@w3bstream/wasm-sdk

This is the official assemblyscript sdk for W3bstream.

Installation

The package requires node.js >=16.0.0

npm install @w3bstream/wasm-sdk

Useage

Your must export alloc function from @w3bstream/wasm-sdk for w3bstream vm

ExecSQL & QuerySQL

First, you need to create a project with database schema for wasm db storage

Create Database Schema

curl --location --request GET 'http://localhost:8888/srv-applet-mgr/v0/project_config/project_01/PROJECT_SCHEMA' \
--header 'Authorization: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJQYXlsb2FkIjoiOTAxNjYzODYzNTI5Njc3NSIsImlzcyI6InczYnN0cmVhbSIsImV4cCI6MTY3NTE0MzA0Nn0.okRRanlER4OwZTSS60m4qdg5F4qjVWDcPys-eAJ5KkE' \
--header 'Content-Type: application/json' \
--data-raw '{
  "tables": [
    {
      "name": "f_table",
      "desc": "test table",
      "cols": [
        {
          "name": "f_gender",
          "constrains": {
            "datatype": "UINT8",
            "length": 255,
            "default": "0",
            "desc": "user name"
          }
        }
      ],
      "keys": [
        {
          "name": "ui_gender",
          "isUnique": true,
          "columnNames": [
            "f_gender"
          ]
        }
      ],
      "withSoftDeletion": true,
      "withPrimaryKey": true
    }
  ]
}'

export { alloc } from "@w3bstream/wasm-sdk";
import { ExecSQL, QuerySQL, Log } from "@w3bstream/wasm-sdk";

export function start(rid: i32): i32 {
  Log("start from typescript");
  const key = GetDataByRID(rid);
  const v = new Map<string, i32>();
  v.set("int32", 1);
  const value = ExecSQL(`INSERT INTO "f_table" (f_id,f_gender) VALUES (?,?);`, [v, v]);
  const res = QuerySQL(`SELECT * FROM "f_table" WHERE f_id = ?;`, [v]);
  Log("wasm get value:" + value);
  Log("wasm get res:" + res);  
  return 0;
}

GetEnv(key:string)

import { GetEnv, Log } from "@w3bstream/wasm-sdk";
export { alloc } from "@w3bstream/wasm-sdk";

export function start(rid: i32): i32 {
  const key = GetDataByRID(rid);
  const value = GetEnv(key);
  Log("wasm get env:" + value);
  return 0;
}

CallContract(chainId:i32,to:string,data:string) : string

import { CallContract, GetDataByRID, Log, SendTx } from "@w3bstream/wasm-sdk";
import { hexToAddress, hexToBool, hexToUtf8 } from "@w3bstream/wasm-sdk/assembly/utility";

export { alloc } from "@w3bstream/wasm-sdk";

export function start(rid: i32): i32 {
  const message = GetDataByRID(rid);
  Log("wasm received message:" + message);
  const ERC20Addr = "0xa00744882684c3e4747faefd68d283ea44099d03";
  const balanceOfHex = CallContract(4689, ERC20Addr, `0x70a082310000000000000000000000009117f5ef4156709092f79740a97b1638ca399a00`);

  Log("balanceOfHex:" + balanceOfHex);
  Log("balanceOfInt:" + parseInt(balanceOfHex, 16).toString());

  const symbolHex = CallContract(4689, ERC20Addr, `0x95d89b41`);
  Log("symbolHex:" + symbolHex);
  Log("symbol:" + hexToUtf8(symbolHex));

  //if return type is 'bool'
  //use hexToBool

  //if return type is 'address'
  //use hexToAddress
  return 0;
}

Api call document

https://github.com/machinefi/w3bstream-wasm-golang-sdk/blob/main/api.md#send-zero-knowledge-proof

Log

Log(message: string)

import { Log } from "@w3bstream/wasm-sdk";
//export alloc for w3bstream vm
export { alloc } from "@w3bstream/wasm-sdk";

export function start(rid: i32): i32 {
  Log("Start from assemblyscript");
  const message = GetDataByRID(rid);
  Log("wasm received message:" + message);
  return 0;
}

GenZkProof

genZkProof(imageID: string, privateInput: string, publicInput: string, receiptType: string, eventType: string = "result") : string

import { Log, GetDataByRID, HTTP } from "@w3bstream/wasm-sdk";
export { alloc } from "@w3bstream/wasm-sdk";
export function start(rid: i32): i32 {
  HTTP.genZkProof(
    "3145991386, 3471678490, 3632776032, 2595288688, 1478438623, 4259749138, 987879707, 1456846509",
    "16",
    "4,30",
    "Stark",
    'handle_result'
  )
  return 0;
}

export function handle_result(rid: i32): i32 {
  const message = GetDataByRID(rid);
  Log(HTTP.parseResult(message))
  return 0;
}

ReadTx

ReadTx(chainName: string, hash: string, eventType: string = "result") : string

import { Log, GetDataByRID, HTTP } from "@w3bstream/wasm-sdk";
export { alloc } from "@w3bstream/wasm-sdk";
export function start(rid: i32): i32 {
  HTTP.readTx("iotex-testnet", "fcaf377ff3cc785d60c58de7e121d6a2e79e1c58c189ea8641f3ea61f7605285")
  return 0;
}

export function handle_result(rid: i32): i32 {
  const message = GetDataByRID(rid);
  Log(HTTP.parseResult(message))
  return 0;
}

SendTx

SendTx(chainId:i32, tx: string) : string

import { Log, GetDataByRID, HTTP } from "@w3bstream/wasm-sdk";
export { alloc } from "@w3bstream/wasm-sdk";
export function start(rid: i32): i32 {
  HTTP.sendTx("iotex-testnet", "default", "0x9117f5EF4156709092f79740a97b1638cA399A00", "10000000000000000000", "0x")
  return 0;
}

export function handle_result(rid: i32): i32 {
  const message = GetDataByRID(rid);
  Log(HTTP.parseResult(message))
  return 0;
}

GetDB & SetDB

SetDB(key: string, value: i32)

GetDB(key: string)

import { SetDB, Log, GetDB } from "@w3bstream/wasm-sdk";
export { alloc } from "@w3bstream/wasm-sdk";

export function start(rid: i32): i32 {
  SetDB("wordCount", word.length);
  let value = GetDB("wordCount");
  Log("wasm get value:" + value.toString());
  return 0;
}

Build

https://www.assemblyscript.org/concepts.html#special-imports

The abort method will be exposed inside w3bstream in later versions issues/308

export function abort(message: string | null, fileName: string | null, lineNumber: u32, columnNumber: u32): void {}

package.json

"scripts": {
    "asbuild:release": "asc assembly/index.ts --use abort=assembly/index/abort --target release",
  },

Some language features need support from the host environment to function, yielding a few special module imports depending on the feature set used within the module. Generated bindings provide these automatically where necessary.

• function env.abort?(message: usize, fileName: usize, line: u32, column: u32): void

The respective implementations of , and can be overridden with, for example, , here redirecting calls to to a custom function in . Useful if an environment does not provide compatible implementations, or when the respective imports are not desired and custom implementations are sufficient.aborttraceseed--use abort=assembly/index/myAbortabortmyAbortassembly/index.ts

Known Issues

• If the pnpm installation package is used, dependencies may not be correctly installed. You can use npm or yarn to install dependencies

Run examples

Examples can be found in the ./examples folder.

To build an example, from the main SDK folder type:

npm install
npm run build:<example_name>

Available examples are:

• abort - Tests the call of the abort function on the W3bstream VM side by calling assert in your applet.
• click2earn - a simple applet that mints ERC20 tokens every 5 "click" messages are received
• env - shows how to retrieve env variable for the parent project (a defined in the project's settings on dev.w3bstream.com)
• erc20_mint - a basic example that shows how to mint ERC20 tokens from an applet according to the info included in the data message
• json - shows how to parse a data message and extract specific fields
• sql - shows how to insert and query data from W3bstreams database using SQL
• token_distribute - another basic example that sends ERC20 tokens to a wallet
• vm - another example of using assert in your applet
• word_count - counts the number of words included in a message payload and shows how to save it in W3bstream's key/value storage.