libs: add murmur2 library

Signed-off-by: flow <flowlnlnln@gmail.com>

CMakeLists.txt

@@ -323,6 +323,7 @@ add_subdirectory(libraries/optional-bare)
 add_subdirectory(libraries/tomlc99) # toml parser
 add_subdirectory(libraries/katabasis) # An OAuth2 library that tried to do too much
 add_subdirectory(libraries/gamemode)
+add_subdirectory(libraries/murmur2) # Hash for usage with the CurseForge API
 
 ############################### Built Artifacts ###############################
 

launcher/CMakeLists.txt

@@ -972,6 +972,7 @@ add_library(Launcher_logic STATIC ${LOGIC_SOURCES} ${LAUNCHER_SOURCES} ${LAUNCHE
 target_link_libraries(Launcher_logic
     systeminfo
     Launcher_classparser
+    Launcher_murmur2
     nbt++
     ${ZLIB_LIBRARIES}
     optional-bare

libraries/README.md

@@ -149,6 +149,12 @@ BSD licensed, derived from [QtSingleApplication](https://github.com/qtproject/qt
 
 Changes are made to make the code more generic and useful in less usual conditions.
 
+## murmur2
+
+Canonical implementation of the murmur2 hash, taken from [SMHasher](https://github.com/aappleby/smhasher).
+
+Public domain (the author disclaimed the copyright).
+
 ## optional-bare
 
 A simple single-file header-only version of a C++17-like optional for default-constructible, copyable types, for C++98 and later.

libraries/murmur2/CMakeLists.txt

@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 3.9.4)
+project(murmur2)
+
+set(MURMUR_SOURCES
+    src/MurmurHash2.h
+    src/MurmurHash2.cpp
+)
+
+add_library(Launcher_murmur2 STATIC ${MURMUR_SOURCES})
+target_include_directories(Launcher_murmur2 PUBLIC ${CMAKE_CURRENT_SOURCE_DIR} "src" )
+
+generate_export_header(Launcher_murmur2)

libraries/murmur2/src/MurmurHash2.cpp

@@ -0,0 +1,86 @@
+//-----------------------------------------------------------------------------
+// MurmurHash2 was written by Austin Appleby, and is placed in the public
+// domain. The author hereby disclaims copyright to this source code.
+
+// Note - This code makes a few assumptions about how your machine behaves -
+
+// 1. We can read a 4-byte value from any address without crashing
+// 2. sizeof(int) == 4
+
+// And it has a few limitations -
+
+// 1. It will not work incrementally.
+// 2. It will not produce the same results on little-endian and big-endian
+//    machines.
+
+#include "MurmurHash2.h"
+
+//-----------------------------------------------------------------------------
+// Platform-specific functions and macros
+
+// Microsoft Visual Studio
+
+#if defined(_MSC_VER)
+
+#define BIG_CONSTANT(x) (x)
+
+// Other compilers
+
+#else	// defined(_MSC_VER)
+
+#define BIG_CONSTANT(x) (x##LLU)
+
+#endif // !defined(_MSC_VER)
+
+//-----------------------------------------------------------------------------
+
+uint64_t MurmurHash2 ( const void* key, int len, uint32_t seed )
+{
+  // 'm' and 'r' are mixing constants generated offline.
+  // They're not really 'magic', they just happen to work well.
+
+  const uint32_t m = 0x5bd1e995;
+  const int r = 24;
+
+  // Initialize the hash to a 'random' value
+
+  uint32_t h = seed ^ len;
+
+  // Mix 4 bytes at a time into the hash
+  const auto* data = (const unsigned char*) key;
+  while(len >= 4)
+  {
+    uint32_t k = *(uint32_t*)data;
+
+    k *= m;
+    k ^= k >> r;
+    k *= m;
+
+    h *= m;
+    h ^= k;
+
+    data += 4*sizeof(char);
+    len -= 4;
+  }
+
+  // Handle the last few bytes of the input array
+
+  switch(len)
+  {
+  case 3: h ^= data[2] << 16;
+  case 2: h ^= data[1] << 8;
+  case 1: h ^= data[0];
+      h *= m;
+  };
+
+  // Do a few final mixes of the hash to ensure the last few
+  // bytes are well-incorporated.
+
+  h ^= h >> 13;
+  h *= m;
+  h ^= h >> 15;
+
+  return h;
+} 
+
+//-----------------------------------------------------------------------------

libraries/murmur2/src/MurmurHash2.h

@@ -0,0 +1,30 @@
+//-----------------------------------------------------------------------------
+// MurmurHash2 was written by Austin Appleby, and is placed in the public
+// domain. The author hereby disclaims copyright to this source code.
+
+#pragma once
+
+//-----------------------------------------------------------------------------
+// Platform-specific functions and macros
+
+// Microsoft Visual Studio
+
+#if defined(_MSC_VER) && (_MSC_VER < 1600)
+
+typedef unsigned char uint8_t;
+typedef unsigned int uint32_t;
+typedef unsigned __int64 uint64_t;
+
+// Other compilers
+
+#else	// defined(_MSC_VER)
+
+#include <stdint.h>
+
+#endif // !defined(_MSC_VER)
+
+//-----------------------------------------------------------------------------
+
+uint64_t MurmurHash2        ( const void* key, int len, uint32_t seed = 1 );
+
+//-----------------------------------------------------------------------------