1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147

//! ContextExtension type
use ergotree_ir::mir::constant::Constant;
use ergotree_ir::serialization::sigma_byte_reader::SigmaByteRead;
use ergotree_ir::serialization::sigma_byte_writer::SigmaByteWrite;
use ergotree_ir::serialization::SerializationError;
use ergotree_ir::serialization::SigmaSerializable;
use indexmap::IndexMap;
use std::collections::HashMap;
use std::{convert::TryFrom, io};
use thiserror::Error;

/// User-defined variables to be put into context
#[derive(Debug, PartialEq, Eq, Clone)]
pub struct ContextExtension {
    /// key-value pairs of variable id and it's value
    pub values: IndexMap<u8, Constant>,
}

impl ContextExtension {
    /// Returns an empty ContextExtension
    pub fn empty() -> Self {
        Self {
            values: IndexMap::new(),
        }
    }
}

impl SigmaSerializable for ContextExtension {
    fn sigma_serialize<W: SigmaByteWrite>(&self, w: &mut W) -> Result<(), io::Error> {
        w.put_u8(self.values.len() as u8)?;
        let mut sorted_values: Vec<(&u8, &Constant)> = self.values.iter().collect();
        // stable order is important for tx id generation
        // since JSON encoding does not preserve the order, JSON roundtrip would result in different order
        // of values and thus a different tx id
        // see https://github.com/ScorexFoundation/sigmastate-interpreter/issues/681
        sorted_values.sort_by_key(|(k, _)| *k);
        sorted_values.iter().try_for_each(|(idx, c)| {
            w.put_u8(**idx)?;
            c.sigma_serialize(w)
        })?;
        Ok(())
    }

    fn sigma_parse<R: SigmaByteRead>(r: &mut R) -> Result<Self, SerializationError> {
        let values_count = r.get_u8()?;
        let mut values: IndexMap<u8, Constant> = IndexMap::with_capacity(values_count as usize);
        for _ in 0..values_count {
            let idx = r.get_u8()?;
            values.insert(idx, Constant::sigma_parse(r)?);
        }
        Ok(ContextExtension { values })
    }
}

// for JSON encoding in ergo-lib
impl From<ContextExtension> for HashMap<String, String> {
    fn from(v: ContextExtension) -> Self {
        v.values
            .into_iter()
            .map(|(k, v)| {
                (
                    format!("{}", k),
                    base16::encode_lower(&v.sigma_serialize_bytes()),
                )
            })
            .collect()
    }
}

/// Error parsing Constant from base16-encoded string
#[derive(Error, Eq, PartialEq, Debug, Clone)]
#[error("Error parsing constant: {0}")]
pub struct ConstantParsingError(pub String);

// for JSON encoding in ergo-lib
impl TryFrom<HashMap<String, String>> for ContextExtension {
    type Error = ConstantParsingError;
    fn try_from(values_str: HashMap<String, String>) -> Result<Self, Self::Error> {
        let values = values_str.iter().try_fold(
            IndexMap::with_capacity(values_str.len()),
            |mut acc, pair| {
                let idx: u8 = pair.0.parse().map_err(|_| {
                    ConstantParsingError(format!("cannot parse index from {0:?}", pair.0))
                })?;
                let constant_bytes = base16::decode(pair.1).map_err(|_| {
                    ConstantParsingError(format!(
                        "cannot decode base16 constant bytes from {0:?}",
                        pair.1
                    ))
                })?;
                acc.insert(
                    idx,
                    Constant::sigma_parse_bytes(constant_bytes).map_err(|_| {
                        ConstantParsingError(format!(
                            "cannot deserialize constant bytes from {0:?}",
                            pair.1
                        ))
                    })?,
                );
                Ok(acc)
            },
        )?;
        Ok(ContextExtension { values })
    }
}

#[cfg(feature = "arbitrary")]
mod arbitrary {
    use super::*;
    use proptest::{arbitrary::Arbitrary, collection::vec, prelude::*};

    impl Arbitrary for ContextExtension {
        type Parameters = ();
        type Strategy = BoxedStrategy<Self>;

        fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy {
            vec(any::<Constant>(), 0..10)
                .prop_map(|constants| {
                    let pairs: Vec<(u8, Constant)> = constants
                        .into_iter()
                        .enumerate()
                        .map(|(idx, c)| (idx as u8, c))
                        .collect();
                    Self {
                        values: pairs.into_iter().collect(),
                    }
                })
                .boxed()
        }
    }
}

#[cfg(test)]
#[cfg(feature = "arbitrary")]
mod tests {
    use super::*;
    use ergotree_ir::serialization::sigma_serialize_roundtrip;
    use proptest::prelude::*;

    proptest! {

        #[test]
        fn ser_roundtrip(v in any::<ContextExtension>()) {
            prop_assert_eq![sigma_serialize_roundtrip(&v), v];
        }
    }
}