/* BFD library -- caching of file descriptors.
- Copyright (C) 1990-1991 Free Software Foundation, Inc.
+ Copyright 1990, 1991, 1992 Free Software Foundation, Inc.
Hacked by Steve Chamberlain of Cygnus Support (steve@cygnus.com).
This file is part of BFD, the Binary File Descriptor library.
/*
SECTION
- File Caching
+ File caching
The file caching mechanism is embedded within BFD and allows
the application to open as many BFDs as it wants without
limit (often as low as 20 open files). The module in
<<cache.c>> maintains a least recently used list of
<<BFD_CACHE_MAX_OPEN>> files, and exports the name
- <<bfd_cache_lookup>> which runs around and makes sure that
+ <<bfd_cache_lookup>>, which runs around and makes sure that
the required BFD is open. If not, then it chooses a file to
close, closes it and opens the one wanted, returning its file
handle.
*/
-/* $Id$ */
-
#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
BFD_CACHE_MAX_OPEN macro
DESCRIPTION
- The maxiumum number of files which the cache will keep open at
+ The maximum number of files which the cache will keep open at
one time.
.#define BFD_CACHE_MAX_OPEN 10
*/
+static boolean
+bfd_cache_delete PARAMS ((bfd *));
+
+/* Number of bfds on the chain. All such bfds have their file open;
+ if it closed, they get snipd()d from the chain. */
+
static int open_files;
-static bfd *cache_sentinel; /* Chain of BFDs with active fds we've
+static bfd *cache_sentinel = 0; /* Chain of BFDs with active fds we've
opened */
/*
bfd *bfd_last_cache;
/*
- * INTERNAL_FUNCTION
- * bfd_cache_lookup
- *
- * DESCRIPTION
- * Checks to see if the required BFD is the same as the last one
- * looked up. If so then it can use the iostream in the BFD with
- * impunity, since it can't have changed since the last lookup,
- * otherwise it has to perform the complicated lookup function
- *
- * .#define bfd_cache_lookup(x) \
- * . ((x)==bfd_last_cache? \
- * . (FILE*)(bfd_last_cache->iostream): \
- * . bfd_cache_lookup_worker(x))
- *
- *
+ INTERNAL_FUNCTION
+ bfd_cache_lookup
+
+ DESCRIPTION
+ Check to see if the required BFD is the same as the last one
+ looked up. If so, then it can use the stream in the BFD with
+ impunity, since it can't have changed since the last lookup;
+ otherwise, it has to perform the complicated lookup function.
+
+ .#define bfd_cache_lookup(x) \
+ . ((x)==bfd_last_cache? \
+ . (FILE*)(bfd_last_cache->iostream): \
+ . bfd_cache_lookup_worker(x))
+
+
*/
-static void bfd_cache_delete();
-
-
static void
DEFUN_VOID(close_one)
{
}
kill->where = ftell((FILE *)(kill->iostream));
- bfd_cache_delete(kill);
+ (void) bfd_cache_delete(kill);
}
/* Cuts the BFD abfd out of the chain in the cache */
if (cache_sentinel == abfd) cache_sentinel = (bfd *)NULL;
}
-static void
+static boolean
DEFUN(bfd_cache_delete,(abfd),
bfd *abfd)
{
- fclose ((FILE *)(abfd->iostream));
+ boolean ret;
+
+ if (fclose ((FILE *)(abfd->iostream)) == 0)
+ ret = true;
+ else
+ {
+ ret = false;
+ bfd_set_error (bfd_error_system_call);
+ }
snip (abfd);
abfd->iostream = NULL;
open_files--;
bfd_last_cache = 0;
+ return ret;
}
static bfd *
}
\f
-/*
-INTERNAL_FUNCTION
- bfd_cache_init
-
-SYNOPSIS
- void bfd_cache_init (bfd *);
-
-DESCRIPTION
- Initialize a BFD by putting it on the cache LRU.
-*/
+/* Initialize a BFD by putting it on the cache LRU. */
void
DEFUN(bfd_cache_init,(abfd),
bfd *abfd)
{
+ if (open_files >= BFD_CACHE_MAX_OPEN)
+ close_one ();
cache_sentinel = insert(abfd, cache_sentinel);
+ ++open_files;
}
INTERNAL_FUNCTION
bfd_cache_close
+SYNOPSIS
+ boolean bfd_cache_close (bfd *abfd);
+
DESCRIPTION
- Remove the BFD from the cache. If the attached file is open,
+ Remove the BFD @var{abfd} from the cache. If the attached file is open,
then close it too.
-SYNOPSIS
- void bfd_cache_close (bfd *);
+RETURNS
+ <<false>> is returned if closing the file fails, <<true>> is
+ returned if all is well.
*/
-void
+boolean
DEFUN(bfd_cache_close,(abfd),
bfd *abfd)
{
/* If this file is open then remove from the chain */
if (abfd->iostream)
{
- bfd_cache_delete(abfd);
+ return bfd_cache_delete(abfd);
+ }
+ else
+ {
+ return true;
}
}
INTERNAL_FUNCTION
bfd_open_file
+SYNOPSIS
+ FILE* bfd_open_file(bfd *abfd);
+
DESCRIPTION
- Call the OS to open a file for this BFD. Returns the FILE *
- (possibly null) that results from this operation. Sets up the
- BFD so that future accesses know the file is open. If the FILE
- * returned is null, then there is won't have been put in the
+ Call the OS to open a file for @var{abfd}. Return the <<FILE *>>
+ (possibly <<NULL>>) that results from this operation. Set up the
+ BFD so that future accesses know the file is open. If the <<FILE *>>
+ returned is <<NULL>>, then it won't have been put in the
cache, so it won't have to be removed from it.
-
-SYNOPSIS
- FILE* bfd_open_file(bfd *);
*/
FILE *
bfd *abfd)
{
abfd->cacheable = true; /* Allow it to be closed later. */
+
if(open_files >= BFD_CACHE_MAX_OPEN) {
close_one();
}
+
switch (abfd->direction) {
case read_direction:
case no_direction:
- abfd->iostream = (char *) fopen(abfd->filename, "rb");
+ abfd->iostream = (char *) fopen(abfd->filename, FOPEN_RB);
break;
case both_direction:
case write_direction:
if (abfd->opened_once == true) {
- abfd->iostream = (char *) fopen(abfd->filename, "r+b");
+ abfd->iostream = (char *) fopen(abfd->filename, FOPEN_RUB);
if (!abfd->iostream) {
- abfd->iostream = (char *) fopen(abfd->filename, "w+b");
+ abfd->iostream = (char *) fopen(abfd->filename, FOPEN_WUB);
}
} else {
/*open for creat */
- abfd->iostream = (char *) fopen(abfd->filename, "wb");
+ abfd->iostream = (char *) fopen(abfd->filename, FOPEN_WB);
abfd->opened_once = true;
}
break;
}
+
if (abfd->iostream) {
- open_files++;
bfd_cache_init (abfd);
}
INTERNAL_FUNCTION
bfd_cache_lookup_worker
+SYNOPSIS
+ FILE *bfd_cache_lookup_worker(bfd *abfd);
+
DESCRIPTION
Called when the macro <<bfd_cache_lookup>> fails to find a
- quick answer. Finds a file descriptor for this BFD. If
- necessary, it open it. If there are already more than
- BFD_CACHE_MAX_OPEN files open, it trys to close one first, to
+ quick answer. Find a file descriptor for @var{abfd}. If
+ necessary, it open it. If there are already more than
+ <<BFD_CACHE_MAX_OPEN>> files open, it tries to close one first, to
avoid running out of file descriptors.
-SYNOPSIS
- FILE *bfd_cache_lookup_worker(bfd *);
-
*/
FILE *
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