feat: 添加 compact 缓存与上下文压缩增强

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/services/compact/cachedMicrocompact.ts

@@ -1,6 +1,3 @@
-// Auto-generated stub — replace with real implementation
-export {};
-
 export type CachedMCState = {
   registeredTools: Set<string>
   toolOrder: string[]
@@ -19,19 +16,97 @@ export type PinnedCacheEdits = {
   block: CacheEditsBlock
 }
 
-export const isCachedMicrocompactEnabled: () => boolean = () => false;
-export const isModelSupportedForCacheEditing: (model: string) => boolean = () => false;
-export const getCachedMCConfig: () => { triggerThreshold: number; keepRecent: number } = () => ({ triggerThreshold: 0, keepRecent: 0 });
-export const createCachedMCState: () => CachedMCState = () => ({
-  registeredTools: new Set(),
-  toolOrder: [],
-  deletedRefs: new Set(),
-  pinnedEdits: [],
-  toolsSentToAPI: false,
-});
-export const markToolsSentToAPI: (state: CachedMCState) => void = () => {};
-export const resetCachedMCState: (state: CachedMCState) => void = () => {};
-export const registerToolResult: (state: CachedMCState, toolId: string) => void = () => {};
-export const registerToolMessage: (state: CachedMCState, groupIds: string[]) => void = () => {};
-export const getToolResultsToDelete: (state: CachedMCState) => string[] = () => [];
-export const createCacheEditsBlock: (state: CachedMCState, toolIds: string[]) => CacheEditsBlock | null = () => null;
+const TRIGGER_THRESHOLD = 10
+const KEEP_RECENT = 5
+
+/**
+ * Returns true when the CLAUDE_CACHED_MICROCOMPACT env var is set to '1'
+ * or the feature is explicitly enabled.
+ */
+export function isCachedMicrocompactEnabled(): boolean {
+  return process.env.CLAUDE_CACHED_MICROCOMPACT === '1'
+}
+
+/**
+ * Returns true for Claude 4.x models that support cache_edits.
+ */
+export function isModelSupportedForCacheEditing(model: string): boolean {
+  return /claude-[a-z]+-4[-\d]/.test(model)
+}
+
+export function getCachedMCConfig(): {
+  triggerThreshold: number
+  keepRecent: number
+} {
+  return { triggerThreshold: TRIGGER_THRESHOLD, keepRecent: KEEP_RECENT }
+}
+
+export function createCachedMCState(): CachedMCState {
+  return {
+    registeredTools: new Set(),
+    toolOrder: [],
+    deletedRefs: new Set(),
+    pinnedEdits: [],
+    toolsSentToAPI: false,
+  }
+}
+
+export function markToolsSentToAPI(state: CachedMCState): void {
+  state.toolsSentToAPI = true
+}
+
+export function resetCachedMCState(state: CachedMCState): void {
+  state.registeredTools.clear()
+  state.toolOrder = []
+  state.deletedRefs.clear()
+  state.pinnedEdits = []
+  state.toolsSentToAPI = false
+}
+
+export function registerToolResult(state: CachedMCState, toolId: string): void {
+  if (!state.registeredTools.has(toolId)) {
+    state.registeredTools.add(toolId)
+    state.toolOrder.push(toolId)
+  }
+}
+
+export function registerToolMessage(
+  state: CachedMCState,
+  groupIds: string[],
+): void {
+  for (const id of groupIds) {
+    registerToolResult(state, id)
+  }
+}
+
+/**
+ * Returns the tool IDs that should be deleted (oldest first) to bring
+ * the count below the threshold, excluding already-deleted tools and
+ * the most recently seen ones.
+ */
+export function getToolResultsToDelete(state: CachedMCState): string[] {
+  const { triggerThreshold, keepRecent } = getCachedMCConfig()
+  const active = state.toolOrder.filter(id => !state.deletedRefs.has(id))
+  if (active.length <= triggerThreshold) return []
+  // Keep the last keepRecent tools
+  const toDelete = active.slice(0, active.length - keepRecent)
+  return toDelete
+}
+
+/**
+ * Creates a cache_edits block that deletes the given tool result IDs.
+ * Returns null if toolIds is empty.
+ */
+export function createCacheEditsBlock(
+  state: CachedMCState,
+  toolIds: string[],
+): CacheEditsBlock | null {
+  if (toolIds.length === 0) return null
+  return {
+    type: 'cache_edits',
+    edits: toolIds.map(id => ({
+      type: 'delete_tool_result',
+      tool_use_id: id,
+    })),
+  }
+}