towards backup based on add/remove set instead of clocks

8 files changed, 47 insertions, 96 deletions

diff --git a/packages/taler-util/src/backupTypes.ts b/packages/taler-util/src/backupTypes.ts
index fc6aaaad5..13ff75190 100644
--- a/packages/taler-util/src/backupTypes.ts
+++ b/packages/taler-util/src/backupTypes.ts
@@ -71,18 +71,12 @@ type BackupAmountString = string;
 type DeviceIdString = string;
 
 /**
- * Lamport clock timestamp.
- */
-export interface ClockStamp {
-  deviceId: string;
-  value: number;
-}
-
-/**
  * Contract terms JSON.
  */
 type RawContractTerms = any;
 
+type OperationUid = string;
+
 /**
  * Content of the backup.
  *
@@ -116,16 +110,6 @@ export interface WalletBackupContentV1 {
   current_device_id: DeviceIdString;
 
   /**
-   * Monotonically increasing clock of the wallet,
-   * used to determine causality when merging backups.
-   *
-   * Information about other clocks, used to delete
-   * tombstones in the hopefully rare case that multiple wallets
-   * are connected to the same sync server.
-   */
-  clocks: { [device_id: string]: number };
-
-  /**
    * Timestamp of the backup.
    *
    * This timestamp should only be advanced if the content
@@ -183,21 +167,6 @@ export interface WalletBackupContentV1 {
   recoup_groups: BackupRecoupGroup[];
 
   /**
-   * Tombstones for deleting purchases.
-   */
-  purchase_tombstones: {
-    /**
-     * Clock when the purchase was deleted
-     */
-    clock_deleted: ClockStamp;
-
-    /**
-     * Proposal ID identifying the purchase.
-     */
-    proposal_id: string;
-  }[];
-
-  /**
    * Trusted auditors, either for official (3 letter) or local (4-12 letter)
    * currencies.
    *
@@ -224,6 +193,17 @@ export interface WalletBackupContentV1 {
    * Permanent error reports.
    */
   error_reports: BackupErrorReport[];
+
+  /**
+   * Deletion tombstones.  Sorted by (type, id)
+   * in ascending order.
+   */
+  tombstones: Tombstone[];
+}
+
+export interface Tombstone {
+  type: string;
+  id: string;
 }
 
 /**
@@ -256,17 +236,10 @@ export interface BackupTrustAuditor {
   auditor_pub: string;
 
   /**
-   * Clock when the auditor trust has been added.
-   *
-   * Can be undefined if this entry represents a removal delta
-   * from the wallet's defaults.
-   */
-  clock_added?: ClockStamp;
-
-  /**
-   * Clock for when the auditor trust has been removed.
+   * UIDs for the operation of adding this auditor
+   * as a trusted auditor.
    */
-  clock_removed?: ClockStamp;
+  uids: OperationUid;
 }
 
 /**
@@ -289,17 +262,10 @@ export interface BackupTrustExchange {
   exchange_master_pub: string;
 
   /**
-   * Clock when the exchange trust has been added.
-   *
-   * Can be undefined if this entry represents a removal delta
-   * from the wallet's defaults.
+   * UIDs for the operation of adding this exchange
+   * as trusted.
    */
-  clock_added?: ClockStamp;
-
-  /**
-   * Clock for when the exchange trust has been removed.
-   */
-  clock_removed?: ClockStamp;
+   uids: OperationUid;
 }
 
 export class BackupBackupProviderTerms {
@@ -483,11 +449,6 @@ export interface BackupCoin {
    * be refreshed in most situations.
    */
   fresh: boolean;
-
-  /**
-   * Clock for the last update to current_amount/fresh.
-   */
-  last_clock?: ClockStamp;
 }
 
 /**
@@ -521,7 +482,6 @@ export interface BackupTip {
   timestamp_created: Timestamp;
 
   timestamp_finished?: Timestamp;
-  finish_clock?: ClockStamp;
   finish_is_failure?: boolean;
 
   /**
@@ -549,7 +509,11 @@ export interface BackupTip {
    */
   selected_denoms: BackupDenomSel;
 
-  selected_denoms_clock?: ClockStamp;
+  /**
+   * UID for the denomination selection.
+   * Used to disambiguate when merging.
+   */
+  selected_denoms_uid: OperationUid;
 }
 
 /**
@@ -640,7 +604,6 @@ export interface BackupRefreshGroup {
   timestamp_created: Timestamp;
 
   timestamp_finish?: Timestamp;
-  finish_clock?: ClockStamp;
   finish_is_failure?: boolean;
 }
 
@@ -664,7 +627,6 @@ export interface BackupWithdrawalGroup {
   timestamp_created: Timestamp;
 
   timestamp_finish?: Timestamp;
-  finish_clock?: ClockStamp;
   finish_is_failure?: boolean;
 
   /**
@@ -682,7 +644,7 @@ export interface BackupWithdrawalGroup {
    */
   selected_denoms: BackupDenomSel;
 
-  selected_denoms_clock?: ClockStamp;
+  selected_denoms_id: OperationUid;
 }
 
 export enum BackupRefundState {
@@ -731,8 +693,6 @@ export interface BackupRefundItemCommon {
    * accurately.
    */
   total_refresh_cost_bound: BackupAmountString;
-
-  last_clock?: ClockStamp;
 }
 
 /**
@@ -795,9 +755,9 @@ export interface BackupPurchase {
   }[];
 
   /**
-   * Clock when the pay coin selection was made/updated.
+   * Unique ID to disambiguate pay coin selection on merge.
    */
-  pay_coins_clock?: ClockStamp;
+  pay_coins_uid: OperationUid;
 
   /**
    * Total cost initially shown to the user.
@@ -842,11 +802,6 @@ export interface BackupPurchase {
   defunct?: boolean;
 
   /**
-   * Clock for last update to defunct status.
-   */
-  defunct_clock?: ClockStamp;
-
-  /**
    * Abort status of the payment.
    */
   abort_status?: "abort-refund" | "abort-finished";
@@ -1042,7 +997,6 @@ export interface BackupReserve {
   withdrawal_groups: BackupWithdrawalGroup[];
 
   defective?: boolean;
-  defective_clock?: ClockStamp;
 }
 
 /**
@@ -1197,16 +1151,9 @@ export interface BackupExchange {
   tos_etag_accepted: string | undefined;
 
   /**
-   * Clock value of the last update.
-   */
-  last_clock?: ClockStamp;
-
-  /**
    * Should this exchange be considered defective?
    */
   defective?: boolean;
-
-  defective_clock?: ClockStamp;
 }
 
 export enum BackupProposalStatus {
@@ -1284,8 +1231,6 @@ export interface BackupProposal {
    */
   proposal_status: BackupProposalStatus;
 
-  proposal_status_clock?: ClockStamp;
-
   /**
    * Proposal that this one got "redirected" to as part of
    * the repurchase detection.
diff --git a/packages/taler-wallet-core/src/db.ts b/packages/taler-wallet-core/src/db.ts
index eb0de5646..22cbd16cc 100644
--- a/packages/taler-wallet-core/src/db.ts
+++ b/packages/taler-wallet-core/src/db.ts
@@ -978,6 +978,8 @@ export interface TipRecord {
    */
   denomsSel: DenomSelectionState;
 
+  denomSelUid: string;
+
   /**
    * Tip ID chosen by the wallet.
    */
@@ -1310,6 +1312,8 @@ export interface PurchaseRecord {
 
   payCoinSelection: PayCoinSelection;
 
+  payCoinSelectionUid: string;
+
   /**
    * Pending removals from pay coin selection.
    * 
@@ -1460,6 +1464,8 @@ export interface WithdrawalGroupRecord {
 
   denomsSel: DenomSelectionState;
 
+  denomSelUid: string;
+
   /**
    * Retry info, always present even on completed operations so that indexing works.
    */
@@ -1564,12 +1570,6 @@ export interface BackupProviderRecord {
    */
   lastBackupHash?: string;
 
-  /**
-   * Clock of the last backup that we already
-   * merged.
-   */
-  lastBackupClock?: number;
-
   lastBackupTimestamp?: Timestamp;
 
   /**
diff --git a/packages/taler-wallet-core/src/operations/backup/export.ts b/packages/taler-wallet-core/src/operations/backup/export.ts
index 07c7b9ece..4ccaf8f42 100644
--- a/packages/taler-wallet-core/src/operations/backup/export.ts
+++ b/packages/taler-wallet-core/src/operations/backup/export.ts
@@ -118,6 +118,7 @@ export async function exportBackup(
           timestamp_finish: wg.timestampFinish,
           withdrawal_group_id: wg.withdrawalGroupId,
           secret_seed: wg.secretSeed,
+          selected_denoms_id: wg.denomSelUid,
         });
       });
 
@@ -160,6 +161,7 @@ export async function exportBackup(
           timestamp_created: tip.createdTimestamp,
           timestamp_expiration: tip.tipExpiration,
           tip_amount_raw: Amounts.stringify(tip.tipAmountRaw),
+          selected_denoms_uid: tip.denomSelUid,
         });
       });
 
@@ -363,6 +365,7 @@ export async function exportBackup(
           nonce_priv: purch.noncePriv,
           merchant_sig: purch.download.contractData.merchantSig,
           total_pay_cost: Amounts.stringify(purch.totalPayCost),
+          pay_coins_uid: purch.payCoinSelectionUid,
         });
       });
 
@@ -446,13 +449,11 @@ export async function exportBackup(
       const backupBlob: WalletBackupContentV1 = {
         schema_id: "gnu-taler-wallet-backup-content",
         schema_version: 1,
-        clocks: bs.clocks,
         exchanges: backupExchanges,
         wallet_root_pub: bs.walletRootPub,
         backup_providers: backupBackupProviders,
         current_device_id: bs.deviceId,
         proposals: backupProposals,
-        purchase_tombstones: [],
         purchases: backupPurchases,
         recoup_groups: backupRecoupGroups,
         refresh_groups: backupRefreshGroups,
@@ -462,13 +463,13 @@ export async function exportBackup(
         trusted_exchanges: {},
         intern_table: {},
         error_reports: [],
+        tombstones: [],
       };
 
       // If the backup changed, we increment our clock.
 
       let h = encodeCrock(hash(stringToBytes(canonicalJson(backupBlob))));
       if (h != bs.lastBackupPlainHash) {
-        backupBlob.clocks[bs.deviceId] = ++bs.clocks[bs.deviceId];
         bs.lastBackupPlainHash = encodeCrock(
           hash(stringToBytes(canonicalJson(backupBlob))),
         );
diff --git a/packages/taler-wallet-core/src/operations/backup/import.ts b/packages/taler-wallet-core/src/operations/backup/import.ts
index e0ae379ab..931e6f92b 100644
--- a/packages/taler-wallet-core/src/operations/backup/import.ts
+++ b/packages/taler-wallet-core/src/operations/backup/import.ts
@@ -302,7 +302,9 @@ export async function importBackup(
             denomPubHash,
           ]);
           if (!existingDenom) {
-            logger.info(`importing backup denomination: ${j2s(backupDenomination)}`);
+            logger.info(
+              `importing backup denomination: ${j2s(backupDenomination)}`,
+            );
 
             await tx.put(Stores.denominations, {
               denomPub: backupDenomination.denom_pub,
@@ -446,6 +448,7 @@ export async function importBackup(
                 timestampStart: backupWg.timestamp_created,
                 timestampFinish: backupWg.timestamp_finish,
                 withdrawalGroupId: backupWg.withdrawal_group_id,
+                denomSelUid: backupWg.selected_denoms_id,
               });
             }
           }
@@ -695,6 +698,7 @@ export async function importBackup(
             coinDepositPermissions: undefined,
             totalPayCost: Amounts.parseOrThrow(backupPurchase.total_pay_cost),
             refunds,
+            payCoinSelectionUid: backupPurchase.pay_coins_uid,
           });
         }
       }
@@ -801,6 +805,7 @@ export async function importBackup(
             tipAmountRaw: Amounts.parseOrThrow(backupTip.tip_amount_raw),
             tipExpiration: backupTip.timestamp_expiration,
             walletTipId: backupTip.wallet_tip_id,
+            denomSelUid: backupTip.selected_denoms_uid,
           });
         }
       }
diff --git a/packages/taler-wallet-core/src/operations/backup/index.ts b/packages/taler-wallet-core/src/operations/backup/index.ts
index 49129d7de..b4c1a6c92 100644
--- a/packages/taler-wallet-core/src/operations/backup/index.ts
+++ b/packages/taler-wallet-core/src/operations/backup/index.ts
@@ -349,7 +349,6 @@ async function runBackupCycleForProvider(
         }
         prov.lastBackupHash = encodeCrock(currentBackupHash);
         prov.lastBackupTimestamp = getTimestampNow();
-        prov.lastBackupClock = backupJson.clocks[backupJson.current_device_id];
         prov.lastError = undefined;
         await tx.put(Stores.backupProviders, prov);
       },
@@ -372,7 +371,6 @@ async function runBackupCycleForProvider(
           return;
         }
         prov.lastBackupHash = encodeCrock(hash(backupEnc));
-        prov.lastBackupClock = blob.clocks[blob.current_device_id];
         prov.lastBackupTimestamp = getTimestampNow();
         prov.lastError = undefined;
         await tx.put(Stores.backupProviders, prov);
@@ -624,7 +622,6 @@ export async function getBackupInfo(
   for (const x of providerRecords) {
     providers.push({
       active: x.active,
-      lastRemoteClock: x.lastBackupClock,
       syncProviderBaseUrl: x.baseUrl,
       lastBackupTimestamp: x.lastBackupTimestamp,
       paymentProposalIds: x.paymentProposalIds,
@@ -696,7 +693,6 @@ async function backupRecoveryTheirs(
       for (const prov of providers) {
         prov.lastBackupTimestamp = undefined;
         prov.lastBackupHash = undefined;
-        prov.lastBackupClock = undefined;
         await tx.put(Stores.backupProviders, prov);
       }
     },
diff --git a/packages/taler-wallet-core/src/operations/pay.ts b/packages/taler-wallet-core/src/operations/pay.ts
index 2e8228e6e..1ed8d72b9 100644
--- a/packages/taler-wallet-core/src/operations/pay.ts
+++ b/packages/taler-wallet-core/src/operations/pay.ts
@@ -406,6 +406,7 @@ async function recordConfirmPay(
     download: d,
     lastSessionId: sessionId,
     payCoinSelection: coinSelection,
+    payCoinSelectionUid: encodeCrock(getRandomBytes(32)),
     totalPayCost: payCostInfo,
     coinDepositPermissions,
     timestampAccept: getTimestampNow(),
diff --git a/packages/taler-wallet-core/src/operations/reserves.ts b/packages/taler-wallet-core/src/operations/reserves.ts
index 984ce5a6b..855ee82ee 100644
--- a/packages/taler-wallet-core/src/operations/reserves.ts
+++ b/packages/taler-wallet-core/src/operations/reserves.ts
@@ -633,6 +633,7 @@ async function updateReserve(
         lastError: undefined,
         denomsSel: denomSelectionInfoToState(denomSelInfo),
         secretSeed: encodeCrock(getRandomBytes(64)),
+        denomSelUid: encodeCrock(getRandomBytes(32)),
       };
 
       newReserve.lastError = undefined;
diff --git a/packages/taler-wallet-core/src/operations/tip.ts b/packages/taler-wallet-core/src/operations/tip.ts
index cc5274647..6de116098 100644
--- a/packages/taler-wallet-core/src/operations/tip.ts
+++ b/packages/taler-wallet-core/src/operations/tip.ts
@@ -107,6 +107,7 @@ export async function prepareTip(
     const selectedDenoms = selectWithdrawalDenominations(amount, denoms);
 
     const secretSeed = encodeCrock(getRandomBytes(64));
+    const denomSelUid = encodeCrock(getRandomBytes(32));
 
     tipRecord = {
       walletTipId: walletTipId,
@@ -127,6 +128,7 @@ export async function prepareTip(
       denomsSel: denomSelectionInfoToState(selectedDenoms),
       pickedUpTimestamp: undefined,
       secretSeed,
+      denomSelUid,
     };
     await ws.db.put(Stores.tips, tipRecord);
   }