Patch PPLX streaming for timeouts (#3130)

Add in-text citations as well for PPLX token streaming
handle timeouts for stream/buffer hanging

server/utils/AiProviders/perplexity/index.js

+const { v4: uuidv4 } = require("uuid");
 const { NativeEmbedder } = require("../../EmbeddingEngines/native");
 const {
-  handleDefaultStreamResponseV2,
+  writeResponseChunk,
+  clientAbortedHandler,
 } = require("../../helpers/chat/responses");
 const {
   LLMPerformanceMonitor,
@@ -137,8 +139,137 @@ class PerplexityLLM {
     return measuredStreamRequest;
   }
 
+  enrichToken(token, citations) {
+    if (Array.isArray(citations) && citations.length !== 0) {
+      return token.replace(/\[(\d+)\]/g, (match, index) => {
+        const citationIndex = parseInt(index) - 1;
+        return citations[citationIndex]
+          ? `[[${index}](${citations[citationIndex]})]`
+          : match;
+      });
+    }
+    return token;
+  }
+
   handleStream(response, stream, responseProps) {
-    return handleDefaultStreamResponseV2(response, stream, responseProps);
+    const timeoutThresholdMs = 800;
+    const { uuid = uuidv4(), sources = [] } = responseProps;
+    let hasUsageMetrics = false;
+    let pplxCitations = []; // Array of links
+    let usage = {
+      completion_tokens: 0,
+    };
+
+    return new Promise(async (resolve) => {
+      let fullText = "";
+      let lastChunkTime = null;
+
+      const handleAbort = () => {
+        stream?.endMeasurement(usage);
+        clientAbortedHandler(resolve, fullText);
+      };
+      response.on("close", handleAbort);
+
+      const timeoutCheck = setInterval(() => {
+        if (lastChunkTime === null) return;
+
+        const now = Number(new Date());
+        const diffMs = now - lastChunkTime;
+        if (diffMs >= timeoutThresholdMs) {
+          console.log(
+            `Perplexity stream did not self-close and has been stale for >${timeoutThresholdMs}ms. Closing response stream.`
+          );
+          writeResponseChunk(response, {
+            uuid,
+            sources,
+            type: "textResponseChunk",
+            textResponse: "",
+            close: true,
+            error: false,
+          });
+          clearInterval(timeoutCheck);
+          response.removeListener("close", handleAbort);
+          stream?.endMeasurement(usage);
+          resolve(fullText);
+        }
+      }, 500);
+
+      // Now handle the chunks from the streamed response and append to fullText.
+      try {
+        for await (const chunk of stream) {
+          lastChunkTime = Number(new Date());
+          const message = chunk?.choices?.[0];
+          const token = message?.delta?.content;
+
+          if (Array.isArray(chunk.citations) && chunk.citations.length !== 0) {
+            pplxCitations = chunk.citations;
+          }
+
+          // If we see usage metrics in the chunk, we can use them directly
+          // instead of estimating them, but we only want to assign values if
+          // the response object is the exact same key:value pair we expect.
+          if (
+            chunk.hasOwnProperty("usage") && // exists
+            !!chunk.usage && // is not null
+            Object.values(chunk.usage).length > 0 // has values
+          ) {
+            if (chunk.usage.hasOwnProperty("prompt_tokens")) {
+              usage.prompt_tokens = Number(chunk.usage.prompt_tokens);
+            }
+
+            if (chunk.usage.hasOwnProperty("completion_tokens")) {
+              hasUsageMetrics = true; // to stop estimating counter
+              usage.completion_tokens = Number(chunk.usage.completion_tokens);
+            }
+          }
+
+          if (token) {
+            let enrichedToken = this.enrichToken(token, pplxCitations);
+            fullText += enrichedToken;
+            if (!hasUsageMetrics) usage.completion_tokens++;
+
+            writeResponseChunk(response, {
+              uuid,
+              sources: [],
+              type: "textResponseChunk",
+              textResponse: enrichedToken,
+              close: false,
+              error: false,
+            });
+          }
+
+          if (message?.finish_reason) {
+            console.log("closing");
+            writeResponseChunk(response, {
+              uuid,
+              sources,
+              type: "textResponseChunk",
+              textResponse: "",
+              close: true,
+              error: false,
+            });
+            response.removeListener("close", handleAbort);
+            stream?.endMeasurement(usage);
+            clearInterval(timeoutCheck);
+            resolve(fullText);
+            break; // Break streaming when a valid finish_reason is first encountered
+          }
+        }
+      } catch (e) {
+        console.log(`\x1b[43m\x1b[34m[STREAMING ERROR]\x1b[0m ${e.message}`);
+        writeResponseChunk(response, {
+          uuid,
+          type: "abort",
+          textResponse: null,
+          sources: [],
+          close: true,
+          error: e.message,
+        });
+        stream?.endMeasurement(usage);
+        clearInterval(timeoutCheck);
+        resolve(fullText); // Return what we currently have - if anything.
+      }
+    });
   }
 
   // Simple wrapper for dynamic embedder & normalize interface for all LLM implementations

server/utils/AiProviders/perplexity/models.js

 const MODELS = {
+  "sonar-reasoning-pro": {
+    id: "sonar-reasoning-pro",
+    name: "sonar-reasoning-pro",
+    maxLength: 127072,
+  },
+  "sonar-reasoning": {
+    id: "sonar-reasoning",
+    name: "sonar-reasoning",
+    maxLength: 127072,
+  },
   "sonar-pro": {
     id: "sonar-pro",
     name: "sonar-pro",

server/utils/AiProviders/perplexity/scripts/chat_models.txt

 | Model                               | Parameter Count | Context Length | Model Type      |
 | :---------------------------------- | :-------------- | :------------- | :-------------- |
+| `sonar-reasoning-pro` | 8B              | 127,072       | Chat Completion |
+| `sonar-reasoning` | 8B             | 127,072        | Chat Completion |
 | `sonar-pro` | 8B              | 200,000       | Chat Completion |
 | `sonar` | 8B             | 127,072        | Chat Completion |
\ No newline at end of file