feat: implement message v0 decompilation

web3.js/src/message/legacy.ts

@@ -13,6 +13,9 @@ import {
   MessageAddressTableLookup,
   MessageCompiledInstruction,
 } from './index';
+import {TransactionInstruction} from '../transaction';
+import {CompiledKeys} from './compiled-keys';
+import {MessageAccountKeys} from './account-keys';
 
 /**
  * An instruction to execute by a program
@@ -37,13 +40,19 @@ export type MessageArgs = {
   /** The message header, identifying signed and read-only `accountKeys` */
   header: MessageHeader;
   /** All the account keys used by this transaction */
-  accountKeys: string[];
+  accountKeys: string[] | PublicKey[];
   /** The hash of a recent ledger block */
   recentBlockhash: Blockhash;
   /** Instructions that will be executed in sequence and committed in one atomic transaction if all succeed. */
   instructions: CompiledInstruction[];
 };
 
+export type CompileLegacyArgs = {
+  payerKey: PublicKey;
+  instructions: Array<TransactionInstruction>;
+  recentBlockhash: Blockhash;
+};
+
 /**
  * List of instructions to be processed atomically
  */
@@ -93,6 +102,29 @@ export class Message {
     return [];
   }
 
+  getAccountKeys(): MessageAccountKeys {
+    return new MessageAccountKeys(this.staticAccountKeys);
+  }
+
+  static compile(args: CompileLegacyArgs): Message {
+    const compiledKeys = CompiledKeys.compile(args.instructions, args.payerKey);
+    const [header, staticAccountKeys] = compiledKeys.getMessageComponents();
+    const accountKeys = new MessageAccountKeys(staticAccountKeys);
+    const instructions = accountKeys.compileInstructions(args.instructions).map(
+      (ix: MessageCompiledInstruction): CompiledInstruction => ({
+        programIdIndex: ix.programIdIndex,
+        accounts: ix.accountKeyIndexes,
+        data: bs58.encode(ix.data),
+      }),
+    );
+    return new Message({
+      header,
+      accountKeys: staticAccountKeys,
+      recentBlockhash: args.recentBlockhash,
+      instructions,
+    });
+  }
+
   isAccountSigner(index: number): boolean {
     return index < this.header.numRequiredSignatures;
   }
@@ -250,7 +282,7 @@ export class Message {
     for (let i = 0; i < accountCount; i++) {
       const account = byteArray.slice(0, PUBLIC_KEY_LENGTH);
       byteArray = byteArray.slice(PUBLIC_KEY_LENGTH);
-      accountKeys.push(bs58.encode(Buffer.from(account)));
+      accountKeys.push(new PublicKey(Buffer.from(account)));
     }
 
     const recentBlockhash = byteArray.slice(0, PUBLIC_KEY_LENGTH);

web3.js/src/message/v0.ts

@@ -40,6 +40,14 @@ export type CompileV0Args = {
   addressLookupTableAccounts?: Array<AddressLookupTableAccount>;
 };
 
+export type GetAccountKeysArgs =
+  | {
+      accountKeysFromLookups: AccountKeysFromLookups;
+    }
+  | {
+      addressLookupTableAccounts: AddressLookupTableAccount[];
+    };
+
 export class MessageV0 {
   header: MessageHeader;
   staticAccountKeys: Array<PublicKey>;
@@ -59,6 +67,88 @@ export class MessageV0 {
     return 0;
   }
 
+  get numAccountKeysFromLookups(): number {
+    let count = 0;
+    for (const lookup of this.addressTableLookups) {
+      count += lookup.readonlyIndexes.length + lookup.writableIndexes.length;
+    }
+    return count;
+  }
+
+  getAccountKeys(args?: GetAccountKeysArgs): MessageAccountKeys {
+    let accountKeysFromLookups: AccountKeysFromLookups | undefined;
+    if (args && 'accountKeysFromLookups' in args) {
+      if (
+        this.numAccountKeysFromLookups !=
+        args.accountKeysFromLookups.writable.length +
+          args.accountKeysFromLookups.readonly.length
+      ) {
+        throw new Error(
+          'Failed to get account keys because of a mismatch in the number of account keys from lookups',
+        );
+      }
+      accountKeysFromLookups = args.accountKeysFromLookups;
+    } else if (args && 'addressLookupTableAccounts' in args) {
+      accountKeysFromLookups = this.resolveAddressTableLookups(
+        args.addressLookupTableAccounts,
+      );
+    } else if (this.addressTableLookups.length > 0) {
+      throw new Error(
+        'Failed to get account keys because address table lookups were not resolved',
+      );
+    }
+    return new MessageAccountKeys(
+      this.staticAccountKeys,
+      accountKeysFromLookups,
+    );
+  }
+
+  resolveAddressTableLookups(
+    addressLookupTableAccounts: AddressLookupTableAccount[],
+  ): AccountKeysFromLookups {
+    const accountKeysFromLookups: AccountKeysFromLookups = {
+      writable: [],
+      readonly: [],
+    };
+
+    for (const tableLookup of this.addressTableLookups) {
+      const tableAccount = addressLookupTableAccounts.find(account =>
+        account.key.equals(tableLookup.accountKey),
+      );
+      if (!tableAccount) {
+        throw new Error(
+          `Failed to find address lookup table account for table key ${tableLookup.accountKey.toBase58()}`,
+        );
+      }
+
+      for (const index of tableLookup.writableIndexes) {
+        if (index < tableAccount.state.addresses.length) {
+          accountKeysFromLookups.writable.push(
+            tableAccount.state.addresses[index],
+          );
+        } else {
+          throw new Error(
+            `Failed to find address for index ${index} in address lookup table ${tableLookup.accountKey.toBase58()}`,
+          );
+        }
+      }
+
+      for (const index of tableLookup.readonlyIndexes) {
+        if (index < tableAccount.state.addresses.length) {
+          accountKeysFromLookups.readonly.push(
+            tableAccount.state.addresses[index],
+          );
+        } else {
+          throw new Error(
+            `Failed to find address for index ${index} in address lookup table ${tableLookup.accountKey.toBase58()}`,
+          );
+        }
+      }
+    }
+
+    return accountKeysFromLookups;
+  }
+
   static compile(args: CompileV0Args): MessageV0 {
     const compiledKeys = CompiledKeys.compile(args.instructions, args.payerKey);
 

web3.js/src/transaction/index.ts

@@ -1,4 +1,5 @@
 export * from './constants';
 export * from './expiry-custom-errors';
 export * from './legacy';
+export * from './message';
 export * from './versioned';

web3.js/src/transaction/message.ts

@@ -0,0 +1,147 @@
+import {
+  AccountKeysFromLookups,
+  MessageAccountKeys,
+} from '../message/account-keys';
+import assert from '../utils/assert';
+import {toBuffer} from '../utils/to-buffer';
+import {Blockhash} from '../blockhash';
+import {Message, MessageV0, VersionedMessage} from '../message';
+import {AddressLookupTableAccount} from '../programs';
+import {AccountMeta, TransactionInstruction} from './legacy';
+
+export type TransactionMessageArgs = {
+  accountKeys: MessageAccountKeys;
+  instructions: Array<TransactionInstruction>;
+  recentBlockhash: Blockhash;
+};
+
+export type DecompileArgs =
+  | {
+      accountKeysFromLookups: AccountKeysFromLookups;
+    }
+  | {
+      addressLookupTableAccounts: AddressLookupTableAccount[];
+    };
+
+export class TransactionMessage {
+  accountKeys: MessageAccountKeys;
+  instructions: Array<TransactionInstruction>;
+  recentBlockhash: Blockhash;
+
+  constructor(args: TransactionMessageArgs) {
+    this.accountKeys = args.accountKeys;
+    this.instructions = args.instructions;
+    this.recentBlockhash = args.recentBlockhash;
+  }
+
+  static decompile(
+    message: VersionedMessage,
+    args?: DecompileArgs,
+  ): TransactionMessage {
+    const {header, compiledInstructions, recentBlockhash} = message;
+
+    const {
+      numRequiredSignatures,
+      numReadonlySignedAccounts,
+      numReadonlyUnsignedAccounts,
+    } = header;
+
+    const numWritableSignedAccounts =
+      numRequiredSignatures - numReadonlySignedAccounts;
+    assert(numWritableSignedAccounts > 0, 'Message header is invalid');
+
+    const numWritableUnsignedAccounts =
+      message.staticAccountKeys.length - numReadonlyUnsignedAccounts;
+    assert(numWritableUnsignedAccounts >= 0, 'Message header is invalid');
+
+    const accountKeys = message.getAccountKeys(args);
+    const instructions: TransactionInstruction[] = [];
+    for (const compiledIx of compiledInstructions) {
+      const keys: AccountMeta[] = [];
+
+      for (const keyIndex of compiledIx.accountKeyIndexes) {
+        const pubkey = accountKeys.get(keyIndex);
+        if (pubkey === undefined) {
+          throw new Error(
+            `Failed to find key for account key index ${keyIndex}`,
+          );
+        }
+
+        const isSigner = keyIndex < numRequiredSignatures;
+
+        let isWritable;
+        if (isSigner) {
+          isWritable = keyIndex < numWritableSignedAccounts;
+        } else if (keyIndex < accountKeys.staticAccountKeys.length) {
+          isWritable =
+            keyIndex - numRequiredSignatures < numWritableUnsignedAccounts;
+        } else {
+          isWritable =
+            keyIndex - accountKeys.staticAccountKeys.length <
+            // accountKeysFromLookups cannot be undefined because we already found a pubkey for this index above
+            accountKeys.accountKeysFromLookups!.writable.length;
+        }
+
+        keys.push({
+          pubkey,
+          isSigner: keyIndex < header.numRequiredSignatures,
+          isWritable,
+        });
+      }
+
+      const programId = accountKeys.get(compiledIx.programIdIndex);
+      if (programId === undefined) {
+        throw new Error(
+          `Failed to find program id for program id index ${compiledIx.programIdIndex}`,
+        );
+      }
+
+      instructions.push(
+        new TransactionInstruction({
+          programId,
+          data: toBuffer(compiledIx.data),
+          keys,
+        }),
+      );
+    }
+
+    return new TransactionMessage({
+      accountKeys,
+      instructions,
+      recentBlockhash,
+    });
+  }
+
+  compileToLegacyMessage(): Message {
+    const payerKey = this.accountKeys.get(0);
+    if (payerKey === undefined) {
+      throw new Error(
+        'Failed to compile message because no account keys were found',
+      );
+    }
+
+    return Message.compile({
+      payerKey,
+      recentBlockhash: this.recentBlockhash,
+      instructions: this.instructions,
+    });
+  }
+
+  compileToV0Message(
+    addressLookupTableAccounts?: AddressLookupTableAccount[],
+  ): MessageV0 {
+    const payerKey = this.accountKeys.get(0);
+    if (payerKey === undefined) {
+      throw new Error(
+        'Failed to compile message because no account keys were found',
+      );
+    }
+
+    return MessageV0.compile({
+      payerKey,
+      recentBlockhash: this.recentBlockhash,
+      instructions: this.instructions,
+      addressLookupTableAccounts,
+    });
+  }
+}