Merge pull request #248 from p-x9/feature/retain-symbol-cache

Author: p-x9

Sources/MachOKit/DyldCache.swift

@@ -37,6 +37,8 @@ public class DyldCache: DyldCacheRepresentable, _DyldCacheFileRepresentable {
     internal var _fullCache: FullDyldCache?
     // Retain the main cache
     private var _mainCache: DyldCache?
+    // Retain the symbol cache
+    internal var _symbolCache: DyldCache?
 
     public var headerSize: Int {
         header.actualSize
@@ -235,16 +237,19 @@ extension DyldCache {
     /// DyldCache containing unmapped local symbols
     public var symbolCache: DyldCache? {
         get throws {
+            if let _symbolCache { return _symbolCache }
             guard header.hasProperty(\.symbolFileUUID),
                   header.symbolFileUUID != .zero else {
                 return nil
             }
             let suffix = ".symbols"
             let path = url.path + suffix
-            return try .init(
+            let symbolCache: DyldCache = try .init(
                 subcacheUrl: .init(fileURLWithPath: path),
                 mainCacheHeader: mainCacheHeader
             )
+            _symbolCache = symbolCache
+            return symbolCache
         }
     }
 

Sources/MachOKit/FullDyldCache.swift

@@ -31,6 +31,9 @@ public class FullDyldCache: DyldCacheRepresentable, _DyldCacheFileRepresentable
     public let url: URL
     let fileHandle: File
 
+    // Retain the symbol cache
+    private var _symbolCache: DyldCache?
+
     public var headerSize: Int {
         header.actualSize
     }
@@ -91,6 +94,7 @@ extension FullDyldCache {
             mainCache: nil
         )
         cache._fullCache = self
+        cache._symbolCache = _symbolCache
         return cache
     }
 
@@ -169,7 +173,10 @@ extension FullDyldCache {
     /// DyldCache containing unmapped local symbols
     public var symbolCache: DyldCache? {
         get throws {
-            try mainCache.symbolCache
+            if let _symbolCache = _symbolCache { return _symbolCache }
+            let symbolCache = try mainCache.symbolCache
+            _symbolCache = symbolCache
+            return symbolCache
         }
     }