[SharedCache] Use `m_exportInfos` as an export list cache

`SharedCache::ParseExportTrie` is getting called a lot during DSC library loading and analysis. In large part due to the hot path `SharedCache::FindSymbolAtAddrAndApplyToAddr`. Its unnecessary for it to be being called more than once per DSC header as the export list symbol information is stored in `SharedCache::m_exportInfos`.

This commit adds the function `SharedCache::GetExportListForHeader`, which will either return the header's list of symbol information cached in `SharedCache::m_exportInfos` or call `SharedCache::ParseExportTrie` and cache the results in `SharedCache::m_exportInfos`.

This should also improve the execution time of `SharedCache::LoadAllSymbolsAndWait`.

Further improvement here would be to add locking to `SharedCache::GetExportListForHeader` so that races don't result in redundant parsing of the export trie for the same header if multiple threads call `SharedCache::GetExportListForHeader` at the same time for the same header. This only really matters during initial loading because from what I can tell that parses all the export trie's anyway.

1 files changed, 3 insertions, 0 deletions

diff --git a/view/sharedcache/core/SharedCache.h b/view/sharedcache/core/SharedCache.h
index 8c06ff6e..0b268e3d 100644
--- a/view/sharedcache/core/SharedCache.h
+++ b/view/sharedcache/core/SharedCache.h
@@ -642,6 +642,9 @@ private:
 		std::vector<Ref<Symbol>> ParseExportTrie(
 			std::shared_ptr<MMappedFileAccessor> linkeditFile, const SharedCacheMachOHeader& header);
 
+		std::vector<std::pair<uint64_t, std::pair<BNSymbolType, std::string>>> GetExportListForHeader(
+			SharedCacheMachOHeader header, std::function<std::shared_ptr<MMappedFileAccessor>()> provideLinkeditFile);
+
 		Ref<TypeLibrary> TypeLibraryForImage(const std::string& installName);
 
 		size_t GetBaseAddress() const;