Added md5 and crc32 hashing utility

es-core/CMakeLists.txt

@@ -17,6 +17,9 @@ set(CORE_HEADERS
 	${CMAKE_CURRENT_SOURCE_DIR}/src/ThemeData.h
 	${CMAKE_CURRENT_SOURCE_DIR}/src/Util.h
 	${CMAKE_CURRENT_SOURCE_DIR}/src/Window.h
+	${CMAKE_CURRENT_SOURCE_DIR}/src/hash.h
+	${CMAKE_CURRENT_SOURCE_DIR}/src/md5.h
+	${CMAKE_CURRENT_SOURCE_DIR}/src/crc32.h
 
 	# Animations
 	${CMAKE_CURRENT_SOURCE_DIR}/src/animations/Animation.h
@@ -76,6 +79,8 @@ set(CORE_SOURCES
 	${CMAKE_CURRENT_SOURCE_DIR}/src/ThemeData.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/src/Util.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/src/Window.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/src/md5.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/src/crc32.cpp
 
 	# Animations
 	${CMAKE_CURRENT_SOURCE_DIR}/src/animations/AnimationController.cpp

es-core/src/Util.cpp

@@ -1,6 +1,9 @@
 #include "Util.h"
 #include "resources/ResourceManager.h"
 #include "platform.h"
+#include "md5.h"
+#include "crc32.h"
+#include <fstream>
 
 namespace fs = boost::filesystem;
 
@@ -64,6 +67,33 @@ Eigen::Vector2f roundVector(const Eigen::Vector2f& vec)
 	return ret;
 }
 
+void hashFile(const boost::filesystem::path& path, Hash& algorithm)
+{
+    std::ifstream fileStream(path.generic_string(), std::ios::binary);
+    if(fileStream.is_open()) {
+        while(!fileStream.eof()) {
+            char buffer[4096];
+            fileStream.read(buffer, 4096);
+            int bytesRead = fileStream.gcount();
+            algorithm.add(buffer, bytesRead);
+        }
+    }
+}
+
+std::string getMd5(const boost::filesystem::path& path)
+{
+    MD5 algorithm;
+    hashFile(path, algorithm);
+    return algorithm.getHash();
+}
+
+std::string getCrc(const boost::filesystem::path& path)
+{
+    CRC32 algorithm;
+    hashFile(path, algorithm);
+    return algorithm.getHash();
+}
+
 // embedded resources, e.g. ":/font.ttf", need to be properly handled too
 std::string getCanonicalPath(const std::string& path)
 {

es-core/src/Util.h

@@ -17,6 +17,9 @@ Eigen::Vector2f roundVector(const Eigen::Vector2f& vec);
 
 float round(float num);
 
+std::string getMd5(const boost::filesystem::path& path);
+std::string getCrc(const boost::filesystem::path& path);
+
 std::string getCanonicalPath(const std::string& str);
 
 // example: removeCommonPath("/home/pi/roms/nes/foo/bar.nes", "/home/pi/roms/nes/") returns "foo/bar.nes"

es-core/src/crc32.h

@@ -0,0 +1,69 @@
+// //////////////////////////////////////////////////////////
+// crc32.h
+// Copyright (c) 2014,2015 Stephan Brumme. All rights reserved.
+// see http://create.stephan-brumme.com/disclaimer.html
+//
+
+#pragma once
+
+#include "hash.h"
+#include <string>
+
+// define fixed size integer types
+#ifdef _MSC_VER
+// Windows
+typedef unsigned __int8  uint8_t;
+typedef unsigned __int32 uint32_t;
+#else
+// GCC
+#include <stdint.h>
+#endif
+
+
+/// compute CRC32 hash, based on Intel's Slicing-by-8 algorithm
+/** Usage:
+    CRC32 crc32;
+    std::string myHash  = crc32("Hello World");     // std::string
+    std::string myHash2 = crc32("How are you", 11); // arbitrary data, 11 bytes
+
+    // or in a streaming fashion:
+
+    CRC32 crc32;
+    while (more data available)
+      crc32.add(pointer to fresh data, number of new bytes);
+    std::string myHash3 = crc32.getHash();
+
+    Note:
+    You can find code for the faster Slicing-by-16 algorithm on my website, too:
+    http://create.stephan-brumme.com/crc32/
+    Its unrolled version is about twice as fast but its look-up table doubled in size as well.
+  */
+class CRC32 : public Hash
+{
+public:
+  /// hash is 4 bytes long
+  enum { HashBytes = 4 };
+
+  /// same as reset()
+  CRC32();
+
+  /// compute CRC32 of a memory block
+  std::string operator()(const void* data, size_t numBytes);
+  /// compute CRC32 of a string, excluding final zero
+  std::string operator()(const std::string& text);
+
+  /// add arbitrary number of bytes
+  void add(const void* data, size_t numBytes);
+
+  /// return latest hash as 8 hex characters
+  std::string getHash();
+  /// return latest hash as bytes
+  void        getHash(unsigned char buffer[HashBytes]);
+
+  /// restart
+  void reset();
+
+private:
+  /// hash
+  uint32_t m_hash;
+};

es-core/src/hash.h

@@ -0,0 +1,28 @@
+// //////////////////////////////////////////////////////////
+// hash.h
+// Copyright (c) 2014,2015 Stephan Brumme. All rights reserved.
+// see http://create.stephan-brumme.com/disclaimer.html
+//
+
+#pragma once
+
+#include <string>
+
+/// abstract base class
+class Hash
+{
+public:
+  /// compute hash of a memory block
+  virtual std::string operator()(const void* data, size_t numBytes) = 0;
+  /// compute hash of a string, excluding final zero
+  virtual std::string operator()(const std::string& text) = 0;
+
+  /// add arbitrary number of bytes
+  virtual void add(const void* data, size_t numBytes) = 0;
+
+  /// return latest hash as hex characters
+  virtual std::string getHash() = 0;
+
+  /// restart
+  virtual void reset() = 0;
+};