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

//! A change store is a trait for change storage facilities. Even though
//! changes are normally stored on disk, there are situations (such as
//! an embedded Pijul) where one might want changes in-memory, in a
//! database, or something else.
use crate::pristine::{ChangeId, Hash, InodeMetadata, Position, Vertex};
use crate::{
    change::{Change, ChangeHeader},
    text_encoding::Encoding,
};

#[cfg(feature = "ondisk-repos")]
/// If this crate is compiled with the `ondisk-repos` feature (the
/// default), this module stores changes on the file system, under
/// `.pijul/changes`.
pub mod filesystem;

/// A change store entirely in memory.
pub mod memory;

/// A trait for storing changes and reading from them.
pub trait ChangeStore {
    type Error: std::error::Error
        + std::fmt::Debug
        + Send
        + Sync
        + From<std::str::Utf8Error>
        + From<crate::change::ChangeError>
        + 'static;
    fn has_contents(&self, hash: Hash, change_id: Option<ChangeId>) -> bool;
    fn get_contents<F: Fn(ChangeId) -> Option<Hash>>(
        &self,
        hash: F,
        key: Vertex<ChangeId>,
        buf: &mut Vec<u8>,
    ) -> Result<usize, Self::Error>;
    fn get_header(&self, h: &Hash) -> Result<ChangeHeader, Self::Error> {
        Ok(self.get_change(h)?.hashed.header)
    }
    fn get_contents_ext(
        &self,
        key: Vertex<Option<Hash>>,
        buf: &mut Vec<u8>,
    ) -> Result<usize, Self::Error>;
    fn get_dependencies(&self, hash: &Hash) -> Result<Vec<Hash>, Self::Error> {
        Ok(self.get_change(hash)?.hashed.dependencies)
    }
    fn get_extra_known(&self, hash: &Hash) -> Result<Vec<Hash>, Self::Error> {
        Ok(self.get_change(hash)?.hashed.extra_known)
    }
    fn get_changes(
        &self,
        hash: &Hash,
    ) -> Result<Vec<crate::change::Hunk<Option<Hash>, crate::change::Local>>, Self::Error> {
        Ok(self.get_change(hash)?.hashed.changes)
    }
    fn knows(&self, hash0: &Hash, hash1: &Hash) -> Result<bool, Self::Error> {
        Ok(self.get_change(hash0)?.knows(hash1))
    }
    fn has_edge(
        &self,
        change: Hash,
        from: Position<Option<Hash>>,
        to: Position<Option<Hash>>,
        flags: crate::pristine::EdgeFlags,
    ) -> Result<bool, Self::Error> {
        let change_ = self.get_change(&change)?;
        Ok(change_.has_edge(change, from, to, flags))
    }
    fn change_deletes_position<F: Fn(ChangeId) -> Option<Hash>>(
        &self,
        hash: F,
        change: ChangeId,
        pos: Position<Option<Hash>>,
    ) -> Result<Vec<Hash>, Self::Error>;
    fn save_change(&self, p: &Change) -> Result<Hash, Self::Error>;
    fn del_change(&self, h: &Hash) -> Result<bool, Self::Error>;
    fn get_change(&self, h: &Hash) -> Result<Change, Self::Error>;
    fn get_file_meta<'a, F: Fn(ChangeId) -> Option<Hash>>(
        &self,
        hash: F,
        vertex: Vertex<ChangeId>,
        buf: &'a mut Vec<u8>,
    ) -> Result<FileMetadata<'a>, Self::Error> {
        buf.clear();
        self.get_contents(hash, vertex, buf)?;
        Ok(FileMetadata::read(buf))
    }
}

#[derive(Serialize, Deserialize)]
pub struct FileMetadata<'a> {
    pub metadata: InodeMetadata,
    pub basename: &'a str,
    pub encoding: Option<Encoding>,
}

impl<'a> FileMetadata<'a> {
    pub fn read(buf: &'a [u8]) -> FileMetadata<'a> {
        // FIXME use ? by adding the From trait somehow
        trace!("filemetadata read: {:?}", buf);
        if let Ok(m) = bincode::deserialize(buf) {
            m
        } else {
            let (a, b) = buf.split_at(2);
            FileMetadata {
                metadata: InodeMetadata::from_basename(a),
                basename: std::str::from_utf8(b).unwrap(),
                encoding: None,
            }
        }
    }

    pub fn write(&self, mut w: &mut Vec<u8>) {
        // FIXME use ? by adding the From trait somehow
        let l = w.len();
        bincode::serialize_into(&mut w, self).unwrap();
        trace!("filemetadata write: {:?}", &w[l..]);
    }
}

impl crate::change::Atom<Option<Hash>> {
    pub fn deletes_pos(&self, pos: Position<Option<Hash>>) -> Vec<Hash> {
        let mut h = Vec::new();
        if let crate::change::Atom::EdgeMap(ref n) = self {
            for edge in n.edges.iter() {
                if edge.to.change == pos.change && edge.to.start <= pos.pos && pos.pos < edge.to.end
                {
                    if let Some(c) = edge.introduced_by {
                        h.push(c)
                    }
                }
            }
        }
        h
    }
}