sqlcx_core/
cache.rs

1use sha2::{Digest, Sha256};
2use std::fs;
3use std::path::Path;
4
5use crate::error::Result;
6use crate::ir::SqlcxIR;
7
8pub struct SqlFile {
9    pub path: String,
10    pub content: String,
11}
12
13#[derive(serde::Serialize, serde::Deserialize)]
14struct CacheFile {
15    hash: String,
16    ir: SqlcxIR,
17}
18
19/// Compute SHA-256 hash of SQL files. Files are sorted by path, each path+content
20/// separated by null bytes (matching the TS implementation).
21pub fn compute_hash(files: &[SqlFile], parser_name: &str) -> String {
22    let mut sorted: Vec<&SqlFile> = files.iter().collect();
23    sorted.sort_by(|a, b| a.path.cmp(&b.path));
24    let mut hasher = Sha256::new();
25    hasher.update(parser_name.as_bytes());
26    hasher.update(b"\0");
27    for f in &sorted {
28        hasher.update(f.path.as_bytes());
29        hasher.update(b"\0");
30        hasher.update(f.content.as_bytes());
31        hasher.update(b"\0");
32    }
33    format!("{:x}", hasher.finalize())
34}
35
36/// Write IR cache atomically (temp file → rename).
37pub fn write_cache(cache_dir: &Path, ir: &SqlcxIR, hash: &str) -> Result<()> {
38    fs::create_dir_all(cache_dir)?;
39    let data = CacheFile {
40        hash: hash.to_string(),
41        ir: ir.clone(),
42    };
43    let cache_path = cache_dir.join("ir.json");
44    let temp_path = cache_path.with_extension("json.tmp");
45    let json = serde_json::to_string(&data)?;
46    fs::write(&temp_path, &json)?;
47    fs::rename(&temp_path, &cache_path)?;
48    Ok(())
49}
50
51/// Read cached IR. Returns None on miss (wrong hash, no file, corrupted).
52pub fn read_cache(cache_dir: &Path, expected_hash: &str) -> Result<Option<SqlcxIR>> {
53    let cache_path = cache_dir.join("ir.json");
54    if !cache_path.exists() {
55        return Ok(None);
56    }
57    let content = fs::read_to_string(&cache_path)?;
58    let data: CacheFile = match serde_json::from_str(&content) {
59        Ok(d) => d,
60        Err(_) => return Ok(None),
61    };
62    if data.hash != expected_hash {
63        return Ok(None);
64    }
65    Ok(Some(data.ir))
66}
67
68#[cfg(test)]
69mod tests {
70    use super::*;
71    use crate::ir::*;
72
73    fn sample_ir() -> SqlcxIR {
74        SqlcxIR {
75            tables: vec![],
76            queries: vec![],
77            enums: vec![],
78        }
79    }
80
81    #[test]
82    fn compute_hash_deterministic() {
83        let files = vec![
84            SqlFile {
85                path: "a.sql".to_string(),
86                content: "SELECT 1;".to_string(),
87            },
88            SqlFile {
89                path: "b.sql".to_string(),
90                content: "SELECT 2;".to_string(),
91            },
92        ];
93        assert_eq!(
94            compute_hash(&files, "postgres"),
95            compute_hash(&files, "postgres")
96        );
97    }
98
99    #[test]
100    fn compute_hash_order_independent() {
101        let a = vec![
102            SqlFile {
103                path: "b.sql".to_string(),
104                content: "SELECT 2;".to_string(),
105            },
106            SqlFile {
107                path: "a.sql".to_string(),
108                content: "SELECT 1;".to_string(),
109            },
110        ];
111        let b = vec![
112            SqlFile {
113                path: "a.sql".to_string(),
114                content: "SELECT 1;".to_string(),
115            },
116            SqlFile {
117                path: "b.sql".to_string(),
118                content: "SELECT 2;".to_string(),
119            },
120        ];
121        assert_eq!(compute_hash(&a, "postgres"), compute_hash(&b, "postgres"));
122    }
123
124    #[test]
125    fn compute_hash_changes_with_parser_name() {
126        let files = vec![SqlFile {
127            path: "a.sql".to_string(),
128            content: "SELECT 1;".to_string(),
129        }];
130        assert_ne!(
131            compute_hash(&files, "postgres"),
132            compute_hash(&files, "mysql")
133        );
134    }
135
136    #[test]
137    fn cache_round_trip() {
138        let dir = tempfile::tempdir().unwrap();
139        let cache_dir = dir.path().join(".sqlcx");
140        let ir = sample_ir();
141        write_cache(&cache_dir, &ir, "abc123").unwrap();
142        let loaded = read_cache(&cache_dir, "abc123").unwrap();
143        assert!(loaded.is_some());
144    }
145
146    #[test]
147    fn cache_miss_on_hash_mismatch() {
148        let dir = tempfile::tempdir().unwrap();
149        let cache_dir = dir.path().join(".sqlcx");
150        write_cache(&cache_dir, &sample_ir(), "v1").unwrap();
151        assert!(read_cache(&cache_dir, "v2").unwrap().is_none());
152    }
153
154    #[test]
155    fn cache_miss_on_no_file() {
156        let dir = tempfile::tempdir().unwrap();
157        assert!(
158            read_cache(&dir.path().join(".sqlcx"), "any")
159                .unwrap()
160                .is_none()
161        );
162    }
163}
sqlcx_core/cache.rs

sqlcx_core/
cache.rs
