From 525fc4fe8a94ecc1d2563fce68536687a4227340 Mon Sep 17 00:00:00 2001
From: spxtr <spextear@gmail.com>
Date: Wed, 30 Dec 2015 19:10:31 -0800
Subject: [PATCH] Allow MemoryWatcher to follow pointers

---
 Source/Core/Core/MemoryWatcher.cpp | 47 +++++++++++++++++++++++-------
 Source/Core/Core/MemoryWatcher.h   | 21 +++++++++----
 2 files changed, 52 insertions(+), 16 deletions(-)

diff --git a/Source/Core/Core/MemoryWatcher.cpp b/Source/Core/Core/MemoryWatcher.cpp
index ecce7aa714..39d355b048 100644
--- a/Source/Core/Core/MemoryWatcher.cpp
+++ b/Source/Core/Core/MemoryWatcher.cpp
@@ -11,7 +11,7 @@
 #include "Core/HW/Memmap.h"
 
 // We don't want to kill the cpu, so sleep for this long after polling.
-static const int SLEEP_DURATION = 10; // ms
+static const int SLEEP_DURATION = 2; // ms
 
 MemoryWatcher::MemoryWatcher()
 {
@@ -39,14 +39,25 @@ bool MemoryWatcher::LoadAddresses(const std::string& path)
 	if (!locations)
 		return false;
 
-	u32 data;
-	locations >> std::hex;
-	while (locations >> data)
-		m_values[data] = 0;
+	std::string line;
+	while (std::getline(locations, line))
+		ParseLine(line);
 
 	return m_values.size() > 0;
 }
 
+void MemoryWatcher::ParseLine(const std::string& line)
+{
+	m_values[line] = 0;
+	m_addresses[line] = std::vector<u32>();
+
+	std::stringstream offsets(line);
+	offsets >> std::hex;
+	u32 offset;
+	while (offsets >> offset)
+		m_addresses[line].push_back(offset);
+}
+
 bool MemoryWatcher::OpenSocket(const std::string& path)
 {
 	memset(&m_addr, 0, sizeof(m_addr));
@@ -57,24 +68,40 @@ bool MemoryWatcher::OpenSocket(const std::string& path)
 	return m_fd >= 0;
 }
 
+u32 MemoryWatcher::ChasePointer(const std::string& line)
+{
+	u32 value = 0;
+	for (u32 offset : m_addresses[line])
+		value = Memory::Read_U32(value + offset);
+	return value;
+}
+
+std::string MemoryWatcher::ComposeMessage(const std::string& line, u32 value)
+{
+	std::stringstream message_stream;
+	message_stream << line << '\n' << std::hex << value;
+	return message_stream.str();
+}
+
 void MemoryWatcher::WatcherThread()
 {
 	while (m_running)
 	{
 		for (auto& entry : m_values)
 		{
-			u32 address = entry.first;
+			std::string address = entry.first;
 			u32& current_value = entry.second;
 
-			u32 new_value = Memory::Read_U32(address);
+			u32 new_value = ChasePointer(address);
 			if (new_value != current_value)
 			{
+				// Update the value
 				current_value = new_value;
-				u32 buf[2] = {address, current_value};
+				std::string message = ComposeMessage(address, new_value);
 				sendto(
 					m_fd,
-					static_cast<void*>(buf),
-					sizeof(buf),
+					message.c_str(),
+					message.size() + 1,
 					0,
 					reinterpret_cast<sockaddr*>(&m_addr),
 					sizeof(m_addr));
diff --git a/Source/Core/Core/MemoryWatcher.h b/Source/Core/Core/MemoryWatcher.h
index 8f2e36c1bc..ebe2b89c50 100644
--- a/Source/Core/Core/MemoryWatcher.h
+++ b/Source/Core/Core/MemoryWatcher.h
@@ -7,16 +7,18 @@
 #include <atomic>
 #include <map>
 #include <thread>
+#include <vector>
 #include <sys/socket.h>
 #include <sys/un.h>
 
 // MemoryWatcher reads a file containing in-game memory addresses and outputs
 // changes to those memory addresses to a unix domain socket as the game runs.
 //
-// The input file is a newline-separated list of hex memory addresses
-// (without the "0x"). The output to the socket is two words long, the first
-// containing the address, and the second containing the data as stored in
-// game memory.
+// The input file is a newline-separated list of hex memory addresses, without
+// the "0x". To follow pointers, separate addresses with a space. For example,
+// "ABCD EF" will watch the address at (*0xABCD) + 0xEF.
+// The output to the socket is two lines. The first is the address from the
+// input file, and the second is the new value in hex.
 class MemoryWatcher final
 {
 public:
@@ -26,6 +28,11 @@ public:
 private:
 	bool LoadAddresses(const std::string& path);
 	bool OpenSocket(const std::string& path);
+
+	void ParseLine(const std::string& line);
+	u32 ChasePointer(const std::string& line);
+	std::string ComposeMessage(const std::string& line, u32 value);
+
 	void WatcherThread();
 
 	std::thread m_watcher_thread;
@@ -34,6 +41,8 @@ private:
 	int m_fd;
 	sockaddr_un m_addr;
 
-	// Address -> last value
-	std::map<u32, u32> m_values;
+	// Address as stored in the file -> list of offsets to follow
+	std::map<std::string, std::vector<u32>> m_addresses;
+	// Address as stored in the file -> current value
+	std::map<std::string, u32> m_values;
 };