Initial commit

engines/ags/shared/util/file_stream.cpp

@@ -0,0 +1,239 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "ags/shared/util/file_stream.h"
+#include "ags/shared/util/stdio_compat.h"
+#include "ags/shared/util/string.h"
+#include "ags/shared/util/directory.h"
+#include "ags/ags.h"
+#include "common/file.h"
+#include "common/system.h"
+
+namespace AGS3 {
+namespace AGS {
+namespace Shared {
+
+FileStream::FileStream(const String &file_name, FileOpenMode open_mode, FileWorkMode work_mode,
+                       DataEndianess stream_endianess)
+		: DataStream(stream_endianess), _workMode(work_mode), _file(nullptr) {
+	Open(file_name, open_mode, work_mode);
+}
+
+FileStream::~FileStream() {
+	FileStream::Close();
+}
+
+bool FileStream::GetError() const {
+	if (!_file)
+		return false;
+	bool err = _file->err();
+	_file->clearErr();
+	return err;
+}
+
+void FileStream::Close() {
+	delete _file;
+	_file = nullptr;
+}
+
+bool FileStream::Flush() {
+	Common::WriteStream *ws = dynamic_cast<Common::WriteStream *>(_file);
+	if (ws)
+		ws->flush();
+
+	return false;
+}
+
+bool FileStream::IsValid() const {
+	return _file != nullptr;
+}
+
+bool FileStream::EOS() const {
+	Common::ReadStream *rs = dynamic_cast<Common::ReadStream *>(_file);
+	return rs && rs->eos();
+}
+
+soff_t FileStream::GetLength() const {
+	soff_t pos = (soff_t)ags_ftell(_file);
+	ags_fseek(_file, 0, SEEK_END);
+	soff_t end = (soff_t)ags_ftell(_file);
+	ags_fseek(_file, pos, SEEK_SET);
+	return end;
+}
+
+soff_t FileStream::GetPosition() const {
+	if (IsValid()) {
+		return (soff_t)ags_ftell(_file);
+	}
+	return -1;
+}
+
+bool FileStream::CanRead() const {
+	return IsValid() && _workMode != kFile_Write;
+}
+
+bool FileStream::CanWrite() const {
+	return IsValid() && _workMode != kFile_Read;
+}
+
+bool FileStream::CanSeek() const {
+	return IsValid();
+}
+
+size_t FileStream::Read(void *buffer, size_t size) {
+	Common::ReadStream *rs = dynamic_cast<Common::ReadStream *>(_file);
+
+	if (rs && buffer) {
+		return rs->read(buffer, size);
+	}
+
+	return 0;
+}
+
+int32_t FileStream::ReadByte() {
+	Common::ReadStream *rs = dynamic_cast<Common::ReadStream *>(_file);
+
+	if (rs) {
+		return rs->eos() ? -1 : (int32_t)rs->readByte();
+	}
+
+	return -1;
+}
+
+size_t FileStream::Write(const void *buffer, size_t size) {
+	Common::WriteStream *ws = dynamic_cast<Common::WriteStream *>(_file);
+
+	if (ws && buffer) {
+		return ws->write(buffer, size);
+	}
+
+	return 0;
+}
+
+int32_t FileStream::WriteByte(uint8_t val) {
+	Common::WriteStream *ws = dynamic_cast<Common::WriteStream *>(_file);
+
+	if (ws) {
+		ws->writeByte(val);
+		return 1;
+	}
+
+	return -1;
+}
+
+soff_t FileStream::Seek(soff_t offset, StreamSeek origin) {
+	int stdclib_origin;
+	switch (origin) {
+	case kSeekBegin:
+		stdclib_origin = SEEK_SET;
+		break;
+	case kSeekCurrent:
+		stdclib_origin = SEEK_CUR;
+		break;
+	case kSeekEnd:
+		stdclib_origin = SEEK_END;
+		break;
+	default:
+		return -1;
+	}
+
+	return (ags_fseek(_file, (file_off_t)offset, stdclib_origin) == 0) ? ags_ftell(_file) : -1;
+}
+
+void FileStream::Open(const String &file_name, FileOpenMode open_mode, FileWorkMode work_mode) {
+	if (open_mode == kFile_Open) {
+		if (!file_name.CompareLeftNoCase(SAVE_FOLDER_PREFIX)) {
+			String saveName = getSaveName(file_name);
+			_file = g_system->getSavefileManager()->openForLoading(saveName);
+
+		} else {
+			// First try to open file in game folder
+			Common::ArchiveMemberPtr desc = getFile(file_name.GetCStr());
+			_file = desc ? desc->createReadStream() : nullptr;
+		}
+
+	} else {
+		String saveName;
+
+		if (!file_name.CompareLeftNoCase(SAVE_FOLDER_PREFIX)) {
+			saveName = getSaveName(file_name);
+
+		} else {
+			Common::String fname = file_name;
+			if (fname.hasPrefix("./"))
+				fname = fname.substr(2);
+			else if (fname.hasPrefix("/"))
+				fname.deleteChar(0);
+			else if (fname.findFirstOf('/') != Common::String::npos)
+				error("Invalid attempt to create file - %s", fname.c_str());
+
+			saveName = fname;
+		}
+
+		_file = openForWriting(saveName, open_mode, work_mode);
+
+		if (!_file)
+			error("Invalid attempt to create file - %s", file_name.GetCStr());
+
+		_path = file_name;
+	}
+}
+
+String FileStream::getSaveName(const String &filename) {
+	return String(filename.GetCStr() + strlen(SAVE_FOLDER_PREFIX));
+}
+
+Common::OutSaveFile *FileStream::openForWriting(const String &saveName, FileOpenMode open_mode, FileWorkMode work_mode) {
+	assert(open_mode != kFile_Open);
+
+	if (work_mode == kFile_Read || work_mode == kFile_ReadWrite)
+		// In the original these modes result in [aw]+b, which seems to result
+		// in a file with arbitrary reading, but writing always appending
+		warning("FileOpen: independent read/write positions not supported");
+
+	Common::InSaveFile *existing = nullptr;
+	if (open_mode == kFile_Create &&
+		(existing = g_system->getSavefileManager()->openForLoading(saveName)) != nullptr) {
+		// kFile_Create mode allows opening existing files for read/write.
+		// Since ScummVM doesn't support this via the save file manager,
+		// we need to do a bit of a hack and load the existing contents,
+		// then recreate the file and write out the contents so that further
+		// writes will be possible without affecting the old data
+		size_t fileSize = existing->size();
+		byte *data = new byte[fileSize];
+		existing->read(data, fileSize);
+		delete existing;
+
+		Common::OutSaveFile *out = g_system->getSavefileManager()->openForSaving(saveName, false);
+		assert(out);
+
+		out->write(data, fileSize);
+		delete[] data;
+
+		return out;
+	}
+
+	return g_system->getSavefileManager()->openForSaving(saveName, false);
+}
+
+} // namespace Shared
+} // namespace AGS
+} // namespace AGS3