From 2868ebac0f00af36a92a56bfbdf67e3555ed544e Mon Sep 17 00:00:00 2001
From: Ari Vuollet <ari.vuollet@goat.moe>
Date: Thu, 3 Jul 2025 19:32:36 +0300
Subject: [PATCH] _fixup

---
 .../Engine/Platform/Apple/AppleFileSystem.cpp | 59 +++++++++++++++
 .../Engine/Platform/Apple/AppleFileSystem.h   |  1 +
 .../Engine/Platform/Linux/LinuxFileSystem.cpp | 72 +++++++++++++++++++
 .../Engine/Platform/Linux/LinuxFileSystem.h   |  1 +
 4 files changed, 133 insertions(+)

diff --git a/Source/Engine/Platform/Apple/AppleFileSystem.cpp b/Source/Engine/Platform/Apple/AppleFileSystem.cpp
index 0f6d8084f..5cccbe3d8 100644
--- a/Source/Engine/Platform/Apple/AppleFileSystem.cpp
+++ b/Source/Engine/Platform/Apple/AppleFileSystem.cpp
@@ -22,6 +22,65 @@
 #include <stdlib.h>
 #include <fcntl.h>
 
+bool AppleFileSystem::CopyFile(const StringView& dst, const StringView& src)
+{
+    const StringAsANSI<> srcANSI(*src, src.Length());
+    const StringAsANSI<> dstANSI(*dst, dst.Length());
+
+    int srcFile, dstFile;
+    char buffer[4096];
+    ssize_t readSize;
+    int cachedError;
+
+    srcFile = open(srcANSI.Get(), O_RDONLY);
+    if (srcFile < 0)
+        return true;
+    dstFile = open(dstANSI.Get(), O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
+    if (dstFile < 0)
+        goto out_error;
+
+    while (readSize = read(srcFile, buffer, sizeof(buffer)), readSize > 0)
+    {
+        char* ptr = buffer;
+        ssize_t writeSize;
+
+        do
+        {
+            writeSize = write(dstFile, ptr, readSize);
+            if (writeSize >= 0)
+            {
+                readSize -= writeSize;
+                ptr += writeSize;
+            }
+            else if (errno != EINTR)
+            {
+                goto out_error;
+            }
+        } while (readSize > 0);
+    }
+
+    if (readSize == 0)
+    {
+        if (close(dstFile) < 0)
+        {
+            dstFile = -1;
+            goto out_error;
+        }
+        close(srcFile);
+
+        // Success
+        return false;
+    }
+
+    out_error:
+        cachedError = errno;
+    close(srcFile);
+    if (dstFile >= 0)
+        close(dstFile);
+    errno = cachedError;
+    return true;
+}
+
 void AppleFileSystem::GetSpecialFolderPath(const SpecialFolder type, String& result)
 {
     String home;
diff --git a/Source/Engine/Platform/Apple/AppleFileSystem.h b/Source/Engine/Platform/Apple/AppleFileSystem.h
index cf4c38a97..45d9e4df6 100644
--- a/Source/Engine/Platform/Apple/AppleFileSystem.h
+++ b/Source/Engine/Platform/Apple/AppleFileSystem.h
@@ -13,6 +13,7 @@ class FLAXENGINE_API AppleFileSystem : public UnixFileSystem
 {
 public:
     // [FileSystemBase]
+    static bool CopyFile(const StringView& dst, const StringView& src);
     static void GetSpecialFolderPath(const SpecialFolder type, String& result);
 };
 
diff --git a/Source/Engine/Platform/Linux/LinuxFileSystem.cpp b/Source/Engine/Platform/Linux/LinuxFileSystem.cpp
index d87b9674f..4452068c7 100644
--- a/Source/Engine/Platform/Linux/LinuxFileSystem.cpp
+++ b/Source/Engine/Platform/Linux/LinuxFileSystem.cpp
@@ -165,6 +165,78 @@ bool LinuxFileSystem::ShowFileExplorer(const StringView& path)
     return false;
 }
 
+bool LinuxFileSystem::CopyFile(const StringView& dst, const StringView& src)
+{
+    const StringAsUTF8<> srcANSI(*src, src.Length());
+    const StringAsUTF8<> dstANSI(*dst, dst.Length());
+
+    int srcFile, dstFile;
+    char buffer[4096];
+    ssize_t readSize;
+    int cachedError;
+
+    srcFile = open(srcANSI.Get(), O_RDONLY);
+    if (srcFile < 0)
+        return true;
+    dstFile = open(dstANSI.Get(), O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
+    if (dstFile < 0)
+        goto out_error;
+
+    // first try the kernel method
+    struct stat statBuf;
+    fstat(srcFile, &statBuf);
+    readSize = 1;
+    while (readSize > 0)
+    {
+        readSize = sendfile(dstFile, srcFile, 0, statBuf.st_size);
+    }
+    // sendfile could fail for example if the input file is not nmap'able
+    // in this case we fall back to the read/write loop
+    if (readSize < 0)
+    {
+        while (readSize = read(srcFile, buffer, sizeof(buffer)), readSize > 0)
+        {
+            char* ptr = buffer;
+            ssize_t writeSize;
+
+            do
+            {
+                writeSize = write(dstFile, ptr, readSize);
+                if (writeSize >= 0)
+                {
+                    readSize -= writeSize;
+                    ptr += writeSize;
+                }
+                else if (errno != EINTR)
+                {
+                    goto out_error;
+                }
+            } while (readSize > 0);
+        }
+    }
+
+    if (readSize == 0)
+    {
+        if (close(dstFile) < 0)
+        {
+            dstFile = -1;
+            goto out_error;
+        }
+        close(srcFile);
+
+        // Success
+        return false;
+    }
+
+    out_error:
+        cachedError = errno;
+    close(srcFile);
+    if (dstFile >= 0)
+        close(dstFile);
+    errno = cachedError;
+    return true;
+}
+
 bool LinuxFileSystem::MoveFileToRecycleBin(const StringView& path)
 {
     String trashDir;
diff --git a/Source/Engine/Platform/Linux/LinuxFileSystem.h b/Source/Engine/Platform/Linux/LinuxFileSystem.h
index e96ea924c..377bbbd99 100644
--- a/Source/Engine/Platform/Linux/LinuxFileSystem.h
+++ b/Source/Engine/Platform/Linux/LinuxFileSystem.h
@@ -16,6 +16,7 @@ public:
     static bool ShowOpenFileDialog(Window* parentWindow, const StringView& initialDirectory, const StringView& filter, bool multiSelect, const StringView& title, Array<String, HeapAllocation>& filenames);
     static bool ShowBrowseFolderDialog(Window* parentWindow, const StringView& initialDirectory, const StringView& title, String& path);
     static bool ShowFileExplorer(const StringView& path);
+    static bool CopyFile(const StringView& dst, const StringView& src);
     static bool MoveFileToRecycleBin(const StringView& path);
     static void GetSpecialFolderPath(const SpecialFolder type, String& result);