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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.
use std::fmt::{self, Display, Formatter};
use datafusion::common::TableReference;
use datafusion::logical_expr::logical_plan::TableScan;
use pyo3::IntoPyObjectExt;
use pyo3::prelude::*;
use crate::common::df_schema::PyDFSchema;
use crate::expr::PyExpr;
use crate::expr::logical_node::LogicalNode;
use crate::sql::logical::PyLogicalPlan;
#[pyclass(
from_py_object,
frozen,
name = "TableScan",
module = "datafusion.expr",
subclass
)]
#[derive(Clone)]
pub struct PyTableScan {
table_scan: TableScan,
}
impl PyTableScan {
pub fn new(table_scan: TableScan) -> Self {
Self { table_scan }
}
}
impl From<PyTableScan> for TableScan {
fn from(tbl_scan: PyTableScan) -> TableScan {
tbl_scan.table_scan
}
}
impl From<TableScan> for PyTableScan {
fn from(table_scan: TableScan) -> PyTableScan {
PyTableScan { table_scan }
}
}
impl Display for PyTableScan {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
write!(
f,
"TableScan\nTable Name: {}
Projections: {:?}
Projected Schema: {:?}
Filters: {:?}",
&self.table_scan.table_name,
&self.py_projections(),
&self.py_schema(),
&self.py_filters(),
)
}
}
#[pymethods]
impl PyTableScan {
/// Retrieves the name of the table represented by this `TableScan` instance
#[pyo3(name = "table_name")]
fn py_table_name(&self) -> PyResult<String> {
Ok(format!("{}", self.table_scan.table_name))
}
#[pyo3(name = "fqn")]
fn fqn(&self) -> PyResult<(Option<String>, Option<String>, String)> {
let table_ref: TableReference = self.table_scan.table_name.clone();
Ok(match table_ref {
TableReference::Bare { table } => (None, None, table.to_string()),
TableReference::Partial { schema, table } => {
(None, Some(schema.to_string()), table.to_string())
}
TableReference::Full {
catalog,
schema,
table,
} => (
Some(catalog.to_string()),
Some(schema.to_string()),
table.to_string(),
),
})
}
/// The column indexes that should be. Note if this is empty then
/// all columns should be read by the `TableProvider`. This function
/// provides a Tuple of the (index, column_name) to make things simpler
/// for the calling code since often times the name is preferred to
/// the index which is a lower level abstraction.
#[pyo3(name = "projection")]
fn py_projections(&self) -> PyResult<Vec<(usize, String)>> {
match &self.table_scan.projection {
Some(indices) => {
let schema = self.table_scan.source.schema();
Ok(indices
.iter()
.map(|i| (*i, schema.field(*i).name().to_string()))
.collect())
}
None => Ok(vec![]),
}
}
/// Resulting schema from the `TableScan` operation
#[pyo3(name = "schema")]
fn py_schema(&self) -> PyResult<PyDFSchema> {
Ok((*self.table_scan.projected_schema).clone().into())
}
/// Certain `TableProvider` physical readers offer the capability to filter rows that
/// are read at read time. These `filters` are contained here.
#[pyo3(name = "filters")]
fn py_filters(&self) -> PyResult<Vec<PyExpr>> {
Ok(self
.table_scan
.filters
.iter()
.map(|expr| PyExpr::from(expr.clone()))
.collect())
}
/// Optional number of rows that should be read at read time by the `TableProvider`
#[pyo3(name = "fetch")]
fn py_fetch(&self) -> PyResult<Option<usize>> {
Ok(self.table_scan.fetch)
}
fn __repr__(&self) -> PyResult<String> {
Ok(format!("TableScan({self})"))
}
}
impl LogicalNode for PyTableScan {
fn inputs(&self) -> Vec<PyLogicalPlan> {
// table scans are leaf nodes and do not have inputs
vec![]
}
fn to_variant<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
self.clone().into_bound_py_any(py)
}
}