Files
ELY-Browser/cloudflare/src/sync_snapshot.ts
T

495 lines
14 KiB
TypeScript

import type { AuthContext } from "./auth.js";
import type { ElyD1DatabaseSession, ElyD1Result, Env } from "./bindings.js";
import { primaryD1Session } from "./bindings.js";
import { StorageObjectError, getVerifiedObject } from "./storage.js";
import {
SyncSnapshotRequestError,
assertOnlyFields,
assertOnlyQueryParams,
assertPayloadHash,
base64FromBytes,
deviceIdValue,
exactInteger,
integer,
payloadBytes,
regionValue,
requestBody,
sha256HexValue,
snapshotIdValue,
} from "./sync_snapshot_codec.js";
import {
type SnapshotHeadRefDocument,
type SyncSnapshotDocument,
type SyncSnapshotRow,
SyncSnapshotConflictError,
SyncSnapshotHeadSchemaError,
currentSyncSnapshotHead,
sameSnapshotHead,
snapshotDocumentFromResult,
snapshotHeadRef,
snapshotHeadRefValue,
syncSnapshotByToken,
} from "./sync_snapshot_head.js";
import {
syncSnapshotStatements,
} from "./sync_snapshot_sql.js";
import {
SyncR2WriteFenceError,
} from "./sync_r2_gc.js";
import {
type SyncR2WriteLease,
claimSnapshotStorageWrite,
persistClaimedSnapshot,
releaseFailedSnapshotWrite,
snapshotStorageKey,
} from "./sync_snapshot_write.js";
import {
SyncVaultConflictError,
SyncVaultNotFoundError,
assertCurrentSyncVaultKey,
} from "./sync_vault.js";
import {
SyncVaultRotationCleanupError,
cleanupRotatedVaultStorage,
} from "./sync_vault_rotation_cleanup.js";
export { SyncSnapshotRequestError } from "./sync_snapshot_codec.js";
export { SyncSnapshotConflictError } from "./sync_snapshot_head.js";
export type { SyncSnapshotDocument } from "./sync_snapshot_head.js";
const MAX_SNAPSHOT_BYTES = 10 * 1024 * 1024;
export interface SyncSnapshotUploadDocument {
version: 3;
user_id: string;
device_id: string;
snapshot: SyncSnapshotDocument;
}
export interface SyncSnapshotDownloadDocument extends SyncSnapshotUploadDocument {
data_base64: string;
}
interface SyncSnapshotUploadRequest {
snapshotId: string;
r2Key: string;
payloadHash: string;
encryptionVersion: 2;
vaultGeneration: number;
keyId: string;
contentHash: string;
schemaRev: number;
logicalClock: number;
headRevision: number;
baseHead: SnapshotHeadRefDocument | null;
bytes: ArrayBuffer;
}
export class SyncSnapshotNotFoundError extends Error {
constructor(message: string) {
super(message);
this.name = "SyncSnapshotNotFoundError";
}
}
export class SyncSnapshotPersistenceError extends Error {
constructor(message: string) {
super(message);
this.name = "SyncSnapshotPersistenceError";
}
}
export async function syncSnapshotUploadDocument(
request: Request,
env: Env,
context: AuthContext,
nowSeconds = Math.floor(Date.now() / 1000),
): Promise<SyncSnapshotUploadDocument> {
const deviceId = currentDeviceId(context);
const upload = await syncSnapshotUploadRequest(request, context.userId);
const database = primaryD1Session(env.ELY_DB);
const currentHead = await readCurrentHead(database, context.userId);
if (currentHead !== null && snapshotMatchesUpload(upload, deviceId, currentHead)) {
try {
await assertCurrentSyncVaultKey(
env,
context.userId,
upload.keyId,
upload.vaultGeneration,
database,
);
} catch (error) {
if (error instanceof SyncVaultConflictError || error instanceof SyncVaultNotFoundError) {
return uploadDocument(context.userId, deviceId, currentHead);
}
throw error;
}
await cleanupAfterSnapshot(env, context.userId, currentHead, nowSeconds);
return uploadDocument(context.userId, deviceId, currentHead);
}
try {
await assertCurrentSyncVaultKey(
env,
context.userId,
upload.keyId,
upload.vaultGeneration,
database,
);
} catch (error) {
if (error instanceof SyncVaultConflictError || error instanceof SyncVaultNotFoundError) {
throw new SyncSnapshotConflictError("sync_vault_key_not_current", currentHead);
}
throw error;
}
assertUploadBase(upload, currentHead);
let writeLease: SyncR2WriteLease;
try {
writeLease = await claimSnapshotStorageWrite(
env,
database,
context.userId,
deviceId,
upload,
nowSeconds,
);
} catch (error) {
if (error instanceof SyncR2WriteFenceError) {
const head = await readCurrentHead(database, context.userId);
throw new SyncSnapshotConflictError("sync_snapshot_head_conflict", head);
}
throw error;
}
try {
await persistClaimedSnapshot(env, upload);
} catch (error) {
await releaseFailedSnapshotWrite(
env,
database,
context.userId,
upload.r2Key,
writeLease,
nowSeconds,
);
throw error;
}
let results: ElyD1Result<SyncSnapshotRow>[];
try {
results = await database.batch<ElyD1Result<SyncSnapshotRow>>(syncSnapshotStatements(
database,
context.userId,
deviceId,
{ ...upload, sizeBytes: upload.bytes.byteLength },
writeLease,
nowSeconds,
));
} catch (error) {
await releaseFailedSnapshotWrite(
env,
database,
context.userId,
upload.r2Key,
writeLease,
nowSeconds,
);
if (!isSnapshotHeadConflict(error)) {
throw error;
}
return concurrentUploadResult(env, database, context.userId, deviceId, upload, nowSeconds);
}
if (
results.length !== 5 ||
results.slice(0, 4).some((result) => changedRowCount(result) !== 1)
) {
await releaseFailedSnapshotWrite(
env,
database,
context.userId,
upload.r2Key,
writeLease,
nowSeconds,
);
return concurrentUploadResult(env, database, context.userId, deviceId, upload, nowSeconds);
}
let saved: SyncSnapshotDocument;
try {
saved = snapshotDocumentFromResult(results[4]);
} catch (error) {
if (error instanceof SyncSnapshotHeadSchemaError) {
throw new SyncSnapshotPersistenceError(error.message);
}
throw error;
}
if (!snapshotMatchesUpload(upload, deviceId, saved)) {
throw new SyncSnapshotPersistenceError("sync_snapshot_mismatch");
}
await cleanupAfterSnapshot(env, context.userId, saved, nowSeconds);
return uploadDocument(context.userId, deviceId, saved);
}
export async function syncSnapshotDownloadDocument(
url: URL,
env: Env,
context: AuthContext,
): Promise<SyncSnapshotDownloadDocument> {
const deviceId = currentDeviceId(context);
const database = primaryD1Session(env.ELY_DB);
const token = syncSnapshotDownloadQuery(url);
const snapshot = await readSnapshotByToken(database, context.userId, token);
if (snapshot === null) {
const currentHead = await readCurrentHead(database, context.userId);
if (currentHead === null) {
throw new SyncSnapshotNotFoundError("sync_snapshot_missing");
}
throw new SyncSnapshotConflictError("sync_snapshot_download_token_stale", currentHead);
}
let payload: ArrayBuffer | null;
try {
payload = await getVerifiedObject(env.ELY_STORAGE, snapshot.r2_key, snapshot.payload_hash);
} catch (error) {
if (error instanceof StorageObjectError) {
await throwDownloadStorageFailure(env, context.userId, token, error.message);
}
throw error;
}
if (payload === null) {
return throwDownloadStorageFailure(
env,
context.userId,
token,
"sync_snapshot_payload_missing",
);
}
return {
...uploadDocument(context.userId, deviceId, snapshot),
data_base64: base64FromBytes(payload),
};
}
async function syncSnapshotUploadRequest(
request: Request,
userId: string,
): Promise<SyncSnapshotUploadRequest> {
const body = await requestBody(request);
assertOnlyFields(body, [
"version",
"snapshot_id",
"region",
"payload_hash",
"encryption_version",
"vault_generation",
"key_id",
"content_hash",
"schema_rev",
"logical_clock",
"head_revision",
"base_head",
"data_base64",
]);
if (body.version !== 3) {
throw new SyncSnapshotRequestError("version_invalid");
}
const snapshotId = snapshotIdValue(body.snapshot_id);
const payloadHash = sha256HexValue(body.payload_hash, "payload_hash");
const headRevision = integer(
body.head_revision,
"head_revision",
1,
Number.MAX_SAFE_INTEGER,
);
const baseHead = snapshotHeadRefValue(body.base_head, headRevision);
const bytes = payloadBytes(body.data_base64, "data_base64", MAX_SNAPSHOT_BYTES);
await assertPayloadHash(bytes, payloadHash);
return {
snapshotId,
r2Key: await snapshotStorageKey(
regionValue(body.region),
userId,
snapshotId,
payloadHash,
),
payloadHash,
encryptionVersion: exactInteger(body.encryption_version, "encryption_version", 2),
vaultGeneration: integer(
body.vault_generation,
"vault_generation",
1,
Number.MAX_SAFE_INTEGER,
),
keyId: sha256HexValue(body.key_id, "key_id"),
contentHash: sha256HexValue(body.content_hash, "content_hash"),
schemaRev: integer(body.schema_rev, "schema_rev", 1, Number.MAX_SAFE_INTEGER),
logicalClock: integer(body.logical_clock, "logical_clock", 0, Number.MAX_SAFE_INTEGER),
headRevision,
baseHead,
bytes,
};
}
function syncSnapshotDownloadQuery(url: URL): SnapshotHeadRefDocument {
assertOnlyQueryParams(url, ["snapshot_id", "head_revision", "payload_hash"]);
return {
snapshot_id: snapshotIdValue(url.searchParams.get("snapshot_id")),
revision: integer(
numberQueryValue(url.searchParams.get("head_revision")),
"head_revision",
1,
Number.MAX_SAFE_INTEGER,
),
payload_hash: sha256HexValue(url.searchParams.get("payload_hash"), "payload_hash"),
};
}
function assertUploadBase(
upload: SyncSnapshotUploadRequest,
currentHead: SyncSnapshotDocument | null,
): void {
const currentRef = currentHead === null ? null : snapshotHeadRef(currentHead);
if (!sameSnapshotHead(upload.baseHead, currentRef)) {
throw new SyncSnapshotConflictError("sync_snapshot_head_conflict", currentHead);
}
if (currentHead !== null && upload.logicalClock <= currentHead.logical_clock) {
throw new SyncSnapshotConflictError("logical_clock_stale", currentHead);
}
}
function snapshotMatchesUpload(
upload: SyncSnapshotUploadRequest,
deviceId: string,
snapshot: SyncSnapshotDocument,
): boolean {
return snapshot.snapshot_id === upload.snapshotId &&
snapshot.r2_key === upload.r2Key &&
snapshot.payload_hash === upload.payloadHash &&
snapshot.encryption_version === upload.encryptionVersion &&
snapshot.vault_generation === upload.vaultGeneration &&
snapshot.key_id === upload.keyId &&
snapshot.content_hash === upload.contentHash &&
snapshot.schema_rev === upload.schemaRev &&
snapshot.logical_clock === upload.logicalClock &&
snapshot.head_revision === upload.headRevision &&
sameSnapshotHead(snapshot.base_head, upload.baseHead) &&
snapshot.device_id === deviceId &&
snapshot.size_bytes === upload.bytes.byteLength;
}
async function readCurrentHead(
database: ElyD1DatabaseSession,
userId: string,
): Promise<SyncSnapshotDocument | null> {
try {
return await currentSyncSnapshotHead(database, userId);
} catch (error) {
if (error instanceof SyncSnapshotHeadSchemaError) {
throw new SyncSnapshotPersistenceError(error.message);
}
throw error;
}
}
async function readSnapshotByToken(
database: ElyD1DatabaseSession,
userId: string,
token: SnapshotHeadRefDocument,
): Promise<SyncSnapshotDocument | null> {
try {
return await syncSnapshotByToken(database, userId, token);
} catch (error) {
if (error instanceof SyncSnapshotHeadSchemaError) {
throw new SyncSnapshotPersistenceError(error.message);
}
throw error;
}
}
async function concurrentUploadResult(
env: Env,
database: ElyD1DatabaseSession,
userId: string,
deviceId: string,
upload: SyncSnapshotUploadRequest,
nowSeconds: number,
): Promise<SyncSnapshotUploadDocument> {
const currentHead = await readCurrentHead(database, userId);
if (currentHead !== null && snapshotMatchesUpload(upload, deviceId, currentHead)) {
await cleanupAfterSnapshot(env, userId, currentHead, nowSeconds);
return uploadDocument(userId, deviceId, currentHead);
}
throw new SyncSnapshotConflictError("sync_snapshot_head_conflict", currentHead);
}
async function throwDownloadStorageFailure(
env: Env,
userId: string,
token: SnapshotHeadRefDocument,
message: string,
): Promise<never> {
const currentHead = await readCurrentHead(primaryD1Session(env.ELY_DB), userId);
if (currentHead === null || !sameSnapshotHead(token, snapshotHeadRef(currentHead))) {
throw new SyncSnapshotConflictError("sync_snapshot_download_token_stale", currentHead);
}
throw new SyncSnapshotPersistenceError(message);
}
async function cleanupAfterSnapshot(
env: Env,
userId: string,
snapshot: SyncSnapshotDocument,
nowSeconds: number,
): Promise<void> {
try {
await cleanupRotatedVaultStorage(
env,
userId,
snapshot.snapshot_id,
snapshot.key_id,
snapshot.vault_generation,
nowSeconds,
);
} catch (error) {
if (error instanceof SyncVaultRotationCleanupError) {
throw new SyncSnapshotPersistenceError(error.message);
}
throw error;
}
}
function uploadDocument(
userId: string,
deviceId: string,
snapshot: SyncSnapshotDocument,
): SyncSnapshotUploadDocument {
return { version: 3, user_id: userId, device_id: deviceId, snapshot };
}
function currentDeviceId(context: AuthContext): string {
return deviceIdValue(context.deviceId);
}
function numberQueryValue(value: string | null): number {
if (value === null || !/^[1-9][0-9]*$/.test(value)) {
throw new SyncSnapshotRequestError("head_revision_invalid");
}
return Number(value);
}
function changedRowCount(result: ElyD1Result): number {
const changes = result.meta?.changes;
return typeof changes === "number" && Number.isSafeInteger(changes) && changes >= 0 ? changes : -1;
}
function isSnapshotHeadConflict(error: unknown): boolean {
if (!(error instanceof Error)) {
return false;
}
return error.message.includes("sync_snapshot_head_cas_failed") ||
error.message.includes("sync_r2_write_fenced") ||
error.message.includes("sync_r2_reference_commit_invalid") ||
error.message.includes("UNIQUE constraint failed: sync_snapshot_heads.user_id") ||
error.message.includes("sync_snapshots.user_id, sync_snapshots.head_revision");
}