@unruggable/gateways/dist/esm/reader.mjs

Trustless Ethereum Multichain CCIP-Read Gateway

import { getBytes, hexlify, toUtf8String } from 'ethers/utils';
import { GatewayRequest } from './vm.mjs';
import { GATEWAY_OP as OP } from './ops.mjs';
const NAMES = [];
Object.entries(OP).forEach(([name, op]) => (NAMES[op] = name));
export class ProgramReader {
    ops;
    static actions(program) {
        const reader = this.fromProgram(program);
        const actions = [];
        if (program instanceof GatewayRequest) {
            actions.push({
                pos: 0,
                op: reader.readByte(), // outputCount,
                name: 'OUTPUT_COUNT',
            });
        }
        while (reader.remaining) {
            actions.push(reader.readAction());
        }
        return actions;
    }
    static fromProgram(program) {
        return new this(Uint8Array.from(program.ops));
    }
    static fromBytes(v) {
        return new this(getBytes(v));
    }
    pos = 0;
    constructor(ops) {
        this.ops = ops;
    }
    get remaining() {
        return this.ops.length - this.pos;
    }
    checkRead(n) {
        if (this.pos + n > this.ops.length)
            throw new Error('reader overflow');
    }
    readByte() {
        this.checkRead(1);
        return this.ops[this.pos++];
    }
    readBytes(n) {
        this.checkRead(n);
        return hexlify(this.ops.subarray(this.pos, (this.pos += n)));
    }
    readUint() {
        const n = this.readByte();
        if (n > 32)
            throw new Error(`expected word size: ${n}`);
        return n ? BigInt(this.readBytes(n)) : 0n;
    }
    readSmallStr() {
        return toUtf8String(this.readBytes(this.readByte()));
    }
    parseArgs(op) {
        // TODO: this is probably incomplete
        switch (op) {
            //case OP.PUSH_0:
            case OP.PUSH_1:
            case OP.PUSH_2:
            case OP.PUSH_3:
            case OP.PUSH_4:
            case OP.PUSH_5:
            case OP.PUSH_6:
            case OP.PUSH_7:
            case OP.PUSH_8:
            case OP.PUSH_9:
            case OP.PUSH_10:
            case OP.PUSH_11:
            case OP.PUSH_12:
            case OP.PUSH_13:
            case OP.PUSH_14:
            case OP.PUSH_15:
            case OP.PUSH_16:
            case OP.PUSH_17:
            case OP.PUSH_18:
            case OP.PUSH_19:
            case OP.PUSH_20:
            case OP.PUSH_21:
            case OP.PUSH_22:
            case OP.PUSH_23:
            case OP.PUSH_24:
            case OP.PUSH_25:
            case OP.PUSH_26:
            case OP.PUSH_27:
            case OP.PUSH_28:
            case OP.PUSH_29:
            case OP.PUSH_30:
            case OP.PUSH_31:
            case OP.PUSH_32:
                return { bytes: this.readBytes(op) };
            case OP.PUSH_BYTES:
                return { bytes: this.readBytes(Number(this.readUint())) };
            case OP.EVAL_LOOP:
                return { flags: this.readByte() };
            case OP.ASSERT:
                return { exitCode: this.readByte() };
            case OP.DEBUG:
                return { label: this.readSmallStr() };
            default:
                return {};
        }
    }
    readAction() {
        const op = this.readByte();
        const name = NAMES[op];
        if (!name)
            throw new Error(`unknown op: ${op}`);
        return { pos: this.pos, op, name, ...this.parseArgs(op) };
    }
}