From ab5694db4399dd7b175eb0e2c401ad2e8757905a Mon Sep 17 00:00:00 2001
From: Kevin Trogant <kevin@trogant.de>
Date: Fri, 16 Dec 2022 16:06:58 +0100
Subject: [PATCH] Write to file interface

---
 app/src/main/cpp/Win32AssetManager.cpp | 51 ++++++++++++++++++++++++++
 app/src/main/cpp/Win32AssetManager.h   | 26 +++++++++++++
 2 files changed, 77 insertions(+)

diff --git a/app/src/main/cpp/Win32AssetManager.cpp b/app/src/main/cpp/Win32AssetManager.cpp
index 190b08c..b45d3ea 100644
--- a/app/src/main/cpp/Win32AssetManager.cpp
+++ b/app/src/main/cpp/Win32AssetManager.cpp
@@ -112,3 +112,54 @@ bool Win32AssetManager::writeFile(const char* path, const FileBuffer& file_buffe
     ZoneScoped;
     return writeFile(path, file_buffer.data, file_buffer.size);
 }
+
+Win32AssetManager::FileHandle Win32AssetManager::createFile(const char* path)
+{
+    ZoneScoped;
+    char _cp[MAX_PATH];
+    strncpy(_cp, m_asset_root, MAX_PATH);
+    strncat(_cp, "\\", MAX_PATH);
+    strncat(_cp, path, MAX_PATH);
+
+    HANDLE h = CreateFileA(_cp, GENERIC_WRITE, 0, nullptr, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
+    if (!h || h == INVALID_HANDLE_VALUE)
+        return nullptr;
+    return (h);
+}
+
+bool Win32AssetManager::writeToFile(FileHandle _file, const void* data, size_t size)
+{
+    ZoneScoped;
+    HANDLE file = (HANDLE)_file;
+    const char* at = reinterpret_cast<const char*>(data);
+    while (size >= UINT32_MAX) {
+        DWORD bytes_written = 0;
+        if (!WriteFile(file, at, UINT32_MAX, &bytes_written, nullptr)) {
+            CloseHandle(file);
+            return false;
+        }
+        size -= bytes_written;
+        at += bytes_written;
+    }
+    if (size > 0) {
+        DWORD bytes_written = 0;
+        if (!WriteFile(file, at, size, &bytes_written, nullptr)) {
+            CloseHandle(file);
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool Win32AssetManager::writeToFile(FileHandle file, const FileBuffer& file_buffer)
+{
+    ZoneScoped;
+    return writeToFile(file, file_buffer.data, file_buffer.size);
+}
+
+void Win32AssetManager::closeFile(FileHandle file)
+{
+    ZoneScoped;
+    CloseHandle((HANDLE)file);
+}
\ No newline at end of file
diff --git a/app/src/main/cpp/Win32AssetManager.h b/app/src/main/cpp/Win32AssetManager.h
index c406d41..a17e277 100644
--- a/app/src/main/cpp/Win32AssetManager.h
+++ b/app/src/main/cpp/Win32AssetManager.h
@@ -6,6 +6,8 @@
 class Win32AssetManager : public AssetManager
 {
 public:
+    typedef void* FileHandle;
+
     /// @brief Create the singleton instance
     ///
     /// Sets @ref AssetManager::ptr to the singleton instance
@@ -29,6 +31,30 @@ public:
     /// @return @c true if writing the file was successfull, @c false otherwise
     bool writeFile(const char* path, const FileBuffer& file_buffer);
 
+    /// @brief Creates a file and opens it for writing.
+    ///
+    /// Overwrites an already existing file.
+    /// @param path Path realtive to the asset root directory
+    /// @return Handle to the open file, or @c nullptr if the file could not be created.
+    FileHandle createFile(const char* path);
+
+    /// @brief Writes data to an open file
+    /// @param file File handle
+    /// @param data Data buffer
+    /// @param size Number of bytes
+    /// @return  @c true if writing to the file was successfull, @c false otherwise
+    bool writeToFile(FileHandle file, const void* data, size_t size);
+
+    /// @brief Write data to an open file.
+    /// @param file File handle
+    /// @param file_buffer Data buffer
+    /// @return @c true if writing to the file was successfull, @c false otherwise
+    bool writeToFile(FileHandle file, const FileBuffer& file_buffer);
+
+    /// @brief Closes an open file.
+    /// @param file The file handle
+    void closeFile(FileHandle file);
+
 private:
     const char* m_asset_root;
 };