Experimenting with zip scanning performance

Author: grendello

src/native/mono/monodroid/embedded-assemblies-zip.cc

@@ -328,14 +328,15 @@ EmbeddedAssemblies::zip_load_assembly_store_entries (std::span<uint8_t> const& b
 	}
 }
 
+[[gnu::flatten]]
 void
 EmbeddedAssemblies::zip_load_entries (int fd, const char *apk_name, [[maybe_unused]] monodroid_should_register should_register) noexcept
 {
 	uint32_t cd_offset;
 	uint32_t cd_size;
 	uint16_t cd_entries;
 
-	if (!zip_read_cd_info (fd, cd_offset, cd_size, cd_entries)) {
+	if (!zip_read_cd_info (fd, cd_offset, cd_size, cd_entries)) [[unlikely]] {
 		Helpers::abort_application (
 			LOG_ASSEMBLY,
 			std::format (
@@ -345,14 +346,12 @@ EmbeddedAssemblies::zip_load_entries (int fd, const char *apk_name, [[maybe_unus
 		);
 	}
 
-	md_mmap_info apk_map = md_mmap_apk_file (fd, cd_offset, cd_size, apk_name);
-
 	log_debug (LOG_ASSEMBLY, "Central directory offset: %u", cd_offset);
 	log_debug (LOG_ASSEMBLY, "Central directory size: %u", cd_size);
 	log_debug (LOG_ASSEMBLY, "Central directory entries: %u", cd_entries);
 
 	// off_t retval = ::lseek (fd, static_cast<off_t>(cd_offset), SEEK_SET);
-	// if (retval < 0) {
+	// if (retval < 0) [[unlikely]] {
 	//	Helpers::abort_application (
 	//		LOG_ASSEMBLY,
 	//		Util::monodroid_strdup_printf (
@@ -365,7 +364,6 @@ EmbeddedAssemblies::zip_load_entries (int fd, const char *apk_name, [[maybe_unus
 	//	);
 	// }
 
-	std::span<uint8_t>  buf (reinterpret_cast<uint8_t*>(apk_map.area), apk_map.size);
 	const auto [prefix, prefix_len] = get_assemblies_prefix_and_length ();
 	ZipEntryLoadState state {
 		.file_fd             = fd,
@@ -402,7 +400,7 @@ EmbeddedAssemblies::zip_load_entries (int fd, const char *apk_name, [[maybe_unus
 		zip_load_individual_assembly_entries (buf, cd_entries, should_register, state);
 	}
 
-	// TODO: unmap here
+	//delete[] raw_data;
 }
 
 template<bool NeedsNameAlloc>

src/native/mono/monodroid/embedded-assemblies.cc

@@ -910,51 +910,6 @@ EmbeddedAssemblies::typemap_managed_to_java (MonoReflectionType *reflection_type
 	return ret;
 }
 
-EmbeddedAssemblies::md_mmap_info
-EmbeddedAssemblies::md_mmap_apk_file (int fd, uint32_t offset, size_t size, const char* filename)
-{
-	md_mmap_info file_info;
-	md_mmap_info mmap_info;
-
-	size_t pageSize        = static_cast<size_t>(Util::monodroid_getpagesize ());
-	size_t offsetFromPage  = offset % pageSize;
-	size_t offsetPage      = offset - offsetFromPage;
-	size_t offsetSize      = size + offsetFromPage;
-
-	mmap_info.area        = mmap (nullptr, offsetSize, PROT_READ, MAP_PRIVATE, fd, static_cast<off_t>(offsetPage));
-
-	if (mmap_info.area == MAP_FAILED) {
-		Helpers::abort_application (
-			LOG_ASSEMBLY,
-			std::format (
-				"Could not mmap APK fd {}: {}; File={}",
-				fd,
-				strerror (errno),
-				optional_string (filename)
-			)
-		);
-	}
-
-	mmap_info.size  = offsetSize;
-	file_info.area  = pointer_add (mmap_info.area, offsetFromPage);
-	file_info.size  = size;
-
-	log_info (
-		LOG_ASSEMBLY,
-			"  mmap_start: {:<8p}; mmap_end: {:<8p}  mmap_len: {:<12}  file_start: {:<8p}  file_end: {:<8p}  file_len: {:<12}     apk descriptor: {}  file: {}",
-			mmap_info.area,
-			pointer_add (mmap_info.area, mmap_info.size),
-			mmap_info.size,
-			file_info.area,
-			pointer_add (file_info.area, file_info.size),
-			file_info.size,
-			fd,
-			optional_string (filename)
-	);
-
-	return file_info;
-}
-
 void
 EmbeddedAssemblies::gather_bundled_assemblies_from_apk (const char* apk, monodroid_should_register should_register) noexcept
 {

src/native/mono/monodroid/embedded-assemblies.hh

@@ -27,7 +27,7 @@
 #include <shared/cpp-util.hh>
 #include "cppcompat.hh"
 #include "shared-constants.hh"
-#include <shared/xxhash.hh>
+#include "xxhash.hh"
 #include "util.hh"
 
 #include <concepts>
@@ -259,7 +259,41 @@ namespace xamarin::android::internal {
 		static const TypeMapEntry *typemap_managed_to_java (const char *managed_type_name) noexcept;
 #endif // DEBUG
 
-		static md_mmap_info md_mmap_apk_file (int fd, uint32_t offset, size_t size, const char* filename);
+		[[gnu::always_inline]]
+		static md_mmap_info md_mmap_apk_file (int fd, uint32_t offset, size_t size, const char* filename, md_mmap_info &original_info, md_mmap_info &adjusted_info) noexcept
+		{
+			size_t pageSize        = static_cast<size_t>(Util::monodroid_getpagesize ());
+			size_t offsetFromPage  = offset % pageSize;
+			size_t offsetPage      = offset - offsetFromPage;
+			size_t offsetSize      = size + offsetFromPage;
+
+			original_info.area        = mmap (nullptr, offsetSize, PROT_READ, MAP_PRIVATE, fd, static_cast<off_t>(offsetPage));
+
+			if (original_info.area == MAP_FAILED) {
+				log_fatal (LOG_DEFAULT, "Could not `mmap` apk fd %d entry `%s`: %s", fd, filename, strerror (errno));
+				Helpers::abort_application ();
+			}
+
+			original_info.size  = offsetSize;
+			adjusted_info.area  = (void*)((const char*)original_info.area + offsetFromPage);
+			adjusted_info.size  = size;
+
+			log_info (LOG_ASSEMBLY, "                       mmap_start: %08p  mmap_end: %08p  mmap_len: % 12u  file_start: %08p  file_end: %08p  file_len: % 12u      apk descriptor: %d  file: %s",
+									original_info.area, reinterpret_cast<int*> (original_info.area) + original_info.size, original_info.size,
+																											  adjusted_info.area, reinterpret_cast<int*> (adjusted_info.area) + adjusted_info.size, adjusted_info.size, fd, filename);
+
+			return adjusted_info;
+		}
+
+		[[gnu::flatten, gnu::always_inline]]
+		static md_mmap_info md_mmap_apk_file (int fd, uint32_t offset, size_t size, const char* filename) noexcept
+		{
+			md_mmap_info file_info;
+			md_mmap_info mmap_info;
+
+			return md_mmap_apk_file (fd, offset, size, filename, mmap_info, file_info);
+		}
+
 		static MonoAssembly* open_from_bundles_full (MonoAssemblyName *aname, char **assemblies_path, void *user_data);
 		static MonoAssembly* open_from_bundles (MonoAssemblyLoadContextGCHandle alc_gchandle, MonoAssemblyName *aname, char **assemblies_path, void *user_data, MonoError *error);