getMany -> list. Add data integrity check.

README.md

@@ -93,12 +93,12 @@ await kvStore.set(["users", "by_id", 5], {
 // Use the index to select users between 2 and 4
 console.log(
   "Users 2-4:",
-  await kvStore.getMany(["users", "by_id", { from: 2, to: 4 }]),
+  await kvStore.list(["users", "by_id", { from: 2, to: 4 }]),
 );
 // ... will output the objects of Alice, Ben and Lisa
 
 // Use a plain JavaScript filter (less performant) to find a user named ben
-const ben = (await kvStore.getMany(["users"])).filter((user) =>
+const ben = (await kvStore.list(["users"])).filter((user) =>
   user.name === "Ben"
 );
 console.log("Ben: ", ben); // Outputs the object of Ben
@@ -113,7 +113,7 @@ await kvStore.close();
   - `open(filepath)`
   - `set(key, value)`
   - `get(key)`
-  - `getMany(key)`
+  - `list(key)`
   - `delete(key)`
   - `beginTransaction()`
   - `endTransaction()`

src/kv.test.ts

@@ -138,7 +138,7 @@ test("KV: supports numeric key ranges", async () => {
   }
 
   // Test if the 'get' function returns the expected values
-  const rangeResults = await kvStore.getMany(["data", { from: 7, to: 9 }]);
+  const rangeResults = await kvStore.list(["data", { from: 7, to: 9 }]);
   assertEquals(rangeResults.length, 3);
   assertEquals(rangeResults[0].data, "Value 7");
   assertEquals(rangeResults[1].data, "Value 8");
@@ -159,7 +159,7 @@ test("KV: supports additional levels after numeric key ranges", async () => {
   }
 
   // Test if the 'get' function returns the expected values
-  const rangeResults = await kvStore.getMany([
+  const rangeResults = await kvStore.list([
     "data",
     { from: 7, to: 9 },
     "doc1",
@@ -184,13 +184,13 @@ test("KV: supports empty numeric key ranges to get all", async () => {
   }
 
   // Test if the 'get' function returns the expected values
-  const rangeResults = await kvStore.getMany(["data", {}, "doc1"]);
+  const rangeResults = await kvStore.list(["data", {}, "doc1"]);
   assertEquals(rangeResults.length, 6);
-  const rangeResults2 = await kvStore.getMany(["data", {}, "doc2"]);
+  const rangeResults2 = await kvStore.list(["data", {}, "doc2"]);
   assertEquals(rangeResults2.length, 6);
-  const rangeResults3 = await kvStore.getMany(["data", {}]);
+  const rangeResults3 = await kvStore.list(["data", {}]);
   assertEquals(rangeResults3.length, 12);
-  const rangeResults4 = await kvStore.getMany(["data"]);
+  const rangeResults4 = await kvStore.list(["data"]);
   assertEquals(rangeResults4.length, 12);
 
   await kvStore.close();
@@ -207,7 +207,7 @@ test("KV: supports string key ranges", async () => {
   await kvStore.set(["files", "image_1"], "Image 1");
 
   // Get all values within the "doc_" range
-  const rangeResults = await kvStore.getMany(["files", {
+  const rangeResults = await kvStore.list(["files", {
     from: "doc_",
     to: "doc_z",
   }]);

src/kv.ts

@@ -141,7 +141,7 @@ export class KV {
    * @returns The retrieved value, or null if not found.
    */
   public async get(key: KVKeyRepresentation): Promise<KVDataEntry | null> {
-    const result = await this.getMany(key, 1);
+    const result = await this.list(key, 1);
     if (result.length) {
       return result[0];
     } else {
@@ -156,7 +156,7 @@ export class KV {
    * @param limit - Optional maximum number of values to retrieve.
    * @returns An array of retrieved values.
    */
-  async getMany(
+  async list(
     key: KVKeyRepresentation,
     limit?: number,
   ): Promise<KVDataEntry[]> {
@@ -173,7 +173,7 @@ export class KV {
       if (result?.transaction) {
         results.push({
           ts: result?.transaction.timestamp,
-          data: result?.transaction.value,
+          data: result?.transaction.data,
         });
         count++;
       }

src/ledger.ts

@@ -10,6 +10,7 @@ import { SUPPORTED_LEDGER_VERSIONS } from "./constants.ts";
 import { KVOperation, KVTransaction } from "./transaction.ts";
 import type { KVKey } from "./key.ts";
 import { rename, unlink } from "@cross/fs";
+import { compareHash, sha1 } from "./utils/hash.ts";
 
 export interface KVTransactionMeta {
   key: KVKey;
@@ -235,12 +236,18 @@ export class KVLedger {
 
       // Read transaction data (optional)
       if (decodeData) {
+        const originalHash: Uint8Array = transaction.hash!;
         const transactionHeaderData = await readAtPosition(
           fd,
           dataLength,
           offset + 8 + headerLength,
         );
-        transaction.dataFromUint8Array(transactionHeaderData);
+        await transaction.dataFromUint8Array(transactionHeaderData);
+
+        // Validate data
+        if (!compareHash(originalHash, transaction.hash!)) {
+          throw new Error("Invalid data");
+        }
       }
       return {
         offset: offset,

src/transaction.ts

@@ -1,3 +1,4 @@
+import { sha1 } from "./utils/hash.ts";
 import { extDecoder, extEncoder } from "./cbor.ts";
 import { KVKey, type KVKeyRepresentation } from "./key.ts";
 
@@ -24,6 +25,11 @@ export interface KVTransactionHeader {
    * Operation timestamp
    */
   t: number;
+
+  /**
+   * Hash
+   */
+  h: Uint8Array;
 }
 
 export type KVTransactionData = Uint8Array;
@@ -33,12 +39,13 @@ export class KVTransaction {
   public key?: KVKey;
   public operation?: KVOperation;
   public timestamp?: number;
-  public value?: unknown;
+  public data?: Uint8Array;
+  public hash?: Uint8Array;
 
   constructor() {
   }
 
-  public create(
+  public async create(
     key: KVKey | KVKeyRepresentation,
     operation: KVOperation,
     timestamp: number,
@@ -51,7 +58,8 @@ export class KVTransaction {
     }
     this.operation = operation;
     this.timestamp = timestamp;
-    this.value = value;
+    this.data = value ? extEncoder.encode(value) : undefined;
+    this.hash = this.data ? await sha1(this.data) : undefined;
   }
 
   public headerFromUint8Array(data: Uint8Array) {
@@ -61,10 +69,14 @@ export class KVTransaction {
     this.key = decoded.k;
     this.operation = decoded.o;
     this.timestamp = decoded.t;
+    this.hash = decoded.h;
   }
 
-  public dataFromUint8Array(data: Uint8Array) {
-    this.value = extDecoder.decode(data);
+  public async dataFromUint8Array(data: Uint8Array) {
+    this.data = extDecoder.decode(data);
+    if (data) {
+      this.hash = await sha1(data);
+    }
   }
 
   /**
@@ -76,6 +88,7 @@ export class KVTransaction {
       k: this.key!,
       o: this.operation!,
       t: this.timestamp!,
+      h: this.hash!,
     };
 
     // Encode header
@@ -84,9 +97,7 @@ export class KVTransaction {
     );
 
     // Encode data
-    const pendingTransactionData = this.value
-      ? extEncoder.encode(this.value)
-      : undefined;
+    const pendingTransactionData = this.data;
     const pendingTransactionDataLength = pendingTransactionData
       ? pendingTransactionData.length
       : 0;

src/utils/hash.ts

@@ -0,0 +1,12 @@
+export async function sha1(data: Uint8Array): Promise<Uint8Array> {
+  return new Uint8Array(await crypto.subtle.digest("SHA-1", data));
+}
+
+export function compareHash(arr1: Uint8Array, arr2: Uint8Array): boolean {
+  if (arr1.length !== arr2.length) return false; // Length mismatch
+
+  for (let i = 0; i < arr1.length; i++) {
+    if (arr1[i] !== arr2[i]) return false; // Value mismatch
+  }
+  return true;
+}