Method read

crates/stdlib/src/_sqlite3.rs:2367–2395

(
            &self,
            length: OptionalArg<c_int>,
            vm: &VirtualMachine,
        )

        #[pymethod]
        fn read(
            &self,
            length: OptionalArg<c_int>,
            vm: &VirtualMachine,
        ) -> PyResult<PyRef<PyBytes>> {
            self.ensure_connection_open(vm)?;

            let mut length = length.unwrap_or(-1);
            let mut inner = self.inner(vm)?;
            let blob_len = inner.blob.bytes();
            let max_read = blob_len - inner.offset;

            if length < 0 || length > max_read {
                length = max_read;
            }

            if length == 0 {
                Ok(vm.ctx.empty_bytes.clone())
            } else {
                let mut buf = Vec::<u8>::with_capacity(length as usize);
                let ret = inner
                    .blob
                    .read(buf.as_mut_ptr().cast(), length, inner.offset);
                self.check(ret, vm)?;
                unsafe { buf.set_len(length as usize) };
                inner.offset += length;
                Ok(vm.ctx.new_bytes(buf))
            }
        }

        #[pymethod]
        fn write(&self, data: PyBuffer, vm: &VirtualMachine) -> PyResult<()> {