vortex-layout 0.84.0

Vortex layouts provide a way to perform lazy push-down scans over abstract storage
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

// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: Copyright the Vortex contributors

pub(crate) mod reader;
pub mod writer;

use std::sync::Arc;

use vortex_array::EmptyMetadata;
use vortex_array::dtype::DType;
use vortex_error::VortexExpect;
use vortex_error::VortexResult;
use vortex_error::vortex_bail;
use vortex_error::vortex_err;
use vortex_session::VortexSession;
use vortex_session::registry::CachedId;

use crate::Layout;
use crate::LayoutChildType;
use crate::LayoutChildren;
use crate::LayoutDeserializeArgs;
use crate::LayoutId;
use crate::LayoutParts;
use crate::LayoutReaderContext;
use crate::LayoutReaderRef;
use crate::LayoutRef;
use crate::VTable;
use crate::children::OwnedLayoutChildren;
use crate::layouts::chunked::reader::ChunkedReader;
use crate::segments::SegmentSource;

/// Chunked layout vtable.
#[derive(Clone, Debug)]
pub struct Chunked;

/// Backwards-compatible name for the chunked layout plugin.
pub use Chunked as ChunkedLayoutEncoding;

/// Chunked-layout-specific data.
#[derive(Clone, Debug)]
pub struct ChunkedData {
    chunk_offsets: Vec<u64>,
}

/// A layout partitioned into independently readable row chunks.
pub type ChunkedLayout = Layout<Chunked>;

impl VTable for Chunked {
    type LayoutData = ChunkedData;
    type Metadata = EmptyMetadata;

    fn id(&self) -> LayoutId {
        static ID: CachedId = CachedId::new("vortex.chunked");
        *ID
    }

    fn metadata(_layout: &Layout<Self>) -> Self::Metadata {
        EmptyMetadata
    }

    fn deserialize(
        &self,
        args: &LayoutDeserializeArgs<'_>,
        _metadata: &EmptyMetadata,
    ) -> VortexResult<Self::LayoutData> {
        let chunk_offsets = chunk_offsets(args.children)?;
        if chunk_offsets.last().copied() != Some(args.row_count) {
            vortex_bail!("Chunked child row counts do not add up to parent row count");
        }
        Ok(ChunkedData { chunk_offsets })
    }

    fn child_dtype(layout: &Layout<Self>, _idx: usize) -> VortexResult<DType> {
        Ok(layout.dtype().clone())
    }

    fn child_type(layout: &Layout<Self>, idx: usize) -> LayoutChildType {
        LayoutChildType::Chunk((idx, layout.chunk_offsets[idx]))
    }

    fn new_reader(
        layout: &Layout<Self>,
        name: Arc<str>,
        segment_source: Arc<dyn SegmentSource>,
        session: &VortexSession,
        ctx: &LayoutReaderContext,
    ) -> VortexResult<LayoutReaderRef> {
        Ok(Arc::new(ChunkedReader::new(
            layout.clone(),
            name,
            segment_source,
            session,
            ctx.clone(),
        )))
    }
}

impl Layout<Chunked> {
    /// Construct a chunked layout.
    pub fn new(row_count: u64, dtype: DType, children: Arc<dyn LayoutChildren>) -> Self {
        let offsets = chunk_offsets(children.as_ref()).vortex_expect("chunk row counts overflow");
        assert_eq!(
            offsets.last().copied(),
            Some(row_count),
            "Row count mismatch"
        );
        LayoutParts::new(
            Chunked,
            dtype,
            row_count,
            Vec::new(),
            children,
            ChunkedData {
                chunk_offsets: offsets,
            },
        )
        .into_typed()
    }

    /// Rebuild this layout with owned children.
    pub fn with_children(&self, children: Vec<LayoutRef>) -> Self {
        Self::new(
            self.row_count(),
            self.dtype().clone(),
            OwnedLayoutChildren::layout_children(children),
        )
    }
}

fn chunk_offsets(children: &dyn LayoutChildren) -> VortexResult<Vec<u64>> {
    let mut offsets = Vec::with_capacity(children.nchildren() + 1);
    offsets.push(0u64);
    for idx in 0..children.nchildren() {
        offsets.push(
            offsets[idx]
                .checked_add(children.child_row_count(idx))
                .ok_or_else(|| vortex_err!("Chunked child row counts overflow"))?,
        );
    }
    Ok(offsets)
}