Source:NetHack 3.3.0/dlb.c

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Below is the full text to dlb.c from the source code of NetHack 3.3.0. To link to a particular line, write [[NetHack 3.3.0/dlb.c#line123]], for example.

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1.    /*	SCCS Id: @(#)dlb.c	3.3	97/07/29	*/
2.    /* Copyright (c) Kenneth Lorber, Bethesda, Maryland, 1993. */
3.    /* NetHack may be freely redistributed.  See license for details. */
4.    
5.    #include "config.h"
6.    #include "dlb.h"
7.    
8.    #ifdef __DJGPP__
9.    #include <string.h>
10.   #endif
11.   
12.   #ifdef DLB
13.   /*
14.    * Data librarian.  Present a STDIO-like interface to NetHack while
15.    * multiplexing on one or more "data libraries".  If a file is not found
16.    * in a given library, look for it outside the libraries.
17.    */
18.   
19.   typedef struct dlb_procs {
20.       boolean NDECL((*dlb_init_proc));
21.       void NDECL((*dlb_cleanup_proc));
22.       boolean FDECL((*dlb_fopen_proc), (DLB_P,const char *,const char *));
23.       int FDECL((*dlb_fclose_proc), (DLB_P));
24.       int FDECL((*dlb_fread_proc), (char *,int,int,DLB_P));
25.       int FDECL((*dlb_fseek_proc), (DLB_P,long,int));
26.       char *FDECL((*dlb_fgets_proc), (char *,int,DLB_P));
27.       int FDECL((*dlb_fgetc_proc), (DLB_P));
28.       long FDECL((*dlb_ftell_proc), (DLB_P));
29.   } dlb_procs_t;
30.   
31.   /* without extern.h via hack.h, these haven't been declared for us */
32.   extern FILE *FDECL(fopen_datafile, (const char *,const char *));
33.   
34.   #ifdef DLBLIB
35.   /*
36.    * Library Implementation:
37.    *
38.    * When initialized, we open all library files and read in their tables
39.    * of contents.  The library files stay open all the time.  When
40.    * a open is requested, the libraries' directories are searched.  If
41.    * successful, we return a descriptor that contains the library, file
42.    * size, and current file mark.  This descriptor is used for all
43.    * successive calls.
44.    *
45.    * The ability to open more than one library is supported but used
46.    * only in the Amiga port (the second library holds the sound files).
47.    * For Unix, the idea would be to split the NetHack library
48.    * into text and binary parts, where the text version could be shared.
49.    */
50.   
51.   #define MAX_LIBS 4
52.   static library dlb_libs[MAX_LIBS];
53.   
54.   static boolean FDECL(readlibdir,(library *lp));
55.   static boolean FDECL(find_file,(const char *name, library **lib, long *startp,
56.   								long *sizep));
57.   static boolean NDECL(lib_dlb_init);
58.   static void NDECL(lib_dlb_cleanup);
59.   static boolean FDECL(lib_dlb_fopen,(dlb *, const char *, const char *));
60.   static int FDECL(lib_dlb_fclose,(dlb *));
61.   static int FDECL(lib_dlb_fread,(char *, int, int, dlb *));
62.   static int FDECL(lib_dlb_fseek,(dlb *, long, int));
63.   static char *FDECL(lib_dlb_fgets,(char *, int, dlb *));
64.   static int FDECL(lib_dlb_fgetc,(dlb *));
65.   static long FDECL(lib_dlb_ftell,(dlb *));
66.   
67.   /* not static because shared with dlb_main.c */
68.   boolean FDECL(open_library,(const char *lib_name, library *lp));
69.   void FDECL(close_library,(library *lp));
70.   
71.   /* without extern.h via hack.h, these haven't been declared for us */
72.   extern char *FDECL(eos, (char *));
73.   
74.   
75.   
76.   /*
77.    * Read the directory out of the library.  Return 1 if successful,
78.    * 0 if it failed.
79.    *
80.    * NOTE: An improvement of the file structure should be the file
81.    * size as part of the directory entry or perhaps in place of the
82.    * offset -- the offset can be calculated by a running tally of
83.    * the sizes.
84.    *
85.    * Library file structure:
86.    *
87.    * HEADER:
88.    * %3ld	library FORMAT revision (currently rev 1)
89.    * %1c	space
90.    * %8ld	# of files in archive (includes 1 for directory)
91.    * %1c	space
92.    * %8ld	size of allocation for string space for directory names
93.    * %1c	space
94.    * %8ld	library offset - sanity check - lseek target for start of first file
95.    * %1c	space
96.    * %8ld	size - sanity check - byte size of complete archive file
97.    *
98.    * followed by one DIRECTORY entry for each file in the archive, including
99.    *  the directory itself:
100.   * %1c	handling information (compression, etc.)  Always ' ' in rev 1.
101.   * %s	file name
102.   * %1c	space
103.   * %8ld	offset in archive file of start of this file
104.   * %c	newline
105.   *
106.   * followed by the contents of the files
107.   */
108.  #define DLB_MIN_VERS  1	/* min library version readable by this code */
109.  #define DLB_MAX_VERS  1	/* max library version readable by this code */
110.  
111.  /*
112.   * Read the directory from the library file.   This will allocate and
113.   * fill in our globals.  The file pointer is reset back to position
114.   * zero.  If any part fails, leave nothing that needs to be deallocated.
115.   *
116.   * Return TRUE on success, FALSE on failure.
117.   */
118.  static boolean
119.  readlibdir(lp)
120.      library *lp;	/* library pointer to fill in */
121.  {
122.      int i;
123.      char *sp;
124.      long liboffset, totalsize;
125.  
126.      if (fscanf(lp->fdata, "%ld %ld %ld %ld %ld\n",
127.  	    &lp->rev,&lp->nentries,&lp->strsize,&liboffset,&totalsize) != 5)
128.  	return FALSE;
129.      if (lp->rev > DLB_MAX_VERS || lp->rev < DLB_MIN_VERS) return FALSE;
130.  
131.      lp->dir = (libdir *) alloc(lp->nentries * sizeof(libdir));
132.      lp->sspace = (char *) alloc(lp->strsize);
133.  
134.      /* read in each directory entry */
135.      for (i = 0, sp = lp->sspace; i < lp->nentries; i++) {
136.  	lp->dir[i].fname = sp;
137.  	if (fscanf(lp->fdata, "%c%s %ld\n",
138.  			&lp->dir[i].handling, sp, &lp->dir[i].foffset) != 3) {
139.  	    free((genericptr_t) lp->dir);
140.  	    free((genericptr_t) lp->sspace);
141.  	    lp->dir = (libdir *) 0;
142.  	    lp->sspace = (char *) 0;
143.  	    return FALSE;
144.  	}
145.  	sp = eos(sp) + 1;
146.      }
147.  
148.      /* calculate file sizes using offset information */
149.      for (i = 0; i < lp->nentries; i++) {
150.  	if (i == lp->nentries - 1)
151.  	    lp->dir[i].fsize = totalsize - lp->dir[i].foffset;
152.  	else
153.  	    lp->dir[i].fsize = lp->dir[i+1].foffset - lp->dir[i].foffset;
154.      }
155.  
156.      (void) fseek(lp->fdata, 0L, SEEK_SET);	/* reset back to zero */
157.      lp->fmark = 0;
158.  
159.      return TRUE;
160.  }
161.  
162.  /*
163.   * Look for the file in our directory structure.  Return 1 if successful,
164.   * 0 if not found.  Fill in the size and starting position.
165.   */
166.  static boolean
167.  find_file(name, lib, startp, sizep)
168.      const char *name;
169.      library **lib;
170.      long *startp, *sizep;
171.  {
172.      int i, j;
173.      library *lp;
174.  
175.      for (i = 0; i < MAX_LIBS && dlb_libs[i].fdata; i++) {
176.  	lp = &dlb_libs[i];
177.  	for (j = 0; j < lp->nentries; j++) {
178.  	    if (FILENAME_CMP(name, lp->dir[j].fname) == 0) {
179.  		*lib = lp;
180.  		*startp = lp->dir[j].foffset;
181.  		*sizep = lp->dir[j].fsize;
182.  		return TRUE;
183.  	    }
184.  	}
185.      }
186.      *lib = (library *) 0;
187.      *startp = *sizep = 0;
188.      return FALSE;
189.  }
190.  
191.  /*
192.   * Open the library of the given name and fill in the given library
193.   * structure.  Return TRUE if successful, FALSE otherwise.
194.   */
195.  boolean
196.  open_library(lib_name, lp)
197.      const char *lib_name;
198.      library *lp;
199.  {
200.      boolean status = FALSE;
201.  
202.      lp->fdata = fopen_datafile(lib_name, RDBMODE);
203.      if (lp->fdata) {
204.  	if (readlibdir(lp)) {
205.  	    status = TRUE;
206.  	} else {
207.  	    (void) fclose(lp->fdata);
208.  	    lp->fdata = (FILE *) 0;
209.  	}
210.      }
211.      return status;
212.  }
213.  
214.  void
215.  close_library(lp)
216.      library *lp;
217.  {
218.      (void) fclose(lp->fdata);
219.      free((genericptr_t) lp->dir);
220.      free((genericptr_t) lp->sspace);
221.  
222.      (void) memset((char *)lp, 0, sizeof(library));
223.  }
224.  
225.  /*
226.   * Open the library file once using stdio.  Keep it open, but
227.   * keep track of the file position.
228.   */
229.  static boolean
230.  lib_dlb_init()
231.  {
232.      /* zero out array */
233.      (void) memset((char *)&dlb_libs[0], 0, sizeof(dlb_libs));
234.  
235.      /* To open more than one library, add open library calls here. */
236.      if (!open_library(DLBFILE, &dlb_libs[0])) return FALSE;
237.  #ifdef DLBFILE2
238.      if (!open_library(DLBFILE2, &dlb_libs[1]))  {
239.  	close_library(&dlb_libs[0]);
240.  	return FALSE;
241.      }
242.  #endif
243.      return TRUE;
244.  }
245.  
246.  static void
247.  lib_dlb_cleanup()
248.  {
249.      int i;
250.  
251.      /* close the data file(s) */
252.      for (i = 0; i < MAX_LIBS && dlb_libs[i].fdata; i++)
253.  	close_library(&dlb_libs[i]);
254.  }
255.  
256.  static boolean
257.  lib_dlb_fopen(dp, name, mode)
258.      dlb *dp;
259.      const char *name, *mode;
260.  {
261.      long start, size;
262.      library *lp;
263.  
264.      /* look up file in directory */
265.      if (find_file(name, &lp, &start, &size)) {
266.  	dp->lib = lp;
267.  	dp->start = start;
268.  	dp->size = size;
269.  	dp->mark = 0;
270.  	return TRUE;
271.  	}
272.  
273.      return FALSE;	/* failed */
274.  }
275.  
276.  static int
277.  lib_dlb_fclose(dp)
278.      dlb *dp;
279.  {
280.      /* nothing needs to be done */
281.      return 0;
282.  }
283.  
284.  static int
285.  lib_dlb_fread(buf, size, quan, dp)
286.      char *buf;
287.      int size, quan;
288.      dlb *dp;
289.  {
290.      long pos, nread, nbytes;
291.  
292.      /* make sure we don't read into the next file */
293.      if ((dp->size - dp->mark) < (size * quan))
294.  	quan = (dp->size - dp->mark) / size;
295.      if (quan == 0) return 0;
296.  
297.      pos = dp->start + dp->mark;
298.      if (dp->lib->fmark != pos) {
299.  	fseek(dp->lib->fdata, pos, SEEK_SET);	/* check for error??? */
300.  	dp->lib->fmark = pos;
301.      }
302.  
303.      nread = fread(buf, size, quan, dp->lib->fdata);
304.      nbytes = nread * size;
305.      dp->mark += nbytes;
306.      dp->lib->fmark += nbytes;
307.  
308.      return nread;
309.  }
310.  
311.  static int
312.  lib_dlb_fseek(dp, pos, whence)
313.      dlb *dp;
314.      long pos;
315.      int whence;
316.  {
317.      long curpos;
318.  
319.      switch (whence) {
320.  	case SEEK_CUR:	   curpos = dp->mark + pos;	break;
321.  	case SEEK_END:	   curpos = dp->size - pos;	break;
322.  	default: /* set */ curpos = pos;		break;
323.      }
324.      if (curpos < 0) curpos = 0;
325.      if (curpos > dp->size) curpos = dp->size;
326.  
327.      dp->mark = curpos;
328.      return 0;
329.  }
330.  
331.  static char *
332.  lib_dlb_fgets(buf, len, dp)
333.      char *buf;
334.      int len;
335.      dlb *dp;
336.  {
337.      int i;
338.      char *bp, c = 0;
339.  
340.      if (len <= 0) return buf;	/* sanity check */
341.  
342.      /* return NULL on EOF */
343.      if (dp->mark >= dp->size) return (char *) 0;
344.  
345.      len--;	/* save room for null */
346.      for (i = 0, bp = buf;
347.  		i < len && dp->mark < dp->size && c != '\n'; i++, bp++) {
348.  	if (dlb_fread(bp, 1, 1, dp) <= 0) break;	/* EOF or error */
349.  	c = *bp;
350.      }
351.      *bp = '\0';
352.  
353.      return buf;
354.  }
355.  
356.  static int
357.  lib_dlb_fgetc(dp)
358.      dlb *dp;
359.  {
360.      char c;
361.  
362.      if (lib_dlb_fread(&c, 1, 1, dp) != 1) return EOF;
363.      return (int) c;
364.  }
365.  
366.  
367.  static long
368.  lib_dlb_ftell(dp)
369.      dlb *dp;
370.  {
371.      return dp->mark;
372.  }
373.  
374.  const dlb_procs_t lib_dlb_procs = {
375.      lib_dlb_init,
376.      lib_dlb_cleanup,
377.      lib_dlb_fopen,
378.      lib_dlb_fclose,
379.      lib_dlb_fread,
380.      lib_dlb_fseek,
381.      lib_dlb_fgets,
382.      lib_dlb_fgetc,
383.      lib_dlb_ftell
384.  };
385.  
386.  #endif /* DLBLIB */
387.  
388.  #ifdef DLBRSRC
389.  const dlb_procs_t rsrc_dlb_procs = {
390.      rsrc_dlb_init,
391.      rsrc_dlb_cleanup,
392.      rsrc_dlb_fopen,
393.      rsrc_dlb_fclose,
394.      rsrc_dlb_fread,
395.      rsrc_dlb_fseek,
396.      rsrc_dlb_fgets,
397.      rsrc_dlb_fgetc,
398.      rsrc_dlb_ftell
399.  };
400.  #endif
401.  
402.  /* Global wrapper functions ------------------------------------------------ */
403.  
404.  #define do_dlb_init (*dlb_procs->dlb_init_proc)
405.  #define do_dlb_cleanup (*dlb_procs->dlb_cleanup_proc)
406.  #define do_dlb_fopen (*dlb_procs->dlb_fopen_proc)
407.  #define do_dlb_fclose (*dlb_procs->dlb_fclose_proc)
408.  #define do_dlb_fread (*dlb_procs->dlb_fread_proc)
409.  #define do_dlb_fseek (*dlb_procs->dlb_fseek_proc)
410.  #define do_dlb_fgets (*dlb_procs->dlb_fgets_proc)
411.  #define do_dlb_fgetc (*dlb_procs->dlb_fgetc_proc)
412.  #define do_dlb_ftell (*dlb_procs->dlb_ftell_proc)
413.  
414.  static const dlb_procs_t *dlb_procs;
415.  static boolean dlb_initialized = FALSE;
416.  
417.  boolean
418.  dlb_init()
419.  {
420.      if (!dlb_initialized) {
421.  #ifdef DLBLIB
422.  	dlb_procs = &lib_dlb_procs;
423.  #endif
424.  #ifdef DLBRSRC
425.  	dlb_procs = &rsrc_dlb_procs;
426.  #endif
427.  
428.  	if (dlb_procs) 
429.  	    dlb_initialized = do_dlb_init();
430.      }
431.  
432.      return dlb_initialized;
433.  }
434.  
435.  void
436.  dlb_cleanup()
437.  {
438.      if (dlb_initialized) {
439.  	do_dlb_cleanup();
440.  	dlb_initialized = FALSE;
441.      }
442.  }
443.  
444.  dlb *
445.  dlb_fopen(name, mode)
446.      const char *name, *mode;
447.  {
448.      FILE *fp;
449.      dlb *dp;
450.  
451.      if (!dlb_initialized) return (dlb *) 0;
452.  
453.      dp = (dlb *) alloc(sizeof(dlb));
454.      if (do_dlb_fopen(dp, name, mode))
455.      	dp->fp = (FILE *) 0;
456.      else if ((fp = fopen_datafile(name, mode)) != 0)
457.  	dp->fp = fp;
458.      else {
459.  	/* can't find anything */
460.  	free((genericptr_t) dp);
461.  	dp = (dlb *) 0;
462.  	}
463.  
464.      return dp;
465.  }
466.  
467.  int
468.  dlb_fclose(dp)
469.      dlb *dp;
470.  {
471.  	int ret = 0;
472.  
473.      if (dlb_initialized) {
474.  	if (dp->fp) ret = fclose(dp->fp);
475.  	else ret = do_dlb_fclose(dp);
476.  
477.  	free((genericptr_t) dp);
478.      }
479.      return ret;
480.  }
481.  
482.  int
483.  dlb_fread(buf, size, quan, dp)
484.      char *buf;
485.      int size, quan;
486.      dlb *dp;
487.  {
488.      if (!dlb_initialized || size <= 0 || quan <= 0) return 0;
489.      if (dp->fp) return (int) fread(buf, size, quan, dp->fp);
490.      return do_dlb_fread(buf, size, quan, dp);
491.  }
492.  
493.  int
494.  dlb_fseek(dp, pos, whence)
495.      dlb *dp;
496.      long pos;
497.      int whence;
498.  {
499.      if (!dlb_initialized) return EOF;
500.      if (dp->fp) return fseek(dp->fp, pos, whence);
501.      return do_dlb_fseek(dp, pos, whence);
502.  }
503.  
504.  char *
505.  dlb_fgets(buf, len, dp)
506.      char *buf;
507.      int len;
508.      dlb *dp;
509.  {
510.      if (!dlb_initialized) return (char *) 0;
511.      if (dp->fp) return fgets(buf, len, dp->fp);
512.      return do_dlb_fgets(buf, len, dp);
513.  }
514.  
515.  int
516.  dlb_fgetc(dp)
517.      dlb *dp;
518.  {
519.      if (!dlb_initialized) return EOF;
520.      if (dp->fp) return fgetc(dp->fp);
521.      return do_dlb_fgetc(dp);
522.  }
523.  
524.  long
525.  dlb_ftell(dp)
526.      dlb *dp;
527.  {
528.      if (!dlb_initialized) return 0;
529.      if (dp->fp) return ftell(dp->fp);
530.      return do_dlb_ftell(dp);
531.  }
532.  
533.  #endif /* DLB */
534.  
535.  /*dlb.c*/