Initial commit

engines/ags/shared/util/iags_stream.h

@@ -0,0 +1,111 @@
+//=============================================================================
+//
+/* 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/>.
+ *
+ */
+
+//=============================================================================
+//
+// IAGSStream is a contract for stream class, provided by engine to plugin
+// on the need, such as saving/restoring the game.
+// The user is advised to use advanced helper methods, such as Read/WriteX
+// and Read/WriteArrayOfX to allow the stream implementation properly control
+// endianness conversions and data padding, when needed.
+//
+//=============================================================================
+
+#ifndef AGS_SHARED_API_STREAM_API_H
+#define AGS_SHARED_API_STREAM_API_H
+
+// TODO: it would probably be better to not include core definition headers
+// in API class headers, but make separate core headers specifically for
+// plugins, and let plugin developers include them manually in plugin sources.
+#include "ags/shared/core/types.h"
+
+namespace AGS3 {
+
+namespace AGS {
+namespace Shared {
+
+enum StreamSeek {
+	kSeekBegin,
+	kSeekCurrent,
+	kSeekEnd
+};
+
+class IAGSStream {
+public:
+	virtual ~IAGSStream() {}
+
+	virtual void        Close() = 0;
+
+	virtual bool        IsValid() const = 0;
+	virtual bool        EOS() const = 0;
+	virtual soff_t      GetLength() const = 0;
+	virtual soff_t      GetPosition() const = 0;
+	virtual bool        CanRead() const = 0;
+	virtual bool        CanWrite() const = 0;
+	virtual bool        CanSeek() const = 0;
+
+	// Reads number of bytes in the provided buffer
+	virtual size_t      Read(void *buffer, size_t size) = 0;
+	// ReadByte conforms to fgetc behavior:
+	// - if stream is valid, then returns an *unsigned char* packed in the int
+	// - if EOS, then returns -1
+	virtual int32_t     ReadByte() = 0;
+	// Writes number of bytes from the provided buffer
+	virtual size_t      Write(const void *buffer, size_t size) = 0;
+	// WriteByte conforms to fputc behavior:
+	// - on success, returns the unsigned char packed in the int
+	// - on failure, returns -1
+	virtual int32_t     WriteByte(uint8_t b) = 0;
+
+	// Convenience methods for reading values of particular size
+	virtual int8_t      ReadInt8() = 0;
+	virtual int16_t     ReadInt16() = 0;
+	virtual int32_t     ReadInt32() = 0;
+	virtual int64_t     ReadInt64() = 0;
+	virtual bool        ReadBool() = 0;
+	virtual size_t      ReadArray(void *buffer, size_t elem_size, size_t count) = 0;
+	virtual size_t      ReadArrayOfInt8(int8_t *buffer, size_t count) = 0;
+	virtual size_t      ReadArrayOfInt16(int16_t *buffer, size_t count) = 0;
+	virtual size_t      ReadArrayOfInt32(int32_t *buffer, size_t count) = 0;
+	virtual size_t      ReadArrayOfInt64(int64_t *buffer, size_t count) = 0;
+
+	// Convenience methods for writing values of particular size
+	virtual size_t      WriteInt8(int8_t val) = 0;
+	virtual size_t      WriteInt16(int16_t val) = 0;
+	virtual size_t      WriteInt32(int32_t val) = 0;
+	virtual size_t      WriteInt64(int64_t val) = 0;
+	virtual size_t      WriteBool(bool val) = 0;
+	virtual size_t      WriteArray(const void *buffer, size_t elem_size, size_t count) = 0;
+	virtual size_t      WriteArrayOfInt8(const int8_t *buffer, size_t count) = 0;
+	virtual size_t      WriteArrayOfInt16(const int16_t *buffer, size_t count) = 0;
+	virtual size_t      WriteArrayOfInt32(const int32_t *buffer, size_t count) = 0;
+	virtual size_t      WriteArrayOfInt64(const int64_t *buffer, size_t count) = 0;
+
+	virtual soff_t      Seek(soff_t offset, StreamSeek origin = kSeekCurrent) = 0;
+};
+
+} // namespace Shared
+} // namespace AGS
+} // namespace AGS3
+
+#endif