Feat: Add file-access methods

include/utility/file_access.h

@@ -0,0 +1,87 @@
+/**
+ * @file file_access.h
+ * @brief File reading and writing.
+ * @author Chen Zhenshuo (chenzs108@outlook.com)
+ * @version 1.0
+ * @date 2020-01-10
+ * 
+ * @par GitHub
+ * https://github.com/czs108/
+ */
+
+#pragma once
+
+#include <windows.h>
+
+#include <stdbool.h>
+
+/**
+ * @brief The view of a file.
+ */
+typedef struct _FILE_VIEW
+{
+    //! The file-mapping returned by `CreateFileMapping` API.
+    HANDLE map;
+
+    //! The base address of the file content returned by `MapViewOfFile` API.
+    const BYTE* base;
+
+    //! The size of the file.
+    DWORD size;
+
+} FILE_VIEW;
+
+
+/**
+ * @brief Write all the data to the file.
+ * 
+ * @param file  The file.
+ * @param data  The base address of the data.
+ * @param size  The size of the data.
+ * @return `true` if the method succeeds, otherwise `false`.
+ */
+bool WriteAllToFile(
+    const HANDLE file,
+    const BYTE *const data,
+    const DWORD size);
+
+
+/**
+ * @brief Open a read-only view of the file.
+ * 
+ * @public @memberof _FILE_VIEW
+ * 
+ * @param file              The file.
+ * @param[out] file_view    The read-only view
+ * @return `true` if the method succeeds, otherwise `false`.
+ * 
+ * @note The constructor of `_FILE_VIEW` structure.
+ */
+bool OpenReadViewOfFile(
+    const HANDLE file,
+    FILE_VIEW *const file_view);
+
+
+/**
+ * @brief Close the view of a file.
+ * 
+ * @public @memberof _FILE_VIEW
+ * 
+ * @param file_view The view.
+ * 
+ * @note The destructor of `_FILE_VIEW` structure.
+ */
+void CloseViewOfFile(
+    const FILE_VIEW *const file_view);
+
+
+/**
+ * @brief Check if the size of the file is smaller than 2GB.
+ * 
+ * @param file  The file.
+ * @return `true` if the size of the file is smaller than 2GB, otherwise `false`.
+ * 
+ * @warning The program can only process files smaller than 2GB.
+ */
+bool IsFileSmallerThan2G(
+    const HANDLE file);

src/utility/CMakeLists.txt

@@ -7,6 +7,8 @@ target_include_directories(utility PUBLIC ${HEADER_PATH})
 target_sources(utility
     PRIVATE
         ${CMAKE_CURRENT_LIST_DIR}/error_handling.c
+        ${CMAKE_CURRENT_LIST_DIR}/file_access.c
     PUBLIC
         ${HEADER_PATH}/error_handling.h
+        ${HEADER_PATH}/file_access.h
 )

src/utility/file_access.c

@@ -0,0 +1,114 @@
+/**
+ * @file file_access.c
+ * @brief File reading and writing.
+ * @author Chen Zhenshuo (chenzs108@outlook.com)
+ * @version 1.0
+ * @date 2020-01-10
+ * 
+ * @par GitHub
+ * https://github.com/czs108/
+ */
+
+#include "file_access.h"
+#include "error_handling.h"
+
+#include <assert.h>
+
+
+bool WriteAllToFile(
+    const HANDLE file,
+    const BYTE *const data,
+    const DWORD size)
+{
+    assert(file != INVALID_HANDLE_VALUE);
+
+    if (size == 0)
+    {
+        return true;
+    }
+
+    assert(data != NULL);
+
+    DWORD remaining = size;
+    const BYTE *current = data;
+    while (remaining > 0)
+    {
+        DWORD written = 0;
+        if (WriteFile(file, current, remaining, &written, NULL) == FALSE)
+        {
+            SetLastErrorCode();
+            return false;
+        }
+
+        remaining -= written;
+        current += written;
+    }
+
+    return true;
+}
+
+
+bool OpenReadViewOfFile(
+    const HANDLE file,
+    FILE_VIEW *const file_view)
+{
+    assert(IsFileSmallerThan2G(file));
+    assert(file_view != NULL);
+
+    bool success = false;
+    ZeroMemory(file_view, sizeof(file_view));
+
+    file_view->size = GetFileSize(file, NULL);
+    file_view->map = CreateFileMapping(file, NULL, PAGE_READONLY, 0, 0, NULL);
+    if (file_view->map == NULL)
+    {
+        SetLastErrorCode();
+        goto _Exit;
+    }
+
+    file_view->base = (BYTE*)MapViewOfFile(file_view->map, FILE_MAP_READ, 0, 0, 0);
+    if (file_view->base == NULL)
+    {
+        SetLastErrorCode();
+        goto _Exit;
+    }
+
+    success = true;
+
+_Exit:
+    if (!success)
+    {
+        CloseViewOfFile(file_view);
+        ZeroMemory(file_view, sizeof(file_view));
+    }
+
+    return success;
+}
+
+
+void CloseViewOfFile(
+    const FILE_VIEW *const file_view)
+{
+    assert(file_view != NULL);
+
+    if (file_view->base != NULL)
+    {
+        UnmapViewOfFile(file_view->base);
+    }
+
+    if (file_view->map != NULL)
+    {
+        CloseHandle(file_view->map);
+    }
+}
+
+
+bool IsFileSmallerThan2G(
+    const HANDLE file)
+{
+    assert(file != INVALID_HANDLE_VALUE);
+
+    DWORD size_high = 0;
+    GetFileSize(file, &size_high);
+    return size_high == 0;
+}