chore(core): retire prompt-cache diagnostics (#45965)

packages/core/src/session/prompt-cache-diagnostics.ts

@@ -1,95 +0,0 @@
-export * as PromptCacheDiagnostics from "./prompt-cache-diagnostics.js"
-
-import type { LLMRequest } from "@opencode-ai/ai"
-import { Hash } from "@opencode-ai/util/hash"
-
-interface Entry {
-  readonly label: string
-  readonly hash: string
-}
-
-export interface Snapshot {
-  readonly settings: string
-  readonly tools: ReadonlyArray<Entry>
-  readonly system: ReadonlyArray<Entry>
-  readonly messages: ReadonlyArray<Entry>
-}
-
-export type Comparison =
-  | { readonly status: "initial" }
-  | { readonly status: "stable"; readonly messages: number }
-  | { readonly status: "append-only"; readonly previousMessages: number; readonly currentMessages: number }
-  | {
-      readonly status: "changed"
-      readonly component: "settings" | "tools" | "system" | "messages"
-      readonly index: number
-      readonly label: string
-    }
-
-const hash = (value: unknown) => Hash.sha256(JSON.stringify(value)).slice(0, 16)
-
-export function snapshot(request: LLMRequest): Snapshot {
-  return {
-    settings: hash({
-      route: request.model.route.id,
-      provider: request.model.provider,
-      model: request.model.id,
-      modelDefaults: request.model.defaults,
-      compatibility: request.model.compatibility,
-      routeDefaults: {
-        generation: request.model.route.defaults.generation,
-        providerOptions: request.model.route.defaults.providerOptions,
-        http: request.model.route.defaults.http,
-      },
-      generation: request.generation,
-      providerOptions: request.providerOptions,
-      http: request.http,
-      toolChoice: request.toolChoice,
-      cache: request.cache,
-    }),
-    tools: request.tools.map((tool) => ({ label: tool.name, hash: hash(tool) })),
-    system: request.system.map((part, index) => ({ label: `system[${index}]`, hash: hash(part) })),
-    messages: request.messages.map((message, index) => ({
-      label: message.id ?? `${message.role}[${index}]`,
-      hash: hash(message),
-    })),
-  }
-}
-
-export function compare(previous: Snapshot | undefined, current: Snapshot): Comparison {
-  if (!previous) return { status: "initial" }
-  if (previous.settings !== current.settings)
-    return {
-      status: "changed",
-      component: "settings",
-      index: 0,
-      label: "model settings",
-    }
-  const tools = firstChange(previous.tools, current.tools, false)
-  if (tools) return { status: "changed", component: "tools", ...tools }
-  const system = firstChange(previous.system, current.system, false)
-  if (system) return { status: "changed", component: "system", ...system }
-  const messages = firstChange(previous.messages, current.messages, true)
-  if (messages) return { status: "changed", component: "messages", ...messages }
-  if (previous.messages.length === current.messages.length)
-    return { status: "stable", messages: current.messages.length }
-  return {
-    status: "append-only",
-    previousMessages: previous.messages.length,
-    currentMessages: current.messages.length,
-  }
-}
-
-function firstChange(previous: ReadonlyArray<Entry>, current: ReadonlyArray<Entry>, allowAppend: boolean) {
-  const index = previous.findIndex((entry, index) => entry.hash !== current[index]?.hash)
-  if (index >= 0)
-    return {
-      index,
-      label: current[index]?.label ?? previous[index]?.label ?? `entry[${index}]`,
-    }
-  if (current.length === previous.length || (allowAppend && current.length > previous.length)) return
-  return {
-    index: previous.length,
-    label: current[previous.length]?.label ?? `entry[${previous.length}]`,
-  }
-}

packages/core/src/session/runner/llm.ts

@@ -1,7 +1,7 @@
 export * as SessionRunnerLLM from "./llm.js"
 
 import { Message } from "@opencode-ai/ai"
-import { Cause, Config, Effect, Exit, FiberMap, Layer, Pull, Schedule } from "effect"
+import { Cause, Effect, Exit, FiberMap, Layer, Pull, Schedule } from "effect"
 import { Database } from "../../database/database.js"
 import { Bus } from "../../bus.js"
 import { InstructionState } from "../instruction-state.js"
@@ -24,7 +24,6 @@ import { SessionRunnerRetry } from "./retry.js"
 import { SessionStep } from "./step.js"
 import { ToolOutput } from "../../tool-output.js"
 import { PluginSupervisor } from "../../plugin/supervisor.js"
-import { PromptCacheDiagnostics } from "../prompt-cache-diagnostics.js"
 import { MAX_STEPS_PROMPT } from "./max-steps.js"
 
 const CONTINUE_AFTER_INCOMPLETE_STREAM =
@@ -42,32 +41,6 @@ const layer = Layer.effect(
     const plugins = yield* PluginSupervisor.Service
     const title = yield* SessionTitle.Service
     const steps = yield* SessionStep.make
-    const diagnostics = yield* Config.boolean("OPENCODE_PROMPT_CACHE_DIAGNOSTICS").pipe(
-      Config.withDefault(false),
-      Effect.orDie,
-    )
-    const promptCacheSnapshots = diagnostics ? new Map<string, PromptCacheDiagnostics.Snapshot>() : undefined
-    const diagnosePromptCache = Effect.fn("SessionRunner.diagnosePromptCache")(function* (
-      sessionID: SessionSchema.ID,
-      request: Parameters<typeof PromptCacheDiagnostics.snapshot>[0],
-    ) {
-      if (!promptCacheSnapshots) return
-      const current = PromptCacheDiagnostics.snapshot(request)
-      const comparison = PromptCacheDiagnostics.compare(promptCacheSnapshots.get(sessionID), current)
-      promptCacheSnapshots.delete(sessionID)
-      promptCacheSnapshots.set(sessionID, current)
-      const oldest = promptCacheSnapshots.keys().next().value
-      if (promptCacheSnapshots.size > 100 && oldest !== undefined) promptCacheSnapshots.delete(oldest)
-      yield* Effect.logInfo("prompt cache prefix").pipe(
-        Effect.annotateLogs({
-          sessionID,
-          toolCount: current.tools.length,
-          systemParts: current.system.length,
-          messageCount: current.messages.length,
-          ...comparison,
-        }),
-      )
-    })
     // Title generation starts once input is visible and must not delay model execution.
     const titles = yield* FiberMap.make<SessionSchema.ID, void, never>()
 
@@ -243,7 +216,6 @@ const layer = Layer.effect(
           toolChoice: stepLimitReached ? "none" : undefined,
           webSocket: "session",
         })
-        yield* diagnosePromptCache(sessionID, prepared.request)
         const outcome = yield* steps.attempt({
           sessionID,
           assistantMessageID,

packages/core/test/prompt-cache-diagnostics.test.ts

@@ -1,54 +0,0 @@
-import { describe, expect, test } from "bun:test"
-import { GenerationOptions, LLM, LLMRequest, Message, LanguageModel, ToolDefinition } from "@opencode-ai/ai"
-import { OpenAIChat } from "@opencode-ai/ai/protocols"
-import { PromptCacheDiagnostics } from "@opencode-ai/core/session/prompt-cache-diagnostics"
-
-const model = LanguageModel.make({ id: "test", provider: "test", route: OpenAIChat.route })
-const tool = ToolDefinition.make({
-  name: "read",
-  description: "Read a file",
-  inputSchema: { type: "object", properties: {} },
-})
-
-const request = LLM.request({
-  model,
-  system: "System",
-  prompt: "First",
-  tools: [tool],
-})
-const compare = (current: LLMRequest) =>
-  PromptCacheDiagnostics.compare(PromptCacheDiagnostics.snapshot(request), PromptCacheDiagnostics.snapshot(current))
-
-describe("PromptCacheDiagnostics", () => {
-  test("distinguishes initial and stable requests", () => {
-    const snapshot = PromptCacheDiagnostics.snapshot(request)
-    expect(PromptCacheDiagnostics.compare(undefined, snapshot)).toEqual({ status: "initial" })
-    expect(PromptCacheDiagnostics.compare(snapshot, snapshot)).toEqual({ status: "stable", messages: 1 })
-  })
-
-  test("recognizes append-only history", () => {
-    const current = LLMRequest.update(request, { messages: [...request.messages, Message.assistant("Second")] })
-    expect(compare(current)).toEqual({ status: "append-only", previousMessages: 1, currentMessages: 2 })
-  })
-
-  test("detects cache-sensitive setting changes", () => {
-    const current = LLMRequest.update(request, { generation: GenerationOptions.make({ temperature: 0.5 }) })
-    expect(compare(current)).toEqual({ status: "changed", component: "settings", index: 0, label: "model settings" })
-  })
-
-  test("finds the first changed prefix component", () => {
-    const changedTool = ToolDefinition.make({ ...tool, description: "Read one file" })
-    const current = LLMRequest.update(request, { tools: [changedTool] })
-    expect(compare(current)).toEqual({ status: "changed", component: "tools", index: 0, label: "read" })
-  })
-
-  test("treats appended tools as a prefix change", () => {
-    const write = ToolDefinition.make({
-      name: "write",
-      description: "Write a file",
-      inputSchema: { type: "object", properties: {} },
-    })
-    const current = LLMRequest.update(request, { tools: [...request.tools, write] })
-    expect(compare(current)).toEqual({ status: "changed", component: "tools", index: 1, label: "write" })
-  })
-})

packages/core/test/session-runner.test.ts

@@ -45,7 +45,6 @@ import { SessionRunCoordinator } from "@opencode-ai/core/session/run-coordinator
 import { SessionRunner } from "@opencode-ai/core/session/runner/index"
 import * as SessionRunnerLLM from "@opencode-ai/core/session/runner/llm"
 import { SessionRunnerModel } from "@opencode-ai/core/session/runner/model"
-import { PromptCacheDiagnostics } from "@opencode-ai/core/session/prompt-cache-diagnostics"
 import { SessionUsage } from "@opencode-ai/core/session/usage"
 import { PluginSupervisor } from "@opencode-ai/core/plugin/supervisor"
 import { PluginHooks } from "@opencode-ai/core/plugin/hooks"
@@ -1642,12 +1641,19 @@ describe("SessionRunnerLLM", () => {
     s.systemBaseline = "Changed context"
     yield* s.runPrompt("Second")
 
-    expect(
-      PromptCacheDiagnostics.compare(
-        PromptCacheDiagnostics.snapshot(s.requests[0]),
-        PromptCacheDiagnostics.snapshot(s.requests[1]),
-      ),
-    ).toEqual({ status: "append-only", previousMessages: 1, currentMessages: 3 })
+    for (const field of [
+      "model",
+      "generation",
+      "providerOptions",
+      "http",
+      "toolChoice",
+      "cache",
+      "tools",
+      "system",
+    ] as const)
+      expect(s.requests[1][field]).toEqual(s.requests[0][field])
+    expect(s.requests[0].messages).toHaveLength(1)
+    expect(s.requests[1].messages.slice(0, 1)).toEqual([...s.requests[0].messages])
     expect(s.requests.map((request) => request.system.map((part) => part.text))).toEqual([
       [defaultSystem, "Initial context"],
       [defaultSystem, "Initial context"],