rd-helpdb 0.5.0-rc.2

Reader for installed R package help databases (aliases, .rdx/.rdb, Meta/hsearch.rds), built on rd-rds
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

use std::path::PathBuf;

use thiserror::Error;

/// Errors produced by `rd-helpdb`.
///
/// New failure categories may be added in minor releases; consumers should
/// match this enum non-exhaustively with a wildcard arm.
#[derive(Debug, Error)]
#[non_exhaustive]
pub enum Error {
    #[error("I/O error at {path}: {source}")]
    Io {
        path: PathBuf,
        #[source]
        source: std::io::Error,
    },

    #[error("unsupported compression magic bytes {magic:02x?} in {path}")]
    UnsupportedCompression { path: PathBuf, magic: Vec<u8> },

    #[error(transparent)]
    Rds(#[from] rd_rds::Error),

    #[error(transparent)]
    RdsFile(#[from] rd_rds::file::ReadError),

    #[error("malformed help-db index: {0}")]
    MalformedIndex(String),

    #[error("help-db index exceeds the {limit}-byte limit")]
    IndexSizeLimitExceeded { limit: usize },

    #[error("stored help-db record exceeds the {limit}-byte limit")]
    StoredRecordSizeLimitExceeded { limit: usize },

    #[error("decompressed help-db record exceeds the {limit}-byte limit")]
    DecompressedRecordSizeLimitExceeded { limit: usize },

    #[error("help database changed while it was being read: {path}")]
    DatabaseChanged { path: PathBuf },

    #[error("record compression {compression:?} is not supported")]
    UnsupportedRecordCompression {
        compression: rd_rds::lazyload::Compression,
    },

    #[error("reference {key:?} does not address a direct record")]
    UnsupportedReference { key: String },

    #[error("unknown topic {topic:?}")]
    UnknownTopic { topic: String },

    #[error("unknown reference key {key:?}")]
    UnknownReference { key: String },

    #[error(
        "record size mismatch: the 4-byte length prefix declares {expected} bytes but zlib decompression produced {actual} bytes"
    )]
    RecordSizeMismatch { expected: usize, actual: usize },
}

impl Error {
    pub(crate) fn io(path: impl Into<PathBuf>, source: std::io::Error) -> Self {
        Self::Io {
            path: path.into(),
            source,
        }
    }
}