Files
turso/extensions/core/src/vtabs.rs
2025-03-19 10:19:19 -04:00

100 lines
3.0 KiB
Rust

use crate::{ResultCode, Value};
use std::ffi::{c_char, c_void};
pub type RegisterModuleFn = unsafe extern "C" fn(
ctx: *mut c_void,
name: *const c_char,
module: VTabModuleImpl,
kind: VTabKind,
) -> ResultCode;
#[repr(C)]
#[derive(Clone, Debug)]
pub struct VTabModuleImpl {
pub ctx: *const c_void,
pub name: *const c_char,
pub create_schema: VtabFnCreateSchema,
pub open: VtabFnOpen,
pub filter: VtabFnFilter,
pub column: VtabFnColumn,
pub next: VtabFnNext,
pub eof: VtabFnEof,
pub update: VtabFnUpdate,
pub rowid: VtabRowIDFn,
}
#[cfg(feature = "core_only")]
impl VTabModuleImpl {
pub fn init_schema(&self, args: Vec<Value>) -> crate::ExtResult<String> {
let schema = unsafe { (self.create_schema)(args.as_ptr(), args.len() as i32) };
if schema.is_null() {
return Err(ResultCode::InvalidArgs);
}
for arg in args {
unsafe { arg.__free_internal_type() };
}
let schema = unsafe { std::ffi::CString::from_raw(schema) };
Ok(schema.to_string_lossy().to_string())
}
}
pub type VtabFnCreateSchema = unsafe extern "C" fn(args: *const Value, argc: i32) -> *mut c_char;
pub type VtabFnOpen = unsafe extern "C" fn(*const c_void) -> *const c_void;
pub type VtabFnFilter =
unsafe extern "C" fn(cursor: *const c_void, argc: i32, argv: *const Value) -> ResultCode;
pub type VtabFnColumn = unsafe extern "C" fn(cursor: *const c_void, idx: u32) -> Value;
pub type VtabFnNext = unsafe extern "C" fn(cursor: *const c_void) -> ResultCode;
pub type VtabFnEof = unsafe extern "C" fn(cursor: *const c_void) -> bool;
pub type VtabRowIDFn = unsafe extern "C" fn(cursor: *const c_void) -> i64;
pub type VtabFnUpdate = unsafe extern "C" fn(
vtab: *const c_void,
argc: i32,
argv: *const Value,
p_out_rowid: *mut i64,
) -> ResultCode;
#[repr(C)]
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum VTabKind {
VirtualTable,
TableValuedFunction,
}
pub trait VTabModule: 'static {
type VCursor: VTabCursor<Error = Self::Error>;
const VTAB_KIND: VTabKind;
const NAME: &'static str;
type Error: std::fmt::Display;
fn create_schema(args: &[Value]) -> String;
fn open(&self) -> Result<Self::VCursor, Self::Error>;
fn filter(cursor: &mut Self::VCursor, args: &[Value]) -> ResultCode;
fn column(cursor: &Self::VCursor, idx: u32) -> Result<Value, Self::Error>;
fn next(cursor: &mut Self::VCursor) -> ResultCode;
fn eof(cursor: &Self::VCursor) -> bool;
fn update(&mut self, _rowid: i64, _args: &[Value]) -> Result<(), Self::Error> {
Ok(())
}
fn insert(&mut self, _args: &[Value]) -> Result<i64, Self::Error> {
Ok(0)
}
fn delete(&mut self, _rowid: i64) -> Result<(), Self::Error> {
Ok(())
}
}
pub trait VTabCursor: Sized {
type Error: std::fmt::Display;
fn rowid(&self) -> i64;
fn column(&self, idx: u32) -> Result<Value, Self::Error>;
fn eof(&self) -> bool;
fn next(&mut self) -> ResultCode;
}