initial commit

sgutil/sgu_mode_apply_patch.cpp

@@ -0,0 +1,151 @@
+#include "sgu_stdafx.h"
+#include "sgu_mode_apply_patch.h"
+#include "sgu_utils.h"
+
+#include "bzlib.h"
+
+extern "C"
+{
+#include "bspatch.h"
+}
+
+
+static int patchFileReader(const struct bspatch_stream* stream, void* buffer, int length)
+{
+	FILE* fp = (FILE*)stream->opaque;
+	size_t n = fread(buffer, 1, (size_t)length, fp);
+	if (n != length)
+		return -1;
+
+	return 0;
+}
+
+static int bzPatchFileReader(const struct bspatch_stream* stream, void* buffer, int length)
+{
+	BZFILE* bz2 = (BZFILE*)stream->opaque;
+
+	int bz2err;
+	int n = BZ2_bzRead(&bz2err, bz2, buffer, length);
+	if (n != length)
+		return -1;
+
+	return 0;
+}
+
+bool applyPatch(const char* inputFilename, const char* patchFilename, const char* outputFilename)
+{
+	if (!inputFilename || inputFilename[0] == 0 || !patchFilename || patchFilename[0] == 0)
+	{
+		printf("Error: Input or Patch filename is not specified.\n");
+		return false;
+	}
+	if (!outputFilename || outputFilename[0] == 0)
+	{
+		printf("Error: Output filename is not specified.\n");
+		return false;
+	}
+
+	uint8_t* pInputBuffer = nullptr;
+	FILE* patchFile = nullptr;
+	FILE* outputFile = nullptr;
+	uint8_t* pOutputBuffer = nullptr;
+
+	bool result = false;
+	do {
+		// Open the input file
+		int64_t inputFileSize;
+		pInputBuffer = readFileToBuffer(inputFilename, inputFileSize);
+		if (pInputBuffer == nullptr)
+		{
+			printf("Error: Failed to read input file: %s\n", inputFilename);
+			break;
+		}
+
+		// Open the patch file
+		fopen_s(&patchFile, patchFilename, "rb");
+		if (!patchFile)
+		{
+			printf("Error: Could not open patch file %s\n", patchFilename);
+			break;
+		}
+
+		// Open the output file
+		fopen_s(&outputFile, outputFilename, "wb");
+		if (!outputFile)
+		{
+			printf("Error: Could not open output file %s\n", outputFilename);
+			break;
+		}
+
+		//read the patch file header and check for appropriate magic
+		uint8_t header[24];
+		if (fread(header, 1, 24, patchFile) != 24 || memcmp(header, "ENDSLEY/BSDIFF43", 16) != 0)
+		{
+			printf("Error: Corrupt patch file %s\n", patchFilename);
+			break;
+		}
+
+		// Read output file lengths from header
+		int64_t outputFileSize = *(int64_t*)(header + 16);
+		pOutputBuffer = new uint8_t[outputFileSize + 1];
+		if(pOutputBuffer == nullptr)
+		{
+			printf("Error: Failed to allocate memory[%lld] for output buffer\n", outputFileSize+1);
+			break;
+		}
+
+		int bz2err;
+		BZFILE* bzHandle = BZ2_bzReadOpen(&bz2err, patchFile, 0, 0, NULL, 0);
+		if (bzHandle == nullptr)
+		{
+			printf("BZ2_bzReadOpen, bz2err=%d", bz2err);
+			break;
+		}
+
+		// Apply the patch
+		struct bspatch_stream stream;
+		stream.read = bzPatchFileReader;
+		stream.opaque = bzHandle;
+		if (bspatch(pInputBuffer, inputFileSize, pOutputBuffer, outputFileSize, &stream))
+		{
+			printf("Error: Failed to apply patch\n");
+			break;
+		}
+
+		// Clean up the bzip2 reads
+		BZ2_bzReadClose(&bz2err, bzHandle);
+
+		// Write the output buffer to the output file
+		if (outputFileSize != fwrite(pOutputBuffer, 1, outputFileSize, outputFile))
+		{
+			printf("Error: Failed to write output file %s\n", outputFilename);
+			break;
+		}
+
+		result = true;
+		printf("Patch applied successfully. Output file: %s\n", outputFilename);
+	}while (false);
+
+	// Close all files and free buffers
+	freeFileBuffer(pInputBuffer);
+	pInputBuffer = nullptr;
+
+	if (pOutputBuffer != nullptr)
+	{
+		delete[] pOutputBuffer;
+		pOutputBuffer = nullptr;
+	}
+
+	if (patchFile != nullptr)
+	{
+		fclose(patchFile);
+		patchFile = nullptr;
+	}
+	if (outputFile != nullptr)
+	{
+		fclose(outputFile);
+		outputFile = nullptr;
+	}
+	
+	return result;
+}