1 files changed, 350 insertions, 0 deletions
diff --git a/cli/cache/incremental.rs b/cli/cache/incremental.rs
new file mode 100644
index 000000000..b5fff0734
--- /dev/null
+++ b/cli/cache/incremental.rs
@@ -0,0 +1,350 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+use std::collections::HashMap;
+use std::path::Path;
+use std::path::PathBuf;
+
+use deno_core::error::AnyError;
+use deno_core::parking_lot::Mutex;
+use deno_core::serde_json;
+use deno_runtime::deno_webstorage::rusqlite::params;
+use deno_runtime::deno_webstorage::rusqlite::Connection;
+use serde::Serialize;
+use tokio::task::JoinHandle;
+
+use super::common::fast_insecure_hash;
+use super::common::run_sqlite_pragma;
+
+/// Cache used to skip formatting/linting a file again when we
+/// know it is already formatted or has no lint diagnostics.
+pub struct IncrementalCache(Option<IncrementalCacheInner>);
+
+impl IncrementalCache {
+  pub fn new<TState: Serialize>(
+    db_file_path: &Path,
+    state: &TState,
+    initial_file_paths: &[PathBuf],
+  ) -> Self {
+    // if creating the incremental cache fails, then we
+    // treat it as not having a cache
+    let result =
+      IncrementalCacheInner::new(db_file_path, state, initial_file_paths);
+    IncrementalCache(match result {
+      Ok(inner) => Some(inner),
+      Err(err) => {
+        log::debug!("Creating the incremental cache failed.\n{:#}", err);
+        // Maybe the cache file is corrupt. Attempt to remove
+        // the cache file for next time
+        let _ = std::fs::remove_file(db_file_path);
+        None
+      }
+    })
+  }
+
+  pub fn is_file_same(&self, file_path: &Path, file_text: &str) -> bool {
+    if let Some(inner) = &self.0 {
+      inner.is_file_same(file_path, file_text)
+    } else {
+      false
+    }
+  }
+
+  pub fn update_file(&self, file_path: &Path, file_text: &str) {
+    if let Some(inner) = &self.0 {
+      inner.update_file(file_path, file_text)
+    }
+  }
+
+  pub async fn wait_completion(&self) {
+    if let Some(inner) = &self.0 {
+      inner.wait_completion().await;
+    }
+  }
+}
+
+enum ReceiverMessage {
+  Update(PathBuf, u64),
+  Exit,
+}
+
+struct IncrementalCacheInner {
+  previous_hashes: HashMap<PathBuf, u64>,
+  sender: tokio::sync::mpsc::UnboundedSender<ReceiverMessage>,
+  handle: Mutex<Option<JoinHandle<()>>>,
+}
+
+impl IncrementalCacheInner {
+  pub fn new<TState: Serialize>(
+    db_file_path: &Path,
+    state: &TState,
+    initial_file_paths: &[PathBuf],
+  ) -> Result<Self, AnyError> {
+    let state_hash =
+      fast_insecure_hash(serde_json::to_string(state).unwrap().as_bytes());
+    let sql_cache = SqlIncrementalCache::new(db_file_path, state_hash)?;
+    Ok(Self::from_sql_incremental_cache(
+      sql_cache,
+      initial_file_paths,
+    ))
+  }
+
+  fn from_sql_incremental_cache(
+    cache: SqlIncrementalCache,
+    initial_file_paths: &[PathBuf],
+  ) -> Self {
+    let mut previous_hashes = HashMap::new();
+    for path in initial_file_paths {
+      if let Some(hash) = cache.get_source_hash(path) {
+        previous_hashes.insert(path.to_path_buf(), hash);
+      }
+    }
+
+    let (sender, mut receiver) =
+      tokio::sync::mpsc::unbounded_channel::<ReceiverMessage>();
+
+    // sqlite isn't `Sync`, so we do all the updating on a dedicated task
+    let handle = tokio::task::spawn(async move {
+      while let Some(message) = receiver.recv().await {
+        match message {
+          ReceiverMessage::Update(path, hash) => {
+            let _ = cache.set_source_hash(&path, hash);
+          }
+          ReceiverMessage::Exit => break,
+        }
+      }
+    });
+
+    IncrementalCacheInner {
+      previous_hashes,
+      sender,
+      handle: Mutex::new(Some(handle)),
+    }
+  }
+
+  pub fn is_file_same(&self, file_path: &Path, file_text: &str) -> bool {
+    match self.previous_hashes.get(file_path) {
+      Some(hash) => *hash == fast_insecure_hash(file_text.as_bytes()),
+      None => false,
+    }
+  }
+
+  pub fn update_file(&self, file_path: &Path, file_text: &str) {
+    let hash = fast_insecure_hash(file_text.as_bytes());
+    if let Some(previous_hash) = self.previous_hashes.get(file_path) {
+      if *previous_hash == hash {
+        return; // do not bother updating the db file because nothing has changed
+      }
+    }
+    let _ = self
+      .sender
+      .send(ReceiverMessage::Update(file_path.to_path_buf(), hash));
+  }
+
+  pub async fn wait_completion(&self) {
+    if self.sender.send(ReceiverMessage::Exit).is_err() {
+      return;
+    }
+    let handle = self.handle.lock().take();
+    if let Some(handle) = handle {
+      handle.await.unwrap();
+    }
+  }
+}
+
+struct SqlIncrementalCache {
+  conn: Connection,
+  /// A hash of the state used to produce the formatting/linting other than
+  /// the CLI version. This state is a hash of the configuration and ensures
+  /// we format/lint a file when the configuration changes.
+  state_hash: u64,
+}
+
+impl SqlIncrementalCache {
+  pub fn new(db_file_path: &Path, state_hash: u64) -> Result<Self, AnyError> {
+    let conn = Connection::open(db_file_path)?;
+    Self::from_connection(conn, state_hash, crate::version::deno())
+  }
+
+  fn from_connection(
+    conn: Connection,
+    state_hash: u64,
+    cli_version: String,
+  ) -> Result<Self, AnyError> {
+    run_sqlite_pragma(&conn)?;
+    create_tables(&conn, cli_version)?;
+
+    Ok(Self { conn, state_hash })
+  }
+
+  pub fn get_source_hash(&self, path: &Path) -> Option<u64> {
+    match self.get_source_hash_result(path) {
+      Ok(option) => option,
+      Err(err) => {
+        if cfg!(debug_assertions) {
+          panic!("Error retrieving hash: {}", err);
+        } else {
+          // fail silently when not debugging
+          None
+        }
+      }
+    }
+  }
+
+  fn get_source_hash_result(
+    &self,
+    path: &Path,
+  ) -> Result<Option<u64>, AnyError> {
+    let query = "
+      SELECT
+        source_hash
+      FROM
+        incrementalcache
+      WHERE
+        file_path=?1
+        AND state_hash=?2
+      LIMIT 1";
+    let mut stmt = self.conn.prepare_cached(query)?;
+    let mut rows = stmt
+      .query(params![path.to_string_lossy(), self.state_hash.to_string()])?;
+    if let Some(row) = rows.next()? {
+      let hash: String = row.get(0)?;
+      Ok(Some(hash.parse::<u64>()?))
+    } else {
+      Ok(None)
+    }
+  }
+
+  pub fn set_source_hash(
+    &self,
+    path: &Path,
+    source_hash: u64,
+  ) -> Result<(), AnyError> {
+    let sql = "
+      INSERT OR REPLACE INTO
+        incrementalcache (file_path, state_hash, source_hash)
+      VALUES
+        (?1, ?2, ?3)";
+    let mut stmt = self.conn.prepare_cached(sql)?;
+    stmt.execute(params![
+      path.to_string_lossy(),
+      &self.state_hash.to_string(),
+      &source_hash.to_string(),
+    ])?;
+    Ok(())
+  }
+}
+
+fn create_tables(
+  conn: &Connection,
+  cli_version: String,
+) -> Result<(), AnyError> {
+  // INT doesn't store up to u64, so use TEXT
+  conn.execute(
+    "CREATE TABLE IF NOT EXISTS incrementalcache (
+        file_path TEXT PRIMARY KEY,
+        state_hash TEXT NOT NULL,
+        source_hash TEXT NOT NULL
+      )",
+    [],
+  )?;
+  conn.execute(
+    "CREATE TABLE IF NOT EXISTS info (
+        key TEXT PRIMARY KEY,
+        value TEXT NOT NULL
+      )",
+    [],
+  )?;
+
+  // delete the cache when the CLI version changes
+  let data_cli_version: Option<String> = conn
+    .query_row(
+      "SELECT value FROM info WHERE key='CLI_VERSION' LIMIT 1",
+      [],
+      |row| row.get(0),
+    )
+    .ok();
+  if data_cli_version != Some(cli_version.to_string()) {
+    conn.execute("DELETE FROM incrementalcache", params![])?;
+    let mut stmt = conn
+      .prepare("INSERT OR REPLACE INTO info (key, value) VALUES (?1, ?2)")?;
+    stmt.execute(params!["CLI_VERSION", &cli_version])?;
+  }
+
+  Ok(())
+}
+
+#[cfg(test)]
+mod test {
+  use std::path::PathBuf;
+
+  use super::*;
+
+  #[test]
+  pub fn sql_cache_general_use() {
+    let conn = Connection::open_in_memory().unwrap();
+    let cache =
+      SqlIncrementalCache::from_connection(conn, 1, "1.0.0".to_string())
+        .unwrap();
+    let path = PathBuf::from("/mod.ts");
+
+    assert_eq!(cache.get_source_hash(&path), None);
+    cache.set_source_hash(&path, 2).unwrap();
+    assert_eq!(cache.get_source_hash(&path), Some(2));
+
+    // try changing the cli version (should clear)
+    let conn = cache.conn;
+    let mut cache =
+      SqlIncrementalCache::from_connection(conn, 1, "2.0.0".to_string())
+        .unwrap();
+    assert_eq!(cache.get_source_hash(&path), None);
+
+    // add back the file to the cache
+    cache.set_source_hash(&path, 2).unwrap();
+    assert_eq!(cache.get_source_hash(&path), Some(2));
+
+    // try changing the state hash
+    cache.state_hash = 2;
+    assert_eq!(cache.get_source_hash(&path), None);
+    cache.state_hash = 1;
+
+    // should return now that everything is back
+    assert_eq!(cache.get_source_hash(&path), Some(2));
+
+    // recreating the cache should not remove the data because the CLI version and state hash is the same
+    let conn = cache.conn;
+    let cache =
+      SqlIncrementalCache::from_connection(conn, 1, "2.0.0".to_string())
+        .unwrap();
+    assert_eq!(cache.get_source_hash(&path), Some(2));
+
+    // now try replacing and using another path
+    cache.set_source_hash(&path, 3).unwrap();
+    cache.set_source_hash(&path, 4).unwrap();
+    let path2 = PathBuf::from("/mod2.ts");
+    cache.set_source_hash(&path2, 5).unwrap();
+    assert_eq!(cache.get_source_hash(&path), Some(4));
+    assert_eq!(cache.get_source_hash(&path2), Some(5));
+  }
+
+  #[tokio::test]
+  pub async fn incremental_cache_general_use() {
+    let conn = Connection::open_in_memory().unwrap();
+    let sql_cache =
+      SqlIncrementalCache::from_connection(conn, 1, "1.0.0".to_string())
+        .unwrap();
+    let file_path = PathBuf::from("/mod.ts");
+    let file_text = "test";
+    let file_hash = fast_insecure_hash(file_text.as_bytes());
+    sql_cache.set_source_hash(&file_path, file_hash).unwrap();
+    let cache = IncrementalCacheInner::from_sql_incremental_cache(
+      sql_cache,
+      &[file_path.clone()],
+    );
+
+    assert!(cache.is_file_same(&file_path, "test"));
+    assert!(!cache.is_file_same(&file_path, "other"));
+
+    // just ensure this doesn't panic
+    cache.update_file(&file_path, "other");
+  }
+}