108 lines
2.4 KiB
C
108 lines
2.4 KiB
C
/* $Id$
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Part of SWI-Prolog
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Author: Jan Wielemaker
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E-mail: jan@swi.psy.uva.nl
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WWW: http://www.swi-prolog.org
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Copyright (C): 1985-2002, University of Amsterdam
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "pl-incl.h"
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int
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growBuffer(Buffer b, size_t minfree)
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{ size_t osz = b->max - b->base, sz = osz;
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size_t top = b->top - b->base;
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char *new;
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if ( b->max - b->top >= (int)minfree )
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return TRUE;
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if ( sz < 512 )
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sz = 512; /* minimum reasonable size */
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while( top + minfree > sz )
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sz *= 2;
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if ( b->base == b->static_buffer )
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{ if ( !(new = malloc(sz)) )
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return FALSE;
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memcpy(new, b->static_buffer, osz);
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} else
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{ if ( !(new = realloc(b->base, sz)) )
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return FALSE;
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}
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b->base = new;
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b->top = b->base + top;
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b->max = b->base + sz;
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return TRUE;
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}
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/*******************************
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* BUFFER RING *
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*******************************/
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#define discardable_buffer (LD->fli._discardable_buffer)
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#define buffer_ring (LD->fli._buffer_ring)
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#define current_buffer_id (LD->fli._current_buffer_id)
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Buffer
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findBuffer(int flags)
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{ GET_LD
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Buffer b;
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if ( flags & BUF_RING )
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{ if ( ++current_buffer_id == BUFFER_RING_SIZE )
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current_buffer_id = 0;
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b = &buffer_ring[current_buffer_id];
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} else
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b = &discardable_buffer;
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if ( !b->base )
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initBuffer(b);
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emptyBuffer(b);
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return b;
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}
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char *
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buffer_string(const char *s, int flags)
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{ Buffer b = findBuffer(flags);
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size_t l = strlen(s) + 1;
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addMultipleBuffer(b, s, l, char);
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return baseBuffer(b, char);
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}
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int
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unfindBuffer(int flags)
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{ GET_LD
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if ( flags & BUF_RING )
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{ if ( --current_buffer_id <= 0 )
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current_buffer_id = BUFFER_RING_SIZE-1;
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}
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fail;
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}
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