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Diffstat (limited to 'src/deh_io.c')
| -rw-r--r-- | src/deh_io.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/src/deh_io.c b/src/deh_io.c new file mode 100644 index 00000000..56b75e6b --- /dev/null +++ b/src/deh_io.c @@ -0,0 +1,169 @@ +// Emacs style mode select -*- C++ -*- +//----------------------------------------------------------------------------- +// +// $Id: deh_io.c 153 2005-10-02 23:49:01Z fraggle $ +// +// Copyright(C) 2005 Simon Howard +// +// 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 2 +// 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, write to the Free Software +// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA +// 02111-1307, USA. +// +// $Log$ +// Revision 1.1 2005/10/02 23:49:01 fraggle +// The beginnings of dehacked support +// +// +//----------------------------------------------------------------------------- +// +// Dehacked I/O code (does all reads from dehacked files) +// +//----------------------------------------------------------------------------- + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "z_zone.h" + +#include "deh_defs.h" +#include "deh_io.h" + +struct deh_context_s +{ + FILE *stream; + char *readbuffer; + int readbuffer_size; +}; + +// Open a dehacked file for reading +// Returns NULL if open failed + +deh_context_t *DEH_OpenFile(char *filename) +{ + FILE *fstream; + deh_context_t *context; + + fstream = fopen(filename, "r"); + + if (fstream == NULL) + return NULL; + + context = Z_Malloc(sizeof(*context), PU_STATIC, NULL); + context->stream = fstream; + + // Initial read buffer size of 128 bytes + + context->readbuffer_size = 128; + context->readbuffer = Z_Malloc(context->readbuffer_size, PU_STATIC, NULL); + + return context; +} + +// Close dehacked file + +void DEH_CloseFile(deh_context_t *context) +{ + fclose(context->stream); + Z_Free(context->readbuffer); + Z_Free(context); +} + +// Reads a single character from a dehacked file + +int DEH_GetChar(deh_context_t *context) +{ + int result; + + // Read characters, but ignore carriage returns + // Essentially this is a DOS->Unix conversion + + do + { + if (feof(context->stream)) + { + // end of file + + result = -1; + } + else + { + result = fgetc(context->stream); + } + + } while (result == '\r'); + + return result; +} + +// Increase the read buffer size + +static void IncreaseReadBuffer(deh_context_t *context) +{ + char *newbuffer; + int newbuffer_size; + + newbuffer_size = context->readbuffer_size * 2; + newbuffer = Z_Malloc(newbuffer_size, PU_STATIC, NULL); + + memcpy(newbuffer, context->readbuffer, context->readbuffer_size); + + Z_Free(context->readbuffer); + + context->readbuffer = newbuffer; + context->readbuffer_size = newbuffer_size; +} + +// Read a whole line + +char *DEH_ReadLine(deh_context_t *context) +{ + char *p; + int c; + int pos; + + for (pos=0; ; ++pos) + { + c = DEH_GetChar(context); + + if (c < 0) + { + // end of file + + return NULL; + } + + // cope with lines of any length: increase the buffer size + + if (pos >= context->readbuffer_size) + { + IncreaseReadBuffer(context); + } + + if (c == '\n') + { + // end of line: a full line has been read + + context->readbuffer[pos] = '\0'; + break; + } + else + { + context->readbuffer[pos] = (char) c; + } + } + + return context->readbuffer; +} + |