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
148
149
150
151
152
153

use_prelude!();

use crate::error::{DittoError, ErrorKind};

#[derive(Debug, Clone, Default, PartialOrd, Ord, PartialEq, Eq, Hash)]
/// An identifier for a [`DittoDocument`](crate::prelude::DittoDocument).
///
/// Each `DocumentId` represents a unique identifier for a document.
pub struct DocumentId {
    pub(crate) bytes: Vec<u8>,
}

impl DocumentId {
    /// Create a new DocumentId from a serializable value.
    /// # panic
    /// This function will panic if the value can't be serialized into cbor.
    pub fn new<V: ::serde::Serialize>(value: &V) -> Result<Self, DittoError> {
        let cbor_bytes = ::serde_cbor::to_vec(value).unwrap();
        let bytes = validate_doc_id_cbor_bytes(cbor_bytes)?;
        Ok(Self { bytes })
    }

    /// Return a String representation of the DocumentId that can be used in a query string.
    pub fn to_query_compatible(
        &self,
        string_primitive_fmt: ffi_sdk::StringPrimitiveFormat,
    ) -> String {
        let str_boxed = ffi_sdk::ditto_document_id_query_compatible(
            self.bytes.as_slice().into(),
            string_primitive_fmt,
        );
        str_boxed.into_string()
    }

    /// Return the inner bytes value in a cbor form
    pub fn value(&self) -> ::serde_cbor::Value {
        self.to_cbor()
    }

    /// Return the inner bytes value in a cbor form
    pub fn to_cbor(&self) -> ::serde_cbor::Value {
        ::serde_cbor::from_slice(&self.bytes[..]).expect("DocumentId can be represented as CBOR")
    }
}

impl From<Vec<u8>> for DocumentId {
    fn from(bytes: Vec<u8>) -> Self {
        Self { bytes }
    }
}

impl From<Box<[u8]>> for DocumentId {
    fn from(bytes: Box<[u8]>) -> Self {
        Self {
            bytes: bytes.into(),
        }
    }
}

impl From<&[u8]> for DocumentId {
    fn from(slice: &[u8]) -> Self {
        Self {
            bytes: slice.to_owned().to_vec(),
        }
    }
}

impl AsRef<[u8]> for DocumentId {
    fn as_ref(&self) -> &[u8] {
        &self.bytes[..]
    }
}

impl std::fmt::Display for DocumentId {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            self.to_query_compatible(ffi_sdk::StringPrimitiveFormat::WithoutQuotes)
        )
    }
}

impl serde::Serialize for DocumentId {
    fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
        // Note (Ham & Daniel): This serialization was previously done by first
        // deserializing the document ID's CBOR bytes into a `serde_cbor::Value`
        // before then serializing that into the serialized form. This was
        // usually fine because the serializer being used to serialize the
        // `serde_cbor::Value` was almost always `serde_cbor`'s, and so while a
        // little bit of a roundabout method of getting back to some CBOR bytes,
        // it always worked fine.
        //
        // However, if you wanted to `upsert` a document into Ditto by
        // specifying the document's content using `serde_json`'s `json!` macro
        // and you wanted to specify the document's ID by providing a
        // `DocumentId` value under the `_id` at the root of the document then
        // this codepath would get hit and would lead to an error if you were
        // using a document ID that contained an integer value. This is because
        // `serde_cbor::Value` has an `Integer` case that stores all integers as
        // `i128`s. `serde_json` does not support serializing `i128`s and would
        // return an error saying as much. It looks like you'd then be able to
        // get this to work by enabling the `"arbitrary_precision"` feature of
        // `serde_json`. This does mean that you don't get an error returned
        // anymore but integers then end up getting serialized as an object
        // like:
        //
        //   { "$serde_json::private::Number": 42 }
        //
        // This does not work well with in a cross-platform world unfortunately.
        //
        // As such, we're instead using `serde_transcode` for now, to avoid all
        // integers getting temporarily represented as `i128`s. This may or may
        // not end up being a suitable long term solution so is something that
        // may need to be re-evaluated in the future.

        let mut deserializer = serde_cbor::Deserializer::from_slice(&self.bytes[..]);
        serde_transcode::transcode(&mut deserializer, serializer)
    }
}

impl<'de> serde::de::Deserialize<'de> for DocumentId {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: serde::de::Deserializer<'de>,
    {
        let cbor_bytes =
            serde_cbor::to_vec(&serde_cbor::Value::deserialize(deserializer)?).unwrap();
        // We have to go to the trouble of crossing the FFI to ensure that the
        // bytes we've got here are in Ditto document ID canonical CBOR form
        let bytes = validate_doc_id_cbor_bytes(cbor_bytes)
            .expect("document id bytes are valid when deserializing");
        Ok(Self { bytes })
    }
}

fn validate_doc_id_cbor_bytes(bytes: Vec<u8>) -> Result<Vec<u8>, DittoError> {
    use ::safer_ffi::prelude::{AsOut, ManuallyDropMut};

    let mut out_cbor_slot = None;
    let out_cbor = out_cbor_slot.manually_drop_mut().as_out();
    {
        let res = ffi_sdk::ditto_validate_document_id(bytes[..].into(), out_cbor);
        if res != 0 {
            return Err(DittoError::from_ffi(ErrorKind::Internal));
        }
    }

    Ok(match out_cbor_slot {
        None => bytes,
        Some(cbor_boxed_slice) => cbor_boxed_slice.to::<Box<[u8]>>().into(),
    })
}