support deepseek-v3-20250324

src/utils/stream.ts

@@ -0,0 +1,268 @@
+import { Response } from "express";
+import { OpenAI } from "openai";
+
+interface ContentBlock {
+  type: string;
+  id?: string;
+  name?: string;
+  input?: any;
+  text?: string;
+}
+
+interface MessageEvent {
+  type: string;
+  message?: {
+    id: string;
+    type: string;
+    role: string;
+    content: any[];
+    model: string;
+    stop_reason: string | null;
+    stop_sequence: string | null;
+    usage: {
+      input_tokens: number;
+      output_tokens: number;
+    };
+  };
+  delta?: {
+    stop_reason?: string;
+    stop_sequence?: string | null;
+    content?: ContentBlock[];
+    type?: string;
+    text?: string;
+    partial_json?: string;
+  };
+  index?: number;
+  content_block?: ContentBlock;
+  usage?: {
+    input_tokens: number;
+    output_tokens: number;
+  };
+}
+
+export async function streamOpenAIResponse(
+  res: Response,
+  completion: AsyncIterable<OpenAI.Chat.Completions.ChatCompletionChunk>,
+  model: string
+) {
+  const messageId = "msg_" + Date.now();
+  let contentBlockIndex = 0;
+  let currentContentBlocks: ContentBlock[] = [];
+
+  // Send message_start event
+  const messageStart: MessageEvent = {
+    type: "message_start",
+    message: {
+      id: messageId,
+      type: "message",
+      role: "assistant",
+      content: [],
+      model,
+      stop_reason: null,
+      stop_sequence: null,
+      usage: { input_tokens: 1, output_tokens: 1 },
+    },
+  };
+  res.write(`event: message_start\ndata: ${JSON.stringify(messageStart)}\n\n`);
+
+  let isToolUse = false;
+  let toolUseJson = "";
+  let hasStartedTextBlock = false;
+
+  try {
+    for await (const chunk of completion) {
+      const delta = chunk.choices[0].delta;
+
+      if (delta.tool_calls && delta.tool_calls.length > 0) {
+        const toolCall = delta.tool_calls[0];
+
+        if (!isToolUse) {
+          // Start new tool call block
+          isToolUse = true;
+          const toolBlock: ContentBlock = {
+            type: "tool_use",
+            id: `toolu_${Date.now()}`,
+            name: toolCall.function?.name,
+            input: {},
+          };
+
+          const toolBlockStart: MessageEvent = {
+            type: "content_block_start",
+            index: contentBlockIndex,
+            content_block: toolBlock,
+          };
+
+          currentContentBlocks.push(toolBlock);
+
+          res.write(
+            `event: content_block_start\ndata: ${JSON.stringify(
+              toolBlockStart
+            )}\n\n`
+          );
+          toolUseJson = "";
+        }
+
+        // Stream tool call JSON
+        if (toolCall.function?.arguments) {
+          const jsonDelta: MessageEvent = {
+            type: "content_block_delta",
+            index: contentBlockIndex,
+            delta: {
+              type: "input_json_delta",
+              partial_json: toolCall.function?.arguments,
+            },
+          };
+
+          toolUseJson += toolCall.function.arguments;
+
+          try {
+            const parsedJson = JSON.parse(toolUseJson);
+            currentContentBlocks[contentBlockIndex].input = parsedJson;
+          } catch (e) {
+            // JSON not yet complete, continue accumulating
+          }
+
+          res.write(
+            `event: content_block_delta\ndata: ${JSON.stringify(jsonDelta)}\n\n`
+          );
+        }
+      } else if (delta.content) {
+        // Handle regular text content
+        if (isToolUse) {
+          // End previous tool call block
+          const contentBlockStop: MessageEvent = {
+            type: "content_block_stop",
+            index: contentBlockIndex,
+          };
+
+          res.write(
+            `event: content_block_stop\ndata: ${JSON.stringify(
+              contentBlockStop
+            )}\n\n`
+          );
+          contentBlockIndex++;
+          isToolUse = false;
+        }
+
+        if (!delta.content) continue;
+
+        // If text block not yet started, send content_block_start
+        if (!hasStartedTextBlock) {
+          const textBlock: ContentBlock = {
+            type: "text",
+            text: "",
+          };
+
+          const textBlockStart: MessageEvent = {
+            type: "content_block_start",
+            index: contentBlockIndex,
+            content_block: textBlock,
+          };
+
+          currentContentBlocks.push(textBlock);
+
+          res.write(
+            `event: content_block_start\ndata: ${JSON.stringify(
+              textBlockStart
+            )}\n\n`
+          );
+          hasStartedTextBlock = true;
+        }
+
+        // Send regular text content
+        const contentDelta: MessageEvent = {
+          type: "content_block_delta",
+          index: contentBlockIndex,
+          delta: {
+            type: "text_delta",
+            text: delta.content,
+          },
+        };
+
+        // Update content block text
+        if (currentContentBlocks[contentBlockIndex]) {
+          currentContentBlocks[contentBlockIndex].text += delta.content;
+        }
+
+        res.write(
+          `event: content_block_delta\ndata: ${JSON.stringify(
+            contentDelta
+          )}\n\n`
+        );
+      }
+    }
+  } catch (e: any) {
+    // If text block not yet started, send content_block_start
+    if (!hasStartedTextBlock) {
+      const textBlock: ContentBlock = {
+        type: "text",
+        text: "",
+      };
+
+      const textBlockStart: MessageEvent = {
+        type: "content_block_start",
+        index: contentBlockIndex,
+        content_block: textBlock,
+      };
+
+      currentContentBlocks.push(textBlock);
+
+      res.write(
+        `event: content_block_start\ndata: ${JSON.stringify(
+          textBlockStart
+        )}\n\n`
+      );
+      hasStartedTextBlock = true;
+    }
+
+    // Send regular text content
+    const contentDelta: MessageEvent = {
+      type: "content_block_delta",
+      index: contentBlockIndex,
+      delta: {
+        type: "text_delta",
+        text: JSON.stringify(e),
+      },
+    };
+
+    // Update content block text
+    if (currentContentBlocks[contentBlockIndex]) {
+      currentContentBlocks[contentBlockIndex].text += JSON.stringify(e);
+    }
+
+    res.write(
+      `event: content_block_delta\ndata: ${JSON.stringify(contentDelta)}\n\n`
+    );
+  }
+
+  // Close last content block
+  const contentBlockStop: MessageEvent = {
+    type: "content_block_stop",
+    index: contentBlockIndex,
+  };
+
+  res.write(
+    `event: content_block_stop\ndata: ${JSON.stringify(contentBlockStop)}\n\n`
+  );
+
+  // Send message_delta event with appropriate stop_reason
+  const messageDelta: MessageEvent = {
+    type: "message_delta",
+    delta: {
+      stop_reason: isToolUse ? "tool_use" : "end_turn",
+      stop_sequence: null,
+      content: currentContentBlocks,
+    },
+    usage: { input_tokens: 100, output_tokens: 150 },
+  };
+
+  res.write(`event: message_delta\ndata: ${JSON.stringify(messageDelta)}\n\n`);
+
+  // Send message_stop event
+  const messageStop: MessageEvent = {
+    type: "message_stop",
+  };
+
+  res.write(`event: message_stop\ndata: ${JSON.stringify(messageStop)}\n\n`);
+  res.end();
+}