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backends/fs/stdiostream.h

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+/* 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/>.
+ *
+ */
+
+#ifndef BACKENDS_FS_STDIOSTREAM_H
+#define BACKENDS_FS_STDIOSTREAM_H
+
+#include "common/scummsys.h"
+#include "common/noncopyable.h"
+#include "common/stream.h"
+#include "common/str.h"
+
+class StdioStream : public Common::SeekableReadStream, public Common::SeekableWriteStream, public Common::NonCopyable {
+public:
+	enum WriteMode {
+		WriteMode_Read = 0,
+		WriteMode_Write = 1,
+		WriteMode_WriteAtomic = 2,
+	};
+
+protected:
+	/** File handle to the actual file. */
+	void *_handle;
+	Common::String *_path;
+
+	static StdioStream *makeFromPathHelper(const Common::String &path, WriteMode writeMode,
+			StdioStream *(*factory)(void *handle));
+
+public:
+	/**
+	 * Given a path, invokes fopen on that path and wrap the result in a
+	 * StdioStream instance.
+	 */
+	static StdioStream *makeFromPath(const Common::String &path, WriteMode writeMode) {
+		return makeFromPathHelper(path, writeMode, [](void *handle) {
+			return new StdioStream(handle);
+		});
+	}
+
+	StdioStream(void *handle);
+	~StdioStream() override;
+
+	bool err() const override;
+	void clearErr() override;
+	bool eos() const override;
+
+	uint32 write(const void *dataPtr, uint32 dataSize) override;
+	bool flush() override;
+
+	int64 pos() const override;
+	int64 size() const override;
+	bool seek(int64 offs, int whence = SEEK_SET) override;
+	uint32 read(void *dataPtr, uint32 dataSize) override;
+
+	/**
+	 * Configure buffered IO
+	 *
+	 * Must be called immediately after opening the file.
+	 * A buffer size of 0 disables buffering.
+	 *
+	 * @param bufferSize the size of the Stdio read / write buffer
+	 * @return success or failure
+	 */
+	bool setBufferSize(uint32 bufferSize);
+
+private:
+	/**
+	 * Move the file from src to dst.
+	 * This must succeed even if the destination file already exists.
+	 *
+	 * This function cannot be overridden as it's called from the destructor.
+	 *
+	 * @param src The file to move
+	 * @param dst The path where the file is to be moved.
+	 *
+	 * @returns Whether the renaming succeeded or not.
+	 */
+	bool moveFile(const Common::String &src, const Common::String &dst);
+};
+
+#endif