Add xxHash submodule and CMake integration for fast hashing

.gitmodules

@@ -10,3 +10,6 @@
 [submodule "3rdparty/slog"]
 	path = 3rdparty/slog
 	url = https://github.com/kala13x/slog
+[submodule "3rdparty/xxHash"]
+	path = 3rdparty/xxHash
+	url = https://github.com/Cyan4973/xxHash

3rdparty/xxhash.cmake

@@ -0,0 +1,57 @@
+# xxHash - Extremely Fast Hash algorithm
+# Copyright (C) 2012-2023 Yann Collet
+# BSD 2-Clause License
+
+set("XXHASH_C_DIRECTORY" "3rdparty/xxHash")
+
+message(STATUS "xxHash: Building static library")
+
+# Create static library target for xxHash
+add_library(xxhash STATIC)
+
+# Add the main xxhash source file
+target_sources(xxhash PRIVATE ${XXHASH_C_DIRECTORY}/xxhash.c)
+
+# Set include directories for xxhash
+target_include_directories(xxhash PUBLIC ${XXHASH_C_DIRECTORY})
+
+# Enable x86/x64 dispatch for better performance on supported platforms
+if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "x86_64" OR
+   ${CMAKE_SYSTEM_PROCESSOR} MATCHES "AMD64" OR
+   ${CMAKE_SYSTEM_PROCESSOR} MATCHES "i386" OR
+   ${CMAKE_SYSTEM_PROCESSOR} MATCHES "i686")
+    message(STATUS "xxHash: Enabling x86 dispatch optimization")
+    target_sources(xxhash PRIVATE ${XXHASH_C_DIRECTORY}/xxh_x86dispatch.c)
+    target_compile_definitions(xxhash PRIVATE XXHSUM_DISPATCH=1)
+endif()
+
+# Set compile definitions for xxhash
+target_compile_definitions(xxhash PRIVATE XXH_STATIC_LINKING_ONLY)
+
+# Optimization flags
+if(CMAKE_BUILD_TYPE STREQUAL "Release")
+    if(MSVC)
+        target_compile_options(xxhash PRIVATE /O2)
+    else()
+        target_compile_options(xxhash PRIVATE -O3 -ffast-math)
+
+        # Enable specific optimizations for x86/x64
+        if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "x86_64" OR
+           ${CMAKE_SYSTEM_PROCESSOR} MATCHES "AMD64" OR
+           ${CMAKE_SYSTEM_PROCESSOR} MATCHES "i386" OR
+           ${CMAKE_SYSTEM_PROCESSOR} MATCHES "i686")
+            if(NOT "${CMAKE_C_COMPILER_ID}" MATCHES "AppleClang")
+                target_compile_options(xxhash PRIVATE -march=core2 -mtune=westmere)
+            endif()
+        endif()
+    endif()
+endif()
+
+# Set position independent code for shared library compatibility
+set_property(TARGET xxhash PROPERTY POSITION_INDEPENDENT_CODE TRUE)
+
+# Link xxhash to the main aaruformat target
+target_link_libraries(aaruformat xxhash)
+
+# Add include directory to main target so it can find xxhash headers
+target_include_directories(aaruformat PRIVATE ${XXHASH_C_DIRECTORY})

CMakeLists.txt

@@ -123,12 +123,15 @@ add_library(aaruformat SHARED include/aaruformat/consts.h include/aaruformat/enu
             src/create.c
             src/time.c
             src/write.c
-            include/log.h)
+            include/log.h
+            src/ddt/hash_map.c
+            include/aaruformat/hash_map.h)
 
 include_directories(include include/aaruformat)
 
 include(3rdparty/flac.cmake)
 include(3rdparty/lzma.cmake)
+include(3rdparty/xxhash.cmake)
 
 macro(TARGET_LINK_LIBRARIES_WHOLE_ARCHIVE target)
   if(MSVC)