diff --git a/cli/bench/console.js b/cli/bench/console.js
index 1e0ebb37a6..b1873953c3 100644
--- a/cli/bench/console.js
+++ b/cli/bench/console.js
@@ -1,3 +1,8 @@
 // Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
 const count = 100000;
+
+const start = Date.now();
 for (let i = 0; i < count; i++) console.log("Hello World");
+const elapsed = Date.now() - start;
+const rate = Math.floor(count / (elapsed / 1000));
+console.log(`time ${elapsed} ms rate ${rate}`);
diff --git a/cli/bench/encode_into.js b/cli/bench/encode_into.js
index 458a88b84c..aaee234348 100644
--- a/cli/bench/encode_into.js
+++ b/cli/bench/encode_into.js
@@ -1,10 +1,11 @@
 // Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+const queueMicrotask = globalThis.queueMicrotask || process.nextTick;
 let [total, count] = typeof Deno !== "undefined"
   ? Deno.args
   : [process.argv[2], process.argv[3]];
 
 total = total ? parseInt(total, 0) : 50;
-count = count ? parseInt(count, 10) : 10000000;
+count = count ? parseInt(count, 10) : 1000000;
 
 function bench(fun) {
   const start = Date.now();
@@ -12,7 +13,7 @@ function bench(fun) {
   const elapsed = Date.now() - start;
   const rate = Math.floor(count / (elapsed / 1000));
   console.log(`time ${elapsed} ms rate ${rate}`);
-  if (--total) bench(fun);
+  if (--total) queueMicrotask(() => bench(fun));
 }
 
 const encoder = new TextEncoder();
diff --git a/cli/bench/webstorage.js b/cli/bench/webstorage.js
deleted file mode 100644
index bdb10e5681..0000000000
--- a/cli/bench/webstorage.js
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
-
-// Note: when benchmarking across different Deno version, make sure to clear
-// the DENO_DIR cache.
-let [total, count] = typeof Deno !== "undefined" ? Deno.args : [];
-
-total = total ? parseInt(total, 0) : 50;
-count = count ? parseInt(count, 10) : 1000000;
-
-function bench(fun) {
-  const start = Date.now();
-  for (let i = 0; i < count; i++) fun(i);
-  const elapsed = Date.now() - start;
-  const rate = Math.floor(count / (elapsed / 1000));
-  console.log(`time ${elapsed} ms rate ${rate}`);
-  if (--total) queueMicrotask(() => bench(fun));
-}
-
-localStorage.clear();
-localStorage.setItem("foo", "bar");
-bench(() => localStorage.getItem("foo"));
diff --git a/cli/tsc/mod.rs b/cli/tsc/mod.rs
index a587de3761..3751712f08 100644
--- a/cli/tsc/mod.rs
+++ b/cli/tsc/mod.rs
@@ -710,9 +710,9 @@ pub fn resolve_npm_package_reference_types(
 }
 
 #[op]
-fn op_is_node_file(state: &mut OpState, path: &str) -> bool {
+fn op_is_node_file(state: &mut OpState, path: String) -> bool {
   let state = state.borrow::<State>();
-  match ModuleSpecifier::parse(path) {
+  match ModuleSpecifier::parse(&path) {
     Ok(specifier) => state
       .maybe_npm_resolver
       .as_ref()
diff --git a/core/ops_builtin.rs b/core/ops_builtin.rs
index 858ce97bd8..6374e9951e 100644
--- a/core/ops_builtin.rs
+++ b/core/ops_builtin.rs
@@ -107,7 +107,7 @@ pub fn op_metrics(state: &mut OpState) -> (OpMetrics, Vec<OpMetrics>) {
 
 /// Builtin utility to print to stdout/stderr
 #[op]
-pub fn op_print(msg: &str, is_err: bool) -> Result<(), Error> {
+pub fn op_print(msg: String, is_err: bool) -> Result<(), Error> {
   if is_err {
     stderr().write_all(msg.as_bytes())?;
     stderr().flush().unwrap();
@@ -152,12 +152,12 @@ pub fn op_wasm_streaming_feed(
 pub fn op_wasm_streaming_set_url(
   state: &mut OpState,
   rid: ResourceId,
-  url: &str,
+  url: String,
 ) -> Result<(), Error> {
   let wasm_streaming =
     state.resource_table.get::<WasmStreamingResource>(rid)?;
 
-  wasm_streaming.0.borrow_mut().set_url(url);
+  wasm_streaming.0.borrow_mut().set_url(&url);
 
   Ok(())
 }
diff --git a/ext/node/lib.rs b/ext/node/lib.rs
index 5282c0660b..b2443db0bb 100644
--- a/ext/node/lib.rs
+++ b/ext/node/lib.rs
@@ -262,7 +262,7 @@ fn op_require_proxy_path(filename: String) -> String {
 }
 
 #[op]
-fn op_require_is_request_relative(request: &str) -> bool {
+fn op_require_is_request_relative(request: String) -> bool {
   if request.starts_with("./") || request.starts_with("../") || request == ".."
   {
     return true;
diff --git a/ext/url/00_url.js b/ext/url/00_url.js
index 754c647b12..5479cb59ce 100644
--- a/ext/url/00_url.js
+++ b/ext/url/00_url.js
@@ -56,12 +56,12 @@
   function opUrlParse(href, maybeBase) {
     let status;
     if (maybeBase === undefined) {
-      status = ops.op_url_parse(href, componentsBuf);
+      status = ops.op_url_parse(href, componentsBuf.buffer);
     } else {
-      status = ops.op_url_parse_with_base(
+      status = core.ops.op_url_parse_with_base(
         href,
         maybeBase,
-        componentsBuf,
+        componentsBuf.buffer,
       );
     }
     return getSerialization(status, href);
@@ -71,7 +71,7 @@
     if (status === 0) {
       return href;
     } else if (status === 1) {
-      return ops.op_url_get_serialization();
+      return core.ops.op_url_get_serialization();
     } else {
       throw new TypeError("Invalid URL");
     }
diff --git a/ext/url/lib.rs b/ext/url/lib.rs
index 01014ccd34..ac668207fd 100644
--- a/ext/url/lib.rs
+++ b/ext/url/lib.rs
@@ -41,11 +41,11 @@ pub fn init() -> Extension {
 #[op]
 pub fn op_url_parse_with_base(
   state: &mut OpState,
-  href: &str,
-  base_href: &str,
-  buf: &mut [u32],
+  href: String,
+  base_href: String,
+  buf: &mut [u8],
 ) -> u32 {
-  let base_url = match Url::parse(base_href) {
+  let base_url = match Url::parse(&base_href) {
     Ok(url) => url,
     Err(_) => return ParseStatus::Err as u32,
   };
@@ -67,8 +67,8 @@ pub fn op_url_get_serialization(state: &mut OpState) -> String {
 }
 
 /// Parse `href` without a `base_url`. Fills the out `buf` with URL components.
-#[op(fast)]
-pub fn op_url_parse(state: &mut OpState, href: &str, buf: &mut [u32]) -> u32 {
+#[op]
+pub fn op_url_parse(state: &mut OpState, href: String, buf: &mut [u8]) -> u32 {
   parse_url(state, href, None, buf)
 }
 
@@ -99,14 +99,15 @@ pub fn op_url_parse(state: &mut OpState, href: &str, buf: &mut [u32]) -> u32 {
 #[inline]
 fn parse_url(
   state: &mut OpState,
-  href: &str,
+  href: String,
   base_href: Option<&Url>,
-  buf: &mut [u32],
+  buf: &mut [u8],
 ) -> u32 {
-  match Url::options().base_url(base_href).parse(href) {
+  match Url::options().base_url(base_href).parse(&href) {
     Ok(url) => {
       let inner_url = quirks::internal_components(&url);
 
+      let buf: &mut [u32] = as_u32_slice(buf);
       buf[0] = inner_url.scheme_end;
       buf[1] = inner_url.username_end;
       buf[2] = inner_url.host_start;
diff --git a/ext/web/blob.rs b/ext/web/blob.rs
index 5f19368609..7da42e178c 100644
--- a/ext/web/blob.rs
+++ b/ext/web/blob.rs
@@ -252,9 +252,9 @@ pub fn op_blob_create_object_url(
 #[op]
 pub fn op_blob_revoke_object_url(
   state: &mut deno_core::OpState,
-  url: &str,
+  url: String,
 ) -> Result<(), AnyError> {
-  let url = Url::parse(url)?;
+  let url = Url::parse(&url)?;
   let blob_store = state.borrow::<BlobStore>();
   blob_store.remove_object_url(&url);
   Ok(())
diff --git a/ext/web/compression.rs b/ext/web/compression.rs
index 05dcf02b19..d2647e4988 100644
--- a/ext/web/compression.rs
+++ b/ext/web/compression.rs
@@ -41,11 +41,11 @@ impl Resource for CompressionResource {
 #[op]
 pub fn op_compression_new(
   state: &mut OpState,
-  format: &str,
+  format: String,
   is_decoder: bool,
 ) -> ResourceId {
   let w = Vec::new();
-  let inner = match (format, is_decoder) {
+  let inner = match (format.as_str(), is_decoder) {
     ("deflate", true) => Inner::DeflateDecoder(ZlibDecoder::new(w)),
     ("deflate", false) => {
       Inner::DeflateEncoder(ZlibEncoder::new(w, Compression::default()))
diff --git a/ext/web/lib.rs b/ext/web/lib.rs
index 7c75a9a288..cfbcee6e3d 100644
--- a/ext/web/lib.rs
+++ b/ext/web/lib.rs
@@ -270,7 +270,7 @@ fn op_encoding_decode_single(
 #[op]
 fn op_encoding_new_decoder(
   state: &mut OpState,
-  label: &str,
+  label: String,
   fatal: bool,
   ignore_bom: bool,
 ) -> Result<ResourceId, AnyError> {
@@ -352,43 +352,25 @@ impl Resource for TextDecoderResource {
   }
 }
 
-#[op]
+#[op(v8)]
 fn op_encoding_encode_into(
-  input: Cow<'_, str>,
+  scope: &mut v8::HandleScope,
+  input: serde_v8::Value,
   buffer: &mut [u8],
   out_buf: &mut [u32],
-) {
-  // Since `input` is already UTF-8, we can simply find the last UTF-8 code
-  // point boundary from input that fits in `buffer`, and copy the bytes up to
-  // that point.
-  let boundary = if buffer.len() >= input.len() {
-    input.len()
-  } else {
-    let mut boundary = buffer.len();
+) -> Result<(), AnyError> {
+  let s = v8::Local::<v8::String>::try_from(input.v8_value)?;
 
-    // The maximum length of a UTF-8 code point is 4 bytes.
-    for _ in 0..4 {
-      if input.is_char_boundary(boundary) {
-        break;
-      }
-      debug_assert!(boundary > 0);
-      boundary -= 1;
-    }
-
-    debug_assert!(input.is_char_boundary(boundary));
-    boundary
-  };
-
-  buffer[..boundary].copy_from_slice(input[..boundary].as_bytes());
-
-  // The `read` output parameter is measured in UTF-16 code units.
-  out_buf[0] = match input {
-    // Borrowed Cow strings are zero-copy views into the V8 heap.
-    // Thus, they are guarantee to be SeqOneByteString.
-    Cow::Borrowed(v) => v[..boundary].len() as u32,
-    Cow::Owned(v) => v[..boundary].encode_utf16().count() as u32,
-  };
-  out_buf[1] = boundary as u32;
+  let mut nchars = 0;
+  out_buf[1] = s.write_utf8(
+    scope,
+    buffer,
+    Some(&mut nchars),
+    v8::WriteOptions::NO_NULL_TERMINATION
+      | v8::WriteOptions::REPLACE_INVALID_UTF8,
+  ) as u32;
+  out_buf[0] = nchars as u32;
+  Ok(())
 }
 
 #[op(v8)]
diff --git a/ext/webstorage/lib.rs b/ext/webstorage/lib.rs
index 58b7c07e43..6284a59bc6 100644
--- a/ext/webstorage/lib.rs
+++ b/ext/webstorage/lib.rs
@@ -139,8 +139,8 @@ pub fn op_webstorage_key(
 #[op]
 pub fn op_webstorage_set(
   state: &mut OpState,
-  key: &str,
-  value: &str,
+  key: String,
+  value: String,
   persistent: bool,
 ) -> Result<(), AnyError> {
   let conn = get_webstorage(state, persistent)?;
@@ -184,7 +184,7 @@ pub fn op_webstorage_get(
 #[op]
 pub fn op_webstorage_remove(
   state: &mut OpState,
-  key_name: &str,
+  key_name: String,
   persistent: bool,
 ) -> Result<(), AnyError> {
   let conn = get_webstorage(state, persistent)?;
diff --git a/ops/fast_call.rs b/ops/fast_call.rs
index 1d6bfa1fa2..f2ed8cb2d7 100644
--- a/ops/fast_call.rs
+++ b/ops/fast_call.rs
@@ -403,9 +403,7 @@ fn q_fast_ty(v: &FastValue) -> Quote {
     FastValue::F64 => q!({ f64 }),
     FastValue::Bool => q!({ bool }),
     FastValue::V8Value => q!({ v8::Local<v8::Value> }),
-    FastValue::Uint8Array
-    | FastValue::Uint32Array
-    | FastValue::SeqOneByteString => unreachable!(),
+    FastValue::Uint8Array | FastValue::Uint32Array => unreachable!(),
   }
 }
 
@@ -423,7 +421,6 @@ fn q_fast_ty_variant(v: &FastValue) -> Quote {
     FastValue::V8Value => q!({ V8Value }),
     FastValue::Uint8Array => q!({ TypedArray(CType::Uint8) }),
     FastValue::Uint32Array => q!({ TypedArray(CType::Uint32) }),
-    FastValue::SeqOneByteString => q!({ SeqOneByteString }),
   }
 }
 
diff --git a/ops/lib.rs b/ops/lib.rs
index 7fa800b14c..b4bef1d138 100644
--- a/ops/lib.rs
+++ b/ops/lib.rs
@@ -411,12 +411,7 @@ fn codegen_arg(
     return quote! { let #ident = (); };
   }
   // Fast path for `String`
-  if let Some(is_ref) = is_string(&**ty) {
-    let ref_block = if is_ref {
-      quote! { let #ident = #ident.as_ref(); }
-    } else {
-      quote! {}
-    };
+  if is_string(&**ty) {
     return quote! {
       let #ident = match #core::v8::Local::<#core::v8::String>::try_from(args.get(#idx as i32)) {
         Ok(v8_string) => #core::serde_v8::to_utf8(v8_string, scope),
@@ -424,18 +419,6 @@ fn codegen_arg(
           return #core::_ops::throw_type_error(scope, format!("Expected string at position {}", #idx));
         }
       };
-      #ref_block
-    };
-  }
-  // Fast path for `Cow<'_, str>`
-  if is_cow_str(&**ty) {
-    return quote! {
-      let #ident = match #core::v8::Local::<#core::v8::String>::try_from(args.get(#idx as i32)) {
-        Ok(v8_string) => ::std::borrow::Cow::Owned(#core::serde_v8::to_utf8(v8_string, scope)),
-        Err(_) => {
-          return #core::_ops::throw_type_error(scope, format!("Expected string at position {}", #idx));
-        }
-      };
     };
   }
   // Fast path for `Option<String>`
@@ -646,25 +629,14 @@ fn is_result(ty: impl ToTokens) -> bool {
   }
 }
 
-fn is_string(ty: impl ToTokens) -> Option<bool> {
-  let toks = tokens(ty);
-  if toks == "String" {
-    return Some(false);
-  }
-  if toks == "& str" {
-    return Some(true);
-  }
-  None
+fn is_string(ty: impl ToTokens) -> bool {
+  tokens(ty) == "String"
 }
 
 fn is_option_string(ty: impl ToTokens) -> bool {
   tokens(ty) == "Option < String >"
 }
 
-fn is_cow_str(ty: impl ToTokens) -> bool {
-  tokens(&ty).starts_with("Cow <") && tokens(&ty).ends_with("str >")
-}
-
 enum SliceType {
   U8,
   U8Mut,
diff --git a/ops/optimizer.rs b/ops/optimizer.rs
index 99de4b4240..2d68a296fd 100644
--- a/ops/optimizer.rs
+++ b/ops/optimizer.rs
@@ -19,20 +19,12 @@ pub(crate) enum BailoutReason {
   FastUnsupportedParamType,
 }
 
-#[derive(Debug, PartialEq)]
-enum StringType {
-  Cow,
-  Ref,
-  Owned,
-}
-
 #[derive(Debug, PartialEq)]
 enum TransformKind {
   // serde_v8::Value
   V8Value,
   SliceU32(bool),
   SliceU8(bool),
-  SeqOneByteString(StringType),
   PtrU8,
   WasmMemory,
 }
@@ -59,13 +51,6 @@ impl Transform {
     }
   }
 
-  fn seq_one_byte_string(index: usize, is_ref: StringType) -> Self {
-    Transform {
-      kind: TransformKind::SeqOneByteString(is_ref),
-      index,
-    }
-  }
-
   fn wasm_memory(index: usize) -> Self {
     Transform {
       kind: TransformKind::WasmMemory,
@@ -147,21 +132,6 @@ impl Transform {
           };
         })
       }
-      // &str
-      TransformKind::SeqOneByteString(str_ty) => {
-        *ty = parse_quote! { *const #core::v8::fast_api::FastApiOneByteString };
-        match str_ty {
-          StringType::Ref => q!(Vars { var: &ident }, {
-            let var = unsafe { &*var }.as_str();
-          }),
-          StringType::Cow => q!(Vars { var: &ident }, {
-            let var = ::std::borrow::Cow::Borrowed(unsafe { &*var }.as_str());
-          }),
-          StringType::Owned => q!(Vars { var: &ident }, {
-            let var = unsafe { &*var }.as_str().to_owned();
-          }),
-        }
-      }
       TransformKind::WasmMemory => {
         // Note: `ty` is correctly set to __opts by the fast call tier.
         q!(Vars { var: &ident, core }, {
@@ -228,7 +198,6 @@ pub(crate) enum FastValue {
   V8Value,
   Uint8Array,
   Uint32Array,
-  SeqOneByteString,
 }
 
 impl Default for FastValue {
@@ -581,58 +550,10 @@ impl Optimizer {
                 }
               }
             }
-            // Cow<'_, str>
-            PathSegment {
-              ident, arguments, ..
-            } if ident == "Cow" => {
-              if let PathArguments::AngleBracketed(
-                AngleBracketedGenericArguments { args, .. },
-              ) = arguments
-              {
-                assert_eq!(args.len(), 2);
-
-                let ty = &args[1];
-                match ty {
-                  GenericArgument::Type(Type::Path(TypePath {
-                    path: Path { segments, .. },
-                    ..
-                  })) => {
-                    let segment = single_segment(segments)?;
-                    match segment {
-                      PathSegment { ident, .. } if ident == "str" => {
-                        self.fast_parameters.push(FastValue::SeqOneByteString);
-                        assert!(self
-                          .transforms
-                          .insert(
-                            index,
-                            Transform::seq_one_byte_string(
-                              index,
-                              StringType::Cow
-                            )
-                          )
-                          .is_none());
-                      }
-                      _ => return Err(BailoutReason::FastUnsupportedParamType),
-                    }
-                  }
-                  _ => return Err(BailoutReason::FastUnsupportedParamType),
-                }
-              }
-            }
             // Is `T` a fast scalar?
             PathSegment { ident, .. } => {
               if let Some(val) = get_fast_scalar(ident.to_string().as_str()) {
                 self.fast_parameters.push(val);
-              } else if ident == "String" {
-                // Is `T` an owned String?
-                self.fast_parameters.push(FastValue::SeqOneByteString);
-                assert!(self
-                  .transforms
-                  .insert(
-                    index,
-                    Transform::seq_one_byte_string(index, StringType::Owned)
-                  )
-                  .is_none());
               } else {
                 return Err(BailoutReason::FastUnsupportedParamType);
               }
@@ -655,17 +576,6 @@ impl Optimizer {
               {
                 self.has_ref_opstate = true;
               }
-              // Is `T` a str?
-              PathSegment { ident, .. } if ident == "str" => {
-                self.fast_parameters.push(FastValue::SeqOneByteString);
-                assert!(self
-                  .transforms
-                  .insert(
-                    index,
-                    Transform::seq_one_byte_string(index, StringType::Ref)
-                  )
-                  .is_none());
-              }
               _ => return Err(BailoutReason::FastUnsupportedParamType),
             }
           }
diff --git a/ops/optimizer_tests/cow_str.expected b/ops/optimizer_tests/cow_str.expected
deleted file mode 100644
index 8b28965bad..0000000000
--- a/ops/optimizer_tests/cow_str.expected
+++ /dev/null
@@ -1,11 +0,0 @@
-=== Optimizer Dump ===
-returns_result: false
-has_ref_opstate: false
-has_rc_opstate: false
-has_fast_callback_option: false
-needs_fast_callback_option: false
-fast_result: Some(Void)
-fast_parameters: [V8Value, SeqOneByteString]
-transforms: {0: Transform { kind: SeqOneByteString(Cow), index: 0 }}
-is_async: false
-fast_compatible: true
diff --git a/ops/optimizer_tests/cow_str.out b/ops/optimizer_tests/cow_str.out
deleted file mode 100644
index da405f451d..0000000000
--- a/ops/optimizer_tests/cow_str.out
+++ /dev/null
@@ -1,87 +0,0 @@
-#[allow(non_camel_case_types)]
-///Auto-generated by `deno_ops`, i.e: `#[op]`
-///
-///Use `op_cow_str::decl()` to get an op-declaration
-///you can include in a `deno_core::Extension`.
-pub struct op_cow_str;
-#[doc(hidden)]
-impl op_cow_str {
-    pub fn name() -> &'static str {
-        stringify!(op_cow_str)
-    }
-    pub fn v8_fn_ptr<'scope>() -> deno_core::v8::FunctionCallback {
-        use deno_core::v8::MapFnTo;
-        Self::v8_func.map_fn_to()
-    }
-    pub fn decl<'scope>() -> deno_core::OpDecl {
-        deno_core::OpDecl {
-            name: Self::name(),
-            v8_fn_ptr: Self::v8_fn_ptr(),
-            enabled: true,
-            fast_fn: Some(
-                Box::new(op_cow_str_fast {
-                    _phantom: ::std::marker::PhantomData,
-                }),
-            ),
-            is_async: false,
-            is_unstable: false,
-            is_v8: false,
-            argc: 1usize,
-        }
-    }
-    #[inline]
-    #[allow(clippy::too_many_arguments)]
-    fn call(c: Cow<'_, str>) {}
-    pub fn v8_func<'scope>(
-        scope: &mut deno_core::v8::HandleScope<'scope>,
-        args: deno_core::v8::FunctionCallbackArguments,
-        mut rv: deno_core::v8::ReturnValue,
-    ) {
-        let ctx = unsafe {
-            &*(deno_core::v8::Local::<deno_core::v8::External>::cast(args.data()).value()
-                as *const deno_core::_ops::OpCtx)
-        };
-        let arg_0 = match deno_core::v8::Local::<
-            deno_core::v8::String,
-        >::try_from(args.get(0usize as i32)) {
-            Ok(v8_string) => {
-                ::std::borrow::Cow::Owned(deno_core::serde_v8::to_utf8(v8_string, scope))
-            }
-            Err(_) => {
-                return deno_core::_ops::throw_type_error(
-                    scope,
-                    format!("Expected string at position {}", 0usize),
-                );
-            }
-        };
-        let result = Self::call(arg_0);
-        let op_state = ::std::cell::RefCell::borrow(&*ctx.state);
-        op_state.tracker.track_sync(ctx.id);
-    }
-}
-struct op_cow_str_fast {
-    _phantom: ::std::marker::PhantomData<()>,
-}
-impl<'scope> deno_core::v8::fast_api::FastFunction for op_cow_str_fast {
-    fn function(&self) -> *const ::std::ffi::c_void {
-        op_cow_str_fast_fn as *const ::std::ffi::c_void
-    }
-    fn args(&self) -> &'static [deno_core::v8::fast_api::Type] {
-        use deno_core::v8::fast_api::Type::*;
-        use deno_core::v8::fast_api::CType;
-        &[V8Value, SeqOneByteString]
-    }
-    fn return_type(&self) -> deno_core::v8::fast_api::CType {
-        deno_core::v8::fast_api::CType::Void
-    }
-}
-fn op_cow_str_fast_fn<'scope>(
-    _: deno_core::v8::Local<deno_core::v8::Object>,
-    c: *const deno_core::v8::fast_api::FastApiOneByteString,
-) -> () {
-    use deno_core::v8;
-    use deno_core::_ops;
-    let c = ::std::borrow::Cow::Borrowed(unsafe { &*c }.as_str());
-    let result = op_cow_str::call(c);
-    result
-}
diff --git a/ops/optimizer_tests/cow_str.rs b/ops/optimizer_tests/cow_str.rs
deleted file mode 100644
index b7214bdc7e..0000000000
--- a/ops/optimizer_tests/cow_str.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-fn op_cow_str(c: Cow<'_, str>) {
-  // ...
-}
diff --git a/ops/optimizer_tests/op_blob_revoke_object_url.expected b/ops/optimizer_tests/op_blob_revoke_object_url.expected
index 5b3e43edc3..0fae25e860 100644
--- a/ops/optimizer_tests/op_blob_revoke_object_url.expected
+++ b/ops/optimizer_tests/op_blob_revoke_object_url.expected
@@ -1,11 +1 @@
-=== Optimizer Dump ===
-returns_result: true
-has_ref_opstate: true
-has_rc_opstate: false
-has_fast_callback_option: false
-needs_fast_callback_option: false
-fast_result: Some(Void)
-fast_parameters: [V8Value, SeqOneByteString]
-transforms: {1: Transform { kind: SeqOneByteString(Owned), index: 1 }}
-is_async: false
-fast_compatible: true
+MustBeSingleSegment
\ No newline at end of file
diff --git a/ops/optimizer_tests/op_blob_revoke_object_url.out b/ops/optimizer_tests/op_blob_revoke_object_url.out
index 28fe17acb8..72bc75e059 100644
--- a/ops/optimizer_tests/op_blob_revoke_object_url.out
+++ b/ops/optimizer_tests/op_blob_revoke_object_url.out
@@ -18,11 +18,7 @@ impl op_blob_revoke_object_url {
             name: Self::name(),
             v8_fn_ptr: Self::v8_fn_ptr(),
             enabled: true,
-            fast_fn: Some(
-                Box::new(op_blob_revoke_object_url_fast {
-                    _phantom: ::std::marker::PhantomData,
-                }),
-            ),
+            fast_fn: None,
             is_async: false,
             is_unstable: false,
             is_v8: false,
@@ -31,7 +27,7 @@ impl op_blob_revoke_object_url {
     }
     #[inline]
     #[allow(clippy::too_many_arguments)]
-    pub fn call(state: &mut OpState, url: String) -> Result<(), AnyError> {
+    pub fn call(state: &mut deno_core::OpState, url: String) -> Result<(), AnyError> {
         let url = Url::parse(&url)?;
         let blob_store = state.borrow::<BlobStore>();
         blob_store.remove_object_url(&url);
@@ -46,18 +42,6 @@ impl op_blob_revoke_object_url {
             &*(deno_core::v8::Local::<deno_core::v8::External>::cast(args.data()).value()
                 as *const deno_core::_ops::OpCtx)
         };
-        {
-            let op_state = &mut std::cell::RefCell::borrow_mut(&ctx.state);
-            if let Some(err) = op_state.last_fast_op_error.take() {
-                let exception = deno_core::error::to_v8_error(
-                    scope,
-                    op_state.get_error_class_fn,
-                    &err,
-                );
-                scope.throw_exception(exception);
-                return;
-            }
-        }
         let arg_0 = match deno_core::v8::Local::<
             deno_core::v8::String,
         >::try_from(args.get(0usize as i32)) {
@@ -85,45 +69,3 @@ impl op_blob_revoke_object_url {
         };
     }
 }
-struct op_blob_revoke_object_url_fast {
-    _phantom: ::std::marker::PhantomData<()>,
-}
-impl<'scope> deno_core::v8::fast_api::FastFunction for op_blob_revoke_object_url_fast {
-    fn function(&self) -> *const ::std::ffi::c_void {
-        op_blob_revoke_object_url_fast_fn as *const ::std::ffi::c_void
-    }
-    fn args(&self) -> &'static [deno_core::v8::fast_api::Type] {
-        use deno_core::v8::fast_api::Type::*;
-        use deno_core::v8::fast_api::CType;
-        &[V8Value, SeqOneByteString, CallbackOptions]
-    }
-    fn return_type(&self) -> deno_core::v8::fast_api::CType {
-        deno_core::v8::fast_api::CType::Void
-    }
-}
-fn op_blob_revoke_object_url_fast_fn<'scope>(
-    _: deno_core::v8::Local<deno_core::v8::Object>,
-    url: *const deno_core::v8::fast_api::FastApiOneByteString,
-    fast_api_callback_options: *mut deno_core::v8::fast_api::FastApiCallbackOptions,
-) -> () {
-    use deno_core::v8;
-    use deno_core::_ops;
-    let __opts: &mut v8::fast_api::FastApiCallbackOptions = unsafe {
-        &mut *fast_api_callback_options
-    };
-    let __ctx = unsafe {
-        &*(v8::Local::<v8::External>::cast(unsafe { __opts.data.data }).value()
-            as *const _ops::OpCtx)
-    };
-    let state = &mut ::std::cell::RefCell::borrow_mut(&__ctx.state);
-    let url = unsafe { &*url }.as_str().to_owned();
-    let result = op_blob_revoke_object_url::call(state, url);
-    match result {
-        Ok(result) => result,
-        Err(err) => {
-            state.last_fast_op_error.replace(err);
-            __opts.fallback = true;
-            Default::default()
-        }
-    }
-}
diff --git a/ops/optimizer_tests/op_blob_revoke_object_url.rs b/ops/optimizer_tests/op_blob_revoke_object_url.rs
index b51a2ed7f5..8e139da06d 100644
--- a/ops/optimizer_tests/op_blob_revoke_object_url.rs
+++ b/ops/optimizer_tests/op_blob_revoke_object_url.rs
@@ -1,5 +1,5 @@
 pub fn op_blob_revoke_object_url(
-  state: &mut OpState,
+  state: &mut deno_core::OpState,
   url: String,
 ) -> Result<(), AnyError> {
   let url = Url::parse(&url)?;
diff --git a/ops/optimizer_tests/op_print.expected b/ops/optimizer_tests/op_print.expected
deleted file mode 100644
index fb52693aa2..0000000000
--- a/ops/optimizer_tests/op_print.expected
+++ /dev/null
@@ -1,11 +0,0 @@
-=== Optimizer Dump ===
-returns_result: true
-has_ref_opstate: true
-has_rc_opstate: false
-has_fast_callback_option: false
-needs_fast_callback_option: false
-fast_result: Some(Void)
-fast_parameters: [V8Value, SeqOneByteString, Bool]
-transforms: {1: Transform { kind: SeqOneByteString(Ref), index: 1 }}
-is_async: false
-fast_compatible: true
diff --git a/ops/optimizer_tests/op_print.out b/ops/optimizer_tests/op_print.out
deleted file mode 100644
index 5d0062a01a..0000000000
--- a/ops/optimizer_tests/op_print.out
+++ /dev/null
@@ -1,141 +0,0 @@
-#[allow(non_camel_case_types)]
-///Auto-generated by `deno_ops`, i.e: `#[op]`
-///
-///Use `op_print::decl()` to get an op-declaration
-///you can include in a `deno_core::Extension`.
-pub struct op_print;
-#[doc(hidden)]
-impl op_print {
-    pub fn name() -> &'static str {
-        stringify!(op_print)
-    }
-    pub fn v8_fn_ptr<'scope>() -> deno_core::v8::FunctionCallback {
-        use deno_core::v8::MapFnTo;
-        Self::v8_func.map_fn_to()
-    }
-    pub fn decl<'scope>() -> deno_core::OpDecl {
-        deno_core::OpDecl {
-            name: Self::name(),
-            v8_fn_ptr: Self::v8_fn_ptr(),
-            enabled: true,
-            fast_fn: Some(
-                Box::new(op_print_fast {
-                    _phantom: ::std::marker::PhantomData,
-                }),
-            ),
-            is_async: false,
-            is_unstable: false,
-            is_v8: false,
-            argc: 2usize,
-        }
-    }
-    #[inline]
-    #[allow(clippy::too_many_arguments)]
-    fn call(state: &mut OpState, msg: &str, is_err: bool) -> Result<(), AnyError> {}
-    pub fn v8_func<'scope>(
-        scope: &mut deno_core::v8::HandleScope<'scope>,
-        args: deno_core::v8::FunctionCallbackArguments,
-        mut rv: deno_core::v8::ReturnValue,
-    ) {
-        let ctx = unsafe {
-            &*(deno_core::v8::Local::<deno_core::v8::External>::cast(args.data()).value()
-                as *const deno_core::_ops::OpCtx)
-        };
-        {
-            let op_state = &mut std::cell::RefCell::borrow_mut(&ctx.state);
-            if let Some(err) = op_state.last_fast_op_error.take() {
-                let exception = deno_core::error::to_v8_error(
-                    scope,
-                    op_state.get_error_class_fn,
-                    &err,
-                );
-                scope.throw_exception(exception);
-                return;
-            }
-        }
-        let arg_0 = match deno_core::v8::Local::<
-            deno_core::v8::String,
-        >::try_from(args.get(0usize as i32)) {
-            Ok(v8_string) => deno_core::serde_v8::to_utf8(v8_string, scope),
-            Err(_) => {
-                return deno_core::_ops::throw_type_error(
-                    scope,
-                    format!("Expected string at position {}", 0usize),
-                );
-            }
-        };
-        let arg_0 = arg_0.as_ref();
-        let arg_1 = args.get(1usize as i32);
-        let arg_1 = match deno_core::serde_v8::from_v8(scope, arg_1) {
-            Ok(v) => v,
-            Err(err) => {
-                let msg = format!(
-                    "Error parsing args at position {}: {}", 1usize,
-                    deno_core::anyhow::Error::from(err)
-                );
-                return deno_core::_ops::throw_type_error(scope, msg);
-            }
-        };
-        let result = Self::call(
-            &mut std::cell::RefCell::borrow_mut(&ctx.state),
-            arg_0,
-            arg_1,
-        );
-        let op_state = ::std::cell::RefCell::borrow(&*ctx.state);
-        op_state.tracker.track_sync(ctx.id);
-        match result {
-            Ok(result) => {}
-            Err(err) => {
-                let exception = deno_core::error::to_v8_error(
-                    scope,
-                    op_state.get_error_class_fn,
-                    &err,
-                );
-                scope.throw_exception(exception);
-            }
-        };
-    }
-}
-struct op_print_fast {
-    _phantom: ::std::marker::PhantomData<()>,
-}
-impl<'scope> deno_core::v8::fast_api::FastFunction for op_print_fast {
-    fn function(&self) -> *const ::std::ffi::c_void {
-        op_print_fast_fn as *const ::std::ffi::c_void
-    }
-    fn args(&self) -> &'static [deno_core::v8::fast_api::Type] {
-        use deno_core::v8::fast_api::Type::*;
-        use deno_core::v8::fast_api::CType;
-        &[V8Value, SeqOneByteString, Bool, CallbackOptions]
-    }
-    fn return_type(&self) -> deno_core::v8::fast_api::CType {
-        deno_core::v8::fast_api::CType::Void
-    }
-}
-fn op_print_fast_fn<'scope>(
-    _: deno_core::v8::Local<deno_core::v8::Object>,
-    msg: *const deno_core::v8::fast_api::FastApiOneByteString,
-    is_err: bool,
-    fast_api_callback_options: *mut deno_core::v8::fast_api::FastApiCallbackOptions,
-) -> () {
-    use deno_core::v8;
-    use deno_core::_ops;
-    let __opts: &mut v8::fast_api::FastApiCallbackOptions = unsafe {
-        &mut *fast_api_callback_options
-    };
-    let __ctx = unsafe {
-        &*(v8::Local::<v8::External>::cast(unsafe { __opts.data.data }).value()
-            as *const _ops::OpCtx)
-    };
-    let state = &mut ::std::cell::RefCell::borrow_mut(&__ctx.state);
-    let msg = unsafe { &*msg }.as_str();
-    let result = op_print::call(state, msg, is_err);
-    match result {
-        Ok(result) => result,
-        Err(err) => {
-            state.last_fast_op_error.replace(err);
-            __opts.fallback = true;
-            Default::default()
-        }
-    }
-}
diff --git a/ops/optimizer_tests/op_print.rs b/ops/optimizer_tests/op_print.rs
deleted file mode 100644
index 516521a0e9..0000000000
--- a/ops/optimizer_tests/op_print.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-fn op_print(
-  state: &mut OpState,
-  msg: &str,
-  is_err: bool,
-) -> Result<(), AnyError> {
-}
diff --git a/ops/optimizer_tests/owned_string.expected b/ops/optimizer_tests/owned_string.expected
deleted file mode 100644
index a152754129..0000000000
--- a/ops/optimizer_tests/owned_string.expected
+++ /dev/null
@@ -1,11 +0,0 @@
-=== Optimizer Dump ===
-returns_result: false
-has_ref_opstate: false
-has_rc_opstate: false
-has_fast_callback_option: false
-needs_fast_callback_option: false
-fast_result: Some(U32)
-fast_parameters: [V8Value, SeqOneByteString]
-transforms: {0: Transform { kind: SeqOneByteString(Owned), index: 0 }}
-is_async: false
-fast_compatible: true
diff --git a/ops/optimizer_tests/owned_string.out b/ops/optimizer_tests/owned_string.out
deleted file mode 100644
index 4892221f81..0000000000
--- a/ops/optimizer_tests/owned_string.out
+++ /dev/null
@@ -1,99 +0,0 @@
-#[allow(non_camel_case_types)]
-///Auto-generated by `deno_ops`, i.e: `#[op]`
-///
-///Use `op_string_length::decl()` to get an op-declaration
-///you can include in a `deno_core::Extension`.
-pub struct op_string_length;
-#[doc(hidden)]
-impl op_string_length {
-    pub fn name() -> &'static str {
-        stringify!(op_string_length)
-    }
-    pub fn v8_fn_ptr<'scope>() -> deno_core::v8::FunctionCallback {
-        use deno_core::v8::MapFnTo;
-        Self::v8_func.map_fn_to()
-    }
-    pub fn decl<'scope>() -> deno_core::OpDecl {
-        deno_core::OpDecl {
-            name: Self::name(),
-            v8_fn_ptr: Self::v8_fn_ptr(),
-            enabled: true,
-            fast_fn: Some(
-                Box::new(op_string_length_fast {
-                    _phantom: ::std::marker::PhantomData,
-                }),
-            ),
-            is_async: false,
-            is_unstable: false,
-            is_v8: false,
-            argc: 1usize,
-        }
-    }
-    #[inline]
-    #[allow(clippy::too_many_arguments)]
-    fn call(string: String) -> u32 {
-        string.len() as u32
-    }
-    pub fn v8_func<'scope>(
-        scope: &mut deno_core::v8::HandleScope<'scope>,
-        args: deno_core::v8::FunctionCallbackArguments,
-        mut rv: deno_core::v8::ReturnValue,
-    ) {
-        let ctx = unsafe {
-            &*(deno_core::v8::Local::<deno_core::v8::External>::cast(args.data()).value()
-                as *const deno_core::_ops::OpCtx)
-        };
-        let arg_0 = match deno_core::v8::Local::<
-            deno_core::v8::String,
-        >::try_from(args.get(0usize as i32)) {
-            Ok(v8_string) => deno_core::serde_v8::to_utf8(v8_string, scope),
-            Err(_) => {
-                return deno_core::_ops::throw_type_error(
-                    scope,
-                    format!("Expected string at position {}", 0usize),
-                );
-            }
-        };
-        let result = Self::call(arg_0);
-        let op_state = ::std::cell::RefCell::borrow(&*ctx.state);
-        op_state.tracker.track_sync(ctx.id);
-        match deno_core::serde_v8::to_v8(scope, result) {
-            Ok(ret) => rv.set(ret),
-            Err(err) => {
-                deno_core::_ops::throw_type_error(
-                    scope,
-                    format!(
-                        "Error serializing return: {}",
-                        deno_core::anyhow::Error::from(err)
-                    ),
-                )
-            }
-        };
-    }
-}
-struct op_string_length_fast {
-    _phantom: ::std::marker::PhantomData<()>,
-}
-impl<'scope> deno_core::v8::fast_api::FastFunction for op_string_length_fast {
-    fn function(&self) -> *const ::std::ffi::c_void {
-        op_string_length_fast_fn as *const ::std::ffi::c_void
-    }
-    fn args(&self) -> &'static [deno_core::v8::fast_api::Type] {
-        use deno_core::v8::fast_api::Type::*;
-        use deno_core::v8::fast_api::CType;
-        &[V8Value, SeqOneByteString]
-    }
-    fn return_type(&self) -> deno_core::v8::fast_api::CType {
-        deno_core::v8::fast_api::CType::Uint32
-    }
-}
-fn op_string_length_fast_fn<'scope>(
-    _: deno_core::v8::Local<deno_core::v8::Object>,
-    string: *const deno_core::v8::fast_api::FastApiOneByteString,
-) -> u32 {
-    use deno_core::v8;
-    use deno_core::_ops;
-    let string = unsafe { &*string }.as_str().to_owned();
-    let result = op_string_length::call(string);
-    result
-}
diff --git a/ops/optimizer_tests/owned_string.rs b/ops/optimizer_tests/owned_string.rs
deleted file mode 100644
index 102cf00fb9..0000000000
--- a/ops/optimizer_tests/owned_string.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-fn op_string_length(string: String) -> u32 {
-  string.len() as u32
-}
diff --git a/ops/optimizer_tests/strings.expected b/ops/optimizer_tests/strings.expected
deleted file mode 100644
index ead741054a..0000000000
--- a/ops/optimizer_tests/strings.expected
+++ /dev/null
@@ -1,11 +0,0 @@
-=== Optimizer Dump ===
-returns_result: false
-has_ref_opstate: false
-has_rc_opstate: false
-has_fast_callback_option: false
-needs_fast_callback_option: false
-fast_result: Some(U32)
-fast_parameters: [V8Value, SeqOneByteString]
-transforms: {0: Transform { kind: SeqOneByteString(Ref), index: 0 }}
-is_async: false
-fast_compatible: true
diff --git a/ops/optimizer_tests/strings.out b/ops/optimizer_tests/strings.out
deleted file mode 100644
index 41f09c4f8d..0000000000
--- a/ops/optimizer_tests/strings.out
+++ /dev/null
@@ -1,100 +0,0 @@
-#[allow(non_camel_case_types)]
-///Auto-generated by `deno_ops`, i.e: `#[op]`
-///
-///Use `op_string_length::decl()` to get an op-declaration
-///you can include in a `deno_core::Extension`.
-pub struct op_string_length;
-#[doc(hidden)]
-impl op_string_length {
-    pub fn name() -> &'static str {
-        stringify!(op_string_length)
-    }
-    pub fn v8_fn_ptr<'scope>() -> deno_core::v8::FunctionCallback {
-        use deno_core::v8::MapFnTo;
-        Self::v8_func.map_fn_to()
-    }
-    pub fn decl<'scope>() -> deno_core::OpDecl {
-        deno_core::OpDecl {
-            name: Self::name(),
-            v8_fn_ptr: Self::v8_fn_ptr(),
-            enabled: true,
-            fast_fn: Some(
-                Box::new(op_string_length_fast {
-                    _phantom: ::std::marker::PhantomData,
-                }),
-            ),
-            is_async: false,
-            is_unstable: false,
-            is_v8: false,
-            argc: 1usize,
-        }
-    }
-    #[inline]
-    #[allow(clippy::too_many_arguments)]
-    fn call(string: &str) -> u32 {
-        string.len() as u32
-    }
-    pub fn v8_func<'scope>(
-        scope: &mut deno_core::v8::HandleScope<'scope>,
-        args: deno_core::v8::FunctionCallbackArguments,
-        mut rv: deno_core::v8::ReturnValue,
-    ) {
-        let ctx = unsafe {
-            &*(deno_core::v8::Local::<deno_core::v8::External>::cast(args.data()).value()
-                as *const deno_core::_ops::OpCtx)
-        };
-        let arg_0 = match deno_core::v8::Local::<
-            deno_core::v8::String,
-        >::try_from(args.get(0usize as i32)) {
-            Ok(v8_string) => deno_core::serde_v8::to_utf8(v8_string, scope),
-            Err(_) => {
-                return deno_core::_ops::throw_type_error(
-                    scope,
-                    format!("Expected string at position {}", 0usize),
-                );
-            }
-        };
-        let arg_0 = arg_0.as_ref();
-        let result = Self::call(arg_0);
-        let op_state = ::std::cell::RefCell::borrow(&*ctx.state);
-        op_state.tracker.track_sync(ctx.id);
-        match deno_core::serde_v8::to_v8(scope, result) {
-            Ok(ret) => rv.set(ret),
-            Err(err) => {
-                deno_core::_ops::throw_type_error(
-                    scope,
-                    format!(
-                        "Error serializing return: {}",
-                        deno_core::anyhow::Error::from(err)
-                    ),
-                )
-            }
-        };
-    }
-}
-struct op_string_length_fast {
-    _phantom: ::std::marker::PhantomData<()>,
-}
-impl<'scope> deno_core::v8::fast_api::FastFunction for op_string_length_fast {
-    fn function(&self) -> *const ::std::ffi::c_void {
-        op_string_length_fast_fn as *const ::std::ffi::c_void
-    }
-    fn args(&self) -> &'static [deno_core::v8::fast_api::Type] {
-        use deno_core::v8::fast_api::Type::*;
-        use deno_core::v8::fast_api::CType;
-        &[V8Value, SeqOneByteString]
-    }
-    fn return_type(&self) -> deno_core::v8::fast_api::CType {
-        deno_core::v8::fast_api::CType::Uint32
-    }
-}
-fn op_string_length_fast_fn<'scope>(
-    _: deno_core::v8::Local<deno_core::v8::Object>,
-    string: *const deno_core::v8::fast_api::FastApiOneByteString,
-) -> u32 {
-    use deno_core::v8;
-    use deno_core::_ops;
-    let string = unsafe { &*string }.as_str();
-    let result = op_string_length::call(string);
-    result
-}
diff --git a/ops/optimizer_tests/strings.rs b/ops/optimizer_tests/strings.rs
deleted file mode 100644
index 860f1e8ec9..0000000000
--- a/ops/optimizer_tests/strings.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-fn op_string_length(string: &str) -> u32 {
-  string.len() as u32
-}
diff --git a/runtime/ops/fs.rs b/runtime/ops/fs.rs
index b661c6ea80..ec60eed62c 100644
--- a/runtime/ops/fs.rs
+++ b/runtime/ops/fs.rs
@@ -530,13 +530,13 @@ fn op_umask(state: &mut OpState, mask: Option<u32>) -> Result<u32, AnyError> {
 }
 
 #[op]
-fn op_chdir(state: &mut OpState, directory: &str) -> Result<(), AnyError> {
+fn op_chdir(state: &mut OpState, directory: String) -> Result<(), AnyError> {
   let d = PathBuf::from(&directory);
   state
     .borrow_mut::<Permissions>()
     .read
     .check(&d, Some("Deno.chdir()"))?;
-  set_current_dir(d).map_err(|err| {
+  set_current_dir(&d).map_err(|err| {
     Error::new(err.kind(), format!("{}, chdir '{}'", err, directory))
   })?;
   Ok(())
@@ -609,10 +609,10 @@ async fn op_mkdir_async(
 #[op]
 fn op_chmod_sync(
   state: &mut OpState,
-  path: &str,
+  path: String,
   mode: u32,
 ) -> Result<(), AnyError> {
-  let path = Path::new(path);
+  let path = Path::new(&path);
   let mode = mode & 0o777;
 
   state
@@ -667,11 +667,11 @@ fn raw_chmod(path: &Path, _raw_mode: u32) -> Result<(), AnyError> {
 #[op]
 fn op_chown_sync(
   state: &mut OpState,
-  path: &str,
+  path: String,
   #[cfg_attr(windows, allow(unused_variables))] uid: Option<u32>,
   #[cfg_attr(windows, allow(unused_variables))] gid: Option<u32>,
 ) -> Result<(), AnyError> {
-  let path = Path::new(path).to_path_buf();
+  let path = Path::new(&path).to_path_buf();
   state
     .borrow_mut::<Permissions>()
     .write
@@ -740,10 +740,10 @@ async fn op_chown_async(
 #[op]
 fn op_remove_sync(
   state: &mut OpState,
-  path: &str,
+  path: String,
   recursive: bool,
 ) -> Result<(), AnyError> {
-  let path = PathBuf::from(path);
+  let path = PathBuf::from(&path);
 
   state
     .borrow_mut::<Permissions>()
@@ -841,11 +841,11 @@ async fn op_remove_async(
 #[op]
 fn op_copy_file_sync(
   state: &mut OpState,
-  from: &str,
-  to: &str,
+  from: String,
+  to: String,
 ) -> Result<(), AnyError> {
-  let from_path = PathBuf::from(from);
-  let to_path = PathBuf::from(to);
+  let from_path = PathBuf::from(&from);
+  let to_path = PathBuf::from(&to);
 
   let permissions = state.borrow_mut::<Permissions>();
   permissions
@@ -1103,11 +1103,11 @@ pub struct StatArgs {
 #[op]
 fn op_stat_sync(
   state: &mut OpState,
-  path: &str,
+  path: String,
   lstat: bool,
   out_buf: &mut [u32],
 ) -> Result<(), AnyError> {
-  let path = PathBuf::from(path);
+  let path = PathBuf::from(&path);
   state
     .borrow_mut::<Permissions>()
     .read
@@ -1319,11 +1319,11 @@ async fn op_read_dir_async(
 #[op]
 fn op_rename_sync(
   state: &mut OpState,
-  oldpath: &str,
-  newpath: &str,
+  oldpath: String,
+  newpath: String,
 ) -> Result<(), AnyError> {
-  let oldpath = PathBuf::from(oldpath);
-  let newpath = PathBuf::from(newpath);
+  let oldpath = PathBuf::from(&oldpath);
+  let newpath = PathBuf::from(&newpath);
 
   let permissions = state.borrow_mut::<Permissions>();
   permissions
@@ -1388,11 +1388,11 @@ async fn op_rename_async(
 #[op]
 fn op_link_sync(
   state: &mut OpState,
-  oldpath: &str,
-  newpath: &str,
+  oldpath: String,
+  newpath: String,
 ) -> Result<(), AnyError> {
-  let oldpath = PathBuf::from(oldpath);
-  let newpath = PathBuf::from(newpath);
+  let oldpath = PathBuf::from(&oldpath);
+  let newpath = PathBuf::from(&newpath);
 
   let permissions = state.borrow_mut::<Permissions>();
   permissions.read.check(&oldpath, Some("Deno.linkSync()"))?;
@@ -1455,12 +1455,12 @@ async fn op_link_async(
 #[op]
 fn op_symlink_sync(
   state: &mut OpState,
-  oldpath: &str,
-  newpath: &str,
+  oldpath: String,
+  newpath: String,
   _type: Option<String>,
 ) -> Result<(), AnyError> {
-  let oldpath = PathBuf::from(oldpath);
-  let newpath = PathBuf::from(newpath);
+  let oldpath = PathBuf::from(&oldpath);
+  let newpath = PathBuf::from(&newpath);
 
   state
     .borrow_mut::<Permissions>()
@@ -1675,10 +1675,10 @@ async fn op_ftruncate_async(
 #[op]
 fn op_truncate_sync(
   state: &mut OpState,
-  path: &str,
+  path: String,
   len: u64,
 ) -> Result<(), AnyError> {
-  let path = PathBuf::from(path);
+  let path = PathBuf::from(&path);
 
   state
     .borrow_mut::<Permissions>()
@@ -1955,13 +1955,13 @@ async fn op_futime_async(
 #[op]
 fn op_utime_sync(
   state: &mut OpState,
-  path: &str,
+  path: String,
   atime_secs: i64,
   atime_nanos: u32,
   mtime_secs: i64,
   mtime_nanos: u32,
 ) -> Result<(), AnyError> {
-  let path = PathBuf::from(path);
+  let path = PathBuf::from(&path);
   let atime = filetime::FileTime::from_unix_time(atime_secs, atime_nanos);
   let mtime = filetime::FileTime::from_unix_time(mtime_secs, mtime_nanos);
 
diff --git a/runtime/ops/io.rs b/runtime/ops/io.rs
index d8a1af69e0..646a540bc4 100644
--- a/runtime/ops/io.rs
+++ b/runtime/ops/io.rs
@@ -670,7 +670,7 @@ impl Resource for StdFileResource {
 #[op]
 pub fn op_print(
   state: &mut OpState,
-  msg: &str,
+  msg: String,
   is_err: bool,
 ) -> Result<(), AnyError> {
   let rid = if is_err { 2 } else { 1 };
diff --git a/runtime/ops/os/mod.rs b/runtime/ops/os/mod.rs
index 844fbaecc0..b93935955b 100644
--- a/runtime/ops/os/mod.rs
+++ b/runtime/ops/os/mod.rs
@@ -78,10 +78,10 @@ fn op_exec_path(state: &mut OpState) -> Result<String, AnyError> {
 #[op]
 fn op_set_env(
   state: &mut OpState,
-  key: &str,
-  value: &str,
+  key: String,
+  value: String,
 ) -> Result<(), AnyError> {
-  state.borrow_mut::<Permissions>().env.check(key)?;
+  state.borrow_mut::<Permissions>().env.check(&key)?;
   if key.is_empty() {
     return Err(type_error("Key is an empty string."));
   }
diff --git a/runtime/ops/signal.rs b/runtime/ops/signal.rs
index 66530a8384..95c166787c 100644
--- a/runtime/ops/signal.rs
+++ b/runtime/ops/signal.rs
@@ -453,9 +453,9 @@ pub fn signal_int_to_str(s: libc::c_int) -> Result<&'static str, AnyError> {
 #[op]
 fn op_signal_bind(
   state: &mut OpState,
-  sig: &str,
+  sig: String,
 ) -> Result<ResourceId, AnyError> {
-  let signo = signal_str_to_int(sig)?;
+  let signo = signal_str_to_int(&sig)?;
   if signal_hook_registry::FORBIDDEN.contains(&signo) {
     return Err(type_error(format!(
       "Binding to signal '{}' is not allowed",
@@ -474,9 +474,9 @@ fn op_signal_bind(
 #[op]
 fn op_signal_bind(
   state: &mut OpState,
-  sig: &str,
+  sig: String,
 ) -> Result<ResourceId, AnyError> {
-  let signo = signal_str_to_int(sig)?;
+  let signo = signal_str_to_int(&sig)?;
   let resource = SignalStreamResource {
     signal: AsyncRefCell::new(match signo {
       // SIGINT