[price_service] Let callers specify VAA encoding (#766)

* Callers can specify encoding

* lint

* changed my mind about this one

* cleanup

* cleanup

* bump version

Author: jayantk

price_service/server/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@pythnetwork/price-service-server",
-  "version": "3.0.0",
+  "version": "3.0.1",
   "description": "Webservice for retrieving prices from the Pyth oracle.",
   "private": "true",
   "main": "index.js",

price_service/server/src/__tests__/rest.test.ts

@@ -152,6 +152,23 @@ describe("Latest Price Feed Endpoint", () => {
     });
   });
 
+  test("When called with a target_chain, returns correct price feed with binary vaa encoded properly", async () => {
+    const ids = [expandTo64Len("abcd"), expandTo64Len("3456")];
+    const resp = await request(app)
+      .get("/api/latest_price_feeds")
+      .query({ ids, target_chain: "evm" });
+    expect(resp.status).toBe(StatusCodes.OK);
+    expect(resp.body.length).toBe(2);
+    expect(resp.body).toContainEqual({
+      ...priceInfoMap.get(ids[0])!.priceFeed.toJson(),
+      vaa: "0x" + priceInfoMap.get(ids[0])!.vaa.toString("hex"),
+    });
+    expect(resp.body).toContainEqual({
+      ...priceInfoMap.get(ids[1])!.priceFeed.toJson(),
+      vaa: "0x" + priceInfoMap.get(ids[1])!.vaa.toString("hex"),
+    });
+  });
+
   test("When called with some non-existent ids within ids, returns error mentioning non-existent ids", async () => {
     const ids = [
       expandTo64Len("ab01"),
@@ -186,6 +203,21 @@ describe("Latest Vaa Bytes Endpoint", () => {
     );
   });
 
+  test("When called with target_chain, returns vaa bytes encoded correctly", async () => {
+    const ids = [
+      expandTo64Len("abcd"),
+      expandTo64Len("ef01"),
+      expandTo64Len("3456"),
+    ];
+    const resp = await request(app)
+      .get("/api/latest_vaas")
+      .query({ ids, target_chain: "evm" });
+    expect(resp.status).toBe(StatusCodes.OK);
+    expect(resp.body.length).toBe(2);
+    expect(resp.body).toContain("0xa1b2c3d4");
+    expect(resp.body).toContain("0xbad01bad");
+  });
+
   test("When called with valid ids with leading 0x, returns vaa bytes as array, merged if necessary", async () => {
     const ids = [
       expandTo64Len("abcd"),
@@ -271,6 +303,26 @@ describe("Get VAA endpoint and Get VAA CCIP", () => {
     });
   });
 
+  test("When called with target_chain, encodes resulting VAA in the right format", async () => {
+    const id = expandTo64Len("abcd");
+    vaasCache.set(id, 10, "abcd10");
+    vaasCache.set(id, 20, "abcd20");
+    vaasCache.set(id, 30, "abcd30");
+
+    const resp = await request(app)
+      .get("/api/get_vaa")
+      .query({
+        id: "0x" + id,
+        publish_time: 16,
+        target_chain: "evm",
+      });
+    expect(resp.status).toBe(StatusCodes.OK);
+    expect(resp.body).toEqual<VaaConfig>({
+      vaa: "0x" + Buffer.from("abcd20", "base64").toString("hex"),
+      publishTime: 20,
+    });
+  });
+
   test("When called with invalid id returns price id found", async () => {
     // dead does not exist in the ids
     const id = expandTo64Len("dead");

price_service/server/src/encoding.ts

@@ -0,0 +1,47 @@
+// Utilities for encoding VAAs for specific target chains
+
+// List of all possible target chains. Note that "default" is an option because we need at least one chain
+// with a base64 encoding (which is the old default behavior of all API methods).
+export type TargetChain = "evm" | "cosmos" | "aptos" | "default";
+export const validTargetChains = ["evm", "cosmos", "aptos", "default"];
+export const defaultTargetChain: TargetChain = "default";
+
+// Possible encodings of the binary VAA data as a string.
+// "0x" is the same as "hex" with a leading "0x" prepended to the hex string.
+export type VaaEncoding = "base64" | "hex" | "0x";
+export const defaultVaaEncoding: VaaEncoding = "base64";
+export const chainToEncoding: Record<TargetChain, VaaEncoding> = {
+  evm: "0x",
+  cosmos: "base64",
+  // TODO: I think aptos actually wants a number[] for this data... need to decide how to
+  // handle that case.
+  aptos: "base64",
+  default: "base64",
+};
+
+// Given a VAA represented as either a string in base64 or a Buffer, encode it as a string
+// appropriate for the given targetChain.
+export function encodeVaaForChain(
+  vaa: string | Buffer,
+  targetChain: TargetChain
+): string {
+  const encoding = chainToEncoding[targetChain];
+
+  let vaaBuffer: Buffer;
+  if (typeof vaa === "string") {
+    if (encoding === defaultVaaEncoding) {
+      return vaa;
+    } else {
+      vaaBuffer = Buffer.from(vaa, defaultVaaEncoding as BufferEncoding);
+    }
+  } else {
+    vaaBuffer = vaa;
+  }
+
+  switch (encoding) {
+    case "0x":
+      return "0x" + vaaBuffer.toString("hex");
+    default:
+      return vaaBuffer.toString(encoding);
+  }
+}

price_service/server/src/helpers.ts

@@ -33,3 +33,13 @@ export function removeLeading0x(s: string): string {
 
   return s;
 }
+
+// Helper for treating T | undefined as an optional value. This lets you pick a
+// default if value is undefined.
+export function getOrElse<T>(value: T | undefined, defaultValue: T): T {
+  if (value === undefined) {
+    return defaultValue;
+  } else {
+    return value;
+  }
+}

price_service/server/src/rest.ts

@@ -16,11 +16,24 @@ import { logger } from "./logging";
 import { PromClient } from "./promClient";
 import { retry } from "ts-retry-promise";
 import { parseVaa } from "@certusone/wormhole-sdk";
+import { getOrElse } from "./helpers";
+import {
+  TargetChain,
+  validTargetChains,
+  defaultTargetChain,
+  VaaEncoding,
+  encodeVaaForChain,
+} from "./encoding";
 
 const MORGAN_LOG_FORMAT =
   ':remote-addr - :remote-user ":method :url HTTP/:http-version"' +
   ' :status :res[content-length] :response-time ms ":referrer" ":user-agent"';
 
+// GET argument string to represent the options for target_chain
+export const targetChainArgString = `target_chain=<${validTargetChains.join(
+  "|"
+)}>`;
+
 export class RestException extends Error {
   statusCode: number;
   message: string;
@@ -144,7 +157,7 @@ export class RestAPI {
   priceInfoToJson(
     priceInfo: PriceInfo,
     verbose: boolean,
-    binary: boolean
+    targetChain: TargetChain | undefined
   ): object {
     return {
       ...priceInfo.priceFeed.toJson(),
@@ -156,8 +169,8 @@ export class RestAPI {
           price_service_receive_time: priceInfo.priceServiceReceiveTime,
         },
       }),
-      ...(binary && {
-        vaa: priceInfo.vaa.toString("base64"),
+      ...(targetChain !== undefined && {
+        vaa: encodeVaaForChain(priceInfo.vaa, targetChain),
       }),
     };
   }
@@ -182,13 +195,20 @@ export class RestAPI {
         ids: Joi.array()
           .items(Joi.string().regex(/^(0x)?[a-f0-9]{64}$/))
           .required(),
+        target_chain: Joi.string()
+          .valid(...validTargetChains)
+          .optional(),
       }).required(),
     };
     app.get(
       "/api/latest_vaas",
       validate(latestVaasInputSchema),
       (req: Request, res: Response) => {
         const priceIds = (req.query.ids as string[]).map(removeLeading0x);
+        const targetChain = getOrElse(
+          req.query.target_chain as TargetChain | undefined,
+          defaultTargetChain
+        );
 
         // Multiple price ids might share same vaa, we use sequence number as
         // key of a vaa and deduplicate using a map of seqnum to vaa bytes.
@@ -212,14 +232,14 @@ export class RestAPI {
         }
 
         const jsonResponse = Array.from(vaaMap.values(), (vaa) =>
-          vaa.toString("base64")
+          encodeVaaForChain(vaa, targetChain)
         );
 
         res.json(jsonResponse);
       }
     );
     endpoints.push(
-      "api/latest_vaas?ids[]=<price_feed_id>&ids[]=<price_feed_id_2>&.."
+      `api/latest_vaas?ids[]=<price_feed_id>&ids[]=<price_feed_id_2>&..&${targetChainArgString}`
     );
 
     const getVaaInputSchema: schema = {
@@ -228,6 +248,9 @@ export class RestAPI {
           .regex(/^(0x)?[a-f0-9]{64}$/)
           .required(),
         publish_time: Joi.number().required(),
+        target_chain: Joi.string()
+          .valid(...validTargetChains)
+          .optional(),
       }).required(),
     };
 
@@ -237,25 +260,32 @@ export class RestAPI {
       asyncWrapper(async (req: Request, res: Response) => {
         const priceFeedId = removeLeading0x(req.query.id as string);
         const publishTime = Number(req.query.publish_time as string);
+        const targetChain = getOrElse(
+          req.query.target_chain as TargetChain | undefined,
+          defaultTargetChain
+        );
 
         if (
           this.priceFeedVaaInfo.getLatestPriceInfo(priceFeedId) === undefined
         ) {
           throw RestException.PriceFeedIdNotFound([priceFeedId]);
         }
 
-        const vaa = await this.getVaaWithDbLookup(priceFeedId, publishTime);
-
-        if (vaa === undefined) {
+        const vaaConfig = await this.getVaaWithDbLookup(
+          priceFeedId,
+          publishTime
+        );
+        if (vaaConfig === undefined) {
           throw RestException.VaaNotFound();
         } else {
-          res.json(vaa);
+          vaaConfig.vaa = encodeVaaForChain(vaaConfig.vaa, targetChain);
+          res.json(vaaConfig);
         }
       })
     );
 
     endpoints.push(
-      "api/get_vaa?id=<price_feed_id>&publish_time=<publish_time_in_unix_timestamp>"
+      `api/get_vaa?id=<price_feed_id>&publish_time=<publish_time_in_unix_timestamp>&${targetChainArgString}`
     );
 
     const getVaaCcipInputSchema: schema = {
@@ -317,6 +347,9 @@ export class RestAPI {
           .required(),
         verbose: Joi.boolean(),
         binary: Joi.boolean(),
+        target_chain: Joi.string()
+          .valid(...validTargetChains)
+          .optional(),
       }).required(),
     };
     app.get(
@@ -326,8 +359,12 @@ export class RestAPI {
         const priceIds = (req.query.ids as string[]).map(removeLeading0x);
         // verbose is optional, default to false
         const verbose = req.query.verbose === "true";
-        // binary is optional, default to false
-        const binary = req.query.binary === "true";
+        // The binary and target_chain are somewhat redundant. Binary still exists for backward compatibility reasons.
+        // No VAA will be returned if both arguments are omitted. binary=true is the same as target_chain=default
+        let targetChain = req.query.target_chain as TargetChain | undefined;
+        if (targetChain === undefined && req.query.binary === "true") {
+          targetChain = defaultTargetChain;
+        }
 
         const responseJson = [];
 
@@ -342,7 +379,7 @@ export class RestAPI {
           }
 
           responseJson.push(
-            this.priceInfoToJson(latestPriceInfo, verbose, binary)
+            this.priceInfoToJson(latestPriceInfo, verbose, targetChain)
           );
         }
 
@@ -362,6 +399,9 @@ export class RestAPI {
     endpoints.push(
       "api/latest_price_feeds?ids[]=<price_feed_id>&ids[]=<price_feed_id_2>&..&verbose=true&binary=true"
     );
+    endpoints.push(
+      `api/latest_price_feeds?ids[]=<price_feed_id>&ids[]=<price_feed_id_2>&..&verbose=true&${targetChainArgString}`
+    );
 
     const getPriceFeedInputSchema: schema = {
       query: Joi.object({
@@ -371,6 +411,9 @@ export class RestAPI {
         publish_time: Joi.number().required(),
         verbose: Joi.boolean(),
         binary: Joi.boolean(),
+        target_chain: Joi.string()
+          .valid(...validTargetChains)
+          .optional(),
       }).required(),
     };
 
@@ -382,8 +425,12 @@ export class RestAPI {
         const publishTime = Number(req.query.publish_time as string);
         // verbose is optional, default to false
         const verbose = req.query.verbose === "true";
-        // binary is optional, default to false
-        const binary = req.query.binary === "true";
+        // The binary and target_chain are somewhat redundant. Binary still exists for backward compatibility reasons.
+        // No VAA will be returned if both arguments are omitted. binary=true is the same as target_chain=default
+        let targetChain = req.query.target_chain as TargetChain | undefined;
+        if (targetChain === undefined && req.query.binary === "true") {
+          targetChain = defaultTargetChain;
+        }
 
         if (
           this.priceFeedVaaInfo.getLatestPriceInfo(priceFeedId) === undefined
@@ -404,7 +451,7 @@ export class RestAPI {
         if (priceInfo === undefined) {
           throw RestException.VaaNotFound();
         } else {
-          res.json(this.priceInfoToJson(priceInfo, verbose, binary));
+          res.json(this.priceInfoToJson(priceInfo, verbose, targetChain));
         }
       })
     );