libpijul_compat/backend/
patch_id.rs

1use bs58;
2use sanakirja::{Alignment, Representable};
3use std;
4
5// Patch Identifiers.
6pub const PATCH_ID_SIZE: usize = 8;
7pub const ROOT_PATCH_ID: PatchId = PatchId([0; PATCH_ID_SIZE]);
8
9/// An internal patch identifier, less random than external patch
10/// identifiers, but more stable in time, and much smaller.
11#[derive(Clone, Copy, PartialEq, PartialOrd, Eq, Ord, Hash, Serialize, Deserialize)]
12pub struct PatchId([u8; PATCH_ID_SIZE]);
13
14impl std::fmt::Debug for PatchId {
15    fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
16        write!(fmt, "PatchId({})", self.to_base58())
17    }
18}
19
20use hex::ToHex;
21use std::fmt::Write;
22impl ToHex for PatchId {
23    fn write_hex<W: Write>(&self, w: &mut W) -> std::fmt::Result {
24        self.0.write_hex(w)
25    }
26    fn write_hex_upper<W: Write>(&self, w: &mut W) -> std::fmt::Result {
27        self.0.write_hex_upper(w)
28    }
29}
30impl PatchId {
31    /// New patch id (initialised to 0).
32    pub fn new() -> Self {
33        PatchId([0; PATCH_ID_SIZE])
34    }
35    /// Encode this patch id in base58.
36    pub fn to_base58(&self) -> String {
37        bs58::encode(&self.0).into_string()
38    }
39    /// Decode this patch id from its base58 encoding.
40    pub fn from_base58(s: &str) -> Option<Self> {
41        let mut p = PatchId::new();
42        if bs58::decode(s).into(&mut p.0).is_ok() {
43            Some(p)
44        } else {
45            None
46        }
47    }
48}
49
50impl std::ops::Deref for PatchId {
51    type Target = [u8];
52    fn deref(&self) -> &Self::Target {
53        &self.0
54    }
55}
56impl std::ops::DerefMut for PatchId {
57    fn deref_mut(&mut self) -> &mut Self::Target {
58        &mut self.0
59    }
60}
61
62impl Representable for PatchId {
63    fn alignment() -> Alignment {
64        Alignment::B1
65    }
66    fn onpage_size(&self) -> u16 {
67        8
68    }
69    unsafe fn write_value(&self, p: *mut u8) {
70        trace!("write_value {:?}", p);
71        std::ptr::copy(self.0.as_ptr(), p, PATCH_ID_SIZE)
72    }
73    unsafe fn read_value(p: *const u8) -> Self {
74        trace!("read_value {:?}", p);
75        let mut patch_id: PatchId = std::mem::uninitialized();
76        std::ptr::copy(p, patch_id.0.as_mut_ptr(), 8);
77        patch_id
78    }
79    unsafe fn cmp_value<T>(&self, _: &T, x: Self) -> std::cmp::Ordering {
80        self.0.cmp(&x.0)
81    }
82    type PageOffsets = std::iter::Empty<u64>;
83    fn page_offsets(&self) -> Self::PageOffsets {
84        std::iter::empty()
85    }
86}
libpijul_compat/backend/patch_id.rs

libpijul_compat/backend/
patch_id.rs
