avm1: Cache ConstantPools for constant pools with more than 1000 entries

Author: Lord-McSweeney

core/src/avm1/activation.rs

@@ -12,7 +12,7 @@ use crate::display_object::{DisplayObject, MovieClip, TDisplayObject, TDisplayOb
 use crate::ecma_conversions::{f64_to_wrapping_i32, f64_to_wrapping_u32};
 use crate::loader::MovieLoaderVMData;
 use crate::string::{AvmString, SwfStrExt as _, WStr, WString};
-use crate::tag_utils::SwfSlice;
+use crate::tag_utils::{SwfPosition, SwfSlice};
 use crate::vminterface::Instantiator;
 use crate::{avm_error, avm_warn};
 use gc_arena::{Gc, GcCell, MutationContext};
@@ -25,6 +25,7 @@ use std::cmp::min;
 use std::fmt;
 use swf::avm1::read::Reader;
 use swf::avm1::types::*;
+use swf::extensions::ReadSwfExt;
 use url::form_urlencoded;
 
 use super::object_reference::MovieClipReference;
@@ -480,7 +481,7 @@ impl<'a, 'gc> Activation<'a, 'gc> {
                 Action::CastOp => self.action_cast_op(),
                 Action::CharToAscii => self.action_char_to_ascii(),
                 Action::CloneSprite => self.action_clone_sprite(),
-                Action::ConstantPool(action) => self.action_constant_pool(action),
+                Action::ConstantPool(action) => self.action_constant_pool(action, data, reader),
                 Action::Decrement => self.action_decrement(),
                 Action::DefineFunction(action) => self.action_define_function(action.into(), data),
                 Action::DefineFunction2(action) => self.action_define_function(action, data),
@@ -863,21 +864,42 @@ impl<'a, 'gc> Activation<'a, 'gc> {
     fn action_constant_pool(
         &mut self,
         action: ConstantPool,
+        data: &SwfSlice,
+        reader: &mut Reader,
     ) -> Result<FrameControl<'gc>, Error<'gc>> {
-        let constants = action
-            .strings
-            .iter()
-            .map(|s| {
+        let current_pos = reader.pos(data.movie.data());
+        let swf_position = SwfPosition::new(data.movie.clone(), current_pos);
+
+        let const_pool_cache = self.context.avm1.constant_pool_cache();
+
+        let constants = if let Some(constants) = const_pool_cache.get(&swf_position) {
+            *constants
+        } else {
+            let constants: Vec<_> = action
+                .strings
+                .iter()
+                .map(|s| {
+                    self.context
+                        .interner
+                        .intern_wstr(self.context.gc_context, s.decode(self.encoding()))
+                        .into()
+                })
+                .collect();
+
+            let consts = Gc::new(self.context.gc_context, constants);
+
+            if consts.len() > 1000 {
                 self.context
-                    .interner
-                    .intern_wstr(self.context.gc_context, s.decode(self.encoding()))
-                    .into()
-            })
-            .collect();
+                    .avm1
+                    .constant_pool_cache()
+                    .insert(swf_position, consts);
+            }
+
+            consts
+        };
+
+        self.context.avm1.set_constant_pool(constants);
 
-        self.context
-            .avm1
-            .set_constant_pool(Gc::new(self.context.gc_context, constants));
         self.set_constant_pool(self.context.avm1.constant_pool());
 
         Ok(FrameControl::Continue)

core/src/avm1/runtime.rs

@@ -10,10 +10,11 @@ use crate::context::{GcContext, UpdateContext};
 use crate::frame_lifecycle::FramePhase;
 use crate::prelude::*;
 use crate::string::AvmString;
-use crate::tag_utils::SwfSlice;
+use crate::tag_utils::{SwfPosition, SwfSlice};
 use crate::{avm1, avm_debug};
 use gc_arena::{Collect, Gc, MutationContext};
 use std::borrow::Cow;
+use std::collections::HashMap;
 use swf::avm1::read::Reader;
 use tracing::instrument;
 
@@ -27,6 +28,8 @@ pub struct Avm1<'gc> {
     /// don't close over the constant pool they were defined with.
     constant_pool: Gc<'gc, Vec<Value<'gc>>>,
 
+    constant_pool_cache: HashMap<SwfPosition, Gc<'gc, Vec<Value<'gc>>>>,
+
     /// The global scope (pre-allocated so that it can be reused by fresh `Activation`s).
     global_scope: Gc<'gc, Scope<'gc>>,
 
@@ -80,6 +83,7 @@ impl<'gc> Avm1<'gc> {
         Self {
             player_version,
             constant_pool: Gc::new(gc_context, vec![]),
+            constant_pool_cache: HashMap::new(),
             global_scope: Gc::new(gc_context, Scope::from_global_object(globals)),
             prototypes,
             broadcaster_functions,
@@ -363,6 +367,10 @@ impl<'gc> Avm1<'gc> {
         self.constant_pool = constant_pool;
     }
 
+    pub fn constant_pool_cache(&mut self) -> &mut HashMap<SwfPosition, Gc<'gc, Vec<Value<'gc>>>> {
+        &mut self.constant_pool_cache
+    }
+
     /// DisplayObject property map.
     pub fn display_properties(&self) -> &stage_object::DisplayPropertyMap<'gc> {
         &self.display_properties

core/src/tag_utils.rs

@@ -1,4 +1,5 @@
 use gc_arena::Collect;
+use std::hash::{Hash, Hasher};
 use std::sync::Arc;
 use swf::{CharacterId, Fixed8, HeaderExt, Rectangle, TagCode, Twips};
 use thiserror::Error;
@@ -409,6 +410,34 @@ impl SwfSlice {
     }
 }
 
+#[derive(Collect)]
+#[collect(no_drop)]
+pub struct SwfPosition {
+    pub movie: Arc<SwfMovie>,
+    pub pos: usize,
+}
+
+impl SwfPosition {
+    pub fn new(movie: Arc<SwfMovie>, pos: usize) -> Self {
+        SwfPosition { movie, pos }
+    }
+}
+
+impl PartialEq for SwfPosition {
+    fn eq(&self, other: &Self) -> bool {
+        Arc::ptr_eq(&self.movie, &other.movie) && self.pos == other.pos
+    }
+}
+
+impl Eq for SwfPosition {}
+
+impl Hash for SwfPosition {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.pos.hash(state);
+        Arc::as_ptr(&self.movie).hash(state);
+    }
+}
+
 /// Decode tags from a SWF stream reader.
 ///
 /// The given `tag_callback` will be called for each decoded tag. It will be