buffer as data encoding (#77)

Author: jowparks

src/cache/index.test.slow.ts

@@ -14,7 +14,7 @@ describe("LightBlockCache creating cache", () => {
     const cacheBlocks = lightBlockCache.cacheBlocks();
     await Promise.race([cacheBlocks, delay()]);
     const head = await lightBlockCache.getHead();
-    const block = await lightBlockCache.getBlockByHash(head!.toString("hex"));
+    const block = await lightBlockCache.getLightBlock(head!);
     expect(block).toHaveProperty("protoVersion");
     expect(block).toHaveProperty("sequence");
     expect(block).toHaveProperty("hash");

src/cache/index.test.ts

@@ -1,10 +1,7 @@
-import { LightBlock } from "../models/lightstreamer";
 import { blockFixture } from "../../test/fixtures";
 import { lightBlockCache } from ".";
 
 describe("LightBlockCache", () => {
-  const fakeHash = "hash1";
-
   beforeAll(async () => {
     await lightBlockCache.open();
   });
@@ -14,24 +11,25 @@ describe("LightBlockCache", () => {
   });
 
   it("storing and retrieving block is successful", async () => {
-    const encoded = LightBlock.encode(blockFixture).finish();
-    await lightBlockCache.put(fakeHash, encoded);
-    await lightBlockCache.put(blockFixture.sequence.toString(), fakeHash);
+    await lightBlockCache.putLightBlock(blockFixture);
 
-    const hashBlock = await lightBlockCache.getBlockByHash(fakeHash);
+    const hashBlock = await lightBlockCache.getLightBlock(blockFixture.hash);
     expect(hashBlock).toEqual(blockFixture);
 
-    const sequenceBlock = await lightBlockCache.getBlockBySequence(
+    const sequenceBlock = await lightBlockCache.getLightBlockBySequence(
       blockFixture.sequence,
     );
     expect(sequenceBlock).toEqual(blockFixture);
   });
 
   it("storing and retrieving hash is successful", async () => {
-    await lightBlockCache.put("head", Buffer.from("deedbeef", "hex"));
+    await lightBlockCache.putHead(Buffer.from("deadbeef", "hex"), 1000);
+
+    const head = await lightBlockCache.getHead();
+    expect(head?.toString("hex")).toEqual("deadbeef");
 
-    const block = await lightBlockCache.getHead();
-    expect(block!.toString("hex")).toEqual("deedbeef");
+    const sequence = await lightBlockCache.getHeadSequence();
+    expect(sequence).toEqual(1000);
   });
 
   it("finality sequence is always behind head sequence by specified amount", async () => {

src/cache/index.ts

@@ -83,31 +83,29 @@ export class LightBlockCache {
         } else if (content.type === "disconnected") {
           logger.warn(`Removing block ${content.block.sequence}...`);
           const block = lightBlock(content);
-          await this.db.put("head", block.previousBlockHash);
-          await this.db.put("headSequence", (block.sequence - 1).toString());
-          await this.db.del(block.sequence);
-          await this.db.del(block.hash);
+          await this.putHead(block.previousBlockHash, block.sequence - 1);
+          await this.del(block.sequence.toString());
+          await this.del(block.hash.toString("hex"));
         }
       }
     }
   }
 
   private async rollbackHead(): Promise<void> {
-    let head = (await this.getHeadSequence()) - 1;
-    if (!head) {
+    let headSequence = (await this.getHeadSequence()) - 1;
+    if (!headSequence) {
       logger.error("Head sequence is not set. Cannot rollback.");
       return;
     }
     let block = null;
     while (!block) {
-      block = await this.getBlockBySequence(head);
+      block = await this.getLightBlockBySequence(headSequence);
       if (!block) {
-        head -= 1;
+        headSequence -= 1;
       }
     }
-    await this.db.put("headSequence", head.toString());
-    await this.db.put("head", block.hash);
-    logger.info(`Rolled back head to block sequence ${head}`);
+    await this.putHead(block.hash, headSequence);
+    logger.info(`Rolled back head to block sequence ${headSequence}`);
   }
 
   async cacheBlock(block: LightBlock): Promise<void> {
@@ -118,14 +116,12 @@ export class LightBlockCache {
       );
     }
     const hash = block.hash;
-    await this.db.put(hash, LightBlock.encode(block).finish());
-    await this.db.put(block.sequence.toString(), hash);
+    await this.putLightBlock(block);
     const finalizedSequence = await this.getFinalizedBlockSequence();
     if (block.sequence - this.finalityBlockCount > finalizedSequence) {
       this.putFinalizedBlockSequence(block.sequence - this.finalityBlockCount);
     }
-    await this.db.put("head", hash);
-    await this.db.put("headSequence", block.sequence.toString());
+    await this.putHead(hash, block.sequence);
   }
 
   async getFinalizedBlockSequence(): Promise<number> {
@@ -135,23 +131,32 @@ export class LightBlockCache {
       : this.finalityBlockCount + 1;
   }
 
-  async getHead(): Promise<Buffer | null> {
-    const head = await this.get("head");
-    return head ? Buffer.from(head) : null;
+  async putFinalizedBlockSequence(sequence: number): Promise<void> {
+    await this.put("finalizedBlockSequence", Buffer.from(sequence.toString()));
   }
 
-  async putFinalizedBlockSequence(sequence: number): Promise<void> {
-    await this.db.put("finalizedBlockSequence", sequence.toString());
+  async putHead(hash: Buffer, sequence: number): Promise<void> {
+    await this.put("head", hash);
+    await this.put("headSequence", Buffer.from(sequence.toString()));
   }
 
-  async getBlockByHash(hash: string): Promise<LightBlock | null> {
-    const block = await this.get(hash);
-    return block ? LightBlock.decode(block) : null;
+  async getLightBlock(hash: Buffer): Promise<LightBlock | null> {
+    try {
+      const data = await this.get(hash.toString("hex"));
+      if (!data) return null;
+      return LightBlock.decode(data);
+    } catch (e) {
+      return null;
+    }
   }
 
-  async getBlockBySequence(sequence: number): Promise<LightBlock | null> {
+  async getLightBlockBySequence(sequence: number): Promise<LightBlock | null> {
     const hash = await this.get(sequence.toString());
-    return hash ? await this.getBlockByHash(hash.toString()) : null;
+    return hash ? await this.getLightBlock(hash) : null;
+  }
+
+  async getHead(): Promise<Buffer | null> {
+    return this.get("head");
   }
 
   async getHeadSequence(): Promise<number> {
@@ -160,7 +165,7 @@ export class LightBlockCache {
     return Number(head.toString());
   }
 
-  async get(key: string): Promise<Uint8Array | null> {
+  async get(key: string): Promise<Buffer | null> {
     try {
       const data = await this.db.get(key);
       return data;
@@ -169,10 +174,17 @@ export class LightBlockCache {
     }
   }
 
-  async put(key: string, value: Uint8Array | string): Promise<void> {
+  private async put(key: string, value: Buffer): Promise<void> {
     await this.db.put(key, value);
   }
 
+  async putLightBlock(block: LightBlock): Promise<void> {
+    const key = block.hash.toString("hex");
+    const value = LightBlock.encode(block).finish();
+    await this.put(block.sequence.toString(), block.hash);
+    await this.put(key, Buffer.from(value));
+  }
+
   async del(key: string): Promise<void> {
     await this.db.del(key);
   }

src/controllers/block.ts

@@ -75,9 +75,9 @@ export class BlockController {
 
     let block = null;
     if (hash) {
-      block = await lightBlockCache.getBlockByHash(String(hash));
+      block = await lightBlockCache.getLightBlock(Buffer.from(hash, "hex"));
     } else if (sequence) {
-      block = await lightBlockCache.getBlockBySequence(Number(sequence));
+      block = await lightBlockCache.getLightBlockBySequence(Number(sequence));
     }
 
     if (block) {
@@ -127,7 +127,7 @@ export class BlockController {
     // Placeholder logic: Fetch blocks from cache or database
     const blocks: LightBlock[] = [];
     for (let i = start; i <= end; i++) {
-      const block = await lightBlockCache.getBlockBySequence(i);
+      const block = await lightBlockCache.getLightBlockBySequence(i);
       if (block) {
         blocks.push(block);
       }

src/upload/index.test.ts

@@ -22,7 +22,7 @@ describe("LightBlockUpload", () => {
 
   it("should gzip blocks/manifest, last block should match", async () => {
     const tempFile = path.join(os.tmpdir(), "test");
-    const firstBlock = (await lightBlockCache.getBlockBySequence(
+    const firstBlock = (await lightBlockCache.getLightBlockBySequence(
       1,
     )) as LightBlock;
     const triggerUploadTime =

src/upload/index.ts

@@ -166,7 +166,7 @@ export class LightBlockUpload {
 
     // eslint-disable-next-line no-constant-condition
     while (true) {
-      const block = await this.cache.getBlockBySequence(currentSequence);
+      const block = await this.cache.getLightBlockBySequence(currentSequence);
       const finalizedSequence = await this.cache.getFinalizedBlockSequence();
       if (!block || block.sequence > finalizedSequence) {
         const currentTimestamp = Date.now();

test/dbfixture/cache/leveldb/000003.log

@@ -1 +1 @@
-MANIFEST-000002
+MANIFEST-000006