking.get(&call_idx)
{
let tool_name = &tool_call.function.name;
// Emit arguments done with final arguments
let args_str = tool_call.function.arguments.as_deref().unwrap_or("");
let event = tool_mode.emit_arguments_done(
emitter,
*output_index,
item_id,
args_str,
);
emitter.send_event_best_effort(&event, tx);
// Emit status event if mode supports it (MCP only)
if tool_mode.emits_status_events() {
let event = emitter.emit_mcp_call_completed(*output_index, item_id);
emitter.send_event_best_effort(&event, tx);
}
// Emit output_item.done wrapper event
let mut item = json!({
"id": item_id,
"type": tool_mode.type_str(),
"name": tool_name,
"call_id": &tool_call.id,
"arguments": args_str,
"status": "completed"
});
// Add server_label for MCP calls
if tool_mode.emits_status_events() {
if let Some(ref server_label) = emitter.mcp_server_label {
item["server_label"] = json!(server_label);
}
}
let event = emitter.emit_output_item_done(*output_index, &item);
// Mark output item as completed before sending
emitter.complete_output_item(*output_index);
emitter.send_event_best_effort(&event, tx);
}
}
}
}
// Mark stream as completed successfully to prevent abort on drop
decode_stream.mark_completed();
// Return result based on whether tool calls were found
if let Some(tool_calls) = accumulated_tool_calls {
if !tool_calls.is_empty() {
let analysis_content = if has_analysis {
// Get analysis from finalized parser output by calling finalize again
// This is safe because finalize can be called multiple times
let output = parser.finalize(finish_reason.clone(), matched_stop.clone())?;
output.analysis
} else {
None
};
return Ok(ResponsesIterationResult::ToolCallsFound {
tool_calls,
analysis: analysis_content,
partial_text: accumulated_final_text,
usage: Usage {
prompt_tokens,
completion_tokens,
total_tokens: prompt_tokens + completion_tokens,
completion_tokens_details: if reasoning_token_count > 0 {
Some(CompletionTokensDetails {
reasoning_tokens: Some(reasoning_token_count),
})
} else {
None
},
},
request_id: emitter.response_id.clone(),
});
}
}
// For streaming, we don't build the full ResponsesResponse here
// The caller will build it from the SSE events
// Return a placeholder Completed result (caller ignores these fields in streaming mode)
Ok(ResponsesIterationResult::Completed {
response: Box::new(
ResponsesResponse::builder(&emitter.response_id, "")
.status(ResponseStatus::Completed)
.usage(ResponsesUsage::Modern(ResponseUsage {
input_tokens: prompt_tokens,
output_tokens: completion_tokens,
total_tokens: prompt_tokens + completion_tokens,
input_tokens_details: None,
output_tokens_details: if reasoning_token_count > 0 {
Some(OutputTokensDetails {
reasoning_tokens: reasoning_token_count,
})
} else {
None
},
}))
.build(),
),
usage: Usage {
prompt_tokens,
completion_tokens,
total_tokens: prompt_tokens + completion_tokens,
completion_tokens_details: if reasoning_token_count > 0 {
Some(CompletionTokensDetails {
reasoning_tokens: Some(reasoning_token_count),
})
} else {
None
},
},
})
}
/// Build SSE response from receiver
fn build_sse_response(rx: mpsc::UnboundedReceiver<Result<Bytes, io::Error>>) -> Response {
let stream = UnboundedReceiverStream::new(rx);
let body = Body::from_stream(stream);
Response::builder()
.status(StatusCode::OK)
.header(
CONTENT_TYPE,
HeaderValue::from_static("text/event-stream; charset=utf-8"),
)
.header("Cache-Control", HeaderValue::from_static("no-cache"))
.header("Connection", HeaderValue::from_static("keep-alive"))
.body(body)
.unwrap()
}
}
impl Default for HarmonyStreamingProcessor {
fn default() -> Self {
Self::new()
}
}