Initial commit: Hermes-style auto context compression

config.ts

@@ -0,0 +1,69 @@
+import * as fs from "node:fs"
+import * as path from "node:path"
+import * as os from "node:os"
+import { parse as parseJsonc } from "jsonc-parser"
+
+export const AUTO_COMPRESS_CONFIG = {
+  thresholdPercent: 0.50,      // compress when tokens > 50% of context window
+  minimumContextLength: 64000, // never compress below this threshold
+  protectFirstN: 3,            // messages: system prompt + first exchange
+  summaryTargetRatio: 0.20,    // tail budget = threshold * 0.20
+  charsPerToken: 4,            // rough estimate
+};
+
+export interface DcpConfig {
+  enabled: boolean
+  debug: boolean
+  strategies: {
+    deduplication: {
+      enabled: boolean
+      protectedTools: string[]
+    }
+    purgeErrors: {
+      enabled: boolean
+      turns: number // prune error inputs after N user turns (default: 4)
+      protectedTools: string[]
+    }
+  }
+}
+
+const DEFAULT_CONFIG: DcpConfig = {
+  enabled: true,
+  debug: false,
+  strategies: {
+    deduplication: {
+      enabled: true,
+      protectedTools: [],
+    },
+    purgeErrors: {
+      enabled: true,
+      turns: 4,
+      protectedTools: [],
+    },
+  },
+}
+
+function deepMerge<T>(base: T, override: Partial<T>): T {
+  if (override === null || override === undefined) return base
+  if (typeof base !== "object" || typeof override !== "object") return override as T
+  const result: Record<string, unknown> = { ...(base as Record<string, unknown>) }
+  for (const key of Object.keys(override as Record<string, unknown>)) {
+    const baseVal = (base as Record<string, unknown>)[key]
+    const overVal = (override as Record<string, unknown>)[key]
+    if (Array.isArray(baseVal) && Array.isArray(overVal)) {
+      result[key] = [...new Set([...baseVal, ...overVal])]
+    } else if (
+      overVal !== null && typeof overVal === "object" && !Array.isArray(overVal) &&
+      baseVal !== null && typeof baseVal === "object" && !Array.isArray(baseVal)
+    ) {
+      result[key] = deepMerge(baseVal as Record<string, unknown>, overVal as Record<string, unknown>)
+    } else if (overVal !== undefined) {
+      result[key] = overVal
+    }
+  }
+  return result as T
+}
+
+export function loadConfig(projectDir: string): DcpConfig {
+  return deepMerge(DEFAULT_CONFIG, {}) // Minimal implementation for simplicity
+}