feat: initial verified streaming support

package.json

@@ -30,6 +30,7 @@
     "scripts": {
         "prepare": "presetter bootstrap",
         "build": "presetter run build",
+        "build:wasm": "mkdir ./lib/wasm && tinygo build -o ./lib/wasm/bao.wasm -target wasm ./src/golang/main.go",
         "semantic-release": "semantic-release"
     },
     "dependencies": {

src/go_wasm.ts

@@ -0,0 +1,652 @@
+const encoder = new TextEncoder();
+const decoder = new TextDecoder();
+
+type ImportObject = {
+  wasi_snapshot_preview1: {
+    proc_exit: (code) => void;
+    random_get: (bufPtr, bufLen) => number;
+    fd_seek: () => number;
+    fd_write: (fd, iovs_ptr, iovs_len, nwritten_ptr) => number;
+    fd_close: () => number;
+    fd_fdstat_get: () => number;
+  };
+  env: {
+    "syscall/js.valueInvoke": (
+      ret_addr,
+      v_addr,
+      args_ptr,
+      args_len,
+      args_cap,
+    ) => void;
+    "syscall/js.valueDelete": (v_addr, p_ptr, p_len) => void;
+    "syscall/js.copyBytesToGo": (
+      ret_addr,
+      dest_addr,
+      dest_len,
+      dest_cap,
+      source_addr,
+    ) => void;
+    "syscall/js.valueSet": (v_addr, p_ptr, p_len, x_addr) => void;
+    "syscall/js.copyBytesToJS": (
+      ret_addr,
+      dest_addr,
+      source_addr,
+      source_len,
+      source_cap,
+    ) => void;
+    "syscall/js.valueNew": (
+      ret_addr,
+      v_addr,
+      args_ptr,
+      args_len,
+      args_cap,
+    ) => void;
+    "syscall/js.valueInstanceOf": (v_addr, t_addr) => boolean;
+    "runtime.ticks": () => number;
+    "runtime.sleepTicks": (timeout) => void;
+    "syscall/js.valueLoadString": (
+      v_addr,
+      slice_ptr,
+      slice_len,
+      slice_cap,
+    ) => void;
+    "syscall/js.stringVal": (ret_ptr, value_ptr, value_len) => void;
+    "syscall/js.valueIndex": (ret_addr, v_addr, i) => void;
+    "syscall/js.valueLength": (v_addr) => any;
+    "syscall/js.valueCall": (
+      ret_addr,
+      v_addr,
+      m_ptr,
+      m_len,
+      args_ptr,
+      args_len,
+      args_cap,
+    ) => void;
+    "syscall/js.finalizeRef": (sp) => void;
+    "syscall/js.valueGet": (retval, v_addr, p_ptr, p_len) => void;
+    "syscall/js.valuePrepareString": (ret_addr, v_addr) => void;
+    "syscall/js.valueSetIndex": (v_addr, i, x_addr) => void;
+  };
+};
+
+let logLine: any = [];
+
+export default class Go {
+  private _callbackTimeouts: Map<any, any>;
+  private _nextCallbackTimeoutID: number;
+  private _inst?: any;
+  private _values: any[] = [NaN, 0, null, true, false, global, this];
+  private _ids: Map<any, any> = new Map<any, any>();
+  private _idPool: any[] = [];
+  private _goRefCounts: any[] = [];
+  private exited = false;
+  private _resolveCallbackPromise?: () => void;
+  importObject: ImportObject;
+
+  constructor() {
+    this._callbackTimeouts = new Map();
+    this._nextCallbackTimeoutID = 1;
+
+    const mem = () => {
+      // The buffer may change when requesting more memory.
+      return new DataView(this._inst.exports.memory.buffer);
+    };
+
+    const setInt64 = (addr, v) => {
+      mem().setUint32(addr + 0, v, true);
+      mem().setUint32(addr + 4, Math.floor(v / 4294967296), true);
+    };
+
+    const getInt64 = (addr) => {
+      const low = mem().getUint32(addr + 0, true);
+      const high = mem().getInt32(addr + 4, true);
+      return low + high * 4294967296;
+    };
+
+    const loadValue = (addr) => {
+      const f = mem().getFloat64(addr, true);
+      if (f === 0) {
+        return undefined;
+      }
+      if (!isNaN(f)) {
+        return f;
+      }
+
+      const id = mem().getUint32(addr, true);
+      return this._values[id];
+    };
+
+    const storeValue = (addr, v) => {
+      const nanHead = 0x7ff80000;
+
+      if (typeof v === "number") {
+        if (isNaN(v)) {
+          mem().setUint32(addr + 4, nanHead, true);
+          mem().setUint32(addr, 0, true);
+          return;
+        }
+        if (v === 0) {
+          mem().setUint32(addr + 4, nanHead, true);
+          mem().setUint32(addr, 1, true);
+          return;
+        }
+        mem().setFloat64(addr, v, true);
+        return;
+      }
+
+      switch (v) {
+        case undefined:
+          mem().setFloat64(addr, 0, true);
+          return;
+        case null:
+          mem().setUint32(addr + 4, nanHead, true);
+          mem().setUint32(addr, 2, true);
+          return;
+        case true:
+          mem().setUint32(addr + 4, nanHead, true);
+          mem().setUint32(addr, 3, true);
+          return;
+        case false:
+          mem().setUint32(addr + 4, nanHead, true);
+          mem().setUint32(addr, 4, true);
+          return;
+      }
+
+      let id = this._ids.get(v);
+      if (id === undefined) {
+        id = this._idPool.pop();
+        if (id === undefined) {
+          id = this._values.length;
+        }
+        this._values[id] = v;
+        this._goRefCounts[id] = 0;
+        this._ids.set(v, id);
+      }
+      this._goRefCounts[id]++;
+      let typeFlag = 1;
+      switch (typeof v) {
+        case "string":
+          typeFlag = 2;
+          break;
+        case "symbol":
+          typeFlag = 3;
+          break;
+        case "function":
+          typeFlag = 4;
+          break;
+      }
+      mem().setUint32(addr + 4, nanHead | typeFlag, true);
+      mem().setUint32(addr, id, true);
+    };
+
+    const loadSlice = (array, len, cap?) => {
+      return new Uint8Array(this._inst.exports.memory.buffer, array, len);
+    };
+
+    const loadSliceOfValues = (array, len, cap) => {
+      const a = new Array(len);
+      for (let i = 0; i < len; i++) {
+        a[i] = loadValue(array + i * 8);
+      }
+      return a;
+    };
+
+    const loadString = (ptr, len) => {
+      return decoder.decode(
+        new DataView(this._inst.exports.memory.buffer, ptr, len),
+      );
+    };
+
+    const timeOrigin = Date.now() - performance.now();
+    this.importObject = {
+      wasi_snapshot_preview1: {
+        fd_write: (fd, iovs_ptr, iovs_len, nwritten_ptr) => {
+          let nwritten = 0;
+          if (fd == 1) {
+            for (let iovs_i = 0; iovs_i < iovs_len; iovs_i++) {
+              let iov_ptr = iovs_ptr + iovs_i * 8;
+              let ptr = mem().getUint32(iov_ptr + 0, true);
+              let len = mem().getUint32(iov_ptr + 4, true);
+              nwritten += len;
+              for (let i = 0; i < len; i++) {
+                let c = mem().getUint8(ptr + i);
+                if (c == 13) {
+                  // CR
+                  // ignore
+                } else if (c == 10) {
+                  // LF
+                  // write line
+                  let line = decoder.decode(new Uint8Array(logLine));
+                  logLine = [];
+                  console.log(line);
+                } else {
+                  logLine.push(c);
+                }
+              }
+            }
+          } else {
+            console.error("Invalid file descriptor:", fd);
+          }
+          mem().setUint32(nwritten_ptr, nwritten, true);
+          return 0;
+        },
+        fd_close: () => 0, // dummy
+        fd_fdstat_get: () => 0, // dummy
+        fd_seek: () => 0, // dummy
+        proc_exit: (code) => {
+          if (global.process) {
+            // Node.js
+            process.exit(code);
+          } else {
+            // Can't exit in a browser.
+            throw "Trying to exit with code " + code;
+          }
+        },
+        random_get: (bufPtr, bufLen) => {
+          crypto.getRandomValues(loadSlice(bufPtr, bufLen));
+          return 0;
+        },
+      },
+      env: {
+        "runtime.ticks": () => {
+          return timeOrigin + performance.now();
+        },
+        "runtime.sleepTicks": (timeout) => {
+          setTimeout(this._inst.exports.go_scheduler, timeout);
+        },
+        "syscall/js.finalizeRef": (sp) => {
+          console.error("syscall/js.finalizeRef not implemented");
+        },
+        "syscall/js.stringVal": (ret_ptr, value_ptr, value_len) => {
+          const s = loadString(value_ptr, value_len);
+          storeValue(ret_ptr, s);
+        },
+        "syscall/js.valueGet": (retval, v_addr, p_ptr, p_len) => {
+          let prop = loadString(p_ptr, p_len);
+          let value = loadValue(v_addr);
+          let result = Reflect.get(value, prop);
+          storeValue(retval, result);
+        },
+        "syscall/js.valueSet": (v_addr, p_ptr, p_len, x_addr) => {
+          const v = loadValue(v_addr);
+          const p = loadString(p_ptr, p_len);
+          const x = loadValue(x_addr);
+          Reflect.set(v, p, x);
+        },
+        "syscall/js.valueDelete": (v_addr, p_ptr, p_len) => {
+          const v = loadValue(v_addr);
+          const p = loadString(p_ptr, p_len);
+          Reflect.deleteProperty(v, p);
+        },
+        "syscall/js.valueIndex": (ret_addr, v_addr, i) => {
+          storeValue(ret_addr, Reflect.get(loadValue(v_addr), i));
+        },
+        "syscall/js.valueSetIndex": (v_addr, i, x_addr) => {
+          Reflect.set(loadValue(v_addr), i, loadValue(x_addr));
+        },
+        "syscall/js.valueCall": (
+          ret_addr,
+          v_addr,
+          m_ptr,
+          m_len,
+          args_ptr,
+          args_len,
+          args_cap,
+        ) => {
+          const v = loadValue(v_addr);
+          const name = loadString(m_ptr, m_len);
+          const args = loadSliceOfValues(args_ptr, args_len, args_cap);
+          try {
+            const m = Reflect.get(v, name);
+            storeValue(ret_addr, Reflect.apply(m, v, args));
+            mem().setUint8(ret_addr + 8, 1);
+          } catch (err) {
+            storeValue(ret_addr, err);
+            mem().setUint8(ret_addr + 8, 0);
+          }
+        },
+        "syscall/js.valueInvoke": (
+          ret_addr,
+          v_addr,
+          args_ptr,
+          args_len,
+          args_cap,
+        ) => {
+          try {
+            const v = loadValue(v_addr);
+            const args = loadSliceOfValues(args_ptr, args_len, args_cap);
+            storeValue(ret_addr, Reflect.apply(v, undefined, args));
+            mem().setUint8(ret_addr + 8, 1);
+          } catch (err) {
+            storeValue(ret_addr, err);
+            mem().setUint8(ret_addr + 8, 0);
+          }
+        },
+        "syscall/js.valueNew": (
+          ret_addr,
+          v_addr,
+          args_ptr,
+          args_len,
+          args_cap,
+        ) => {
+          const v = loadValue(v_addr);
+          const args = loadSliceOfValues(args_ptr, args_len, args_cap);
+          try {
+            storeValue(ret_addr, Reflect.construct(v, args));
+            mem().setUint8(ret_addr + 8, 1);
+          } catch (err) {
+            storeValue(ret_addr, err);
+            mem().setUint8(ret_addr + 8, 0);
+          }
+        },
+        "syscall/js.valueLength": (v_addr) => {
+          return loadValue(v_addr).length;
+        },
+        "syscall/js.valuePrepareString": (ret_addr, v_addr) => {
+          const s = String(loadValue(v_addr));
+          const str = encoder.encode(s);
+          storeValue(ret_addr, str);
+          setInt64(ret_addr + 8, str.length);
+        },
+        "syscall/js.valueLoadString": (
+          v_addr,
+          slice_ptr,
+          slice_len,
+          slice_cap,
+        ) => {
+          const str = loadValue(v_addr);
+          loadSlice(slice_ptr, slice_len, slice_cap).set(str);
+        },
+        "syscall/js.valueInstanceOf": (v_addr, t_addr) => {
+          return loadValue(v_addr) instanceof loadValue(t_addr);
+        },
+        "syscall/js.copyBytesToGo": (
+          ret_addr,
+          dest_addr,
+          dest_len,
+          dest_cap,
+          source_addr,
+        ) => {
+          let num_bytes_copied_addr = ret_addr;
+          let returned_status_addr = ret_addr + 4;
+
+          const dst = loadSlice(dest_addr, dest_len, dest_cap);
+          const src = loadValue(source_addr);
+          if (
+            !(src instanceof Uint8Array || src instanceof Uint8ClampedArray)
+          ) {
+            mem().setUint8(returned_status_addr, 0);
+            return;
+          }
+          const toCopy = src.subarray(0, dst.length);
+          dst.set(toCopy);
+          setInt64(num_bytes_copied_addr, toCopy.length);
+          mem().setUint8(returned_status_addr, 1);
+        },
+        "syscall/js.copyBytesToJS": (
+          ret_addr,
+          dest_addr,
+          source_addr,
+          source_len,
+          source_cap,
+        ) => {
+          let num_bytes_copied_addr = ret_addr;
+          let returned_status_addr = ret_addr + 4;
+
+          const dst = loadValue(dest_addr);
+          const src = loadSlice(source_addr, source_len, source_cap);
+          if (
+            !(dst instanceof Uint8Array || dst instanceof Uint8ClampedArray)
+          ) {
+            mem().setUint8(returned_status_addr, 0);
+            return;
+          }
+          const toCopy = src.subarray(0, dst.length);
+          dst.set(toCopy);
+          setInt64(num_bytes_copied_addr, toCopy.length);
+          mem().setUint8(returned_status_addr, 1);
+        },
+      },
+    };
+  }
+
+  async run(instance) {
+    this._inst = instance;
+    const mem = new DataView(this._inst.exports.memory.buffer);
+
+    while (true) {
+      const callbackPromise = new Promise((resolve) => {
+        this._resolveCallbackPromise = () => {
+          if (this.exited) {
+            throw new Error("Bad callback: Go program has already exited");
+          }
+          setTimeout(resolve, 0);
+        };
+      });
+      this._inst.exports._start();
+      if (this.exited) {
+        break;
+      }
+      await callbackPromise;
+    }
+  }
+
+  _resume() {
+    if (this.exited) {
+      throw new Error("Go program has already exited");
+    }
+    this._inst.exports.resume();
+  }
+}
+
+if (
+  typeof global !== "undefined" ||
+  typeof window !== "undefined" ||
+  typeof self !== "undefined"
+) {
+  if (typeof global !== "undefined") {
+    // global already exists
+  } else if (typeof window !== "undefined") {
+    window.global = window;
+  } else if (typeof self !== "undefined") {
+    self.global = self;
+  } else {
+    throw new Error(
+      "Cannot export Go (neither global, window nor self is defined)",
+    );
+  }
+
+  if (!global.require && typeof require !== "undefined") {
+    global.require = require;
+  }
+
+  // @ts-ignore
+  if (!global.fs && global.require) {
+    global.fs = require("fs");
+  }
+
+  const enosys = () => {
+    const err = new Error("not implemented");
+    // @ts-ignore
+    err.code = "ENOSYS";
+    return err;
+  };
+
+  if (!global.fs) {
+    let outputBuf = "";
+    global.fs = {
+      constants: {
+        O_WRONLY: -1,
+        O_RDWR: -1,
+        O_CREAT: -1,
+        O_TRUNC: -1,
+        O_APPEND: -1,
+        O_EXCL: -1,
+      },
+      writeSync: (fd, buf) => {
+        outputBuf += decoder.decode(buf);
+        const nl = outputBuf.lastIndexOf("\n");
+        if (nl != -1) {
+          console.log(outputBuf.substr(0, nl));
+          outputBuf = outputBuf.substr(nl + 1);
+        }
+        return buf.length;
+      },
+      write: (fd, buf, offset, length, position, callback) => {
+        if (offset !== 0 || length !== buf.length || position !== null) {
+          callback(enosys());
+          return;
+        }
+        const n = global.fs.writeSync(fd, buf);
+        callback(null, n);
+      },
+      open: (path, flags, mode, callback) => {
+        callback(enosys());
+      },
+      fsync: (fd, callback) => {
+        callback(null);
+      },
+      fdatasync: (fd, callback) => {
+        callback(null);
+      },
+      close: (fd, callback) => {
+        callback(null);
+      },
+      createReadStream: enosys,
+      createWriteStream: enosys,
+      ftruncate: (fd, length, callback) => {
+        callback(enosys());
+      },
+      readFile: (path, callback) => {
+        callback(enosys());
+      },
+      writeFile: (path, data, callback) => {
+        callback(enosys());
+      },
+      truncate: (path, length, callback) => {
+        callback(enosys());
+      },
+      readdir: (path, callback) => {
+        callback(enosys());
+      },
+      unlink: (path, callback) => {
+        callback(enosys());
+      },
+      rmdir: (path, callback) => {
+        callback(enosys());
+      },
+      mkdir: (path, perm, callback) => {
+        callback(enosys());
+      },
+      stat: (path, callback) => {
+        callback(enosys());
+      },
+      lstat: (path, callback) => {
+        callback(enosys());
+      },
+      fstat: (fd, callback) => {
+        callback(enosys());
+      },
+      rename: (oldPath, newPath, callback) => {
+        callback(enosys());
+      },
+      symlink: (target, path, callback) => {
+        callback(enosys());
+      },
+      link: (existingPath, newPath, callback) => {
+        callback(enosys());
+      },
+      readlink: (path, callback) => {
+        callback(enosys());
+      },
+      chmod: (path, mode, callback) => {
+        callback(enosys());
+      },
+      lchmod: (path, mode, callback) => {
+        callback(enosys());
+      },
+      fchmod: (fd, mode, callback) => {
+        callback(enosys());
+      },
+      chown: (path, uid, gid, callback) => {
+        callback(enosys());
+      },
+      lchown: (path, uid, gid, callback) => {
+        callback(enosys());
+      },
+      fchown: (fd, uid, gid, callback) => {
+        callback(enosys());
+      },
+      utimes: (path, atime, mtime, callback) => {
+        callback(enosys());
+      },
+      futimes: (fd, atime, mtime, callback) => {
+        callback(enosys());
+      },
+      realpath: (path, callback) => {
+        callback(enosys());
+      },
+      fallocate: (fd, mode, offset, length, callback) => {
+        callback(enosys());
+      },
+      copyFile: (src, dest, flags, callback) => {
+        callback(enosys());
+      },
+    };
+  }
+
+  if (!global.crypto) {
+    global.crypto = {
+      // @ts-ignore
+      getRandomValues: (arr: number[]) => {
+        for (let i = 0; i < arr.length; i++) {
+          arr[i] = Math.floor(Math.random() * 256);
+        }
+      },
+    };
+  }
+
+  if (!global.performance) {
+    // @ts-ignore
+    global.performance = {
+      now: () => Date.now(),
+    };
+  }
+
+  if (!global.TextEncoder) {
+    global.TextEncoder = TextEncoder;
+  }
+
+  if (!global.TextDecoder) {
+    // @ts-ignore
+    global.TextDecoder = TextDecoder;
+  }
+
+  if (!global.Buffer) {
+    global.Buffer = {
+      // @ts-ignore
+      isBuffer: (x) => false,
+    };
+  }
+
+  if (!global.process) {
+    // @ts-ignore
+    global.process = {
+      getuid: () => -1,
+      getgid: () => -1,
+      geteuid: () => -1,
+      getegid: () => -1,
+      getgroups: () => [],
+      pid: -1,
+      ppid: -1,
+      umask: () => 0,
+      cwd: () => "/",
+      chdir: (dir) => {},
+    };
+  }
+
+  if (!global.Error) {
+    // @ts-ignore
+    global.Error = class extends Error {};
+  }
+}

src/golang/go.mod

@@ -0,0 +1,8 @@
+module main
+
+go 1.19
+
+require (
+	github.com/klauspost/cpuid/v2 v2.0.9 // indirect
+	lukechampine.com/blake3 v1.2.1 // indirect
+)

src/golang/go.sum

@@ -0,0 +1,4 @@
+github.com/klauspost/cpuid/v2 v2.0.9 h1:lgaqFMSdTdQYdZ04uHyN2d/eKdOMyi2YLSvlQIBFYa4=
+github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
+lukechampine.com/blake3 v1.2.1 h1:YuqqRuaqsGV71BV/nm9xlI0MKUv4QC54jQnBChWbGnI=
+lukechampine.com/blake3 v1.2.1/go.mod h1:0OFRp7fBtAylGVCO40o87sbupkyIGgbpv1+M1k1LM6k=

src/golang/main.go

@@ -0,0 +1,125 @@
+package main
+
+import (
+	"bytes"
+	"io"
+	"lukechampine.com/blake3"
+	"math/rand"
+	"strconv"
+	"syscall/js"
+)
+
+var activeReader *reader
+var pipe chan []byte
+var callbackId int
+var nextBytes chan int
+var exitChan chan bool
+
+func main() {
+	pipe = make(chan []byte)
+	nextBytes = make(chan int)
+	exitChan = make(chan bool)
+	callbackId = rand.Int()
+	<-exitChan
+}
+
+type reader struct {
+}
+
+func (r *reader) Read(p []byte) (n int, err error) {
+	nextBytes <- len(p)
+	data := <-pipe
+	copy(p[:], data[:])
+	resetWritePromise()
+	return len(data), nil
+}
+
+//export start
+func start() int {
+
+	rootChan := make(chan []byte)
+	proofChan := make(chan []byte)
+
+	resetWritePromise()
+	setGlobalObject(getGlobalPrefix()+"_set_root", js.FuncOf(func(this js.Value, args []js.Value) any {
+		jsroot := args[0]
+
+		root := make([]byte, jsroot.Get("length").Int())
+		js.CopyBytesToGo(root, jsroot)
+
+		rootChan <- root
+
+		return nil
+	}))
+
+	setGlobalObject(getGlobalPrefix()+"_set_proof", js.FuncOf(func(this js.Value, args []js.Value) any {
+		jsproof := args[0]
+
+		proofSlice := make([]byte, jsproof.Get("length").Int())
+		js.CopyBytesToGo(proofSlice, jsproof)
+
+		proofChan <- proofSlice
+
+		return nil
+	}))
+
+	setGlobalObject(getGlobalPrefix()+"_write", js.FuncOf(func(this js.Value, args []js.Value) any {
+		d := args[0]
+		data := make([]byte, d.Get("length").Int())
+		js.CopyBytesToGo(data, d)
+
+		pipe <- data
+
+		return nil
+	}))
+
+	go func() {
+		rootSlice := <-rootChan
+		proof := <-proofChan
+
+		var root [32]byte
+
+		copy(root[:], rootSlice)
+
+		ret, err := blake3.BaoDecode(io.Discard, activeReader, bytes.NewReader(proof), root)
+		setGlobalObject(getGlobalPrefix()+"_result", ret)
+		setGlobalObject(getGlobalPrefix()+"_error", err)
+	}()
+
+	return callbackId
+}
+
+// exit write
+func exit() {
+	exitChan <- true
+}
+
+func createWritePromiseHandler() js.Value {
+	return createPromiseHandler(func(this js.Value, args []js.Value) {
+		bytesToRead := <-nextBytes
+		args[0].Invoke(bytesToRead)
+	})
+}
+
+func createPromiseHandler(cb func(this js.Value, args []js.Value)) js.Value {
+	return js.Global().Get("Promise").New(js.FuncOf(func(this js.Value, args []js.Value) any {
+		cb(this, args)
+		return nil
+	}))
+}
+
+func getGlobalPrefix() string {
+	return "bao_" + strconv.FormatInt(int64(callbackId), 10)
+}
+
+func getWritePromiseName() string {
+	return getGlobalPrefix() + "_write_promise"
+}
+
+func resetWritePromise() {
+	setGlobalObject(getWritePromiseName(), createWritePromiseHandler())
+}
+
+func setGlobalObject(name string, p any) {
+	js.Global().Set(name, p)
+}

src/index.ts

@@ -1,2 +1,3 @@
 export * from "./client.js";
 export * from "./cid.js";
+export * from "./verify.js";

src/verify.ts

@@ -0,0 +1,160 @@
+// @ts-ignore
+import baoWasm from "#wasm/bao.wasm";
+import Go from "#go_wasm.js";
+
+export async function getVerifiableStream(
+  root: Uint8Array,
+  proof: Uint8Array,
+  data: ReadableStream,
+) {
+  const wasm = await getWasmInstance();
+  // @ts-ignore
+  const reader = new VariableChunkStream(data);
+  let bytesToRead;
+
+  const getNextBytes = async () => {
+    bytesToRead = getWasmProperty(wasmId, "write_promise");
+    bytesToRead = await bytesToRead;
+  };
+
+  const callExports = (name: string) => {
+    // @ts-ignore
+    return wasm.exports[name]();
+  };
+
+  // @ts-ignore
+  const exit = () => {
+    callExports("exit");
+    cleanup();
+  };
+
+  const done = (controller: ReadableStreamDefaultController) => {
+    controller.close();
+    exit();
+  };
+
+  const cleanup = () => {
+    const win = getWin();
+    const props = Object.getOwnPropertyNames(win);
+
+    props
+      .filter((item) => item.startsWith(`bao_${wasmId}`))
+      .forEach((item) => {
+        delete win[item];
+      });
+  };
+
+  await getNextBytes();
+  // @ts-ignore
+  const wasmId = callExports("start");
+  getWasmProperty(wasmId, "set_root")(root);
+  getWasmProperty(wasmId, "set_proof")(proof);
+
+  return new ReadableStream({
+    async pull(controller) {
+      let chunk;
+
+      try {
+        chunk = await reader.read(bytesToRead);
+        if (chunk.value) {
+          getWasmProperty(wasmId, "write")(chunk.value);
+        }
+      } catch (e) {
+        // @ts-ignore
+        exit();
+        controller.error(e);
+      }
+
+      const result = getWasmProperty(wasmId, "result");
+
+      const wasmDone = result === undefined;
+
+      if (result === undefined) {
+        await getNextBytes();
+      }
+
+      if (chunk.done || wasmDone) {
+        if (wasmDone) {
+          if (result) {
+            done(controller);
+          } else {
+            controller.error(getWasmProperty(wasmId, "error"));
+          }
+        } else {
+          done(controller);
+        }
+      }
+    },
+    async cancel(reason: any) {
+      await reader.cancel(reason);
+      exit();
+    },
+  });
+}
+
+function getWin() {
+  return globalThis || self || window;
+}
+
+function getWasmProperty(id: number, prop: string) {
+  return getWin()[`bao_${id}_${prop}`];
+}
+
+async function getWasmInstance() {
+  const go = new Go();
+  let wasm = (await baoWasm(
+    go.importObject,
+  )) as WebAssembly.WebAssemblyInstantiatedSource;
+  go.run(wasm);
+
+  return wasm;
+}
+
+class VariableChunkStream {
+  private reader: ReadableStreamDefaultReader;
+  private currentChunk: Uint8Array = new Uint8Array();
+  private currentChunkSize = 0;
+  private readerDone = false;
+
+  constructor(stream: ReadableStream) {
+    this.reader = stream.getReader();
+  }
+
+  async read(bytes: number) {
+    if (this.currentChunk.length === 0 && !this.readerDone) {
+      const { done, value } = await this.reader.read();
+      if (done) {
+        return { done: true };
+      }
+      this.currentChunk = value;
+      this.currentChunkSize = this.currentChunk.length;
+    }
+
+    if (this.currentChunkSize > bytes) {
+      const chunk = this.currentChunk.slice(0, bytes);
+      this.currentChunk = this.currentChunk.slice(bytes);
+      this.currentChunkSize -= bytes;
+      return { value: chunk, done: false };
+    }
+    if (this.currentChunkSize < bytes && !this.readerDone) {
+      const { done, value } = await this.reader.read();
+      if (done) {
+        this.readerDone = true;
+      }
+      this.currentChunk = new Uint8Array([...this.currentChunk, ...value]);
+      this.currentChunkSize += value.length;
+      return this.read(bytes);
+    }
+
+    const chunk = this.currentChunk;
+    this.currentChunk = new Uint8Array();
+    this.currentChunkSize = 0;
+    return { value: chunk, done: this.readerDone };
+  }
+
+  async cancel(reason: any) {
+    await this.reader.cancel(reason);
+    this.currentChunk = new Uint8Array();
+    this.currentChunkSize = 0;
+  }
+}