43 lines
1.4 KiB
Rust
43 lines
1.4 KiB
Rust
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use std::mem;
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use std::slice;
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use std::str;
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use cel::{Context, ExecutionError, Program, Value};
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#[unsafe(no_mangle)]
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pub extern "C" fn allocation(n: usize) -> *mut u8 {
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mem::ManuallyDrop::new(Vec::with_capacity(n)).as_mut_ptr()
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}
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#[unsafe(no_mangle)]
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pub unsafe extern "C" fn evaluate(s: *const u8) -> *mut u8 {
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unsafe {
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let length = u32::from_le_bytes(*(s as *const [u8; 4])) as usize;
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let input = slice::from_raw_parts(s.offset(4), length);
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let output = evaluate_buffers(input);
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mem::ManuallyDrop::new(output).as_mut_ptr()
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}
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}
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fn evaluate_buffers(input: &[u8]) -> Vec<u8> {
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let contents = str::from_utf8(input).unwrap();
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let result = evaluate_cel(contents);
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let success = result.is_ok();
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let message = result.unwrap_or_else(|e| e.to_string());
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let len = message.len();
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let mut buffer = Vec::with_capacity(len + 8);
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buffer.push(if success { 1 } else { 0 });
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buffer.extend(vec![0; 3]);
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buffer.extend_from_slice(&(len as u32).to_le_bytes());
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buffer.extend_from_slice(message.as_bytes());
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buffer
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}
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fn evaluate_cel(content: &str) -> Result<String, ExecutionError> {
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let program = Program::compile(content).unwrap();
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let mut context = Context::default();
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// context.add_function("add", |a: i64, b: i64| a + b);
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let value = program.execute(&context)?;
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Ok(format!("{:?}", value))
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}
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