hypersync_client/
decode_call.rs

1use alloy_dyn_abi::{DynSolType, DynSolValue, JsonAbiExt};
2use alloy_json_abi::Function;
3use anyhow::{Context, Result};
4use hypersync_format::Data;
5use std::collections::HashMap;
6
7#[derive(Debug, Hash, Eq, PartialEq)]
8struct FunctionKey {
9    signature: Vec<u8>,
10}
11
12type DecoderMap = HashMap<FunctionKey, Function>;
13
14/// Decode input data parsing input data.
15pub struct CallDecoder {
16    // A map of signature => Function decoder
17    map: DecoderMap,
18}
19
20impl CallDecoder {
21    /// Initialize decoder from event signatures.
22    ///
23    ///     use hypersync_client::CallDecoder;
24    ///     let decoder = CallDecoder::from_signatures(&[
25    ///        "transfer(address to,uint256 amount)",
26    ///     ]).unwrap();
27    pub fn from_signatures<S: AsRef<str>>(signatures: &[S]) -> Result<Self> {
28        let map: DecoderMap = signatures
29            .iter()
30            .map(|sig| {
31                let function = Function::parse(sig.as_ref()).context("parse event signature")?;
32                let signature = function.selector().to_vec();
33                let event_key = FunctionKey { signature };
34                Ok((event_key, function))
35            })
36            .collect::<Result<DecoderMap>>()
37            .context("construct function decoder map")?;
38
39        Ok(Self { map })
40    }
41
42    /// Parse input data and return result
43    ///
44    /// Returns Ok(None) if signature not found.
45    pub fn decode_input(&self, data: &Data) -> Result<Option<Vec<DynSolValue>>> {
46        let function_key = FunctionKey {
47            signature: data[0..4].to_vec(),
48        };
49        let function = match self.map.get(&function_key) {
50            Some(function) => function,
51            None => return Ok(None),
52        };
53        let decoded = function
54            .abi_decode_input(data.as_ref())
55            .context("decoding input data")?;
56        Ok(Some(decoded))
57    }
58
59    /// Parse output data and return result
60    ///
61    /// Decodes the output field from a trace
62    /// and returns the decoded values in a `Vec<DynSolValue>`. If the function
63    /// signature is not found or the decoding fails, it returns `Ok(None)` as
64    /// the result to match the behavior of `decode_input`
65    pub fn decode_output(
66        &self,
67        data: &Data,
68        function_signature: &str,
69    ) -> Result<Option<Vec<DynSolValue>>> {
70        // Parse the provided function signature into a Function object
71        let function = Function::parse(function_signature).context("parsing function signature")?;
72
73        //Extract the output types of the function
74        let output_types = function.outputs;
75
76        // Convert the output types into the corresponding DynSolType representations,
77        let output_types: Vec<DynSolType> = output_types
78            .into_iter()
79            .map(|param| param.ty.parse::<DynSolType>())
80            .collect::<Result<_, _>>() // Parse each type as DynSolType
81            .context("parsing output types")?;
82
83        // Create a tuple type from the output parameters
84        let tuple_type = DynSolType::Tuple(output_types);
85
86        // Attempt to decode the data using the constructed tuple type
87        match tuple_type.abi_decode(data.as_ref()) {
88            // If decoding succeeds, return the decoded values as a tuple or single value
89            Ok(decoded) => {
90                if let DynSolValue::Tuple(values) = decoded {
91                    Ok(Some(values)) // Return the decoded values as a Vec if it's a tuple
92                } else {
93                    Ok(Some(vec![decoded])) // Return a single value wrapped in a Vec
94                }
95            }
96            // If decoding fails, return None (to match the behavior of decode_input)
97            Err(_) => {
98                Ok(None) // Return None to signal that decoding failed
99            }
100        }
101    }
102}
103
104#[cfg(test)]
105mod tests {
106    use super::*;
107    use hypersync_format::{Data, Hex};
108
109    #[test]
110    fn test_decode_input_with_single_signature() {
111        let function =
112            alloy_json_abi::Function::parse("transfer(address dst, uint256 wad)").unwrap();
113        let input = "0xa9059cbb000000000000000000000000dc4bde73fa35b7478a574f78d5dfd57a0b2e22810000000000000000000000000000000000000000000000004710ca26d3eeae0a";
114        let input = Data::decode_hex(input).unwrap();
115        let expected = function.abi_decode_input(input.as_ref()).unwrap();
116
117        let decoder =
118            CallDecoder::from_signatures(&["transfer(address dst, uint256 wad)"]).unwrap();
119        let got = decoder.decode_input(&input).unwrap().unwrap();
120
121        for (expected, got) in expected.iter().zip(got.iter()) {
122            assert_eq!(expected, got, "Checking that decodes are the same");
123        }
124    }
125
126    #[test]
127    fn test_decode_input_with_multiple_signature() {
128        let function =
129            alloy_json_abi::Function::parse("transfer(address dst, uint256 wad)").unwrap();
130        let input = "0xa9059cbb000000000000000000000000dc4bde73fa35b7478a574f78d5dfd57a0b2e22810000000000000000000000000000000000000000000000004710ca26d3eeae0a";
131        let input = Data::decode_hex(input).unwrap();
132        let expected = function.abi_decode_input(input.as_ref()).unwrap();
133
134        let decoder = CallDecoder::from_signatures(&[
135            "transfer(address dst, uint256 wad)",
136            "approve(address usr, uint256 wad)",
137        ])
138        .unwrap();
139        let got = decoder.decode_input(&input).unwrap().unwrap();
140
141        for (expected, got) in expected.iter().zip(got.iter()) {
142            assert_eq!(expected, got, "Checking that decodes are the same");
143        }
144    }
145
146    #[test]
147    #[should_panic]
148    fn test_decode_input_with_incorrect_signature() {
149        let _function = alloy_json_abi::Function::parse("incorrect signature").unwrap();
150    }
151
152    #[test]
153    fn test_decode_output_single_value() {
154        let output = "0x0000000000000000000000000000000000000000000000056bc75e2d63100000";
155        let output = Data::decode_hex(output).unwrap();
156        let function_signature = "balanceOf(address)(uint256)";
157
158        let decoder = CallDecoder::from_signatures(&["balanceOf(address)"]).unwrap();
159        let result = decoder
160            .decode_output(&output, function_signature)
161            .unwrap()
162            .unwrap();
163
164        assert_eq!(result.len(), 1, "Should return a single value");
165        assert!(
166            matches!(result[0], DynSolValue::Uint(..)),
167            "Should be a uint value"
168        );
169    }
170
171    #[test]
172    fn test_decode_output_multiple_values() {
173        let output = "0x000000000000000000000000dc4bde73fa35b7478a574f78d5dfd57a0b2e22810000000000000000000000000000000000000000000000004710ca26d3eeae0a";
174        let output = Data::decode_hex(output).unwrap();
175        let function_signature = "someFunction()(address,uint256)";
176
177        let decoder = CallDecoder::from_signatures(&["someFunction()"]).unwrap();
178        let result = decoder
179            .decode_output(&output, function_signature)
180            .unwrap()
181            .unwrap();
182
183        assert_eq!(result.len(), 2, "Should return two values");
184        assert!(
185            matches!(result[0], DynSolValue::Address(..)),
186            "First value should be an address"
187        );
188        assert!(
189            matches!(result[1], DynSolValue::Uint(..)),
190            "Second value should be a uint"
191        );
192    }
193
194    #[test]
195    fn test_decode_output_invalid_data() {
196        let output = "invalid_data";
197        let _output = Data::decode_hex(output).unwrap_err();
198        let function_signature = "balanceOf(address)(uint256)";
199
200        let decoder = CallDecoder::from_signatures(&["balanceOf(address)"]).unwrap();
201        let result = decoder
202            .decode_output(&Data::default(), function_signature)
203            .unwrap();
204
205        assert!(result.is_none(), "Should return None for invalid data");
206    }
207
208    #[test]
209    #[should_panic(expected = "parsing function signature")]
210    fn test_decode_output_invalid_signature() {
211        let output = "0x0000000000000000000000000000000000000000000000056bc75e2d63100000";
212        let output = Data::decode_hex(output).unwrap();
213        let function_signature = "invalid signature";
214
215        let decoder = CallDecoder::from_signatures(&["balanceOf(address)"]).unwrap();
216        decoder.decode_output(&output, function_signature).unwrap();
217    }
218}
hypersync_client/decode_call.rs

hypersync_client/
decode_call.rs
