initial commit

sgutil/sgu_mode_apply_patch.h

@@ -0,0 +1,21 @@
+#pragma once
+
+/**
+ * Applies a BSDIFF43 binary patch to an input file and writes the patched result to an output file.
+ *
+ * @param inputFilename   The path to the original input file to be patched.
+ * @param patchFilename   The path to the BSDIFF43 patch file (bzip2-compressed).
+ * @param outputFilename  The path to the output file where the patched result will be written.
+ * @return true if the patch is applied successfully; false otherwise.
+ *
+ * The function performs the following steps:
+ * 1. Validates input, patch, and output file names.
+ * 2. Reads the input file into memory.
+ * 3. Opens the patch file and verifies its BSDIFF43 header.
+ * 4. Reads the expected output file size from the patch header and allocates a buffer for the output.
+ * 5. Initializes bzip2 decompression for the patch data.
+ * 6. Uses the bspatch algorithm to apply the patch, writing the result to the output buffer.
+ * 7. Writes the patched data to the output file.
+ * 8. Cleans up all resources and returns true on success, or false if any error occurs.
+ */
+bool applyPatch(const char* inputFilename, const char* patchFilename, const char* outputFilename);