056cdff7ce
This functionality allows us to read data out of a buffer without irrevocably consuming it. We read what we can, and when we're done we throw the reader away. The plan is to read as much of a stream of data as is available, and if we can't read a complete message, we simply toss the reader away and try again when we get more data. I think that perhaps this strategy might be easier than coming up with a state machine to parse the stream. Please do not advance the underlying buffer while trying to use a reader.
54 lines
1.7 KiB
C
54 lines
1.7 KiB
C
//
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// Copyright(C) 2017 Alex Mayfield
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//
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// This program is free software; you can redistribute it and/or
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// modify it under the terms of the GNU General Public License
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// as published by the Free Software Foundation; either version 2
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// of the License, or (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// DESCRIPTION:
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// A simple buffer and reader implementation.
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//
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#ifndef __BUFFER__
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#define __BUFFER__
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#include "../src/doomtype.h"
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#define BUFFER_SIZE 1024
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typedef struct {
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byte buffer[BUFFER_SIZE]; // Buffer.
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byte *buffer_end; // End of Buffer.
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byte *data; // Start of actual data.
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byte *data_end; // End of actual data.
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int data_len; // Length of actual data.
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} buffer_t;
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typedef struct {
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buffer_t *buffer;
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byte *pos;
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} buffer_reader_t;
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buffer_t *NewBuffer();
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void DeleteBuffer(buffer_t* buf);
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int Buffer_Data(buffer_t *buf, byte **data);
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boolean Buffer_Push(buffer_t *buf, const void *data, int len);
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void Buffer_Shift(buffer_t *buf, int len);
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void Buffer_Clear(buffer_t *buf);
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buffer_reader_t *NewReader(buffer_t* buffer);
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void DeleteReader(buffer_reader_t *reader);
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int Reader_BytesRead(buffer_reader_t *reader);
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boolean Reader_ReadInt8(buffer_reader_t *reader, uint8_t *out);
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boolean Reader_ReadInt16(buffer_reader_t *reader, uint16_t *out);
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boolean Reader_ReadInt32(buffer_reader_t *reader, uint32_t *out);
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char *Reader_ReadString(buffer_reader_t *reader);
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#endif
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