serde_v8: move common key code to keys.rs

serde_v8/src/de.rs

@@ -2,10 +2,10 @@ use rusty_v8 as v8;
 use serde::de::{self, Visitor};
 use serde::Deserialize;
 
-use std::collections::HashMap;
 use std::convert::TryFrom;
 
 use crate::error::{Error, Result};
+use crate::keys::{v8_struct_key, KeyCache};
 use crate::payload::ValueType;
 
 use crate::magic;
@@ -15,7 +15,6 @@ pub struct Deserializer<'a, 'b, 's> {
  scope: &'b mut v8::HandleScope<'s>,
  _key_cache: Option<&'b mut KeyCache>,
 }
-pub type KeyCache = HashMap<&'static str, v8::Global<v8::String>>;
 
 impl<'a, 'b, 's> Deserializer<'a, 'b, 's> {
  pub fn new(
@@ -457,30 +456,6 @@ impl<'de, 'a, 'b, 's> de::MapAccess<'de> for ObjectAccess<'a, 'b, 's> {
  }
 }
 
-// creates an optimized v8::String for a struct field
-// TODO: experiment with external strings
-// TODO: evaluate if own KeyCache is better than v8's dedupe
-fn v8_struct_key<'s>(
- scope: &mut v8::HandleScope<'s>,
- field: &'static str,
-) -> v8::Local<'s, v8::String> {
- // Internalized v8 strings are significantly faster than "normal" v8 strings
- // since v8 deduplicates re-used strings minimizing new allocations
- // see: https://github.com/v8/v8/blob/14ac92e02cc3db38131a57e75e2392529f405f2f/include/v8.h#L3165-L3171
- v8::String::new_from_utf8(
- scope,
- field.as_ref(),
- v8::NewStringType::Internalized,
- )
- .unwrap()
-
- // TODO: consider external strings later
- // right now non-deduped external strings (without KeyCache)
- // are slower than the deduped internalized strings by ~2.5x
- // since they're a new string in v8's eyes and needs to be hashed, etc...
- // v8::String::new_external_onebyte_static(scope, field).unwrap()
-}
-
 struct SeqAccess<'a, 'b, 's> {
  obj: v8::Local<'a, v8::Object>,
  scope: &'b mut v8::HandleScope<'s>,

serde_v8/src/keys.rs

@@ -0,0 +1,32 @@
+use rusty_v8 as v8;
+
+use std::collections::HashMap;
+
+// KeyCache stores a pool struct keys mapped to v8,
+// to minimize allocs and speed up decoding/encoding `v8::Object`s
+// TODO: experiment with in from_v8/to_v8
+pub struct KeyCache(HashMap<&'static str, v8::Global<v8::String>>);
+
+// creates an optimized v8::String for a struct field
+// TODO: experiment with external strings
+// TODO: evaluate if own KeyCache is better than v8's dedupe
+pub fn v8_struct_key<'s>(
+ scope: &mut v8::HandleScope<'s>,
+ field: &'static str,
+) -> v8::Local<'s, v8::String> {
+ // Internalized v8 strings are significantly faster than "normal" v8 strings
+ // since v8 deduplicates re-used strings minimizing new allocations
+ // see: https://github.com/v8/v8/blob/14ac92e02cc3db38131a57e75e2392529f405f2f/include/v8.h#L3165-L3171
+ v8::String::new_from_utf8(
+ scope,
+ field.as_ref(),
+ v8::NewStringType::Internalized,
+ )
+ .unwrap()
+
+ // TODO: consider external strings later
+ // right now non-deduped external strings (without KeyCache)
+ // are slower than the deduped internalized strings by ~2.5x
+ // since they're a new string in v8's eyes and needs to be hashed, etc...
+ // v8::String::new_external_onebyte_static(scope, field).unwrap()
+}

serde_v8/src/lib.rs

@@ -1,11 +1,13 @@
 mod de;
 mod error;
+mod keys;
 mod magic;
 mod payload;
 mod ser;
 pub mod utils;
 
-pub use de::{from_v8, from_v8_cached, Deserializer, KeyCache};
+pub use de::{from_v8, from_v8_cached, Deserializer};
 pub use error::{Error, Result};
+pub use keys::KeyCache;
 pub use magic::Value;
 pub use ser::{to_v8, Serializer};

serde_v8/src/ser.rs

@@ -6,6 +6,7 @@ use std::cell::RefCell;
 use std::rc::Rc;
 
 use crate::error::{Error, Result};
+use crate::keys::v8_struct_key;
 use crate::magic;
 
 type JsValue<'s> = v8::Local<'s, v8::Value>;
@@ -629,21 +630,3 @@ impl<'a, 'b> ser::Serializer for MagicTransmuter<'a, 'b> {
  unreachable!();
  }
 }
-
-// creates an optimized v8::String for a struct field
-// TODO: experiment with external strings
-// TODO: evaluate if own KeyCache is better than v8's dedupe
-fn v8_struct_key<'s>(
- scope: &mut v8::HandleScope<'s>,
- field: &'static str,
-) -> v8::Local<'s, v8::String> {
- // Internalized v8 strings are significantly faster than "normal" v8 strings
- // since v8 deduplicates re-used strings minimizing new allocations
- // see: https://github.com/v8/v8/blob/14ac92e02cc3db38131a57e75e2392529f405f2f/include/v8.h#L3165-L3171
- v8::String::new_from_utf8(
- scope,
- field.as_ref(),
- v8::NewStringType::Internalized,
- )
- .unwrap()
-}