denoland-deno/runtime/snapshot.rs

// Copyright 2018-2025 the Deno authors. MIT license.

use std::borrow::Cow;
use std::io::Write;
use std::path::Path;
use std::path::PathBuf;
use std::rc::Rc;
use std::sync::Arc;

use deno_ast::MediaType;
use deno_ast::ParseParams;
use deno_ast::SourceMapOption;
use deno_cache::SqliteBackedCache;
use deno_core::snapshot::*;
use deno_core::v8;
use deno_core::Extension;
use deno_core::ModuleCodeString;
use deno_core::ModuleName;
use deno_core::SourceMapData;
use deno_error::JsErrorBox;
use deno_http::DefaultHttpPropertyExtractor;
use deno_io::fs::FsError;
use deno_permissions::PermissionCheckError;
use deno_resolver::npm::DenoInNpmPackageChecker;
use deno_resolver::npm::NpmResolver;

use crate::ops;
use crate::ops::bootstrap::SnapshotOptions;
use crate::shared::runtime;

#[derive(Clone)]
struct Permissions;

impl deno_websocket::WebSocketPermissions for Permissions {
  fn check_net_url(
    &mut self,
    _url: &deno_core::url::Url,
    _api_name: &str,
  ) -> Result<(), PermissionCheckError> {
    unreachable!("snapshotting!")
  }
}

impl deno_web::TimersPermission for Permissions {
  fn allow_hrtime(&mut self) -> bool {
    unreachable!("snapshotting!")
  }
}

impl deno_fetch::FetchPermissions for Permissions {
  fn check_net_url(
    &mut self,
    _url: &deno_core::url::Url,
    _api_name: &str,
  ) -> Result<(), PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_read<'a>(
    &mut self,
    _p: &'a Path,
    _api_name: &str,
  ) -> Result<Cow<'a, Path>, PermissionCheckError> {
    unreachable!("snapshotting!")
  }
}

impl deno_ffi::FfiPermissions for Permissions {
  fn check_partial_no_path(&mut self) -> Result<(), PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_partial_with_path(
    &mut self,
    _path: &str,
  ) -> Result<PathBuf, PermissionCheckError> {
    unreachable!("snapshotting!")
  }
}

impl deno_napi::NapiPermissions for Permissions {
  fn check(&mut self, _path: &str) -> Result<PathBuf, PermissionCheckError> {
    unreachable!("snapshotting!")
  }
}

impl deno_node::NodePermissions for Permissions {
  fn check_net_url(
    &mut self,
    _url: &deno_core::url::Url,
    _api_name: &str,
  ) -> Result<(), PermissionCheckError> {
    unreachable!("snapshotting!")
  }
  fn check_net(
    &mut self,
    _host: (&str, Option<u16>),
    _api_name: &str,
  ) -> Result<(), PermissionCheckError> {
    unreachable!("snapshotting!")
  }
  fn check_read_path<'a>(
    &mut self,
    _path: &'a Path,
  ) -> Result<Cow<'a, Path>, PermissionCheckError> {
    unreachable!("snapshotting!")
  }
  fn check_read_with_api_name(
    &mut self,
    _p: &str,
    _api_name: Option<&str>,
  ) -> Result<PathBuf, PermissionCheckError> {
    unreachable!("snapshotting!")
  }
  fn query_read_all(&mut self) -> bool {
    unreachable!("snapshotting!")
  }
  fn check_write_with_api_name(
    &mut self,
    _p: &str,
    _api_name: Option<&str>,
  ) -> Result<PathBuf, PermissionCheckError> {
    unreachable!("snapshotting!")
  }
  fn check_sys(
    &mut self,
    _kind: &str,
    _api_name: &str,
  ) -> Result<(), PermissionCheckError> {
    unreachable!("snapshotting!")
  }
}

impl deno_net::NetPermissions for Permissions {
  fn check_net<T: AsRef<str>>(
    &mut self,
    _host: &(T, Option<u16>),
    _api_name: &str,
  ) -> Result<(), PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_read(
    &mut self,
    _p: &str,
    _api_name: &str,
  ) -> Result<PathBuf, PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_write(
    &mut self,
    _p: &str,
    _api_name: &str,
  ) -> Result<PathBuf, PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_write_path<'a>(
    &mut self,
    _p: &'a Path,
    _api_name: &str,
  ) -> Result<Cow<'a, Path>, PermissionCheckError> {
    unreachable!("snapshotting!")
  }
}

impl deno_fs::FsPermissions for Permissions {
  fn check_open<'a>(
    &mut self,
    _resolved: bool,
    _read: bool,
    _write: bool,
    _path: &'a Path,
    _api_name: &str,
  ) -> Result<Cow<'a, Path>, FsError> {
    unreachable!("snapshotting!")
  }

  fn check_read(
    &mut self,
    _path: &str,
    _api_name: &str,
  ) -> Result<PathBuf, PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_read_all(
    &mut self,
    _api_name: &str,
  ) -> Result<(), PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_read_blind(
    &mut self,
    _path: &Path,
    _display: &str,
    _api_name: &str,
  ) -> Result<(), PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_write(
    &mut self,
    _path: &str,
    _api_name: &str,
  ) -> Result<PathBuf, PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_write_partial(
    &mut self,
    _path: &str,
    _api_name: &str,
  ) -> Result<PathBuf, PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_write_all(
    &mut self,
    _api_name: &str,
  ) -> Result<(), PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_write_blind(
    &mut self,
    _path: &Path,
    _display: &str,
    _api_name: &str,
  ) -> Result<(), PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_read_path<'a>(
    &mut self,
    _path: &'a Path,
    _api_name: &str,
  ) -> Result<Cow<'a, Path>, PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_write_path<'a>(
    &mut self,
    _path: &'a Path,
    _api_name: &str,
  ) -> Result<Cow<'a, Path>, PermissionCheckError> {
    unreachable!("snapshotting!")
  }
}

impl deno_kv::sqlite::SqliteDbHandlerPermissions for Permissions {
  fn check_read(
    &mut self,
    _path: &str,
    _api_name: &str,
  ) -> Result<PathBuf, PermissionCheckError> {
    unreachable!("snapshotting!")
  }

  fn check_write<'a>(
    &mut self,
    _path: &'a Path,
    _api_name: &str,
  ) -> Result<Cow<'a, Path>, PermissionCheckError> {
    unreachable!("snapshotting!")
  }
}

pub fn create_runtime_snapshot(
  snapshot_path: PathBuf,
  snapshot_options: SnapshotOptions,
  // NOTE: For embedders that wish to add additional extensions to the snapshot
  custom_extensions: Vec<Extension>,
) {
  // NOTE(bartlomieju): ordering is important here, keep it in sync with
  // `runtime/worker.rs`, `runtime/web_worker.rs` and `runtime/snapshot.rs`!
  let fs = std::sync::Arc::new(deno_fs::RealFs);
  let mut extensions: Vec<Extension> = vec![
    deno_telemetry::deno_telemetry::init_ops_and_esm(),
    deno_webidl::deno_webidl::init_ops_and_esm(),
    deno_console::deno_console::init_ops_and_esm(),
    deno_url::deno_url::init_ops_and_esm(),
    deno_web::deno_web::init_ops_and_esm::<Permissions>(
      Default::default(),
      Default::default(),
    ),
    deno_webgpu::deno_webgpu::init_ops_and_esm(),
    deno_canvas::deno_canvas::init_ops_and_esm(),
    deno_fetch::deno_fetch::init_ops_and_esm::<Permissions>(Default::default()),
    deno_cache::deno_cache::init_ops_and_esm::<SqliteBackedCache>(None),
    deno_websocket::deno_websocket::init_ops_and_esm::<Permissions>(
      "".to_owned(),
      None,
      None,
    ),
    deno_webstorage::deno_webstorage::init_ops_and_esm(None),
    deno_crypto::deno_crypto::init_ops_and_esm(None),
    deno_broadcast_channel::deno_broadcast_channel::init_ops_and_esm(
      deno_broadcast_channel::InMemoryBroadcastChannel::default(),
    ),
    deno_ffi::deno_ffi::init_ops_and_esm::<Permissions>(),
    deno_net::deno_net::init_ops_and_esm::<Permissions>(None, None),
    deno_tls::deno_tls::init_ops_and_esm(),
    deno_kv::deno_kv::init_ops_and_esm(
      deno_kv::sqlite::SqliteDbHandler::<Permissions>::new(None, None),
      deno_kv::KvConfig::builder().build(),
    ),
    deno_cron::deno_cron::init_ops_and_esm(
      deno_cron::local::LocalCronHandler::new(),
    ),
    deno_napi::deno_napi::init_ops_and_esm::<Permissions>(),
    deno_http::deno_http::init_ops_and_esm::<DefaultHttpPropertyExtractor>(
      deno_http::Options::default(),
    ),
    deno_io::deno_io::init_ops_and_esm(Default::default()),
    deno_fs::deno_fs::init_ops_and_esm::<Permissions>(fs.clone()),
    deno_os::deno_os::init_ops_and_esm(Default::default()),
    deno_process::deno_process::init_ops_and_esm(Default::default()),
    deno_node::deno_node::init_ops_and_esm::<
      Permissions,
      DenoInNpmPackageChecker,
      NpmResolver<sys_traits::impls::RealSys>,
      sys_traits::impls::RealSys,
    >(None, fs.clone()),
    runtime::init_ops_and_esm(),
    ops::runtime::deno_runtime::init_ops("deno:runtime".parse().unwrap()),
    ops::worker_host::deno_worker_host::init_ops(
      Arc::new(|_| unreachable!("not used in snapshot.")),
      None,
    ),
    ops::fs_events::deno_fs_events::init_ops(),
    ops::permissions::deno_permissions::init_ops(),
    ops::tty::deno_tty::init_ops(),
    ops::http::deno_http_runtime::init_ops(),
    ops::bootstrap::deno_bootstrap::init_ops(Some(snapshot_options)),
    ops::web_worker::deno_web_worker::init_ops(),
  ];
  extensions.extend(custom_extensions);

  let output = create_snapshot(
    CreateSnapshotOptions {
      cargo_manifest_dir: env!("CARGO_MANIFEST_DIR"),
      startup_snapshot: None,
      extensions,
      extension_transpiler: Some(Rc::new(|specifier, source| {
        maybe_transpile_source(specifier, source)
      })),
      with_runtime_cb: Some(Box::new(|rt| {
        let isolate = rt.v8_isolate();
        let scope = &mut v8::HandleScope::new(isolate);

        let tmpl = deno_node::init_global_template(
          scope,
          deno_node::ContextInitMode::ForSnapshot,
        );
        let ctx = deno_node::create_v8_context(
          scope,
          tmpl,
          deno_node::ContextInitMode::ForSnapshot,
          std::ptr::null_mut(),
        );
        assert_eq!(scope.add_context(ctx), deno_node::VM_CONTEXT_INDEX);
      })),
      skip_op_registration: false,
    },
    None,
  )
  .unwrap();
  let mut snapshot = std::fs::File::create(snapshot_path).unwrap();
  snapshot.write_all(&output.output).unwrap();

  #[allow(clippy::print_stdout)]
  for path in output.files_loaded_during_snapshot {
    println!("cargo:rerun-if-changed={}", path.display());
  }
}

deno_error::js_error_wrapper!(
  deno_ast::ParseDiagnostic,
  JsParseDiagnostic,
  "Error"
);
deno_error::js_error_wrapper!(
  deno_ast::TranspileError,
  JsTranspileError,
  "Error"
);

pub fn maybe_transpile_source(
  name: ModuleName,
  source: ModuleCodeString,
) -> Result<(ModuleCodeString, Option<SourceMapData>), JsErrorBox> {
  // Always transpile `node:` built-in modules, since they might be TypeScript.
  let media_type = if name.starts_with("node:") {
    MediaType::TypeScript
  } else {
    MediaType::from_path(Path::new(&name))
  };

  match media_type {
    MediaType::TypeScript => {}
    MediaType::JavaScript => return Ok((source, None)),
    MediaType::Mjs => return Ok((source, None)),
    _ => panic!(
      "Unsupported media type for snapshotting {media_type:?} for file {}",
      name
    ),
  }

  let parsed = deno_ast::parse_module(ParseParams {
    specifier: deno_core::url::Url::parse(&name).unwrap(),
    text: source.into(),
    media_type,
    capture_tokens: false,
    scope_analysis: false,
    maybe_syntax: None,
  })
  .map_err(|e| JsErrorBox::from_err(JsParseDiagnostic(e)))?;
  let transpiled_source = parsed
    .transpile(
      &deno_ast::TranspileOptions {
        imports_not_used_as_values: deno_ast::ImportsNotUsedAsValues::Remove,
        ..Default::default()
      },
      &deno_ast::TranspileModuleOptions::default(),
      &deno_ast::EmitOptions {
        source_map: if cfg!(debug_assertions) {
          SourceMapOption::Separate
        } else {
          SourceMapOption::None
        },
        ..Default::default()
      },
    )
    .map_err(|e| JsErrorBox::from_err(JsTranspileError(e)))?
    .into_source();

  let maybe_source_map: Option<SourceMapData> = transpiled_source
    .source_map
    .map(|sm| sm.into_bytes().into());
  let source_text = transpiled_source.text;
  Ok((source_text.into(), maybe_source_map))
}