kglite 0.14.2

Pure-Rust embedded Cypher knowledge graph engine with in-memory, mmap, and disk storage, and agent-facing schema introspection
Documentation 
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

//! Frozen bincode 1.x adapter. No other production module may import bincode.

use super::CodecError;
use bincode::Options;
use serde::de::{Deserialize, DeserializeOwned};
use serde::Serialize;
use std::collections::HashMap;
use std::hash::Hash;
use std::io::Read;

const CODEC: &str = "bincode-v1";

fn encode_error(error: impl ToString) -> CodecError {
    CodecError::Encode {
        codec: CODEC,
        message: error.to_string(),
    }
}

fn decode_error(error: impl ToString) -> CodecError {
    CodecError::Decode {
        codec: CODEC,
        message: error.to_string(),
    }
}

fn permissive_bounded_options(limit: u64) -> impl Options {
    bincode::options()
        .with_fixint_encoding()
        .with_little_endian()
        .allow_trailing_bytes()
        .with_limit(limit)
}

fn exact_bounded_options(limit: u64) -> impl Options {
    bincode::options()
        .with_fixint_encoding()
        .with_little_endian()
        .reject_trailing_bytes()
        .with_limit(limit)
}

fn check_size(bytes: &[u8], limit: u64) -> Result<(), CodecError> {
    let actual = bytes.len() as u64;
    if actual > limit {
        return Err(CodecError::SizeLimit { actual, limit });
    }
    Ok(())
}

#[cfg(test)]
pub(super) fn encode<T: Serialize + ?Sized>(value: &T) -> Result<Vec<u8>, CodecError> {
    bincode::serialize(value).map_err(encode_error)
}

pub(super) fn encode_bounded<T: Serialize + ?Sized>(
    value: &T,
    limit: u64,
) -> Result<Vec<u8>, CodecError> {
    permissive_bounded_options(limit)
        .serialize(value)
        .map_err(encode_error)
}

pub(super) fn decode<'de, T: Deserialize<'de>>(bytes: &'de [u8]) -> Result<T, CodecError> {
    bincode::deserialize(bytes).map_err(decode_error)
}

pub(super) fn decode_bounded<'de, T: Deserialize<'de>>(
    bytes: &'de [u8],
    limit: u64,
) -> Result<T, CodecError> {
    check_size(bytes, limit)?;
    permissive_bounded_options(limit)
        .deserialize(bytes)
        .map_err(decode_error)
}

pub(super) fn decode_exact<'de, T: Deserialize<'de>>(
    bytes: &'de [u8],
    limit: u64,
) -> Result<T, CodecError> {
    check_size(bytes, limit)?;
    exact_bounded_options(limit)
        .deserialize(bytes)
        .map_err(decode_error)
}

pub(super) fn decode_from_bounded<R: Read, T: DeserializeOwned>(
    reader: R,
    limit: u64,
) -> Result<T, CodecError> {
    permissive_bounded_options(limit)
        .deserialize_from(reader)
        .map_err(decode_error)
}

pub(super) fn decode_counted_map_exact<'de, K, V>(
    bytes: &'de [u8],
    expected_entries: u64,
    limit: u64,
) -> Result<HashMap<K, V>, CodecError>
where
    K: Deserialize<'de> + Eq + Hash,
    V: Deserialize<'de>,
{
    check_size(bytes, limit)?;
    let encoded = bytes
        .get(..8)
        .map(|count| u64::from_le_bytes(count.try_into().unwrap()))
        .ok_or(CodecError::TruncatedCollectionCount)?;
    if encoded != expected_entries {
        return Err(CodecError::CollectionCountMismatch {
            encoded,
            expected: expected_entries,
        });
    }

    // Every current general-ID-index entry contains at least an enum
    // discriminant and a u32 NodeIndex. Keeping this preflight inside the
    // adapter prevents corrupt counts from reaching bincode's allocator.
    let minimum = 8u64
        .checked_add(expected_entries.checked_mul(8).ok_or(
            CodecError::CollectionPayloadTooSmall {
                actual: bytes.len() as u64,
                minimum: u64::MAX,
            },
        )?)
        .ok_or(CodecError::CollectionPayloadTooSmall {
            actual: bytes.len() as u64,
            minimum: u64::MAX,
        })?;
    if (bytes.len() as u64) < minimum {
        return Err(CodecError::CollectionPayloadTooSmall {
            actual: bytes.len() as u64,
            minimum,
        });
    }

    decode_exact(bytes, limit)
}