pgrx_sql_entity_graph/to_sql/
entity.rs

1//LICENSE Portions Copyright 2019-2021 ZomboDB, LLC.
2//LICENSE
3//LICENSE Portions Copyright 2021-2023 Technology Concepts & Design, Inc.
4//LICENSE
5//LICENSE Portions Copyright 2023-2023 PgCentral Foundation, Inc. <contact@pgcentral.org>
6//LICENSE
7//LICENSE All rights reserved.
8//LICENSE
9//LICENSE Use of this source code is governed by the MIT license that can be found in the LICENSE file.
10/*!
11
12`sql = ...` fragment related entities for Rust to SQL translation
13
14> Like all of the [`sql_entity_graph`][crate] APIs, this is considered **internal**
15> to the `pgrx` framework and very subject to change between versions. While you may use this, please do it with caution.
16
17*/
18use crate::pgrx_sql::PgrxSql;
19use crate::to_sql::ToSqlFn;
20use crate::SqlGraphEntity;
21
22/// Represents configuration options for tuning the SQL generator.
23///
24/// When an item that can be rendered to SQL has these options at hand, they should be
25/// respected. If an item does not have them, then it is not expected that the SQL generation
26/// for those items can be modified.
27///
28/// The default configuration has `enabled` set to `true`, and `callback` to `None`, which indicates
29/// that the default SQL generation behavior will be used. These are intended to be mutually exclusive
30/// options, so `callback` should only be set if generation is enabled.
31///
32/// When `enabled` is false, no SQL is generated for the item being configured.
33///
34/// When `callback` has a value, the corresponding `ToSql` implementation should invoke the
35/// callback instead of performing their default behavior.
36#[derive(Default, Clone)]
37pub struct ToSqlConfigEntity {
38    pub enabled: bool,
39    pub callback: Option<ToSqlFn>,
40    pub content: Option<&'static str>,
41}
42impl ToSqlConfigEntity {
43    /// Helper used to implement traits (`Eq`, `Ord`, etc) despite `ToSqlFn` not
44    /// having an implementation for them.
45    #[inline]
46    fn fields(&self) -> (bool, Option<&str>, Option<usize>) {
47        (self.enabled, self.content, self.callback.map(|f| f as usize))
48    }
49    /// Given a SqlGraphEntity, this function converts it to SQL based on the current configuration.
50    ///
51    /// If the config overrides the default behavior (i.e. using the `ToSql` trait), then `Some(eyre::Result)`
52    /// is returned. If the config does not override the default behavior, then `None` is returned. This can
53    /// be used to dispatch SQL generation in a single line, e.g.:
54    ///
55    /// ```rust,ignore
56    /// config.to_sql(entity, context).unwrap_or_else(|| entity.to_sql(context))?
57    /// ```
58    pub fn to_sql(
59        &self,
60        entity: &SqlGraphEntity,
61        context: &PgrxSql,
62    ) -> Option<eyre::Result<String>> {
63        use eyre::{eyre, WrapErr};
64
65        if !self.enabled {
66            return Some(Ok(format!(
67                "\n\
68                {sql_anchor_comment}\n\
69                -- Skipped due to `#[pgrx(sql = false)]`\n",
70                sql_anchor_comment = entity.sql_anchor_comment(),
71            )));
72        }
73
74        if let Some(content) = self.content {
75            let module_pathname = context.get_module_pathname();
76
77            let content = content.replace("@MODULE_PATHNAME@", &module_pathname);
78
79            return Some(Ok(format!(
80                "\n\
81                {sql_anchor_comment}\n\
82                {content}\n\
83            ",
84                content = content,
85                sql_anchor_comment = entity.sql_anchor_comment()
86            )));
87        }
88
89        if let Some(callback) = self.callback {
90            let content = callback(entity, context)
91                .map_err(|e| eyre!(e))
92                .wrap_err("Failed to run specified `#[pgrx(sql = path)] function`");
93            return match content {
94                Ok(content) => {
95                    let module_pathname = &context.get_module_pathname();
96
97                    let content = content.replace("@MODULE_PATHNAME@", module_pathname);
98
99                    Some(Ok(format!(
100                        "\n\
101                        {sql_anchor_comment}\n\
102                        {content}\
103                    ",
104                        content = content,
105                        sql_anchor_comment = entity.sql_anchor_comment(),
106                    )))
107                }
108                Err(e) => Some(Err(e)),
109            };
110        }
111
112        None
113    }
114}
115
116impl std::cmp::PartialOrd for ToSqlConfigEntity {
117    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
118        Some(self.cmp(other))
119    }
120}
121impl std::cmp::Ord for ToSqlConfigEntity {
122    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
123        self.fields().cmp(&other.fields())
124    }
125}
126impl std::cmp::PartialEq for ToSqlConfigEntity {
127    fn eq(&self, other: &Self) -> bool {
128        self.fields() == other.fields()
129    }
130}
131impl std::cmp::Eq for ToSqlConfigEntity {}
132impl std::hash::Hash for ToSqlConfigEntity {
133    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
134        self.fields().hash(state);
135    }
136}
137impl std::fmt::Debug for ToSqlConfigEntity {
138    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
139        let (enabled, content, callback) = self.fields();
140        f.debug_struct("ToSqlConfigEntity")
141            .field("enabled", &enabled)
142            .field("callback", &callback)
143            .field("content", &content)
144            .finish()
145    }
146}
pgrx_sql_entity_graph/to_sql/entity.rs

pgrx_sql_entity_graph/to_sql/
entity.rs
