Add BpfLoader (#34)

feat: Add BpfLoader

web3.js/src/bpf-loader.js

@@ -0,0 +1,55 @@
+// @flow
+
+import fs from 'mz/fs';
+import elfy from 'elfy';
+
+import {Account, PublicKey, Loader, SystemProgram} from '.';
+import {sendAndConfirmTransaction} from './util/send-and-confirm-transaction';
+import type {Connection} from '.';
+
+/**
+ * Factory class for transactions to interact with a program loader
+ */
+export class BpfLoader {
+  /**
+   * Public key that identifies the NativeLoader
+   */
+  static get programId(): PublicKey {
+    return new PublicKey('0x0606060606060606060606060606060606060606060606060606060606060606');
+  }
+
+  /**
+   * Loads a BPF program
+   *
+   * @param connection The connection to use
+   * @param owner User account to load the program with
+   * @param programName Name of the BPF program
+   */
+  static async load(
+    connection: Connection,
+    owner: Account,
+    programName: string,
+  ): Promise<PublicKey> {
+    const programAccount = new Account();
+
+    const data = await fs.readFile(programName);
+    const elf = elfy.parse(data);
+    const section = elf.body.sections.find(section => section.name === '.text.entrypoint');
+
+    // Allocate memory for the program account
+    const transaction = SystemProgram.createAccount(
+      owner.publicKey,
+      programAccount.publicKey,
+      1,
+      section.data.length,
+      BpfLoader.programId,
+    );
+    await sendAndConfirmTransaction(connection, owner, transaction);
+
+    const loader = new Loader(connection, BpfLoader.programId);
+    await loader.load(programAccount, section.data);
+    await loader.finalize(programAccount);
+
+    return programAccount.publicKey;
+  }
+}

web3.js/src/index.js

@@ -1,5 +1,6 @@
 // @flow
 export {Account} from './account';
+export {BpfLoader} from './bpf-loader';
 export {BudgetProgram} from './budget-program';
 export {Connection} from './connection';
 export {Loader} from './loader';

web3.js/src/loader.js

@@ -32,10 +32,9 @@ export class Loader {
    * Load program data
    *
    * @param program Account to load the program info
-   * @param offset Account userdata offset to write `bytes` into
-   * @param bytes Program data
+   * @param data Program data
    */
-  async load(program: Account, offset: number, bytes: Array<number>) {
+  async load(program: Account, data: Array<number>) {
     const userdataLayout = BufferLayout.struct([
       BufferLayout.u32('instruction'),
       BufferLayout.u32('offset'),
@@ -43,27 +42,35 @@ export class Loader {
       BufferLayout.u32('bytesLengthPadding'),
       BufferLayout.seq(
         BufferLayout.u8('byte'),
-        BufferLayout.offset(BufferLayout.u32(), -8),
-        'bytes'
-      ),
+        BufferLayout.offset(BufferLayout.u32(), -8), 'bytes'),
     ]);
 
-    let userdata = Buffer.alloc(bytes.length + 16);
-    userdataLayout.encode(
-      {
-        instruction: 0, // Load instruction
-        offset,
-        bytes,
-      },
-      userdata,
-    );
+    const chunkSize = 256;
+    let userdata = Buffer.alloc(chunkSize + 16);
+    let offset = 0;
+    let array = data;
+    while (array.length > 0) {
+      const bytes = array.slice(0, chunkSize);
 
-    const transaction = new Transaction().add({
-      keys: [program.publicKey],
-      programId: this.programId,
-      userdata,
-    });
-    await sendAndConfirmTransaction(this.connection, program, transaction);
+      userdataLayout.encode(
+        {
+          instruction: 0, // Load instruction
+          offset,
+          bytes,
+        },
+        userdata,
+      );
+
+      const transaction = new Transaction().add({
+        keys: [program.publicKey],
+        programId: this.programId,
+        userdata,
+      });
+      await sendAndConfirmTransaction(this.connection, program, transaction);
+
+      offset += chunkSize;
+      array = array.slice(chunkSize);
+    }
   }
 
   /**

web3.js/src/native-loader.js

@@ -42,7 +42,7 @@ export class NativeLoader {
     await sendAndConfirmTransaction(connection, owner, transaction);
 
     const loader = new Loader(connection, NativeLoader.programId);
-    await loader.load(programAccount, 0, bytes);
+    await loader.load(programAccount, bytes);
     await loader.finalize(programAccount);
 
     return programAccount.publicKey;