Source:NetHack 3.4.3/src/dlb.c

Below is the full text to src/dlb.c from NetHack 3.4.3. To link to a particular line, write [[dlb.c#line123]], for example.

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1.    /*	SCCS Id: @(#)dlb.c	3.4	1997/07/29	*/
2.    /* Copyright (c) Kenneth Lorber, Bethesda, Maryland, 1993. */
3.    /* NetHack may be freely redistributed.  See license for details. */
4.    

The NetHack General Public License applies to screenshots, source code and other content from NetHack.

This content was modified from the original NetHack source code distribution (by splitting up NetHack content between wiki pages, and possibly further editing). See the page history for a list of who changed it, and on what dates.

5.    #include "config.h"
6.    #include "dlb.h"
7.    
8.    #ifdef __DJGPP__
9.    #include <string.h>
10.   #endif
11.   
12.   #define DATAPREFIX 4
13.   
14.   #ifdef DLB
15.   /*
16.    * Data librarian.  Present a STDIO-like interface to NetHack while
17.    * multiplexing on one or more "data libraries".  If a file is not found
18.    * in a given library, look for it outside the libraries.
19.    */
20.   
21.   typedef struct dlb_procs {
22.       boolean NDECL((*dlb_init_proc));
23.       void NDECL((*dlb_cleanup_proc));
24.       boolean FDECL((*dlb_fopen_proc), (DLB_P,const char *,const char *));
25.       int FDECL((*dlb_fclose_proc), (DLB_P));
26.       int FDECL((*dlb_fread_proc), (char *,int,int,DLB_P));
27.       int FDECL((*dlb_fseek_proc), (DLB_P,long,int));
28.       char *FDECL((*dlb_fgets_proc), (char *,int,DLB_P));
29.       int FDECL((*dlb_fgetc_proc), (DLB_P));
30.       long FDECL((*dlb_ftell_proc), (DLB_P));
31.   } dlb_procs_t;
32.   
33.   /* without extern.h via hack.h, these haven't been declared for us */
34.   extern FILE *FDECL(fopen_datafile, (const char *,const char *,int));
35.   
36.   #ifdef DLBLIB
37.   /*
38.    * Library Implementation:
39.    *
40.    * When initialized, we open all library files and read in their tables
41.    * of contents.  The library files stay open all the time.  When
42.    * a open is requested, the libraries' directories are searched.  If
43.    * successful, we return a descriptor that contains the library, file
44.    * size, and current file mark.  This descriptor is used for all
45.    * successive calls.
46.    *
47.    * The ability to open more than one library is supported but used
48.    * only in the Amiga port (the second library holds the sound files).
49.    * For Unix, the idea would be to split the NetHack library
50.    * into text and binary parts, where the text version could be shared.
51.    */
52.   
53.   #define MAX_LIBS 4
54.   static library dlb_libs[MAX_LIBS];
55.   
56.   static boolean FDECL(readlibdir,(library *lp));
57.   static boolean FDECL(find_file,(const char *name, library **lib, long *startp,
58.   								long *sizep));
59.   static boolean NDECL(lib_dlb_init);
60.   static void NDECL(lib_dlb_cleanup);
61.   static boolean FDECL(lib_dlb_fopen,(dlb *, const char *, const char *));
62.   static int FDECL(lib_dlb_fclose,(dlb *));
63.   static int FDECL(lib_dlb_fread,(char *, int, int, dlb *));
64.   static int FDECL(lib_dlb_fseek,(dlb *, long, int));
65.   static char *FDECL(lib_dlb_fgets,(char *, int, dlb *));
66.   static int FDECL(lib_dlb_fgetc,(dlb *));
67.   static long FDECL(lib_dlb_ftell,(dlb *));
68.   
69.   /* not static because shared with dlb_main.c */
70.   boolean FDECL(open_library,(const char *lib_name, library *lp));
71.   void FDECL(close_library,(library *lp));
72.   
73.   /* without extern.h via hack.h, these haven't been declared for us */
74.   extern char *FDECL(eos, (char *));
75.   
76.   
77.   

readlibdir

78.   /*
79.    * Read the directory out of the library.  Return 1 if successful,
80.    * 0 if it failed.
81.    *
82.    * NOTE: An improvement of the file structure should be the file
83.    * size as part of the directory entry or perhaps in place of the
84.    * offset -- the offset can be calculated by a running tally of
85.    * the sizes.
86.    *
87.    * Library file structure:
88.    *
89.    * HEADER:
90.    * %3ld	library FORMAT revision (currently rev 1)
91.    * %1c	space
92.    * %8ld	# of files in archive (includes 1 for directory)
93.    * %1c	space
94.    * %8ld	size of allocation for string space for directory names
95.    * %1c	space
96.    * %8ld	library offset - sanity check - lseek target for start of first file
97.    * %1c	space
98.    * %8ld	size - sanity check - byte size of complete archive file
99.    *
100.   * followed by one DIRECTORY entry for each file in the archive, including
101.   *  the directory itself:
102.   * %1c	handling information (compression, etc.)  Always ' ' in rev 1.
103.   * %s	file name
104.   * %1c	space
105.   * %8ld	offset in archive file of start of this file
106.   * %c	newline
107.   *
108.   * followed by the contents of the files
109.   */
110.  #define DLB_MIN_VERS  1	/* min library version readable by this code */
111.  #define DLB_MAX_VERS  1	/* max library version readable by this code */
112.  
113.  /*
114.   * Read the directory from the library file.   This will allocate and
115.   * fill in our globals.  The file pointer is reset back to position
116.   * zero.  If any part fails, leave nothing that needs to be deallocated.
117.   *
118.   * Return TRUE on success, FALSE on failure.
119.   */
120.  static boolean
121.  readlibdir(lp)
122.      library *lp;	/* library pointer to fill in */
123.  {
124.      int i;
125.      char *sp;
126.      long liboffset, totalsize;
127.  
128.      if (fscanf(lp->fdata, "%ld %ld %ld %ld %ld\n",
129.  	    &lp->rev,&lp->nentries,&lp->strsize,&liboffset,&totalsize) != 5)
130.  	return FALSE;
131.      if (lp->rev > DLB_MAX_VERS || lp->rev < DLB_MIN_VERS) return FALSE;
132.  
133.      lp->dir = (libdir *) alloc(lp->nentries * sizeof(libdir));
134.      lp->sspace = (char *) alloc(lp->strsize);
135.  
136.      /* read in each directory entry */
137.      for (i = 0, sp = lp->sspace; i < lp->nentries; i++) {
138.  	lp->dir[i].fname = sp;
139.  	if (fscanf(lp->fdata, "%c%s %ld\n",
140.  			&lp->dir[i].handling, sp, &lp->dir[i].foffset) != 3) {
141.  	    free((genericptr_t) lp->dir);
142.  	    free((genericptr_t) lp->sspace);
143.  	    lp->dir = (libdir *) 0;
144.  	    lp->sspace = (char *) 0;
145.  	    return FALSE;
146.  	}
147.  	sp = eos(sp) + 1;
148.      }
149.  
150.      /* calculate file sizes using offset information */
151.      for (i = 0; i < lp->nentries; i++) {
152.  	if (i == lp->nentries - 1)
153.  	    lp->dir[i].fsize = totalsize - lp->dir[i].foffset;
154.  	else
155.  	    lp->dir[i].fsize = lp->dir[i+1].foffset - lp->dir[i].foffset;
156.      }
157.  
158.      (void) fseek(lp->fdata, 0L, SEEK_SET);	/* reset back to zero */
159.      lp->fmark = 0;
160.  
161.      return TRUE;
162.  }
163.  

find_file

164.  /*
165.   * Look for the file in our directory structure.  Return 1 if successful,
166.   * 0 if not found.  Fill in the size and starting position.
167.   */
168.  static boolean
169.  find_file(name, lib, startp, sizep)
170.      const char *name;
171.      library **lib;
172.      long *startp, *sizep;
173.  {
174.      int i, j;
175.      library *lp;
176.  
177.      for (i = 0; i < MAX_LIBS && dlb_libs[i].fdata; i++) {
178.  	lp = &dlb_libs[i];
179.  	for (j = 0; j < lp->nentries; j++) {
180.  	    if (FILENAME_CMP(name, lp->dir[j].fname) == 0) {
181.  		*lib = lp;
182.  		*startp = lp->dir[j].foffset;
183.  		*sizep = lp->dir[j].fsize;
184.  		return TRUE;
185.  	    }
186.  	}
187.      }
188.      *lib = (library *) 0;
189.      *startp = *sizep = 0;
190.      return FALSE;
191.  }
192.  

open_library

193.  /*
194.   * Open the library of the given name and fill in the given library
195.   * structure.  Return TRUE if successful, FALSE otherwise.
196.   */
197.  boolean
198.  open_library(lib_name, lp)
199.      const char *lib_name;
200.      library *lp;
201.  {
202.      boolean status = FALSE;
203.  
204.      lp->fdata = fopen_datafile(lib_name, RDBMODE, DATAPREFIX);
205.      if (lp->fdata) {
206.  	if (readlibdir(lp)) {
207.  	    status = TRUE;
208.  	} else {
209.  	    (void) fclose(lp->fdata);
210.  	    lp->fdata = (FILE *) 0;
211.  	}
212.      }
213.      return status;
214.  }
215.  

close_library

216.  void
217.  close_library(lp)
218.      library *lp;
219.  {
220.      (void) fclose(lp->fdata);
221.      free((genericptr_t) lp->dir);
222.      free((genericptr_t) lp->sspace);
223.  
224.      (void) memset((char *)lp, 0, sizeof(library));
225.  }
226.  

lib_dlb_init

227.  /*
228.   * Open the library file once using stdio.  Keep it open, but
229.   * keep track of the file position.
230.   */
231.  static boolean
232.  lib_dlb_init()
233.  {
234.      /* zero out array */
235.      (void) memset((char *)&dlb_libs[0], 0, sizeof(dlb_libs));
236.  
237.      /* To open more than one library, add open library calls here. */
238.      if (!open_library(DLBFILE, &dlb_libs[0])) return FALSE;
239.  #ifdef DLBFILE2
240.      if (!open_library(DLBFILE2, &dlb_libs[1]))  {
241.  	close_library(&dlb_libs[0]);
242.  	return FALSE;
243.      }
244.  #endif
245.      return TRUE;
246.  }
247.  

lib_dlb_cleanup

248.  static void
249.  lib_dlb_cleanup()
250.  {
251.      int i;
252.  
253.      /* close the data file(s) */
254.      for (i = 0; i < MAX_LIBS && dlb_libs[i].fdata; i++)
255.  	close_library(&dlb_libs[i]);
256.  }
257.  

lib_dlb_fopen

258.  static boolean
259.  lib_dlb_fopen(dp, name, mode)
260.      dlb *dp;
261.      const char *name, *mode;
262.  {
263.      long start, size;
264.      library *lp;
265.  
266.      /* look up file in directory */
267.      if (find_file(name, &lp, &start, &size)) {
268.  	dp->lib = lp;
269.  	dp->start = start;
270.  	dp->size = size;
271.  	dp->mark = 0;
272.  	return TRUE;
273.  	}
274.  
275.      return FALSE;	/* failed */
276.  }
277.  

lib_dlb_fclose

278.  static int
279.  lib_dlb_fclose(dp)
280.      dlb *dp;
281.  {
282.      /* nothing needs to be done */
283.      return 0;
284.  }
285.  

lib_dlb_fread

286.  static int
287.  lib_dlb_fread(buf, size, quan, dp)
288.      char *buf;
289.      int size, quan;
290.      dlb *dp;
291.  {
292.      long pos, nread, nbytes;
293.  
294.      /* make sure we don't read into the next file */
295.      if ((dp->size - dp->mark) < (size * quan))
296.  	quan = (dp->size - dp->mark) / size;
297.      if (quan == 0) return 0;
298.  
299.      pos = dp->start + dp->mark;
300.      if (dp->lib->fmark != pos) {
301.  	fseek(dp->lib->fdata, pos, SEEK_SET);	/* check for error??? */
302.  	dp->lib->fmark = pos;
303.      }
304.  
305.      nread = fread(buf, size, quan, dp->lib->fdata);
306.      nbytes = nread * size;
307.      dp->mark += nbytes;
308.      dp->lib->fmark += nbytes;
309.  
310.      return nread;
311.  }
312.  

lib_dlb_fseek

313.  static int
314.  lib_dlb_fseek(dp, pos, whence)
315.      dlb *dp;
316.      long pos;
317.      int whence;
318.  {
319.      long curpos;
320.  
321.      switch (whence) {
322.  	case SEEK_CUR:	   curpos = dp->mark + pos;	break;
323.  	case SEEK_END:	   curpos = dp->size - pos;	break;
324.  	default: /* set */ curpos = pos;		break;
325.      }
326.      if (curpos < 0) curpos = 0;
327.      if (curpos > dp->size) curpos = dp->size;
328.  
329.      dp->mark = curpos;
330.      return 0;
331.  }
332.  

lib_dlb_fgets

333.  static char *
334.  lib_dlb_fgets(buf, len, dp)
335.      char *buf;
336.      int len;
337.      dlb *dp;
338.  {
339.      int i;
340.      char *bp, c = 0;
341.  
342.      if (len <= 0) return buf;	/* sanity check */
343.  
344.      /* return NULL on EOF */
345.      if (dp->mark >= dp->size) return (char *) 0;
346.  
347.      len--;	/* save room for null */
348.      for (i = 0, bp = buf;
349.  		i < len && dp->mark < dp->size && c != '\n'; i++, bp++) {
350.  	if (dlb_fread(bp, 1, 1, dp) <= 0) break;	/* EOF or error */
351.  	c = *bp;
352.      }
353.      *bp = '\0';
354.  
355.  #if defined(MSDOS) || defined(WIN32)
356.      if ((bp = index(buf, '\r')) != 0) {
357.  	*bp++ = '\n';
358.  	*bp = '\0';
359.      }
360.  #endif
361.  
362.      return buf;
363.  }
364.  

lib_dlb_fgetc

365.  static int
366.  lib_dlb_fgetc(dp)
367.      dlb *dp;
368.  {
369.      char c;
370.  
371.      if (lib_dlb_fread(&c, 1, 1, dp) != 1) return EOF;
372.      return (int) c;
373.  }
374.  
375.  

lib_dlb_ftell

376.  static long
377.  lib_dlb_ftell(dp)
378.      dlb *dp;
379.  {
380.      return dp->mark;
381.  }
382.  

383.  const dlb_procs_t lib_dlb_procs = {
384.      lib_dlb_init,
385.      lib_dlb_cleanup,
386.      lib_dlb_fopen,
387.      lib_dlb_fclose,
388.      lib_dlb_fread,
389.      lib_dlb_fseek,
390.      lib_dlb_fgets,
391.      lib_dlb_fgetc,
392.      lib_dlb_ftell
393.  };
394.  
395.  #endif /* DLBLIB */
396.  
397.  #ifdef DLBRSRC
398.  const dlb_procs_t rsrc_dlb_procs = {
399.      rsrc_dlb_init,
400.      rsrc_dlb_cleanup,
401.      rsrc_dlb_fopen,
402.      rsrc_dlb_fclose,
403.      rsrc_dlb_fread,
404.      rsrc_dlb_fseek,
405.      rsrc_dlb_fgets,
406.      rsrc_dlb_fgetc,
407.      rsrc_dlb_ftell
408.  };
409.  #endif
410.  
411.  /* Global wrapper functions ------------------------------------------------ */
412.  
413.  #define do_dlb_init (*dlb_procs->dlb_init_proc)
414.  #define do_dlb_cleanup (*dlb_procs->dlb_cleanup_proc)
415.  #define do_dlb_fopen (*dlb_procs->dlb_fopen_proc)
416.  #define do_dlb_fclose (*dlb_procs->dlb_fclose_proc)
417.  #define do_dlb_fread (*dlb_procs->dlb_fread_proc)
418.  #define do_dlb_fseek (*dlb_procs->dlb_fseek_proc)
419.  #define do_dlb_fgets (*dlb_procs->dlb_fgets_proc)
420.  #define do_dlb_fgetc (*dlb_procs->dlb_fgetc_proc)
421.  #define do_dlb_ftell (*dlb_procs->dlb_ftell_proc)
422.  
423.  static const dlb_procs_t *dlb_procs;
424.  static boolean dlb_initialized = FALSE;
425.  

dlb_init

426.  boolean
427.  dlb_init()
428.  {
429.      if (!dlb_initialized) {
430.  #ifdef DLBLIB
431.  	dlb_procs = &lib_dlb_procs;
432.  #endif
433.  #ifdef DLBRSRC
434.  	dlb_procs = &rsrc_dlb_procs;
435.  #endif
436.  
437.  	if (dlb_procs) 
438.  	    dlb_initialized = do_dlb_init();
439.      }
440.  
441.      return dlb_initialized;
442.  }
443.  

dlb_cleanup

444.  void
445.  dlb_cleanup()
446.  {
447.      if (dlb_initialized) {
448.  	do_dlb_cleanup();
449.  	dlb_initialized = FALSE;
450.      }
451.  }
452.  

dlb_fopen

453.  dlb *
454.  dlb_fopen(name, mode)
455.      const char *name, *mode;
456.  {
457.      FILE *fp;
458.      dlb *dp;
459.  
460.      if (!dlb_initialized) return (dlb *) 0;
461.  
462.      dp = (dlb *) alloc(sizeof(dlb));
463.      if (do_dlb_fopen(dp, name, mode))
464.      	dp->fp = (FILE *) 0;
465.      else if ((fp = fopen_datafile(name, mode, DATAPREFIX)) != 0)
466.  	dp->fp = fp;
467.      else {
468.  	/* can't find anything */
469.  	free((genericptr_t) dp);
470.  	dp = (dlb *) 0;
471.  	}
472.  
473.      return dp;
474.  }
475.  

dlb_fclose

476.  int
477.  dlb_fclose(dp)
478.      dlb *dp;
479.  {
480.  	int ret = 0;
481.  
482.      if (dlb_initialized) {
483.  	if (dp->fp) ret = fclose(dp->fp);
484.  	else ret = do_dlb_fclose(dp);
485.  
486.  	free((genericptr_t) dp);
487.      }
488.      return ret;
489.  }
490.  

dlb_fread

491.  int
492.  dlb_fread(buf, size, quan, dp)
493.      char *buf;
494.      int size, quan;
495.      dlb *dp;
496.  {
497.      if (!dlb_initialized || size <= 0 || quan <= 0) return 0;
498.      if (dp->fp) return (int) fread(buf, size, quan, dp->fp);
499.      return do_dlb_fread(buf, size, quan, dp);
500.  }
501.  

dlb_fseek

502.  int
503.  dlb_fseek(dp, pos, whence)
504.      dlb *dp;
505.      long pos;
506.      int whence;
507.  {
508.      if (!dlb_initialized) return EOF;
509.      if (dp->fp) return fseek(dp->fp, pos, whence);
510.      return do_dlb_fseek(dp, pos, whence);
511.  }
512.  

dlb_fgets

513.  char *
514.  dlb_fgets(buf, len, dp)
515.      char *buf;
516.      int len;
517.      dlb *dp;
518.  {
519.      if (!dlb_initialized) return (char *) 0;
520.      if (dp->fp) return fgets(buf, len, dp->fp);
521.      return do_dlb_fgets(buf, len, dp);
522.  }
523.  

dlb_fgetc

524.  int
525.  dlb_fgetc(dp)
526.      dlb *dp;
527.  {
528.      if (!dlb_initialized) return EOF;
529.      if (dp->fp) return fgetc(dp->fp);
530.      return do_dlb_fgetc(dp);
531.  }
532.  

dlb_ftell

533.  long
534.  dlb_ftell(dp)
535.      dlb *dp;
536.  {
537.      if (!dlb_initialized) return 0;
538.      if (dp->fp) return ftell(dp->fp);
539.      return do_dlb_ftell(dp);
540.  }
541.  
542.  #endif /* DLB */
543.  
544.  /*dlb.c*/