static_files/mods/
sets.rs

1/*!
2Support for module based generations. Use it for large data sets (more than 128 Mb).
3 */
4use std::{
5    fs::{self, File, Metadata},
6    io::{self, Write},
7    path::{Path, PathBuf},
8};
9
10use super::resource::{
11    collect_resources, generate_function_end, generate_function_header, generate_resource_insert,
12    generate_uses, generate_variable_header, generate_variable_return, DEFAULT_VARIABLE_NAME,
13};
14
15/// Defines the split strategie.
16pub trait SetSplitStrategie {
17    /// Register next file from resources.
18    fn register(&mut self, path: &Path, metadata: &Metadata);
19    /// Determine, should we split modules now.
20    fn should_split(&self) -> bool;
21    /// Resets internal counters after split.
22    fn reset(&mut self);
23}
24
25/// Split modules by files count.
26pub struct SplitByCount {
27    current: usize,
28    max: usize,
29}
30
31impl SplitByCount {
32    #[must_use]
33    pub fn new(max: usize) -> Self {
34        Self { current: 0, max }
35    }
36}
37
38impl SetSplitStrategie for SplitByCount {
39    fn register(&mut self, _path: &Path, _metadata: &Metadata) {
40        self.current += 1;
41    }
42
43    fn should_split(&self) -> bool {
44        self.current >= self.max
45    }
46
47    fn reset(&mut self) {
48        self.current = 0;
49    }
50}
51
52/// Generate resources for `project_dir` using `filter`
53/// breaking them into separate modules using `set_split_strategy` (recommended for large > 128 Mb setups).
54///
55/// Result saved in module named `module_name`. It exports
56/// only one function named `fn_name`. It is then exported from
57/// `generated_filename`. `generated_filename` is also used to determine
58/// the parent directory for the module.
59///
60/// in `build.rs`:
61/// ```rust
62///
63/// use std::{env, path::Path};
64/// use static_files::sets::{generate_resources_sets, SplitByCount};
65///
66/// fn main() {
67///     let out_dir = env::var("OUT_DIR").unwrap();
68///     let generated_filename = Path::new(&out_dir).join("generated_sets.rs");
69///     generate_resources_sets(
70///         "./tests",
71///         None,
72///         generated_filename,
73///         "sets",
74///         "generate",
75///         &mut SplitByCount::new(2),
76///     )
77///     .unwrap();
78/// }
79/// ```
80///
81/// in `main.rs`:
82/// ```rust
83/// include!(concat!(env!("OUT_DIR"), "/generated_sets.rs"));
84///
85/// fn main() {
86///     let generated_file = generate();
87///
88///     assert_eq!(generated_file.len(), 4);
89///
90/// }
91/// ```
92pub fn generate_resources_sets<P, G, S>(
93    project_dir: P,
94    filter: Option<fn(p: &Path) -> bool>,
95    generated_filename: G,
96    module_name: &str,
97    fn_name: &str,
98    set_split_strategy: &mut S,
99) -> io::Result<()>
100where
101    P: AsRef<Path>,
102    G: AsRef<Path>,
103    S: SetSplitStrategie,
104{
105    let resources = collect_resources(&project_dir, filter)?;
106
107    let mut generated_file = File::create(&generated_filename)?;
108
109    let module_dir = generated_filename.as_ref().parent().map_or_else(
110        || PathBuf::from(module_name),
111        |parent| parent.join(module_name),
112    );
113    fs::create_dir_all(&module_dir)?;
114
115    let mut module_file = File::create(module_dir.join("mod.rs"))?;
116
117    generate_uses(&mut module_file)?;
118    writeln!(
119        module_file,
120        "\
121use ::std::collections::HashMap;
122use ::static_files::Resource;"
123    )?;
124
125    let mut modules_count = 1;
126
127    let mut set_file = create_set_module_file(&module_dir, modules_count)?;
128    let mut should_split = set_split_strategy.should_split();
129
130    for resource in &resources {
131        let (path, metadata) = &resource;
132        if should_split {
133            set_split_strategy.reset();
134            modules_count += 1;
135            generate_function_end(&mut set_file)?;
136            set_file = create_set_module_file(&module_dir, modules_count)?;
137        }
138        set_split_strategy.register(path, metadata);
139        should_split = set_split_strategy.should_split();
140
141        generate_resource_insert(&mut set_file, &project_dir, DEFAULT_VARIABLE_NAME, resource)?;
142    }
143
144    generate_function_end(&mut set_file)?;
145
146    for module_index in 1..=modules_count {
147        writeln!(module_file, "mod set_{module_index};")?;
148    }
149
150    generate_function_header(&mut module_file, fn_name)?;
151
152    generate_variable_header(&mut module_file, DEFAULT_VARIABLE_NAME)?;
153
154    for module_index in 1..=modules_count {
155        writeln!(
156            module_file,
157            "set_{module_index}::generate(&mut {DEFAULT_VARIABLE_NAME});",
158        )?;
159    }
160
161    generate_variable_return(&mut module_file, DEFAULT_VARIABLE_NAME)?;
162
163    generate_function_end(&mut module_file)?;
164
165    writeln!(
166        generated_file,
167        "\
168mod {module_name};
169pub use {module_name}::{fn_name};",
170    )?;
171
172    Ok(())
173}
174
175fn create_set_module_file(module_dir: &Path, module_index: usize) -> io::Result<File> {
176    let mut set_module = File::create(module_dir.join(format!("set_{module_index}.rs")))?;
177
178    writeln!(
179        set_module,
180        "\
181#[allow(clippy::wildcard_imports)]
182use super::*;
183#[allow(clippy::unreadable_literal)]
184pub(crate) fn generate({DEFAULT_VARIABLE_NAME}: &mut HashMap<&'static str, Resource>) {{",
185    )?;
186
187    Ok(set_module)
188}
static_files/mods/sets.rs

static_files/mods/
sets.rs
