Feature : RTK compress

open-sse/rtk/index.js

@@ -0,0 +1,102 @@
+// RTK port: compress tool_result content in LLM request bodies
+// Injected at the top of translateRequest (before any format translation)
+import { RAW_CAP, MIN_COMPRESS_SIZE } from "./constants.js";
+import { autoDetectFilter } from "./autodetect.js";
+import { safeApply } from "./applyFilter.js";
+import { isRtkEnabled } from "./flag.js";
+
+export { isRtkEnabled, setRtkEnabled } from "./flag.js";
+
+// Compress tool_result content in-place. Returns stats or null if disabled/failed.
+export function compressMessages(body) {
+  if (!isRtkEnabled()) return null;
+  if (!body || !Array.isArray(body.messages)) return null;
+
+  const stats = { bytesBefore: 0, bytesAfter: 0, hits: [] };
+  try {
+    for (let i = 0; i < body.messages.length; i++) {
+      const msg = body.messages[i];
+      if (!msg) continue;
+
+      // Shape 1: OpenAI tool message — { role:"tool", content: "string" }
+      if (msg.role === "tool" && typeof msg.content === "string") {
+        msg.content = compressText(msg.content, stats, "openai-tool");
+        continue;
+      }
+
+      if (!Array.isArray(msg.content)) continue;
+
+      // Shape 1b: OpenAI tool message — { role:"tool", content:[{type:"text", text:"..."}] }
+      if (msg.role === "tool") {
+        for (let k = 0; k < msg.content.length; k++) {
+          const part = msg.content[k];
+          if (part && part.type === "text" && typeof part.text === "string") {
+            part.text = compressText(part.text, stats, "openai-tool-array");
+          }
+        }
+        continue;
+      }
+
+      // Shape 2/3: blocks array with tool_result entries
+      for (let j = 0; j < msg.content.length; j++) {
+        const block = msg.content[j];
+        if (!block || block.type !== "tool_result") continue;
+        if (block.is_error === true) continue; // preserve error traces
+
+        if (typeof block.content === "string") {
+          // Shape 2: claude string form
+          block.content = compressText(block.content, stats, "claude-string");
+        } else if (Array.isArray(block.content)) {
+          // Shape 3: claude array form — compress each text part
+          for (let k = 0; k < block.content.length; k++) {
+            const part = block.content[k];
+            if (part && part.type === "text" && typeof part.text === "string") {
+              part.text = compressText(part.text, stats, "claude-array");
+            }
+          }
+        }
+      }
+    }
+  } catch (e) {
+    console.warn("[RTK] compressMessages error:", e.message);
+    return null;
+  }
+  return stats;
+}
+
+function compressText(text, stats, shape) {
+  const bytesIn = text.length;
+  stats.bytesBefore += bytesIn;
+
+  if (bytesIn < MIN_COMPRESS_SIZE || bytesIn > RAW_CAP) {
+    stats.bytesAfter += bytesIn;
+    return text;
+  }
+
+  const fn = autoDetectFilter(text);
+  if (!fn) {
+    stats.bytesAfter += bytesIn;
+    return text;
+  }
+
+  const out = safeApply(fn, text);
+
+  // Safety: never return empty, never grow the input
+  if (!out || out.length === 0 || out.length >= bytesIn) {
+    stats.bytesAfter += bytesIn;
+    return text;
+  }
+
+  stats.bytesAfter += out.length;
+  stats.hits.push({ shape, filter: fn.filterName || fn.name, saved: bytesIn - out.length });
+  return out;
+}
+
+// Convenience: format a log line from stats
+export function formatRtkLog(stats) {
+  if (!stats || !stats.hits || stats.hits.length === 0) return null;
+  const saved = stats.bytesBefore - stats.bytesAfter;
+  const pct = stats.bytesBefore > 0 ? ((saved / stats.bytesBefore) * 100).toFixed(1) : "0";
+  const filters = Array.from(new Set(stats.hits.map(h => h.filter))).join(",");
+  return `[RTK] saved ${saved}B / ${stats.bytesBefore}B (${pct}%) via [${filters}] hits=${stats.hits.length}`;
+}