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


mod proof;

use proof::{ Proof, Lemma, Positioned };
pub use self::proof::{ ProofProto, LemmaProto };

use protobuf::Message;
use protobuf::error::ProtobufResult;
use protobuf::core::parse_from_bytes;

impl <D, T> Proof<D, T> {

    pub fn from_protobuf(digest: D, proto: ProofProto) -> Option<Self> {
        proto.to(digest)
    }

    pub fn to_protobuf(self) -> ProofProto {
        ProofProto::from(self)
    }

    pub fn write_to_bytes(self) -> ProtobufResult<Vec<u8>> {
        self.to_protobuf().write_to_bytes()
    }

    pub fn parse_from_bytes(bytes: &[u8], digest: D) -> ProtobufResult<Option<Proof<D, T>>> {
        parse_from_bytes::<ProofProto>(bytes).map(|proto| proto.to(digest))
    }

}

impl ProofProto {

    pub fn from<D, T>(proof: Proof<D, T>) -> Self  {
        let mut proto = Self::new();

        match proof {
            Proof { root_hash, lemma, .. } => {
                proto.set_root_hash(root_hash);
                proto.set_lemma(LemmaProto::from(lemma));
            }
        }

        proto
    }

    pub fn to<D, T>(mut self, digest: D) -> Option<Proof<D, T>> {
        if !self.has_root_hash() || !self.has_lemma() {
            return None;
        }

        self.take_lemma().to().map(|lemma| {
            Proof::new(
                digest,
                self.take_root_hash(),
                lemma
            )
        })
    }

}

impl LemmaProto {

    pub fn from(lemma: Lemma) -> Self {
        let mut proto = Self::new();

        match lemma {
            Lemma { node_hash, sibling_hash, sub_lemma } => {
                proto.set_node_hash(node_hash);

                if let Some(sub_proto) = sub_lemma.map(|l| Self::from(*l)) {
                    proto.set_sub_lemma(sub_proto);
                }

                match sibling_hash {
                    Some(Positioned::Left(hash)) =>
                        proto.set_left_sibling_hash(hash),

                    Some(Positioned::Right(hash)) =>
                        proto.set_right_sibling_hash(hash),

                    None => {}
                }
            }
        }

        proto
    }

    pub fn to(mut self) -> Option<Lemma> {
        if !self.has_node_hash() {
            return None;
        }

        let node_hash = self.take_node_hash();

        let sibling_hash =
            if self.has_left_sibling_hash() {
                Some(Positioned::Left(self.take_left_sibling_hash()))
            }
            else if self.has_right_sibling_hash() {
                Some(Positioned::Left(self.take_right_sibling_hash()))
            }
            else {
                None
            };

        if self.has_sub_lemma() {
            // If a `sub_lemma` is present is the Protobuf,
            // then we expect it to unserialize to a valid `Lemma`,
            // otherwise we return `None`
            self.take_sub_lemma().to().map(|sub_lemma| {
                Lemma {
                    node_hash: node_hash,
                    sibling_hash: sibling_hash,
                    sub_lemma: Some(Box::new(sub_lemma))
                }
            })
        }
        else {
            // We might very well not have a sub_lemma,
            // in which case we just set it to `None`,
            // but still return a potentially valid `Lemma`.
            Some(Lemma {
                node_hash: node_hash,
                sibling_hash: sibling_hash,
                sub_lemma: None
            })
        }
    }

}