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Diffstat (limited to 'common/dbuf_def.h')
| -rw-r--r-- | common/dbuf_def.h | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/common/dbuf_def.h b/common/dbuf_def.h new file mode 100644 index 0000000..1295d2d --- /dev/null +++ b/common/dbuf_def.h @@ -0,0 +1,96 @@ +/************************************************************************ + * IRC - Internet Relay Chat, common/dbuf_def.h + * Copyright (C) 1990 Markku Savela + * + * 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 1, 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, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#define DBUF_TAIL + +/* +** dbuf is a collection of functions which can be used to +** maintain a dynamic buffering of a byte stream. +** Functions allocate and release memory dynamically as +** required [Actually, there is nothing that prevents +** this package maintaining the buffer on disk, either] +*/ + +/* +** These structure definitions are only here to be used +** as a whole, *DO NOT EVER REFER TO THESE FIELDS INSIDE +** THE STRUCTURES*! It must be possible to change the internal +** implementation of this package without changing the +** interface. +*/ +#if !defined(_SEQUENT_) +typedef struct dbuf + { + u_int length; /* Current number of bytes stored */ + u_int offset; /* Offset to the first byte */ + struct dbufbuf *head; /* First data buffer, if length > 0 */ +#ifdef DBUF_TAIL + /* added by mnystrom@mit.edu: */ + struct dbufbuf *tail; /* last data buffer, if length > 0 */ +#endif + } dbuf; +#else +typedef struct dbuf + { + uint length; /* Current number of bytes stored */ + uint offset; /* Offset to the first byte */ + struct dbufbuf *head; /* First data buffer, if length > 0 */ +#ifdef DBUF_TAIL + /* added by mnystrom@mit.edu: */ + struct dbufbuf *tail; /* last data buffer, if length > 0 */ +#endif + } dbuf; +#endif +/* +** And this 'dbufbuf' should never be referenced outside the +** implementation of 'dbuf'--would be "hidden" if C had such +** keyword... +** If it was possible, this would compile to be exactly 1 memory +** page in size. 2048 bytes seems to be the most common size, so +** as long as a pointer is 4 bytes, we get 2032 bytes for buffer +** data after we take away a bit for malloc to play with. -avalon +*/ +typedef struct dbufbuf + { + struct dbufbuf *next; /* Next data buffer, NULL if this is last */ + char data[2032]; /* Actual data stored here */ + } dbufbuf; + +/* +** DBufLength +** Return the current number of bytes stored into the buffer. +** (One should use this instead of referencing the internal +** length field explicitly...) +*/ +#define DBufLength(dyn) ((dyn)->length) + +/* +** DBufClear +** Scratch the current content of the buffer. Release all +** allocated buffers and make it empty. +*/ +#define DBufClear(dyn) dbuf_delete((dyn),DBufLength(dyn)) + +/* This is a dangerous define because a broken compiler will set DBUFSIZ +** to 4, which will work but will be very inefficient. However, there +** are other places where the code breaks badly if this is screwed +** up, so... -- Wumpus +*/ + +#define DBUFSIZ sizeof(((dbufbuf *)0)->data) |