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

mod binary;
mod boolean;
mod fixed_len_binary;
mod primitive;

use std::{any::Any, sync::Arc};

pub use crate::thrift_format::Statistics as ParquetStatistics;

use crate::error::Result;
use crate::schema::types::{PhysicalType, PrimitiveType};

pub use binary::BinaryStatistics;
pub use boolean::BooleanStatistics;
pub use fixed_len_binary::FixedLenStatistics;
pub use primitive::PrimitiveStatistics;

/// A trait used to describe specific statistics. Each physical type has its own struct.
/// Match the [`Statistics::physical_type`] to each type and downcast accordingly.
pub trait Statistics: Send + Sync + std::fmt::Debug {
    fn as_any(&self) -> &dyn Any;

    fn physical_type(&self) -> &PhysicalType;

    fn null_count(&self) -> Option<i64>;
}

impl PartialEq for &dyn Statistics {
    fn eq(&self, other: &Self) -> bool {
        self.physical_type() == other.physical_type() && {
            match self.physical_type() {
                PhysicalType::Boolean => {
                    self.as_any().downcast_ref::<BooleanStatistics>().unwrap()
                        == other.as_any().downcast_ref::<BooleanStatistics>().unwrap()
                }
                PhysicalType::Int32 => {
                    self.as_any()
                        .downcast_ref::<PrimitiveStatistics<i32>>()
                        .unwrap()
                        == other
                            .as_any()
                            .downcast_ref::<PrimitiveStatistics<i32>>()
                            .unwrap()
                }
                PhysicalType::Int64 => {
                    self.as_any()
                        .downcast_ref::<PrimitiveStatistics<i64>>()
                        .unwrap()
                        == other
                            .as_any()
                            .downcast_ref::<PrimitiveStatistics<i64>>()
                            .unwrap()
                }
                PhysicalType::Int96 => {
                    self.as_any()
                        .downcast_ref::<PrimitiveStatistics<[u32; 3]>>()
                        .unwrap()
                        == other
                            .as_any()
                            .downcast_ref::<PrimitiveStatistics<[u32; 3]>>()
                            .unwrap()
                }
                PhysicalType::Float => {
                    self.as_any()
                        .downcast_ref::<PrimitiveStatistics<f32>>()
                        .unwrap()
                        == other
                            .as_any()
                            .downcast_ref::<PrimitiveStatistics<f32>>()
                            .unwrap()
                }
                PhysicalType::Double => {
                    self.as_any()
                        .downcast_ref::<PrimitiveStatistics<f64>>()
                        .unwrap()
                        == other
                            .as_any()
                            .downcast_ref::<PrimitiveStatistics<f64>>()
                            .unwrap()
                }
                PhysicalType::ByteArray => {
                    self.as_any().downcast_ref::<BinaryStatistics>().unwrap()
                        == other.as_any().downcast_ref::<BinaryStatistics>().unwrap()
                }
                PhysicalType::FixedLenByteArray(_) => {
                    self.as_any().downcast_ref::<FixedLenStatistics>().unwrap()
                        == other.as_any().downcast_ref::<FixedLenStatistics>().unwrap()
                }
            }
        }
    }
}

/// Deserializes a raw parquet statistics into [`Statistics`].
/// # Error
/// This function errors if it is not possible to read the statistics to the
/// corresponding `physical_type`.
pub fn deserialize_statistics(
    statistics: &ParquetStatistics,
    primitive_type: PrimitiveType,
) -> Result<Arc<dyn Statistics>> {
    match primitive_type.physical_type {
        PhysicalType::Boolean => boolean::read(statistics),
        PhysicalType::Int32 => primitive::read::<i32>(statistics, primitive_type),
        PhysicalType::Int64 => primitive::read::<i64>(statistics, primitive_type),
        PhysicalType::Int96 => primitive::read::<[u32; 3]>(statistics, primitive_type),
        PhysicalType::Float => primitive::read::<f32>(statistics, primitive_type),
        PhysicalType::Double => primitive::read::<f64>(statistics, primitive_type),
        PhysicalType::ByteArray => binary::read(statistics, primitive_type),
        PhysicalType::FixedLenByteArray(size) => {
            fixed_len_binary::read(statistics, size, primitive_type)
        }
    }
}

/// Serializes [`Statistics`] into a raw parquet statistics.
pub fn serialize_statistics(statistics: &dyn Statistics) -> ParquetStatistics {
    match statistics.physical_type() {
        PhysicalType::Boolean => boolean::write(statistics.as_any().downcast_ref().unwrap()),
        PhysicalType::Int32 => primitive::write::<i32>(statistics.as_any().downcast_ref().unwrap()),
        PhysicalType::Int64 => primitive::write::<i64>(statistics.as_any().downcast_ref().unwrap()),
        PhysicalType::Int96 => {
            primitive::write::<[u32; 3]>(statistics.as_any().downcast_ref().unwrap())
        }
        PhysicalType::Float => primitive::write::<f32>(statistics.as_any().downcast_ref().unwrap()),
        PhysicalType::Double => {
            primitive::write::<f64>(statistics.as_any().downcast_ref().unwrap())
        }
        PhysicalType::ByteArray => binary::write(statistics.as_any().downcast_ref().unwrap()),
        PhysicalType::FixedLenByteArray(_) => {
            fixed_len_binary::write(statistics.as_any().downcast_ref().unwrap())
        }
    }
}