redquark-amiberry-rb/src/fsdb.cpp

357 lines
7.4 KiB
C++

/*
* UAE - The Un*x Amiga Emulator
*
* Library of functions to make emulated filesystem as independent as
* possible of the host filesystem's capabilities.
*
* Copyright 1999 Bernd Schmidt
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include "sysdeps.h"
#include "options.h"
#include "memory.h"
#include "fsdb.h"
/* The on-disk format is as follows:
* Offset 0, 1 byte, valid
* Offset 1, 4 bytes, mode
* Offset 5, 257 bytes, aname
* Offset 263, 257 bytes, nname
* Offset 519, 81 bytes, comment
*/
static TCHAR *nname_begin (TCHAR *nname)
{
TCHAR *p = _tcsrchr (nname, FSDB_DIR_SEPARATOR);
if (p)
return p + 1;
return nname;
}
#ifndef _WIN32
/* Find the name REL in directory DIRNAME. If we find a file that
* has exactly the same name, return REL. If we find a file that
* has the same name when compared case-insensitively, return a
* malloced string that contains the name we found. If no file
* exists that compares equal to REL, return 0. */
TCHAR *fsdb_search_dir (const TCHAR *dirname, TCHAR *rel)
{
TCHAR *p = 0;
int de;
my_opendir_s *dir;
TCHAR fn[MAX_DPATH];
dir = my_opendir (dirname);
/* This really shouldn't happen... */
if (! dir)
return 0;
while (p == 0 && (de = my_readdir (dir, fn)) != 0) {
if (strcmp (fn, rel) == 0)
p = rel;
else if (stricmp(fn, rel) == 0)
p = my_strdup (fn);
}
my_closedir (dir);
return p;
}
#endif
static FILE *get_fsdb (a_inode *dir, const TCHAR *mode)
{
TCHAR *n;
FILE *f;
if (!dir->nname)
return NULL;
n = build_nname (dir->nname, FSDB_FILE);
f = uae_tfopen (n, mode);
xfree (n);
return f;
}
static void kill_fsdb (a_inode *dir)
{
if (!dir->nname)
return;
TCHAR *n = build_nname (dir->nname, FSDB_FILE);
_wunlink (n);
xfree (n);
}
static void fsdb_fixup (FILE *f, uae_u8 *buf, int size, a_inode *base)
{
TCHAR *nname;
int ret;
if (buf[0] == 0)
return;
TCHAR *fnname = au ((char*)buf + 5 + 257);
nname = build_nname (base->nname, fnname);
xfree (fnname);
ret = fsdb_exists (nname);
if (ret) {
xfree (nname);
return;
}
/* someone deleted this file/dir outside of emulation.. */
buf[0] = 0;
xfree (nname);
}
/* Prune the db file the first time this directory is opened in a session. */
void fsdb_clean_dir (a_inode *dir)
{
uae_u8 buf[1 + 4 + 257 + 257 + 81];
TCHAR *n;
FILE *f;
off_t pos1 = 0, pos2;
if (!dir->nname)
return;
n = build_nname (dir->nname, FSDB_FILE);
f = uae_tfopen (n, _T("r+b"));
if (f == 0) {
xfree (n);
return;
}
for (;;) {
pos2 = ftell (f);
if (fread (buf, 1, sizeof buf, f) < sizeof buf)
break;
fsdb_fixup (f, buf, sizeof buf, dir);
if (buf[0] == 0)
continue;
if (pos1 != pos2) {
fseek (f, pos1, SEEK_SET);
fwrite (buf, 1, sizeof buf, f);
fseek (f, pos2 + sizeof buf, SEEK_SET);
}
pos1 += sizeof buf;
}
fclose (f);
if (pos1 == 0) {
kill_fsdb (dir);
} else {
my_truncate (n, pos1);
}
xfree (n);
}
static a_inode *aino_from_buf (a_inode *base, uae_u8 *buf, long off)
{
uae_u32 mode;
a_inode *aino = xcalloc (a_inode, 1);
TCHAR *s;
mode = do_get_mem_long ((uae_u32 *)(buf + 1));
buf += 5;
aino->aname = au ((char*)buf);
buf += 257;
s = au ((char*)buf);
aino->nname = build_nname (base->nname, s);
xfree (s);
buf += 257;
aino->comment = *buf != '\0' ? au ((char*)buf) : 0;
fsdb_fill_file_attrs (base, aino);
aino->amigaos_mode = mode;
aino->has_dbentry = 1;
aino->dirty = 0;
aino->db_offset = off;
return aino;
}
a_inode *fsdb_lookup_aino_aname (a_inode *base, const TCHAR *aname)
{
FILE *f;
f = get_fsdb (base, _T("r+b"));
if (f == 0) {
return 0;
}
for (;;) {
uae_u8 buf[1 + 4 + 257 + 257 + 81];
TCHAR *s;
if (fread (buf, 1, sizeof buf, f) < sizeof buf)
break;
s = au ((char*)buf + 5);
if (buf[0] != 0 && same_aname (s, aname)) {
long pos = ftell (f) - sizeof buf;
fclose (f);
xfree (s);
return aino_from_buf (base, buf, pos);
}
xfree (s);
}
fclose (f);
return 0;
}
a_inode *fsdb_lookup_aino_nname (a_inode *base, const TCHAR *nname)
{
FILE *f;
char *s;
f = get_fsdb (base, _T("r+b"));
if (f == 0) {
return 0;
}
s = ua (nname);
for (;;) {
uae_u8 buf[1 + 4 + 257 + 257 + 81];
if (fread (buf, 1, sizeof buf, f) < sizeof buf)
break;
if (buf[0] != 0 && strcmp ((char*)buf + 5 + 257, s) == 0) {
long pos = ftell (f) - sizeof buf;
fclose (f);
xfree (s);
return aino_from_buf (base, buf, pos);
}
}
xfree (s);
fclose (f);
return 0;
}
int fsdb_used_as_nname (a_inode *base, const TCHAR *nname)
{
FILE *f;
uae_u8 buf[1 + 4 + 257 + 257 + 81];
f = get_fsdb (base, _T("r+b"));
if (f == 0) {
return 0;
}
for (;;) {
TCHAR *s;
if (fread (buf, 1, sizeof buf, f) < sizeof buf)
break;
if (buf[0] == 0)
continue;
s = au ((char*)buf + 5 + 257);
if (_tcscmp (s, nname) == 0) {
xfree (s);
fclose (f);
return 1;
}
xfree (s);
}
fclose (f);
return 0;
}
static int needs_dbentry (a_inode *aino)
{
const TCHAR *nn_begin;
if (aino->deleted)
return 0;
if (! fsdb_mode_representable_p (aino, aino->amigaos_mode) || aino->comment != 0)
return 1;
nn_begin = nname_begin (aino->nname);
return _tcscmp (nn_begin, aino->aname) != 0;
}
static void write_aino (FILE *f, a_inode *aino)
{
uae_u8 buf[1 + 4 + 257 + 257 + 81] = { 0 };
buf[0] = aino->needs_dbentry ? 1 : 0;
do_put_mem_long ((uae_u32 *)(buf + 1), aino->amigaos_mode);
ua_copy ((char*)buf + 5, 256, aino->aname);
buf[5 + 256] = '\0';
ua_copy ((char*)buf + 5 + 257, 256, nname_begin (aino->nname));
buf[5 + 257 + 256] = '\0';
ua_copy ((char*)buf + 5 + 2 * 257, 80, aino->comment ? aino->comment : _T(""));
buf[5 + 2 * 257 + 80] = '\0';
aino->db_offset = ftell (f);
fwrite (buf, 1, sizeof buf, f);
aino->has_dbentry = aino->needs_dbentry;
}
/* Write back the db file for a directory. */
void fsdb_dir_writeback (a_inode *dir)
{
FILE *f;
int changes_needed = 0;
int entries_needed = 0;
a_inode *aino;
uae_u8 *tmpbuf;
int size, i;
/* First pass: clear dirty bits where unnecessary, and see if any work
* needs to be done. */
for (aino = dir->child; aino; aino = aino->sibling) {
int old_needs_dbentry = aino->has_dbentry;
int need = needs_dbentry (aino);
aino->needs_dbentry = need;
entries_needed |= need;
if (! aino->dirty)
continue;
if (! aino->needs_dbentry && ! old_needs_dbentry)
aino->dirty = 0;
else
changes_needed = 1;
}
if (! entries_needed) {
kill_fsdb (dir);
return;
}
if (! changes_needed) {
return;
}
f = get_fsdb (dir, _T("r+b"));
if (f == 0) {
f = get_fsdb (dir, _T("w+b"));
if (f == 0) {
/* This shouldn't happen... */
return;
}
}
fseek (f, 0, SEEK_END);
size = ftell (f);
fseek (f, 0, SEEK_SET);
tmpbuf = 0;
if (size > 0) {
tmpbuf = (uae_u8 *)malloc (size);
fread (tmpbuf, 1, size, f);
}
for (aino = dir->child; aino; aino = aino->sibling) {
if (! aino->dirty)
continue;
aino->dirty = 0;
i = 0;
while (!aino->has_dbentry && i < size) {
TCHAR *s = au ((char*)tmpbuf + i + 5);
if (!_tcscmp (s, aino->aname)) {
aino->has_dbentry = 1;
aino->db_offset = i;
}
xfree (s);
i += 1 + 4 + 257 + 257 + 81;
}
if (! aino->has_dbentry) {
fseek (f, 0, SEEK_END);
aino->has_dbentry = 1;
} else {
fseek (f, aino->db_offset, SEEK_SET);
}
write_aino (f, aino);
}
fclose (f);
xfree (tmpbuf);
}