From 5e9e80eddc209edb14a3438e4ed2e19a872d45f4 Mon Sep 17 00:00:00 2001
From: harry <hrosen2016@gmail.com>
Date: Wed, 25 Jan 2023 21:46:30 -0500
Subject: [PATCH] Change EMUFILE fseek,ftell, and other related functions to
 use types that follow the C standard (long int for position offsets and
 size_t for sizes). This allows for larger max file sizes on unix platforms
 and cleaner code that better maps to the C standard.

---
 src/emufile.cpp |  2 +-
 src/emufile.h   | 47 ++++++++++++++++++++++++-----------------------
 src/file.cpp    |  2 +-
 src/file.h      |  2 +-
 4 files changed, 27 insertions(+), 26 deletions(-)

diff --git a/src/emufile.cpp b/src/emufile.cpp
index e0e83115..63de55ff 100644
--- a/src/emufile.cpp
+++ b/src/emufile.cpp
@@ -78,7 +78,7 @@ void EMUFILE_FILE::open(const char* fname, const char* mode)
 }
 
 
-void EMUFILE_FILE::truncate(s32 length)
+void EMUFILE_FILE::truncate(size_t length)
 {
 	::fflush(fp);
 	#ifdef _MSC_VER
diff --git a/src/emufile.h b/src/emufile.h
index 78e4d6ee..5ea94a2b 100644
--- a/src/emufile.h
+++ b/src/emufile.h
@@ -109,13 +109,13 @@ public:
 	double readdouble();
 	size_t readdouble(double* val);
 
-	virtual int fseek(int offset, int origin) = 0;
+	virtual int fseek(long int offset, int origin) = 0;
 
-	virtual int ftell() = 0;
-	virtual int size() = 0;
+	virtual long int ftell() = 0;
+	virtual size_t size() = 0;
 	virtual void fflush() = 0;
 
-	virtual void truncate(s32 length) = 0;
+	virtual void truncate(size_t length) = 0;
 };
 
 //todo - handle read-only specially?
@@ -123,9 +123,10 @@ class EMUFILE_MEMORY : public EMUFILE {
 protected:
 	std::vector<u8> *vec;
 	bool ownvec;
-	s32 pos, len;
+	long int pos;
+	size_t len;
 
-	void reserve(u32 amt) {
+	void reserve(size_t amt) {
 		if(vec->size() < amt)
 			vec->resize(amt);
 	}
@@ -133,12 +134,12 @@ protected:
 public:
 
 	EMUFILE_MEMORY(std::vector<u8> *underlying) : vec(underlying), ownvec(false), pos(0), len((s32)underlying->size()) { }
-	EMUFILE_MEMORY(u32 preallocate) : vec(new std::vector<u8>()), ownvec(true), pos(0), len(0) {
+	EMUFILE_MEMORY(size_t preallocate) : vec(new std::vector<u8>()), ownvec(true), pos(0), len(0) {
 		vec->resize(preallocate);
 		len = preallocate;
 	}
 	EMUFILE_MEMORY() : vec(new std::vector<u8>()), ownvec(true), pos(0), len(0) { vec->reserve(1024); }
-	EMUFILE_MEMORY(void* buf, s32 size) : vec(new std::vector<u8>()), ownvec(true), pos(0), len(size) {
+	EMUFILE_MEMORY(void* buf, size_t size) : vec(new std::vector<u8>()), ownvec(true), pos(0), len(size) {
 		vec->resize(size);
 		if(size != 0)
 			memcpy(&vec->front(),buf,size);
@@ -150,7 +151,7 @@ public:
 
 	virtual EMUFILE* memwrap();
 
-	virtual void truncate(s32 length)
+	virtual void truncate(size_t length)
 	{
 		vec->resize(length);
 		len = length;
@@ -216,13 +217,13 @@ public:
 	//they handle the return values correctly
 
 	virtual void fwrite(const void *ptr, size_t bytes){
-		reserve(pos+(s32)bytes);
+		reserve(pos+bytes);
 		memcpy(buf()+pos,ptr,bytes);
-		pos += (s32)bytes;
+		pos += bytes;
 		len = std::max<int>(pos,len);
 	}
 
-	virtual int fseek(int offset, int origin){
+	virtual int fseek(long int offset, int origin){
 		//work differently for read-only...?
 		switch(origin) {
 			case SEEK_SET:
@@ -241,13 +242,13 @@ public:
 		return 0;
 	}
 
-	virtual int ftell() {
+	virtual long int ftell() {
 		return pos;
 	}
 
 	virtual void fflush() {}
 
-	void set_len(s32 length)
+	void set_len(size_t length)
 	{
 		len = length;
 		if(pos > length)
@@ -258,7 +259,7 @@ public:
 		vec->resize(len);
 	}
 
-	virtual int size() { return (int)len; }
+	virtual size_t size() { return len; }
 };
 
 class EMUFILE_FILE : public EMUFILE {
@@ -288,7 +289,7 @@ public:
 
 	bool is_open() { return fp != NULL; }
 
-	virtual void truncate(s32 length);
+	virtual void truncate(size_t length);
 
 	virtual int fprintf(const char *format, ...) {
 		va_list argptr;
@@ -321,20 +322,20 @@ public:
 			failbit = true;
 	}
 
-	virtual int fseek(int offset, int origin) {
+	virtual int fseek(long int offset, int origin) {
 		return ::fseek(fp, offset, origin);
 	}
 
-	virtual int ftell() {
-		return (u32)::ftell(fp);
+	virtual long int ftell() {
+		return ::ftell(fp);
 	}
 
-	virtual int size() {
-		int oldpos = ftell();
+	virtual size_t size() {
+		long int oldpos = ftell();
 		fseek(0,SEEK_END);
-		int len = ftell();
+		long int len = ftell();
 		fseek(oldpos,SEEK_SET);
-		return len;
+		return static_cast<size_t>(len);
 	}
 
 	virtual void fflush() {
diff --git a/src/file.cpp b/src/file.cpp
index 74091a52..0a18b240 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -327,7 +327,7 @@ FCEUFILE * FCEU_fopen(const char *path, const char *ipsfn, const char *mode, cha
 					if(gzfile) {
 						delete fp;
 
-						int size;
+						size_t size;
 						for(size=0; gzgetc(gzfile) != EOF; size++) {}
 						EMUFILE_MEMORY* ms = new EMUFILE_MEMORY(size);
 						gzseek(gzfile,0,SEEK_SET);
diff --git a/src/file.h b/src/file.h
index 84235f70..05ee2eaf 100644
--- a/src/file.h
+++ b/src/file.h
@@ -35,7 +35,7 @@ struct FCEUFILE {
 	int archiveIndex;
 
 	//the size of the file
-	int size;
+	size_t size;
 
 	//whether the file is contained in an archive
 	bool isArchive() { return archiveCount > 0; }