constant smallvec capacity

Author: sydney-runkle

src/serializers/type_serializers/union.rs

@@ -6,7 +6,7 @@ use std::borrow::Cow;
 
 use crate::build_tools::py_schema_err;
 use crate::definitions::DefinitionsBuilder;
-use crate::tools::SchemaDict;
+use crate::tools::{SchemaDict, UNION_ERR_SMALLVEC_CAPACITY};
 use crate::PydanticSerializationUnexpectedValue;
 
 use super::{
@@ -79,7 +79,7 @@ impl TypeSerializer for UnionSerializer {
         // try the serializers in left to right order with error_on fallback=true
         let mut new_extra = extra.clone();
         new_extra.check = SerCheck::Strict;
-        let mut errors: SmallVec<[PyErr; 16]> = SmallVec::new();
+        let mut errors: SmallVec<[PyErr; UNION_ERR_SMALLVEC_CAPACITY]> = SmallVec::new();
 
         for comb_serializer in &self.choices {
             match comb_serializer.to_python(value, include, exclude, &new_extra) {
@@ -114,7 +114,7 @@ impl TypeSerializer for UnionSerializer {
     fn json_key<'a>(&self, key: &'a Bound<'_, PyAny>, extra: &Extra) -> PyResult<Cow<'a, str>> {
         let mut new_extra = extra.clone();
         new_extra.check = SerCheck::Strict;
-        let mut errors: SmallVec<[PyErr; 16]> = SmallVec::new();
+        let mut errors: SmallVec<[PyErr; UNION_ERR_SMALLVEC_CAPACITY]> = SmallVec::new();
 
         for comb_serializer in &self.choices {
             match comb_serializer.json_key(key, &new_extra) {
@@ -157,7 +157,7 @@ impl TypeSerializer for UnionSerializer {
         let py = value.py();
         let mut new_extra = extra.clone();
         new_extra.check = SerCheck::Strict;
-        let mut errors: SmallVec<[PyErr; 16]> = SmallVec::new();
+        let mut errors: SmallVec<[PyErr; UNION_ERR_SMALLVEC_CAPACITY]> = SmallVec::new();
 
         for comb_serializer in &self.choices {
             match comb_serializer.to_python(value, include, exclude, &new_extra) {

src/tools.rs

@@ -146,3 +146,5 @@ pub(crate) fn new_py_string<'py>(py: Python<'py>, s: &str, cache_str: StringCach
         pystring_fast_new(py, s, ascii_only)
     }
 }
+
+pub(crate) const UNION_ERR_SMALLVEC_CAPACITY: usize = 4;

src/validators/union.rs

@@ -12,7 +12,7 @@ use crate::errors::{ErrorType, ToErrorValue, ValError, ValLineError, ValResult};
 use crate::input::{BorrowInput, Input, ValidatedDict};
 use crate::lookup_key::LookupKey;
 use crate::py_gc::PyGcTraverse;
-use crate::tools::SchemaDict;
+use crate::tools::{SchemaDict, UNION_ERR_SMALLVEC_CAPACITY};
 
 use super::custom_error::CustomError;
 use super::literal::LiteralLookup;
@@ -249,7 +249,7 @@ struct ChoiceLineErrors<'a> {
 
 enum MaybeErrors<'a> {
     Custom(&'a CustomError),
-    Errors(SmallVec<[ChoiceLineErrors<'a>; 4]>),
+    Errors(SmallVec<[ChoiceLineErrors<'a>; UNION_ERR_SMALLVEC_CAPACITY]>),
 }
 
 impl<'a> MaybeErrors<'a> {