feat(index): port index::insert()

src/index.rs

@@ -0,0 +1,84 @@
+use std::fs::{self, OpenOptions};
+use std::io::Write;
+use std::path::{Path, PathBuf};
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use digest::Digest;
+use hex;
+use serde_derive::{Deserialize, Serialize};
+use serde_json::{self, json, Value};
+use sha1::Sha1;
+use sha2::Sha256;
+use ssri::Integrity;
+
+const INDEX_VERSION: &str = "5";
+
+#[derive(Deserialize, Serialize)]
+struct Entry {
+    key: String,
+    integrity: String,
+    time: u128,
+    size: u128,
+    metadata: Value,
+}
+
+pub fn insert(cache: &Path, key: &str, sri: Integrity) -> std::io::Result<()> {
+    let bucket = bucket_path(&cache, &key);
+    fs::create_dir_all(bucket.parent().unwrap())?;
+    let stringified = serde_json::to_string(&Entry {
+        key: String::from(key),
+        integrity: sri.to_string(),
+        time: now(),
+        size: 0, // TODO - probably do something about this.
+        metadata: json!(null),
+    })
+    .expect("Failed to serialize entry.");
+    let str = format!("\n{}\t{}", hash_entry(&stringified), stringified);
+    OpenOptions::new()
+        .create(true)
+        .append(true)
+        .open(bucket)?
+        .write_all(&str.into_bytes())
+}
+
+pub fn find(_cache: &Path, _key: &str) {
+    unimplemented!();
+}
+
+pub fn delete(_cache: &Path, _key: &str) {
+    unimplemented!();
+}
+
+pub fn ls(_cache: &Path) {
+    unimplemented!();
+}
+
+fn bucket_path(cache: &Path, key: &str) -> PathBuf {
+    let hashed = hash_key(&key);
+    let mut path = PathBuf::new();
+    path.push(cache);
+    path.push(format!("index-v{}", INDEX_VERSION));
+    path.push(&hashed[0..2]);
+    path.push(&hashed[2..4]);
+    path.push(&hashed[4..]);
+    path
+}
+
+fn hash_key(key: &str) -> String {
+    let mut hasher = Sha1::new();
+    hasher.input(&key);
+    hex::encode(hasher.result())
+}
+
+fn hash_entry(key: &str) -> String {
+    let mut hasher = Sha256::new();
+    hasher.input(&key);
+    hex::encode(hasher.result())
+}
+
+fn now() -> u128 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap()
+        .as_millis()
+}