Cross-Consensus Query Language (XCQ)

xlc · May 2, 2024, 9:52am

I have the very first PoC running

I have a simple PolkaVM program calling into host and do some simple calculation

open-web3-stack/XCQ/blob/bf3112529290093c73bf86b84eeec9a324bacf57/poc/guest/src/main.rs

#![no_std]
#![no_main]

#[panic_handler]
fn panic(_info: &core::panic::PanicInfo) -> ! {
    unsafe {
        core::arch::asm!("unimp", options(noreturn));
    }
}

#[polkavm_derive::polkavm_import]
extern "C" {
    fn host_call() -> u32;
}

#[polkavm_derive::polkavm_export]
extern "C" fn main() -> u32 {
    42 + unsafe { host_call() }
}

The hex of the this PolkaVM program is:

50564d0001010400009000040e0100000000686f73745f63616c6c05070100046d61696e061500001002110703104e02775401100211081300694a00

I have a runtime implements the XCQ Runtime API

github.com

open-web3-stack/XCQ/blob/bf3112529290093c73bf86b84eeec9a324bacf57/poc/runtime/src/lib.rs#L213-L217


      
          impl xcq::XcqApi<Block> for Runtime {
              fn execute_query(query: Vec<u8>) -> xcq::XcqResult {
                  xcq::execute_query(query)
              }
          }

It implements the host function and execute the provided XCQ program and return the result

github.com

open-web3-stack/XCQ/blob/bf3112529290093c73bf86b84eeec9a324bacf57/poc/runtime/src/xcq.rs

use frame::deps::sp_api::decl_runtime_apis;
use frame::prelude::*;
use scale_info::prelude::{format, string::String};

pub type XcqResponse = u32;
pub type XcqError = String;
pub type XcqResult = Result<XcqResponse, XcqError>;

decl_runtime_apis! {
    pub trait XcqApi {
        fn execute_query(query: Vec<u8>) -> XcqResult;
    }
}

struct HostFunctions;

impl poc_executor::XcqExecutorContext for HostFunctions {
    fn register_host_functions<T>(&mut self, linker: &mut poc_executor::Linker<T>) {
        linker.func_wrap("host_call", || -> u32 { 100 }).unwrap();
    }

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Cross-Consensus Query Language (XCQ)

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