fix: compression tool (#935)

This commit is contained in:
tanzhenxin
2025-10-31 18:09:08 +08:00
committed by GitHub
parent 5386099559
commit ea4a7a2368
8 changed files with 749 additions and 245 deletions

View File

@@ -16,11 +16,11 @@ import {
import type { Content, GenerateContentResponse, Part } from '@google/genai';
import {
findCompressSplitPoint,
isThinkingDefault,
isThinkingSupported,
GeminiClient,
} from './client.js';
import { findCompressSplitPoint } from '../services/chatCompressionService.js';
import {
AuthType,
type ContentGenerator,
@@ -42,7 +42,6 @@ import { setSimulate429 } from '../utils/testUtils.js';
import { tokenLimit } from './tokenLimits.js';
import { ideContextStore } from '../ide/ideContext.js';
import { uiTelemetryService } from '../telemetry/uiTelemetry.js';
import { QwenLogger } from '../telemetry/index.js';
// Mock fs module to prevent actual file system operations during tests
const mockFileSystem = new Map<string, string>();
@@ -101,6 +100,22 @@ vi.mock('../utils/errorReporting', () => ({ reportError: vi.fn() }));
vi.mock('../utils/nextSpeakerChecker', () => ({
checkNextSpeaker: vi.fn().mockResolvedValue(null),
}));
vi.mock('../utils/environmentContext', () => ({
getEnvironmentContext: vi
.fn()
.mockResolvedValue([{ text: 'Mocked env context' }]),
getInitialChatHistory: vi.fn(async (_config, extraHistory) => [
{
role: 'user',
parts: [{ text: 'Mocked env context' }],
},
{
role: 'model',
parts: [{ text: 'Got it. Thanks for the context!' }],
},
...(extraHistory ?? []),
]),
}));
vi.mock('../utils/generateContentResponseUtilities', () => ({
getResponseText: (result: GenerateContentResponse) =>
result.candidates?.[0]?.content?.parts?.map((part) => part.text).join('') ||
@@ -136,6 +151,10 @@ vi.mock('../ide/ideContext.js');
vi.mock('../telemetry/uiTelemetry.js', () => ({
uiTelemetryService: mockUiTelemetryService,
}));
vi.mock('../telemetry/loggers.js', () => ({
logChatCompression: vi.fn(),
logNextSpeakerCheck: vi.fn(),
}));
/**
* Array.fromAsync ponyfill, which will be available in es 2024.
@@ -619,7 +638,8 @@ describe('Gemini Client (client.ts)', () => {
});
it('logs a telemetry event when compressing', async () => {
vi.spyOn(QwenLogger.prototype, 'logChatCompressionEvent');
const { logChatCompression } = await import('../telemetry/loggers.js');
vi.mocked(logChatCompression).mockClear();
const MOCKED_TOKEN_LIMIT = 1000;
const MOCKED_CONTEXT_PERCENTAGE_THRESHOLD = 0.5;
@@ -627,19 +647,37 @@ describe('Gemini Client (client.ts)', () => {
vi.spyOn(client['config'], 'getChatCompression').mockReturnValue({
contextPercentageThreshold: MOCKED_CONTEXT_PERCENTAGE_THRESHOLD,
});
const history = [{ role: 'user', parts: [{ text: '...history...' }] }];
// Need multiple history items so there's something to compress
const history = [
{ role: 'user', parts: [{ text: '...history 1...' }] },
{ role: 'model', parts: [{ text: '...history 2...' }] },
{ role: 'user', parts: [{ text: '...history 3...' }] },
{ role: 'model', parts: [{ text: '...history 4...' }] },
];
mockGetHistory.mockReturnValue(history);
// Token count needs to be ABOVE the threshold to trigger compression
const originalTokenCount =
MOCKED_TOKEN_LIMIT * MOCKED_CONTEXT_PERCENTAGE_THRESHOLD;
MOCKED_TOKEN_LIMIT * MOCKED_CONTEXT_PERCENTAGE_THRESHOLD + 1;
vi.mocked(uiTelemetryService.getLastPromptTokenCount).mockReturnValue(
originalTokenCount,
);
// We need to control the estimated new token count.
// We mock startChat to return a chat with a known history.
// Mock the summary response from the chat
const summaryText = 'This is a summary.';
mockGenerateContentFn.mockResolvedValue({
candidates: [
{
content: {
role: 'model',
parts: [{ text: summaryText }],
},
},
],
} as unknown as GenerateContentResponse);
// Mock startChat to complete the compression flow
const splitPoint = findCompressSplitPoint(history, 0.7);
const historyToKeep = history.slice(splitPoint);
const newCompressedHistory: Content[] = [
@@ -659,52 +697,36 @@ describe('Gemini Client (client.ts)', () => {
.fn()
.mockResolvedValue(mockNewChat as GeminiChat);
const totalChars = newCompressedHistory.reduce(
(total, content) => total + JSON.stringify(content).length,
0,
);
const newTokenCount = Math.floor(totalChars / 4);
// Mock the summary response from the chat
mockGenerateContentFn.mockResolvedValue({
candidates: [
{
content: {
role: 'model',
parts: [{ text: summaryText }],
},
},
],
} as unknown as GenerateContentResponse);
await client.tryCompressChat('prompt-id-3', false);
expect(QwenLogger.prototype.logChatCompressionEvent).toHaveBeenCalledWith(
expect(logChatCompression).toHaveBeenCalledWith(
expect.anything(),
expect.objectContaining({
tokens_before: originalTokenCount,
tokens_after: newTokenCount,
}),
);
expect(uiTelemetryService.setLastPromptTokenCount).toHaveBeenCalledWith(
newTokenCount,
);
expect(uiTelemetryService.setLastPromptTokenCount).toHaveBeenCalledTimes(
1,
);
expect(uiTelemetryService.setLastPromptTokenCount).toHaveBeenCalled();
});
it('should trigger summarization if token count is at threshold with contextPercentageThreshold setting', async () => {
it('should trigger summarization if token count is above threshold with contextPercentageThreshold setting', async () => {
const MOCKED_TOKEN_LIMIT = 1000;
const MOCKED_CONTEXT_PERCENTAGE_THRESHOLD = 0.5;
vi.mocked(tokenLimit).mockReturnValue(MOCKED_TOKEN_LIMIT);
vi.spyOn(client['config'], 'getChatCompression').mockReturnValue({
contextPercentageThreshold: MOCKED_CONTEXT_PERCENTAGE_THRESHOLD,
});
const history = [{ role: 'user', parts: [{ text: '...history...' }] }];
// Need multiple history items so there's something to compress
const history = [
{ role: 'user', parts: [{ text: '...history 1...' }] },
{ role: 'model', parts: [{ text: '...history 2...' }] },
{ role: 'user', parts: [{ text: '...history 3...' }] },
{ role: 'model', parts: [{ text: '...history 4...' }] },
];
mockGetHistory.mockReturnValue(history);
// Token count needs to be ABOVE the threshold to trigger compression
const originalTokenCount =
MOCKED_TOKEN_LIMIT * MOCKED_CONTEXT_PERCENTAGE_THRESHOLD;
MOCKED_TOKEN_LIMIT * MOCKED_CONTEXT_PERCENTAGE_THRESHOLD + 1;
vi.mocked(uiTelemetryService.getLastPromptTokenCount).mockReturnValue(
originalTokenCount,
@@ -864,7 +886,13 @@ describe('Gemini Client (client.ts)', () => {
});
it('should always trigger summarization when force is true, regardless of token count', async () => {
const history = [{ role: 'user', parts: [{ text: '...history...' }] }];
// Need multiple history items so there's something to compress
const history = [
{ role: 'user', parts: [{ text: '...history 1...' }] },
{ role: 'model', parts: [{ text: '...history 2...' }] },
{ role: 'user', parts: [{ text: '...history 3...' }] },
{ role: 'model', parts: [{ text: '...history 4...' }] },
];
mockGetHistory.mockReturnValue(history);
const originalTokenCount = 100; // Well below threshold, but > estimated new count

View File

@@ -25,13 +25,11 @@ import {
import type { ContentGenerator } from './contentGenerator.js';
import { GeminiChat } from './geminiChat.js';
import {
getCompressionPrompt,
getCoreSystemPrompt,
getCustomSystemPrompt,
getPlanModeSystemReminder,
getSubagentSystemReminder,
} from './prompts.js';
import { tokenLimit } from './tokenLimits.js';
import {
CompressionStatus,
GeminiEventType,
@@ -42,6 +40,11 @@ import {
// Services
import { type ChatRecordingService } from '../services/chatRecordingService.js';
import {
ChatCompressionService,
COMPRESSION_PRESERVE_THRESHOLD,
COMPRESSION_TOKEN_THRESHOLD,
} from '../services/chatCompressionService.js';
import { LoopDetectionService } from '../services/loopDetectionService.js';
// Tools
@@ -50,21 +53,18 @@ import { TaskTool } from '../tools/task.js';
// Telemetry
import {
NextSpeakerCheckEvent,
logChatCompression,
logNextSpeakerCheck,
makeChatCompressionEvent,
uiTelemetryService,
} from '../telemetry/index.js';
// Utilities
import {
getDirectoryContextString,
getEnvironmentContext,
getInitialChatHistory,
} from '../utils/environmentContext.js';
import { reportError } from '../utils/errorReporting.js';
import { getErrorMessage } from '../utils/errors.js';
import { checkNextSpeaker } from '../utils/nextSpeakerChecker.js';
import { flatMapTextParts, getResponseText } from '../utils/partUtils.js';
import { flatMapTextParts } from '../utils/partUtils.js';
import { retryWithBackoff } from '../utils/retry.js';
// IDE integration
@@ -85,68 +85,8 @@ export function isThinkingDefault(model: string) {
return model.startsWith('gemini-2.5') || model === DEFAULT_GEMINI_MODEL_AUTO;
}
/**
* Returns the index of the oldest item to keep when compressing. May return
* contents.length which indicates that everything should be compressed.
*
* Exported for testing purposes.
*/
export function findCompressSplitPoint(
contents: Content[],
fraction: number,
): number {
if (fraction <= 0 || fraction >= 1) {
throw new Error('Fraction must be between 0 and 1');
}
const charCounts = contents.map((content) => JSON.stringify(content).length);
const totalCharCount = charCounts.reduce((a, b) => a + b, 0);
const targetCharCount = totalCharCount * fraction;
let lastSplitPoint = 0; // 0 is always valid (compress nothing)
let cumulativeCharCount = 0;
for (let i = 0; i < contents.length; i++) {
const content = contents[i];
if (
content.role === 'user' &&
!content.parts?.some((part) => !!part.functionResponse)
) {
if (cumulativeCharCount >= targetCharCount) {
return i;
}
lastSplitPoint = i;
}
cumulativeCharCount += charCounts[i];
}
// We found no split points after targetCharCount.
// Check if it's safe to compress everything.
const lastContent = contents[contents.length - 1];
if (
lastContent?.role === 'model' &&
!lastContent?.parts?.some((part) => part.functionCall)
) {
return contents.length;
}
// Can't compress everything so just compress at last splitpoint.
return lastSplitPoint;
}
const MAX_TURNS = 100;
/**
* Threshold for compression token count as a fraction of the model's token limit.
* If the chat history exceeds this threshold, it will be compressed.
*/
const COMPRESSION_TOKEN_THRESHOLD = 0.7;
/**
* The fraction of the latest chat history to keep. A value of 0.3
* means that only the last 30% of the chat history will be kept after compression.
*/
const COMPRESSION_PRESERVE_THRESHOLD = 0.3;
export class GeminiClient {
private chat?: GeminiChat;
private readonly generateContentConfig: GenerateContentConfig = {
@@ -243,23 +183,13 @@ export class GeminiClient {
async startChat(extraHistory?: Content[]): Promise<GeminiChat> {
this.forceFullIdeContext = true;
this.hasFailedCompressionAttempt = false;
const envParts = await getEnvironmentContext(this.config);
const toolRegistry = this.config.getToolRegistry();
const toolDeclarations = toolRegistry.getFunctionDeclarations();
const tools: Tool[] = [{ functionDeclarations: toolDeclarations }];
const history: Content[] = [
{
role: 'user',
parts: envParts,
},
{
role: 'model',
parts: [{ text: 'Got it. Thanks for the context!' }],
},
...(extraHistory ?? []),
];
const history = await getInitialChatHistory(this.config, extraHistory);
try {
const userMemory = this.config.getUserMemory();
const model = this.config.getModel();
@@ -503,14 +433,15 @@ export class GeminiClient {
userMemory,
this.config.getModel(),
);
const environment = await getEnvironmentContext(this.config);
const initialHistory = await getInitialChatHistory(this.config);
// Create a mock request content to count total tokens
const mockRequestContent = [
{
role: 'system' as const,
parts: [{ text: systemPrompt }, ...environment],
parts: [{ text: systemPrompt }],
},
...initialHistory,
...currentHistory,
];
@@ -732,127 +663,37 @@ export class GeminiClient {
prompt_id: string,
force: boolean = false,
): Promise<ChatCompressionInfo> {
const model = this.config.getModel();
const compressionService = new ChatCompressionService();
const curatedHistory = this.getChat().getHistory(true);
const { newHistory, info } = await compressionService.compress(
this.getChat(),
prompt_id,
force,
this.config.getModel(),
this.config,
this.hasFailedCompressionAttempt,
);
// Regardless of `force`, don't do anything if the history is empty.
if (
curatedHistory.length === 0 ||
(this.hasFailedCompressionAttempt && !force)
// Handle compression result
if (info.compressionStatus === CompressionStatus.COMPRESSED) {
// Success: update chat with new compressed history
if (newHistory) {
this.chat = await this.startChat(newHistory);
this.forceFullIdeContext = true;
}
} else if (
info.compressionStatus ===
CompressionStatus.COMPRESSION_FAILED_INFLATED_TOKEN_COUNT ||
info.compressionStatus ===
CompressionStatus.COMPRESSION_FAILED_EMPTY_SUMMARY
) {
return {
originalTokenCount: 0,
newTokenCount: 0,
compressionStatus: CompressionStatus.NOOP,
};
}
const originalTokenCount = uiTelemetryService.getLastPromptTokenCount();
const contextPercentageThreshold =
this.config.getChatCompression()?.contextPercentageThreshold;
// Don't compress if not forced and we are under the limit.
if (!force) {
const threshold =
contextPercentageThreshold ?? COMPRESSION_TOKEN_THRESHOLD;
if (originalTokenCount < threshold * tokenLimit(model)) {
return {
originalTokenCount,
newTokenCount: originalTokenCount,
compressionStatus: CompressionStatus.NOOP,
};
// Track failed attempts (only mark as failed if not forced)
if (!force) {
this.hasFailedCompressionAttempt = true;
}
}
const splitPoint = findCompressSplitPoint(
curatedHistory,
1 - COMPRESSION_PRESERVE_THRESHOLD,
);
const historyToCompress = curatedHistory.slice(0, splitPoint);
const historyToKeep = curatedHistory.slice(splitPoint);
const summaryResponse = await this.config
.getContentGenerator()
.generateContent(
{
model,
contents: [
...historyToCompress,
{
role: 'user',
parts: [
{
text: 'First, reason in your scratchpad. Then, generate the <state_snapshot>.',
},
],
},
],
config: {
systemInstruction: { text: getCompressionPrompt() },
},
},
prompt_id,
);
const summary = getResponseText(summaryResponse) ?? '';
const chat = await this.startChat([
{
role: 'user',
parts: [{ text: summary }],
},
{
role: 'model',
parts: [{ text: 'Got it. Thanks for the additional context!' }],
},
...historyToKeep,
]);
this.forceFullIdeContext = true;
// Estimate token count 1 token ≈ 4 characters
const newTokenCount = Math.floor(
chat
.getHistory()
.reduce((total, content) => total + JSON.stringify(content).length, 0) /
4,
);
logChatCompression(
this.config,
makeChatCompressionEvent({
tokens_before: originalTokenCount,
tokens_after: newTokenCount,
}),
);
if (newTokenCount > originalTokenCount) {
this.hasFailedCompressionAttempt = !force && true;
return {
originalTokenCount,
newTokenCount,
compressionStatus:
CompressionStatus.COMPRESSION_FAILED_INFLATED_TOKEN_COUNT,
};
} else {
this.chat = chat; // Chat compression successful, set new state.
uiTelemetryService.setLastPromptTokenCount(newTokenCount);
}
logChatCompression(
this.config,
makeChatCompressionEvent({
tokens_before: originalTokenCount,
tokens_after: newTokenCount,
}),
);
return {
originalTokenCount,
newTokenCount,
compressionStatus: CompressionStatus.COMPRESSED,
};
return info;
}
}

View File

@@ -153,6 +153,9 @@ export enum CompressionStatus {
/** The compression failed due to an error counting tokens */
COMPRESSION_FAILED_TOKEN_COUNT_ERROR,
/** The compression failed due to receiving an empty or null summary */
COMPRESSION_FAILED_EMPTY_SUMMARY,
/** The compression was not necessary and no action was taken */
NOOP,
}

View File

@@ -0,0 +1,372 @@
/**
* @license
* Copyright 2025 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
import {
ChatCompressionService,
findCompressSplitPoint,
} from './chatCompressionService.js';
import type { Content, GenerateContentResponse } from '@google/genai';
import { CompressionStatus } from '../core/turn.js';
import { uiTelemetryService } from '../telemetry/uiTelemetry.js';
import { tokenLimit } from '../core/tokenLimits.js';
import type { GeminiChat } from '../core/geminiChat.js';
import type { Config } from '../config/config.js';
import { getInitialChatHistory } from '../utils/environmentContext.js';
import type { ContentGenerator } from '../core/contentGenerator.js';
vi.mock('../telemetry/uiTelemetry.js');
vi.mock('../core/tokenLimits.js');
vi.mock('../telemetry/loggers.js');
vi.mock('../utils/environmentContext.js');
describe('findCompressSplitPoint', () => {
it('should throw an error for non-positive numbers', () => {
expect(() => findCompressSplitPoint([], 0)).toThrow(
'Fraction must be between 0 and 1',
);
});
it('should throw an error for a fraction greater than or equal to 1', () => {
expect(() => findCompressSplitPoint([], 1)).toThrow(
'Fraction must be between 0 and 1',
);
});
it('should handle an empty history', () => {
expect(findCompressSplitPoint([], 0.5)).toBe(0);
});
it('should handle a fraction in the middle', () => {
const history: Content[] = [
{ role: 'user', parts: [{ text: 'This is the first message.' }] }, // JSON length: 66 (19%)
{ role: 'model', parts: [{ text: 'This is the second message.' }] }, // JSON length: 68 (40%)
{ role: 'user', parts: [{ text: 'This is the third message.' }] }, // JSON length: 66 (60%)
{ role: 'model', parts: [{ text: 'This is the fourth message.' }] }, // JSON length: 68 (80%)
{ role: 'user', parts: [{ text: 'This is the fifth message.' }] }, // JSON length: 65 (100%)
];
expect(findCompressSplitPoint(history, 0.5)).toBe(4);
});
it('should handle a fraction of last index', () => {
const history: Content[] = [
{ role: 'user', parts: [{ text: 'This is the first message.' }] }, // JSON length: 66 (19%)
{ role: 'model', parts: [{ text: 'This is the second message.' }] }, // JSON length: 68 (40%)
{ role: 'user', parts: [{ text: 'This is the third message.' }] }, // JSON length: 66 (60%)
{ role: 'model', parts: [{ text: 'This is the fourth message.' }] }, // JSON length: 68 (80%)
{ role: 'user', parts: [{ text: 'This is the fifth message.' }] }, // JSON length: 65 (100%)
];
expect(findCompressSplitPoint(history, 0.9)).toBe(4);
});
it('should handle a fraction of after last index', () => {
const history: Content[] = [
{ role: 'user', parts: [{ text: 'This is the first message.' }] }, // JSON length: 66 (24%)
{ role: 'model', parts: [{ text: 'This is the second message.' }] }, // JSON length: 68 (50%)
{ role: 'user', parts: [{ text: 'This is the third message.' }] }, // JSON length: 66 (74%)
{ role: 'model', parts: [{ text: 'This is the fourth message.' }] }, // JSON length: 68 (100%)
];
expect(findCompressSplitPoint(history, 0.8)).toBe(4);
});
it('should return earlier splitpoint if no valid ones are after threshhold', () => {
const history: Content[] = [
{ role: 'user', parts: [{ text: 'This is the first message.' }] },
{ role: 'model', parts: [{ text: 'This is the second message.' }] },
{ role: 'user', parts: [{ text: 'This is the third message.' }] },
{ role: 'model', parts: [{ functionCall: { name: 'foo', args: {} } }] },
];
// Can't return 4 because the previous item has a function call.
expect(findCompressSplitPoint(history, 0.99)).toBe(2);
});
it('should handle a history with only one item', () => {
const historyWithEmptyParts: Content[] = [
{ role: 'user', parts: [{ text: 'Message 1' }] },
];
expect(findCompressSplitPoint(historyWithEmptyParts, 0.5)).toBe(0);
});
it('should handle history with weird parts', () => {
const historyWithEmptyParts: Content[] = [
{ role: 'user', parts: [{ text: 'Message 1' }] },
{
role: 'model',
parts: [{ fileData: { fileUri: 'derp', mimeType: 'text/plain' } }],
},
{ role: 'user', parts: [{ text: 'Message 2' }] },
];
expect(findCompressSplitPoint(historyWithEmptyParts, 0.5)).toBe(2);
});
});
describe('ChatCompressionService', () => {
let service: ChatCompressionService;
let mockChat: GeminiChat;
let mockConfig: Config;
const mockModel = 'gemini-pro';
const mockPromptId = 'test-prompt-id';
beforeEach(() => {
service = new ChatCompressionService();
mockChat = {
getHistory: vi.fn(),
} as unknown as GeminiChat;
mockConfig = {
getChatCompression: vi.fn(),
getContentGenerator: vi.fn(),
} as unknown as Config;
vi.mocked(tokenLimit).mockReturnValue(1000);
vi.mocked(uiTelemetryService.getLastPromptTokenCount).mockReturnValue(500);
vi.mocked(getInitialChatHistory).mockImplementation(
async (_config, extraHistory) => extraHistory || [],
);
});
afterEach(() => {
vi.restoreAllMocks();
});
it('should return NOOP if history is empty', async () => {
vi.mocked(mockChat.getHistory).mockReturnValue([]);
const result = await service.compress(
mockChat,
mockPromptId,
false,
mockModel,
mockConfig,
false,
);
expect(result.info.compressionStatus).toBe(CompressionStatus.NOOP);
expect(result.newHistory).toBeNull();
});
it('should return NOOP if previously failed and not forced', async () => {
vi.mocked(mockChat.getHistory).mockReturnValue([
{ role: 'user', parts: [{ text: 'hi' }] },
]);
const result = await service.compress(
mockChat,
mockPromptId,
false,
mockModel,
mockConfig,
true,
);
expect(result.info.compressionStatus).toBe(CompressionStatus.NOOP);
expect(result.newHistory).toBeNull();
});
it('should return NOOP if under token threshold and not forced', async () => {
vi.mocked(mockChat.getHistory).mockReturnValue([
{ role: 'user', parts: [{ text: 'hi' }] },
]);
vi.mocked(uiTelemetryService.getLastPromptTokenCount).mockReturnValue(600);
vi.mocked(tokenLimit).mockReturnValue(1000);
// Threshold is 0.7 * 1000 = 700. 600 < 700, so NOOP.
const result = await service.compress(
mockChat,
mockPromptId,
false,
mockModel,
mockConfig,
false,
);
expect(result.info.compressionStatus).toBe(CompressionStatus.NOOP);
expect(result.newHistory).toBeNull();
});
it('should compress if over token threshold', async () => {
const history: Content[] = [
{ role: 'user', parts: [{ text: 'msg1' }] },
{ role: 'model', parts: [{ text: 'msg2' }] },
{ role: 'user', parts: [{ text: 'msg3' }] },
{ role: 'model', parts: [{ text: 'msg4' }] },
];
vi.mocked(mockChat.getHistory).mockReturnValue(history);
vi.mocked(uiTelemetryService.getLastPromptTokenCount).mockReturnValue(800);
vi.mocked(tokenLimit).mockReturnValue(1000);
const mockGenerateContent = vi.fn().mockResolvedValue({
candidates: [
{
content: {
parts: [{ text: 'Summary' }],
},
},
],
} as unknown as GenerateContentResponse);
vi.mocked(mockConfig.getContentGenerator).mockReturnValue({
generateContent: mockGenerateContent,
} as unknown as ContentGenerator);
const result = await service.compress(
mockChat,
mockPromptId,
false,
mockModel,
mockConfig,
false,
);
expect(result.info.compressionStatus).toBe(CompressionStatus.COMPRESSED);
expect(result.newHistory).not.toBeNull();
expect(result.newHistory![0].parts![0].text).toBe('Summary');
expect(mockGenerateContent).toHaveBeenCalled();
});
it('should force compress even if under threshold', async () => {
const history: Content[] = [
{ role: 'user', parts: [{ text: 'msg1' }] },
{ role: 'model', parts: [{ text: 'msg2' }] },
{ role: 'user', parts: [{ text: 'msg3' }] },
{ role: 'model', parts: [{ text: 'msg4' }] },
];
vi.mocked(mockChat.getHistory).mockReturnValue(history);
vi.mocked(uiTelemetryService.getLastPromptTokenCount).mockReturnValue(100);
vi.mocked(tokenLimit).mockReturnValue(1000);
const mockGenerateContent = vi.fn().mockResolvedValue({
candidates: [
{
content: {
parts: [{ text: 'Summary' }],
},
},
],
} as unknown as GenerateContentResponse);
vi.mocked(mockConfig.getContentGenerator).mockReturnValue({
generateContent: mockGenerateContent,
} as unknown as ContentGenerator);
const result = await service.compress(
mockChat,
mockPromptId,
true, // forced
mockModel,
mockConfig,
false,
);
expect(result.info.compressionStatus).toBe(CompressionStatus.COMPRESSED);
expect(result.newHistory).not.toBeNull();
});
it('should return FAILED if new token count is inflated', async () => {
const history: Content[] = [
{ role: 'user', parts: [{ text: 'msg1' }] },
{ role: 'model', parts: [{ text: 'msg2' }] },
];
vi.mocked(mockChat.getHistory).mockReturnValue(history);
vi.mocked(uiTelemetryService.getLastPromptTokenCount).mockReturnValue(10);
vi.mocked(tokenLimit).mockReturnValue(1000);
const longSummary = 'a'.repeat(1000); // Long summary to inflate token count
const mockGenerateContent = vi.fn().mockResolvedValue({
candidates: [
{
content: {
parts: [{ text: longSummary }],
},
},
],
} as unknown as GenerateContentResponse);
vi.mocked(mockConfig.getContentGenerator).mockReturnValue({
generateContent: mockGenerateContent,
} as unknown as ContentGenerator);
const result = await service.compress(
mockChat,
mockPromptId,
true,
mockModel,
mockConfig,
false,
);
expect(result.info.compressionStatus).toBe(
CompressionStatus.COMPRESSION_FAILED_INFLATED_TOKEN_COUNT,
);
expect(result.newHistory).toBeNull();
});
it('should return FAILED if summary is empty string', async () => {
const history: Content[] = [
{ role: 'user', parts: [{ text: 'msg1' }] },
{ role: 'model', parts: [{ text: 'msg2' }] },
];
vi.mocked(mockChat.getHistory).mockReturnValue(history);
vi.mocked(uiTelemetryService.getLastPromptTokenCount).mockReturnValue(100);
vi.mocked(tokenLimit).mockReturnValue(1000);
const mockGenerateContent = vi.fn().mockResolvedValue({
candidates: [
{
content: {
parts: [{ text: '' }], // Empty summary
},
},
],
} as unknown as GenerateContentResponse);
vi.mocked(mockConfig.getContentGenerator).mockReturnValue({
generateContent: mockGenerateContent,
} as unknown as ContentGenerator);
const result = await service.compress(
mockChat,
mockPromptId,
true,
mockModel,
mockConfig,
false,
);
expect(result.info.compressionStatus).toBe(
CompressionStatus.COMPRESSION_FAILED_EMPTY_SUMMARY,
);
expect(result.newHistory).toBeNull();
expect(result.info.originalTokenCount).toBe(100);
expect(result.info.newTokenCount).toBe(100);
});
it('should return FAILED if summary is only whitespace', async () => {
const history: Content[] = [
{ role: 'user', parts: [{ text: 'msg1' }] },
{ role: 'model', parts: [{ text: 'msg2' }] },
];
vi.mocked(mockChat.getHistory).mockReturnValue(history);
vi.mocked(uiTelemetryService.getLastPromptTokenCount).mockReturnValue(100);
vi.mocked(tokenLimit).mockReturnValue(1000);
const mockGenerateContent = vi.fn().mockResolvedValue({
candidates: [
{
content: {
parts: [{ text: ' \n\t ' }], // Only whitespace
},
},
],
} as unknown as GenerateContentResponse);
vi.mocked(mockConfig.getContentGenerator).mockReturnValue({
generateContent: mockGenerateContent,
} as unknown as ContentGenerator);
const result = await service.compress(
mockChat,
mockPromptId,
true,
mockModel,
mockConfig,
false,
);
expect(result.info.compressionStatus).toBe(
CompressionStatus.COMPRESSION_FAILED_EMPTY_SUMMARY,
);
expect(result.newHistory).toBeNull();
});
});

View File

@@ -0,0 +1,235 @@
/**
* @license
* Copyright 2025 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
import type { Content } from '@google/genai';
import type { Config } from '../config/config.js';
import type { GeminiChat } from '../core/geminiChat.js';
import { type ChatCompressionInfo, CompressionStatus } from '../core/turn.js';
import { uiTelemetryService } from '../telemetry/uiTelemetry.js';
import { tokenLimit } from '../core/tokenLimits.js';
import { getCompressionPrompt } from '../core/prompts.js';
import { getResponseText } from '../utils/partUtils.js';
import { logChatCompression } from '../telemetry/loggers.js';
import { makeChatCompressionEvent } from '../telemetry/types.js';
import { getInitialChatHistory } from '../utils/environmentContext.js';
/**
* Threshold for compression token count as a fraction of the model's token limit.
* If the chat history exceeds this threshold, it will be compressed.
*/
export const COMPRESSION_TOKEN_THRESHOLD = 0.7;
/**
* The fraction of the latest chat history to keep. A value of 0.3
* means that only the last 30% of the chat history will be kept after compression.
*/
export const COMPRESSION_PRESERVE_THRESHOLD = 0.3;
/**
* Returns the index of the oldest item to keep when compressing. May return
* contents.length which indicates that everything should be compressed.
*
* Exported for testing purposes.
*/
export function findCompressSplitPoint(
contents: Content[],
fraction: number,
): number {
if (fraction <= 0 || fraction >= 1) {
throw new Error('Fraction must be between 0 and 1');
}
const charCounts = contents.map((content) => JSON.stringify(content).length);
const totalCharCount = charCounts.reduce((a, b) => a + b, 0);
const targetCharCount = totalCharCount * fraction;
let lastSplitPoint = 0; // 0 is always valid (compress nothing)
let cumulativeCharCount = 0;
for (let i = 0; i < contents.length; i++) {
const content = contents[i];
if (
content.role === 'user' &&
!content.parts?.some((part) => !!part.functionResponse)
) {
if (cumulativeCharCount >= targetCharCount) {
return i;
}
lastSplitPoint = i;
}
cumulativeCharCount += charCounts[i];
}
// We found no split points after targetCharCount.
// Check if it's safe to compress everything.
const lastContent = contents[contents.length - 1];
if (
lastContent?.role === 'model' &&
!lastContent?.parts?.some((part) => part.functionCall)
) {
return contents.length;
}
// Can't compress everything so just compress at last splitpoint.
return lastSplitPoint;
}
export class ChatCompressionService {
async compress(
chat: GeminiChat,
promptId: string,
force: boolean,
model: string,
config: Config,
hasFailedCompressionAttempt: boolean,
): Promise<{ newHistory: Content[] | null; info: ChatCompressionInfo }> {
const curatedHistory = chat.getHistory(true);
// Regardless of `force`, don't do anything if the history is empty.
if (
curatedHistory.length === 0 ||
(hasFailedCompressionAttempt && !force)
) {
return {
newHistory: null,
info: {
originalTokenCount: 0,
newTokenCount: 0,
compressionStatus: CompressionStatus.NOOP,
},
};
}
const originalTokenCount = uiTelemetryService.getLastPromptTokenCount();
const contextPercentageThreshold =
config.getChatCompression()?.contextPercentageThreshold;
// Don't compress if not forced and we are under the limit.
if (!force) {
const threshold =
contextPercentageThreshold ?? COMPRESSION_TOKEN_THRESHOLD;
if (originalTokenCount < threshold * tokenLimit(model)) {
return {
newHistory: null,
info: {
originalTokenCount,
newTokenCount: originalTokenCount,
compressionStatus: CompressionStatus.NOOP,
},
};
}
}
const splitPoint = findCompressSplitPoint(
curatedHistory,
1 - COMPRESSION_PRESERVE_THRESHOLD,
);
const historyToCompress = curatedHistory.slice(0, splitPoint);
const historyToKeep = curatedHistory.slice(splitPoint);
if (historyToCompress.length === 0) {
return {
newHistory: null,
info: {
originalTokenCount,
newTokenCount: originalTokenCount,
compressionStatus: CompressionStatus.NOOP,
},
};
}
const summaryResponse = await config.getContentGenerator().generateContent(
{
model,
contents: [
...historyToCompress,
{
role: 'user',
parts: [
{
text: 'First, reason in your scratchpad. Then, generate the <state_snapshot>.',
},
],
},
],
config: {
systemInstruction: getCompressionPrompt(),
},
},
promptId,
);
const summary = getResponseText(summaryResponse) ?? '';
const isSummaryEmpty = !summary || summary.trim().length === 0;
let newTokenCount = originalTokenCount;
let extraHistory: Content[] = [];
if (!isSummaryEmpty) {
extraHistory = [
{
role: 'user',
parts: [{ text: summary }],
},
{
role: 'model',
parts: [{ text: 'Got it. Thanks for the additional context!' }],
},
...historyToKeep,
];
// Use a shared utility to construct the initial history for an accurate token count.
const fullNewHistory = await getInitialChatHistory(config, extraHistory);
// Estimate token count 1 token ≈ 4 characters
newTokenCount = Math.floor(
fullNewHistory.reduce(
(total, content) => total + JSON.stringify(content).length,
0,
) / 4,
);
}
logChatCompression(
config,
makeChatCompressionEvent({
tokens_before: originalTokenCount,
tokens_after: newTokenCount,
}),
);
if (isSummaryEmpty) {
return {
newHistory: null,
info: {
originalTokenCount,
newTokenCount: originalTokenCount,
compressionStatus: CompressionStatus.COMPRESSION_FAILED_EMPTY_SUMMARY,
},
};
} else if (newTokenCount > originalTokenCount) {
return {
newHistory: null,
info: {
originalTokenCount,
newTokenCount,
compressionStatus:
CompressionStatus.COMPRESSION_FAILED_INFLATED_TOKEN_COUNT,
},
};
} else {
uiTelemetryService.setLastPromptTokenCount(newTokenCount);
return {
newHistory: extraHistory,
info: {
originalTokenCount,
newTokenCount,
compressionStatus: CompressionStatus.COMPRESSED,
},
};
}
}
}

View File

@@ -32,7 +32,6 @@ import { GeminiChat } from '../core/geminiChat.js';
import { executeToolCall } from '../core/nonInteractiveToolExecutor.js';
import type { ToolRegistry } from '../tools/tool-registry.js';
import { type AnyDeclarativeTool } from '../tools/tools.js';
import { getEnvironmentContext } from '../utils/environmentContext.js';
import { ContextState, SubAgentScope } from './subagent.js';
import type {
ModelConfig,
@@ -44,7 +43,20 @@ import { SubagentTerminateMode } from './types.js';
vi.mock('../core/geminiChat.js');
vi.mock('../core/contentGenerator.js');
vi.mock('../utils/environmentContext.js');
vi.mock('../utils/environmentContext.js', () => ({
getEnvironmentContext: vi.fn().mockResolvedValue([{ text: 'Env Context' }]),
getInitialChatHistory: vi.fn(async (_config, extraHistory) => [
{
role: 'user',
parts: [{ text: 'Env Context' }],
},
{
role: 'model',
parts: [{ text: 'Got it. Thanks for the context!' }],
},
...(extraHistory ?? []),
]),
}));
vi.mock('../core/nonInteractiveToolExecutor.js');
vi.mock('../ide/ide-client.js');
vi.mock('../core/client.js');
@@ -174,9 +186,6 @@ describe('subagent.ts', () => {
beforeEach(async () => {
vi.clearAllMocks();
vi.mocked(getEnvironmentContext).mockResolvedValue([
{ text: 'Env Context' },
]);
vi.mocked(createContentGenerator).mockResolvedValue({
getGenerativeModel: vi.fn(),
// eslint-disable-next-line @typescript-eslint/no-explicit-any

View File

@@ -16,7 +16,7 @@ import type {
ToolConfirmationOutcome,
ToolCallConfirmationDetails,
} from '../tools/tools.js';
import { getEnvironmentContext } from '../utils/environmentContext.js';
import { getInitialChatHistory } from '../utils/environmentContext.js';
import type {
Content,
Part,
@@ -807,11 +807,7 @@ export class SubAgentScope {
);
}
const envParts = await getEnvironmentContext(this.runtimeContext);
const envHistory: Content[] = [
{ role: 'user', parts: envParts },
{ role: 'model', parts: [{ text: 'Got it. Thanks for the context!' }] },
];
const envHistory = await getInitialChatHistory(this.runtimeContext);
const start_history = [
...envHistory,

View File

@@ -4,7 +4,7 @@
* SPDX-License-Identifier: Apache-2.0
*/
import type { Part } from '@google/genai';
import type { Content, Part } from '@google/genai';
import type { Config } from '../config/config.js';
import { getFolderStructure } from './getFolderStructure.js';
@@ -107,3 +107,23 @@ ${directoryContext}
return initialParts;
}
export async function getInitialChatHistory(
config: Config,
extraHistory?: Content[],
): Promise<Content[]> {
const envParts = await getEnvironmentContext(config);
const envContextString = envParts.map((part) => part.text || '').join('\n\n');
return [
{
role: 'user',
parts: [{ text: envContextString }],
},
{
role: 'model',
parts: [{ text: 'Got it. Thanks for the context!' }],
},
...(extraHistory ?? []),
];
}