swc_common/plugin/
metadata.rs

1use std::env;
2
3use once_cell::sync::Lazy;
4use rustc_hash::FxHashMap;
5
6/// Indexable key to the metadata context for a transform plugin.
7///
8/// Avoiding serialization & allocation to the host by using incremental number.
9/// TransformPluginMetadataContext does not implement Index trait, instead
10/// host does manual matching to corresponding value.
11#[derive(Copy, Clone)]
12pub enum TransformPluginMetadataContextKind {
13    // This value always should increase, even if some keys are removed in the
14    // future.
15    Filename = 1,
16    Env = 2,
17    Cwd = 3,
18}
19
20impl From<u32> for TransformPluginMetadataContextKind {
21    fn from(key: u32) -> TransformPluginMetadataContextKind {
22        match key {
23            1 => TransformPluginMetadataContextKind::Filename,
24            2 => TransformPluginMetadataContextKind::Env,
25            3 => TransformPluginMetadataContextKind::Cwd,
26            _ => panic!("Invalid TransformPluginMetadataContextKind key"),
27        }
28    }
29}
30
31/// Host side metadata context plugin may need to access.
32/// This is a global context - any plugin in single transform will have same
33/// values.
34pub struct TransformPluginMetadataContext {
35    /// The path of the file being processed. This includes all of the path as
36    /// much as possible.
37    pub filename: Option<String>,
38    /// The current environment resolved as process.env.SWC_ENV ||
39    /// process.env.NODE_ENV || "development"
40    pub env: String,
41    /// The current working directory.
42    pub cwd: Option<String>,
43    pub experimental: FxHashMap<String, String>,
44}
45
46impl TransformPluginMetadataContext {
47    pub fn new(
48        filename: Option<String>,
49        env: String,
50        experimental: Option<FxHashMap<String, String>>,
51    ) -> Self {
52        static CWD: Lazy<Option<String>> = Lazy::new(|| {
53            env::current_dir()
54                .map(|cwd| cwd.as_path().to_string_lossy().to_string())
55                .ok()
56        });
57
58        TransformPluginMetadataContext {
59            filename,
60            env,
61            cwd: CWD.clone(),
62            experimental: experimental.unwrap_or_default(),
63        }
64    }
65
66    pub fn get(&self, key: &TransformPluginMetadataContextKind) -> Option<String> {
67        match key {
68            TransformPluginMetadataContextKind::Filename => self.filename.clone(),
69            TransformPluginMetadataContextKind::Env => Some(self.env.clone()),
70            TransformPluginMetadataContextKind::Cwd => self.cwd.clone(),
71        }
72    }
73}
74
75pub struct Context(pub FxHashMap<String, String>);
76
77#[cfg(feature = "encoding-impl")]
78impl cbor4ii::core::enc::Encode for Context {
79    #[inline]
80    fn encode<W: cbor4ii::core::enc::Write>(
81        &self,
82        writer: &mut W,
83    ) -> Result<(), cbor4ii::core::enc::Error<W::Error>> {
84        use cbor4ii::core::types;
85
86        types::Map::bounded(self.0.len(), writer)?;
87        for (k, v) in self.0.iter() {
88            k.encode(writer)?;
89            v.encode(writer)?;
90        }
91
92        Ok(())
93    }
94}
95
96#[cfg(feature = "encoding-impl")]
97impl<'de> cbor4ii::core::dec::Decode<'de> for Context {
98    #[inline]
99    fn decode<R: cbor4ii::core::dec::Read<'de>>(
100        reader: &mut R,
101    ) -> Result<Self, cbor4ii::core::dec::Error<R::Error>> {
102        use cbor4ii::core::types;
103
104        let len = types::Map::len(reader)?.ok_or_else(|| cbor4ii::core::dec::Error::Mismatch {
105            name: &"Context",
106            found: 0,
107        })?;
108        let len = std::cmp::min(len, 4096);
109        let mut map = FxHashMap::with_capacity_and_hasher(len, Default::default());
110        for _ in 0..len {
111            let k = String::decode(reader)?;
112            let v = String::decode(reader)?;
113            map.insert(k, v);
114        }
115
116        Ok(Context(map))
117    }
118}
swc_common/plugin/metadata.rs

swc_common/plugin/
metadata.rs
