perf(es/minifier): Cache var_or_default calls (#9909)

**Description:** This is a simple fix to ensure that we hash the `Id` only once.
swc-project · Jan 21, 2025 · 4a3be8d · 4a3be8d
1 parent eb84548
commit 4a3be8d
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Showing 2 changed files with 14 additions and 10 deletions.
diff --git a/.changeset/six-rats-fetch.md b/.changeset/six-rats-fetch.md
@@ -0,0 +1,6 @@
+---
+swc_core: patch
+swc_ecma_minifier: patch
+---
+
+perf(es/minifier): Cache `var_or_default` calls
diff --git a/crates/swc_ecma_usage_analyzer/src/analyzer/mod.rs b/crates/swc_ecma_usage_analyzer/src/analyzer/mod.rs
@@ -294,16 +294,15 @@ where
             };
 
             if let Some(left) = left {
+                let v = self.data.var_or_default(left.clone());
                 for id in collect_infects_from(
                     &n.right,
                     AliasConfig {
                         marks: self.marks,
                         ..Default::default()
                     },
                 ) {
-                    self.data
-                        .var_or_default(left.clone())
-                        .add_infects_to(id.clone());
+                    v.add_infects_to(id.clone());
                 }
             }
         }
@@ -743,16 +742,15 @@ where
         self.used_recursively.remove(&id);
 
         {
+            let v = self.data.var_or_default(id);
             for id in collect_infects_from(
                 &n.function,
                 AliasConfig {
                     marks: self.marks,
                     ..Default::default()
                 },
             ) {
-                self.data
-                    .var_or_default(n.ident.to_id())
-                    .add_infects_to(id.clone());
+                v.add_infects_to(id.clone());
             }
         }
     }
@@ -770,14 +768,15 @@ where
             n.visit_children_with(self);
 
             {
+                let v = self.data.var_or_default(n_id.to_id());
                 for id in collect_infects_from(
                     &n.function,
                     AliasConfig {
                         marks: self.marks,
                         ..Default::default()
                     },
                 ) {
-                    self.data.var_or_default(n_id.to_id()).add_infects_to(id);
+                    v.add_infects_to(id);
                 }
             }
             self.used_recursively.remove(&n_id.to_id());
@@ -1262,16 +1261,15 @@ where
 
         for decl in &n.decls {
             if let (Pat::Ident(var), Some(init)) = (&decl.name, decl.init.as_deref()) {
+                let v = self.data.var_or_default(var.to_id());
                 for id in collect_infects_from(
                     init,
                     AliasConfig {
                         marks: self.marks,
                         ..Default::default()
                     },
                 ) {
-                    self.data
-                        .var_or_default(var.to_id())
-                        .add_infects_to(id.clone());
+                    v.add_infects_to(id.clone());
                 }
             }
         }