From 11df83713e5c37a6d5ff0193efadc0bb7e007521 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Fri, 13 Mar 2026 12:36:07 +0900
Subject: [PATCH] refactor(preemptive-compaction): use shared context-limit
 resolver to eliminate duplicated logic

---
 .../preemptive-compaction.aws-bedrock.test.ts | 64 +++++++++++++++++++
 src/hooks/preemptive-compaction.ts            | 56 ++++++----------
 2 files changed, 82 insertions(+), 38 deletions(-)
 create mode 100644 src/hooks/preemptive-compaction.aws-bedrock.test.ts

diff --git a/src/hooks/preemptive-compaction.aws-bedrock.test.ts b/src/hooks/preemptive-compaction.aws-bedrock.test.ts
new file mode 100644
index 000000000..9ce47ac8c
--- /dev/null
+++ b/src/hooks/preemptive-compaction.aws-bedrock.test.ts
@@ -0,0 +1,64 @@
+/// <reference types="bun-types" />
+
+import { describe, expect, it, mock } from "bun:test"
+
+import { OhMyOpenCodeConfigSchema } from "../config"
+
+const { createPreemptiveCompactionHook } = await import("./preemptive-compaction")
+
+type HookContext = Parameters<typeof createPreemptiveCompactionHook>[0]
+
+function createMockContext(): HookContext {
+  return {
+    client: {
+      session: {
+        messages: mock(() => Promise.resolve({ data: [] })),
+        summarize: mock(() => Promise.resolve({})),
+      },
+      tui: {
+        showToast: mock(() => Promise.resolve()),
+      },
+    },
+    directory: "/tmp/test",
+  }
+}
+
+describe("preemptive-compaction aws-bedrock-anthropic", () => {
+  it("triggers compaction for aws-bedrock-anthropic provider when usage exceeds threshold", async () => {
+    // given
+    const ctx = createMockContext()
+    const pluginConfig = OhMyOpenCodeConfigSchema.parse({})
+    const hook = createPreemptiveCompactionHook(ctx, pluginConfig)
+    const sessionID = "ses_aws_bedrock_anthropic_high"
+
+    await hook.event({
+      event: {
+        type: "message.updated",
+        properties: {
+          info: {
+            role: "assistant",
+            sessionID,
+            providerID: "aws-bedrock-anthropic",
+            modelID: "claude-sonnet-4-6",
+            finish: true,
+            tokens: {
+              input: 170000,
+              output: 1000,
+              reasoning: 0,
+              cache: { read: 10000, write: 0 },
+            },
+          },
+        },
+      },
+    })
+
+    // when
+    await hook["tool.execute.after"](
+      { tool: "bash", sessionID, callID: "call_aws_bedrock_1" },
+      { title: "", output: "test", metadata: null },
+    )
+
+    // then
+    expect(ctx.client.session.summarize).toHaveBeenCalledTimes(1)
+  })
+})
diff --git a/src/hooks/preemptive-compaction.ts b/src/hooks/preemptive-compaction.ts
index b1b6c3bbf..b75679e40 100644
--- a/src/hooks/preemptive-compaction.ts
+++ b/src/hooks/preemptive-compaction.ts
@@ -1,23 +1,13 @@
 import { log } from "../shared/logger"
 import type { OhMyOpenCodeConfig } from "../config"
+import {
+  resolveActualContextLimit,
+  type ContextLimitModelCacheState,
+} from "../shared/context-limit-resolver"
 
 import { resolveCompactionModel } from "./shared/compaction-model-resolver"
-const DEFAULT_ACTUAL_LIMIT = 200_000
 const PREEMPTIVE_COMPACTION_TIMEOUT_MS = 120_000
 
-type ModelCacheStateLike = {
-  anthropicContext1MEnabled: boolean
-  modelContextLimitsCache?: Map<string, number>
-}
-
-function getAnthropicActualLimit(modelCacheState?: ModelCacheStateLike): number {
-  return (modelCacheState?.anthropicContext1MEnabled ?? false) ||
-    process.env.ANTHROPIC_1M_CONTEXT === "true" ||
-    process.env.VERTEX_ANTHROPIC_1M_CONTEXT === "true"
-    ? 1_000_000
-    : DEFAULT_ACTUAL_LIMIT
-}
-
 const PREEMPTIVE_COMPACTION_THRESHOLD = 0.78
 
 interface TokenInfo {
@@ -33,7 +23,7 @@ interface CachedCompactionState {
   tokens: TokenInfo
 }
 
-function withTimeout<TValue>(
+async function withTimeout<TValue>(
   promise: Promise<TValue>,
   timeoutMs: number,
   errorMessage: string,
@@ -46,17 +36,13 @@ function withTimeout<TValue>(
     }, timeoutMs)
   })
 
-  return Promise.race([promise, timeoutPromise]).finally(() => {
+  return await Promise.race([promise, timeoutPromise]).finally(() => {
     if (timeoutID !== undefined) {
       clearTimeout(timeoutID)
     }
   })
 }
 
-function isAnthropicProvider(providerID: string): boolean {
-  return providerID === "anthropic" || providerID === "google-vertex-anthropic"
-}
-
 type PluginInput = {
   client: {
     session: {
@@ -76,7 +62,7 @@ type PluginInput = {
 export function createPreemptiveCompactionHook(
   ctx: PluginInput,
   pluginConfig: OhMyOpenCodeConfig,
-  modelCacheState?: ModelCacheStateLike,
+  modelCacheState?: ContextLimitModelCacheState,
 ) {
   const compactionInProgress = new Set<string>()
   const compactedSessions = new Set<string>()
@@ -92,24 +78,18 @@ export function createPreemptiveCompactionHook(
     const cached = tokenCache.get(sessionID)
     if (!cached) return
 
-    const isAnthropic = isAnthropicProvider(cached.providerID)
-    const modelSpecificLimit = !isAnthropic
-      ? modelCacheState?.modelContextLimitsCache?.get(`${cached.providerID}/${cached.modelID}`)
-      : undefined
+    const actualLimit = resolveActualContextLimit(
+      cached.providerID,
+      cached.modelID,
+      modelCacheState,
+    )
 
-    let actualLimit: number
-    if (isAnthropic) {
-      actualLimit = getAnthropicActualLimit(modelCacheState)
-    } else {
-      if (modelSpecificLimit === undefined) {
-        log("[preemptive-compaction] Skipping preemptive compaction: unknown context limit for model", {
-          providerID: cached.providerID,
-          modelID: cached.modelID,
-        })
-        return
-      }
-
-      actualLimit = modelSpecificLimit
+    if (actualLimit === null) {
+      log("[preemptive-compaction] Skipping preemptive compaction: unknown context limit for model", {
+        providerID: cached.providerID,
+        modelID: cached.modelID,
+      })
+      return
     }
 
     const lastTokens = cached.tokens