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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176

use std::convert::TryInto;
use std::fmt;

use async_trait::async_trait;
use destream::{de, en};
use futures::TryFutureExt;
use log::debug;

use tc_btree::BTreeView;
use tc_error::*;
use tc_transact::fs::Dir;
use tc_transact::{IntoView, Transaction};
use tcgeneric::{
    path_label, Class, Instance, NativeClass, PathLabel, PathSegment, TCPath, TCPathBuf,
};

use crate::fs;
use crate::txn::Txn;

const PREFIX: PathLabel = path_label(&["state", "collection"]);

pub use tc_btree::BTreeType;

pub type BTree = tc_btree::BTree<fs::File<tc_btree::Node>, fs::Dir, Txn>;
pub type BTreeFile = tc_btree::BTreeFile<fs::File<tc_btree::Node>, fs::Dir, Txn>;

#[derive(Clone, Copy, Eq, PartialEq)]
pub enum CollectionType {
    BTree(BTreeType),
}

impl Class for CollectionType {}

impl NativeClass for CollectionType {
    fn from_path(path: &[PathSegment]) -> Option<Self> {
        debug!("CollectionType::from_path {}", TCPath::from(path));

        if path.len() > 2 && &path[0..2] == &PREFIX[..] {
            match path[2].as_str() {
                "btree" => BTreeType::from_path(path).map(Self::BTree),
                _ => None,
            }
        } else {
            None
        }
    }

    fn path(&self) -> TCPathBuf {
        match self {
            Self::BTree(btree) => btree.path(),
        }
    }
}

impl fmt::Display for CollectionType {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Self::BTree(btt) => fmt::Display::fmt(btt, f),
        }
    }
}

#[derive(Clone)]
pub enum Collection {
    BTree(BTree),
}

impl Instance for Collection {
    type Class = CollectionType;

    fn class(&self) -> Self::Class {
        match self {
            Self::BTree(btree) => CollectionType::BTree(btree.class()),
        }
    }
}

impl From<BTree> for Collection {
    fn from(btree: BTree) -> Self {
        Self::BTree(btree)
    }
}

pub struct CollectionVisitor {
    txn: Txn,
}

impl CollectionVisitor {
    pub fn new(txn: Txn) -> Self {
        Self { txn }
    }

    pub async fn visit_map_value<A: de::MapAccess>(
        self,
        class: CollectionType,
        access: &mut A,
    ) -> Result<Collection, A::Error> {
        match class {
            CollectionType::BTree(_) => {
                let file = self
                    .txn
                    .context()
                    .create_file_tmp(*self.txn.id(), BTreeType::default().into())
                    .map_err(de::Error::custom)
                    .await?;

                let file = file.try_into().map_err(de::Error::custom)?;

                access
                    .next_value((self.txn.clone(), file))
                    .map_ok(Collection::BTree)
                    .await
            }
        }
    }
}

#[async_trait]
impl de::Visitor for CollectionVisitor {
    type Value = Collection;

    fn expecting() -> &'static str {
        "a Collection"
    }

    async fn visit_map<A: de::MapAccess>(self, mut map: A) -> Result<Self::Value, A::Error> {
        let classpath = map
            .next_key::<TCPathBuf>(())
            .await?
            .ok_or_else(|| de::Error::custom("expected a Collection type"))?;
        let class = CollectionType::from_path(&classpath)
            .ok_or_else(|| de::Error::invalid_value(classpath, "a Collection type"))?;
        self.visit_map_value(class, &mut map).await
    }
}

#[async_trait]
impl de::FromStream for Collection {
    type Context = Txn;

    async fn from_stream<D: de::Decoder>(txn: Txn, decoder: &mut D) -> Result<Self, D::Error> {
        decoder.decode_map(CollectionVisitor { txn }).await
    }
}

#[async_trait]
impl<'en> IntoView<'en, fs::Dir> for Collection {
    type Txn = Txn;
    type View = CollectionView<'en>;

    async fn into_view(self, txn: Self::Txn) -> TCResult<Self::View> {
        match self {
            Self::BTree(btree) => btree.into_view(txn).map_ok(CollectionView::BTree).await,
        }
    }
}

impl fmt::Display for Collection {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Self::BTree(btree) => fmt::Display::fmt(btree, f),
        }
    }
}

pub enum CollectionView<'en> {
    BTree(BTreeView<'en>),
}

impl<'en> en::IntoStream<'en> for CollectionView<'en> {
    fn into_stream<E: en::Encoder<'en>>(self, encoder: E) -> Result<E::Ok, E::Error> {
        match self {
            Self::BTree(btree) => btree.into_stream(encoder),
        }
    }
}