ethabi_next/
function.rs

1// Copyright 2015-2020 Parity Technologies
2//
3// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
5// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
6// option. This file may not be copied, modified, or distributed
7// except according to those terms.
8
9//! Contract function call builder.
10
11use std::string::ToString;
12
13use crate::{
14	decode, encode, signature::short_signature, Bytes, Error, Param, ParamType, Result, StateMutability, Token,
15};
16use serde::Deserialize;
17
18/// Contract function specification.
19#[derive(Debug, Clone, PartialEq, Deserialize)]
20pub struct Function {
21	/// Function name.
22	pub name: String,
23	/// Function input.
24	pub inputs: Vec<Param>,
25	/// Function output.
26	pub outputs: Vec<Param>,
27	#[deprecated(note = "The constant attribute was removed in Solidity 0.5.0 and has been \
28				replaced with stateMutability. If parsing a JSON AST created with \
29				this version or later this value will always be false, which may be wrong.")]
30	/// Constant function.
31	#[serde(default)]
32	pub constant: bool,
33	/// Whether the function reads or modifies blockchain state
34	#[serde(rename = "stateMutability", default)]
35	pub state_mutability: StateMutability,
36}
37
38impl Function {
39	/// Returns all input params of given function.
40	fn input_param_types(&self) -> Vec<ParamType> {
41		self.inputs.iter().map(|p| p.kind.clone()).collect()
42	}
43
44	/// Returns all output params of given function.
45	fn output_param_types(&self) -> Vec<ParamType> {
46		self.outputs.iter().map(|p| p.kind.clone()).collect()
47	}
48
49	/// Prepares ABI function call with given input params.
50	pub fn encode_input(&self, tokens: &[Token]) -> Result<Bytes> {
51		let params = self.input_param_types();
52
53		if !Token::types_check(tokens, &params) {
54			return Err(Error::InvalidData);
55		}
56
57		let signed = short_signature(&self.name, &params).to_vec();
58		let encoded = encode(tokens);
59		Ok(signed.into_iter().chain(encoded.into_iter()).collect())
60	}
61
62	/// Parses the ABI function output to list of tokens.
63	pub fn decode_output(&self, data: &[u8]) -> Result<Vec<Token>> {
64		decode(&self.output_param_types(), &data)
65	}
66
67	/// Parses the ABI function input to a list of tokens.
68	pub fn decode_input(&self, data: &[u8]) -> Result<Vec<Token>> {
69		decode(&self.input_param_types(), &data)
70	}
71
72	/// Returns a signature that uniquely identifies this function.
73	///
74	/// Examples:
75	/// - `functionName()`
76	/// - `functionName():(uint256)`
77	/// - `functionName(bool):(uint256,string)`
78	/// - `functionName(uint256,bytes32):(string,uint256)`
79	pub fn signature(&self) -> String {
80		let inputs = self.inputs.iter().map(|p| p.kind.to_string()).collect::<Vec<_>>().join(",");
81
82		let outputs = self.outputs.iter().map(|p| p.kind.to_string()).collect::<Vec<_>>().join(",");
83
84		match (inputs.len(), outputs.len()) {
85			(_, 0) => format!("{}({})", self.name, inputs),
86			(_, _) => format!("{}({}):({})", self.name, inputs, outputs),
87		}
88	}
89}
90
91#[cfg(test)]
92mod tests {
93	use crate::{Function, Param, ParamType, StateMutability, Token};
94	use hex_literal::hex;
95
96	#[test]
97	fn test_function_encode_call() {
98		let func = Function {
99			name: "baz".to_owned(),
100			inputs: vec![
101				Param { name: "a".to_owned(), kind: ParamType::Uint(32) },
102				Param { name: "b".to_owned(), kind: ParamType::Bool },
103			],
104			outputs: vec![],
105			constant: false,
106			state_mutability: StateMutability::Payable,
107		};
108
109		let mut uint = [0u8; 32];
110		uint[31] = 69;
111		let encoded = func.encode_input(&[Token::Uint(uint.into()), Token::Bool(true)]).unwrap();
112		let expected = hex!("cdcd77c000000000000000000000000000000000000000000000000000000000000000450000000000000000000000000000000000000000000000000000000000000001").to_vec();
113		assert_eq!(encoded, expected);
114	}
115}
ethabi_next/function.rs

ethabi_next/
function.rs
