duckdb/
config.rs

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
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
use super::{ffi, Result};
use crate::error::Error;
use std::{default::Default, ffi::CString, os::raw::c_char, ptr};

use strum::{Display, EnumString};

/// duckdb access mode, default is Automatic
#[derive(Debug, Eq, PartialEq, EnumString, Display)]
pub enum AccessMode {
    /// Access mode of the database AUTOMATIC
    #[strum(to_string = "AUTOMATIC")]
    Automatic,
    /// Access mode of the database READ_ONLY
    #[strum(to_string = "READ_ONLY")]
    ReadOnly,
    /// Access mode of the database READ_WRITE
    #[strum(to_string = "READ_WRITE")]
    ReadWrite,
}

/// duckdb default order, default is Asc
#[derive(Debug, Eq, PartialEq, EnumString, Display)]
pub enum DefaultOrder {
    /// The order type, ASC
    #[strum(to_string = "ASC")]
    Asc,
    /// The order type, DESC
    #[strum(to_string = "DESC")]
    Desc,
}

/// duckdb default null order, default is nulls first
#[derive(Debug, Eq, PartialEq, EnumString, Display)]
pub enum DefaultNullOrder {
    /// Null ordering, NullsFirst
    #[strum(to_string = "NULLS_FIRST")]
    NullsFirst,
    /// Null ordering, NullsLast
    #[strum(to_string = "NULLS_LAST")]
    NullsLast,
}

/// duckdb configuration
/// Refer to https://github.com/duckdb/duckdb/blob/master/src/main/config.cpp
#[derive(Default)]
pub struct Config {
    config: Option<ffi::duckdb_config>,
}

impl Config {
    pub(crate) fn duckdb_config(&self) -> ffi::duckdb_config {
        self.config.unwrap_or(std::ptr::null_mut() as ffi::duckdb_config)
    }

    /// Access mode of the database ([AUTOMATIC], READ_ONLY or READ_WRITE)
    pub fn access_mode(mut self, mode: AccessMode) -> Result<Config> {
        self.set("access_mode", &mode.to_string())?;
        Ok(self)
    }

    /// The order type used when none is specified ([ASC] or DESC)
    pub fn default_order(mut self, order: DefaultOrder) -> Result<Config> {
        self.set("default_order", &order.to_string())?;
        Ok(self)
    }

    /// Null ordering used when none is specified ([NULLS_FIRST] or NULLS_LAST)
    pub fn default_null_order(mut self, null_order: DefaultNullOrder) -> Result<Config> {
        self.set("default_null_order", &null_order.to_string())?;
        Ok(self)
    }

    /// Allow the database to access external state (through e.g. COPY TO/FROM, CSV readers, pandas replacement scans, etc)
    pub fn enable_external_access(mut self, enabled: bool) -> Result<Config> {
        self.set("enable_external_access", &enabled.to_string())?;
        Ok(self)
    }

    /// Whether or not object cache is used to cache e.g. Parquet metadata
    pub fn enable_object_cache(mut self, enabled: bool) -> Result<Config> {
        self.set("enable_object_cache", &enabled.to_string())?;
        Ok(self)
    }

    /// Allow to load third-party duckdb extensions.
    pub fn allow_unsigned_extensions(mut self) -> Result<Config> {
        self.set("allow_unsigned_extensions", "true")?;
        Ok(self)
    }

    /// The maximum memory of the system (e.g. 1GB)
    pub fn max_memory(mut self, memory: &str) -> Result<Config> {
        self.set("max_memory", memory)?;
        Ok(self)
    }

    /// The number of total threads used by the system
    pub fn threads(mut self, thread_num: i64) -> Result<Config> {
        self.set("threads", &thread_num.to_string())?;
        Ok(self)
    }

    fn set(&mut self, key: &str, value: &str) -> Result<()> {
        if self.config.is_none() {
            let mut config: ffi::duckdb_config = ptr::null_mut();
            let state = unsafe { ffi::duckdb_create_config(&mut config) };
            assert_eq!(state, ffi::DuckDBSuccess);
            self.config = Some(config);
        }
        let c_key = CString::new(key).unwrap();
        let c_value = CString::new(value).unwrap();
        let state = unsafe {
            ffi::duckdb_set_config(
                self.config.unwrap(),
                c_key.as_ptr() as *const c_char,
                c_value.as_ptr() as *const c_char,
            )
        };
        if state != ffi::DuckDBSuccess {
            return Err(Error::DuckDBFailure(
                ffi::Error::new(state),
                Some(format!("set {key}:{value} error")),
            ));
        }
        Ok(())
    }
}

impl Drop for Config {
    fn drop(&mut self) {
        if self.config.is_some() {
            unsafe { ffi::duckdb_destroy_config(&mut self.config.unwrap()) };
        }
    }
}

#[cfg(test)]
mod test {
    use crate::{types::Value, Config, Connection, Result};

    #[test]
    fn test_default_config() -> Result<()> {
        let config = Config::default();
        let db = Connection::open_in_memory_with_flags(config)?;
        db.execute_batch("CREATE TABLE foo(x Text)")?;

        let mut stmt = db.prepare("INSERT INTO foo(x) VALUES (?)")?;
        stmt.execute([&"a"])?;
        stmt.execute([&"b"])?;
        stmt.execute([&"c"])?;
        stmt.execute([Value::Null])?;

        let val: Result<Vec<Option<String>>> = db
            .prepare("SELECT x FROM foo ORDER BY x")?
            .query_and_then([], |row| row.get(0))?
            .collect();
        let val = val?;
        let mut iter = val.iter();
        assert_eq!(val.len(), 4);
        assert_eq!(iter.next().unwrap().as_ref().unwrap(), "a");
        assert_eq!(iter.next().unwrap().as_ref().unwrap(), "b");
        assert_eq!(iter.next().unwrap().as_ref().unwrap(), "c");
        assert!(iter.next().unwrap().is_none());
        assert_eq!(iter.next(), None);

        Ok(())
    }

    #[test]
    fn test_all_config() -> Result<()> {
        let config = Config::default()
            .access_mode(crate::AccessMode::ReadWrite)?
            .default_null_order(crate::DefaultNullOrder::NullsLast)?
            .default_order(crate::DefaultOrder::Desc)?
            .enable_external_access(true)?
            .enable_object_cache(false)?
            .allow_unsigned_extensions()?
            .max_memory("2GB")?
            .threads(4)?;
        let db = Connection::open_in_memory_with_flags(config)?;
        db.execute_batch("CREATE TABLE foo(x Text)")?;

        let mut stmt = db.prepare("INSERT INTO foo(x) VALUES (?)")?;
        stmt.execute([&"a"])?;
        stmt.execute([&"b"])?;
        stmt.execute([&"c"])?;
        stmt.execute([Value::Null])?;

        let val: Result<Vec<Option<String>>> = db
            .prepare("SELECT x FROM foo ORDER BY x")?
            .query_and_then([], |row| row.get(0))?
            .collect();
        let val = val?;
        let mut iter = val.iter();
        assert_eq!(iter.next().unwrap().as_ref().unwrap(), "c");
        assert_eq!(iter.next().unwrap().as_ref().unwrap(), "b");
        assert_eq!(iter.next().unwrap().as_ref().unwrap(), "a");
        assert!(iter.next().unwrap().is_none());
        assert_eq!(iter.next(), None);

        Ok(())
    }
}