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Annotation of uae/src/fsdb.c, revision 1.1

1.1     ! root        1:  /*
        !             2:   * UAE - The Un*x Amiga Emulator
        !             3:   *
        !             4:   * Library of functions to make emulated filesystem as independent as
        !             5:   * possible of the host filesystem's capabilities.
        !             6:   *
        !             7:   * Copyright 1999 Bernd Schmidt
        !             8:   */
        !             9: 
        !            10: #include "sysconfig.h"
        !            11: #include "sysdeps.h"
        !            12: 
        !            13: #include "config.h"
        !            14: #include "threaddep/penguin.h"
        !            15: #include "options.h"
        !            16: #include "uae.h"
        !            17: #include "memory.h"
        !            18: #include "custom.h"
        !            19: #include "readcpu.h"
        !            20: #include "newcpu.h"
        !            21: #include "filesys.h"
        !            22: #include "autoconf.h"
        !            23: #include "compiler.h"
        !            24: #include "fsusage.h"
        !            25: #include "native2amiga.h"
        !            26: #include "scsidev.h"
        !            27: #include "fsdb.h"
        !            28: 
        !            29: /* The on-disk format is as follows:
        !            30:  * Offset 0, 1 byte, valid
        !            31:  * Offset 1, 4 bytes, mode
        !            32:  * Offset 5, 257 bytes, aname
        !            33:  * Offset 263, 257 bytes, nname
        !            34:  * Offset 518, 81 bytes, comment
        !            35:  */
        !            36: 
        !            37: char *nname_begin (char *nname)
        !            38: {
        !            39:     char *p = strrchr (nname, FSDB_DIR_SEPARATOR);
        !            40:     if (p)
        !            41:        return p + 1;
        !            42:     return nname;
        !            43: }
        !            44: 
        !            45: /* Find the name REL in directory DIRNAME.  If we find a file that
        !            46:  * has exactly the same name, return REL.  If we find a file that
        !            47:  * has the same name when compared case-insensitively, return a
        !            48:  * malloced string that contains the name we found.  If no file
        !            49:  * exists that compares equal to REL, return 0.  */
        !            50: char *fsdb_search_dir (const char *dirname, char *rel)
        !            51: {
        !            52:     char *p = 0;
        !            53:     struct dirent *de;
        !            54:     DIR *dir = opendir (dirname);
        !            55: 
        !            56:     /* This really shouldn't happen...  */
        !            57:     if (! dir)
        !            58:        return 0;
        !            59:     
        !            60:     while (p == 0 && (de = readdir (dir)) != 0) {
        !            61:        if (strcmp (de->d_name, rel) == 0)
        !            62:            p = rel;
        !            63:        else if (strcasecmp (de->d_name, rel) == 0)
        !            64:            p = my_strdup (de->d_name);
        !            65:     }
        !            66:     closedir (dir);
        !            67:     return p;
        !            68: }
        !            69: 
        !            70: static FILE *get_fsdb (a_inode *dir, const char *mode)
        !            71: {
        !            72:     char *n = build_nname (dir->nname, FSDB_FILE);
        !            73:     FILE *f = fopen (n, mode);
        !            74:     free (n);
        !            75:     return f;
        !            76: }
        !            77: 
        !            78: /* Prune the db file the first time this directory is opened in a session.  */
        !            79: void fsdb_clean_dir (a_inode *dir)
        !            80: {
        !            81:     char buf[1 + 4 + 257 + 257 + 81];
        !            82:     char *n = build_nname (dir->nname, FSDB_FILE);
        !            83:     FILE *f = fopen (n, "r+b");
        !            84:     off_t pos1 = 0, pos2 = 0;
        !            85: 
        !            86:     if (f == 0)
        !            87:        return;
        !            88:     for (;; pos2 += sizeof buf) {
        !            89:        if (fread (buf, 1, sizeof buf, f) < sizeof buf)
        !            90:            break;
        !            91:        if (buf[0] == 0)
        !            92:            continue;
        !            93:        if (pos1 != pos2) {
        !            94:            fseek (f, pos1, SEEK_SET);
        !            95:            fwrite (buf, 1, sizeof buf, f);
        !            96:            fseek (f, pos2 + sizeof buf, SEEK_SET);
        !            97:        }
        !            98:        pos1 += sizeof buf;
        !            99:     }
        !           100:     fclose (f);
        !           101:     truncate (n, pos1);
        !           102:     free (n);
        !           103: }
        !           104: 
        !           105: static a_inode *aino_from_buf (a_inode *base, char *buf)
        !           106: {
        !           107:     uae_u32 mode;
        !           108:     a_inode *aino = (a_inode *) xmalloc (sizeof (a_inode));
        !           109: 
        !           110:     mode = do_get_mem_long ((uae_u32 *)(buf + 1));
        !           111:     buf += 5;
        !           112:     aino->aname = my_strdup (buf);
        !           113:     buf += 257;
        !           114:     aino->nname = build_nname (base->nname, buf);
        !           115:     buf += 257;
        !           116:     aino->comment = *buf != '\0' ? my_strdup (buf) : 0;
        !           117:     fsdb_fill_file_attrs (aino);
        !           118:     aino->amigaos_mode = mode;
        !           119:     aino->has_dbentry = 1;
        !           120:     aino->dirty = 0;
        !           121:     return aino;
        !           122: }
        !           123: 
        !           124: a_inode *fsdb_lookup_aino_aname (a_inode *base, const char *aname)
        !           125: {
        !           126:     FILE *f = get_fsdb (base, "rb");
        !           127:     if (f == 0)
        !           128:        return 0;
        !           129:     for (;;) {
        !           130:        char buf[1 + 4 + 257 + 257 + 81];
        !           131:        if (fread (buf, 1, sizeof buf, f) < sizeof buf)
        !           132:            return 0;
        !           133:        if (buf[0] == 0)
        !           134:            continue;
        !           135:        if (same_aname (buf + 5, aname)) {
        !           136:            fclose (f);
        !           137:            return aino_from_buf (base, buf);
        !           138:        }
        !           139:     }
        !           140:     fclose (f);
        !           141:     return 0;
        !           142: }
        !           143: 
        !           144: a_inode *fsdb_lookup_aino_nname (a_inode *base, const char *nname)
        !           145: {
        !           146:     char buf[1 + 4 + 257 + 257 + 81];
        !           147:     FILE *f = get_fsdb (base, "rb");
        !           148:     if (f == 0)
        !           149:        return 0;
        !           150:     for (;;) {
        !           151:        if (fread (buf, 1, sizeof buf, f) < sizeof buf)
        !           152:            return 0;
        !           153:        if (buf[0] == 0)
        !           154:            continue;
        !           155:        if (strcmp (buf + 5 + 257, nname) == 0) {
        !           156:            fclose (f);
        !           157:            return aino_from_buf (base, buf);
        !           158:        }
        !           159:     }
        !           160:     fclose (f);
        !           161:     return 0;
        !           162: }
        !           163: 
        !           164: int fsdb_used_as_nname (a_inode *base, const char *nname)
        !           165: {
        !           166:     char buf[1 + 4 + 257 + 257 + 81];
        !           167:     FILE *f = get_fsdb (base, "rb");
        !           168:     if (f == 0)
        !           169:        return 0;
        !           170:     for (;;) {
        !           171:        if (fread (buf, 1, sizeof buf, f) < sizeof buf)
        !           172:            return 0;
        !           173:        if (buf[0] == 0)
        !           174:            continue;
        !           175:        if (strcmp (buf + 5 + 257, nname) == 0) {
        !           176:            fclose (f);
        !           177:            return 1;
        !           178:        }
        !           179:     }
        !           180:     fclose (f);
        !           181:     return 0;
        !           182: }
        !           183: 
        !           184: static int needs_dbentry (a_inode *aino)
        !           185: {
        !           186:     const char *an_begin, *nn_begin;
        !           187: 
        !           188:     if (aino->deleted)
        !           189:        return 0;
        !           190:     
        !           191:     if (! fsdb_mode_representable_p (aino) || aino->comment != 0)
        !           192:        return 1;
        !           193: 
        !           194:     nn_begin = nname_begin (aino->nname);
        !           195:     return strcmp (nn_begin, aino->aname) != 0;
        !           196: }
        !           197: 
        !           198: static void write_aino (FILE *f, a_inode *aino)
        !           199: {
        !           200:     char buf[1 + 4 + 257 + 257 + 81];
        !           201:     buf[0] = aino->needs_dbentry;
        !           202:     do_put_mem_long ((uae_u32 *)(buf + 1), aino->amigaos_mode);
        !           203:     strncpy (buf + 5, aino->aname, 256);
        !           204:     buf[5 + 256] = '\0';
        !           205:     strncpy (buf + 5 + 257, nname_begin (aino->nname), 256);
        !           206:     buf[5 + 257 + 256] = '\0';
        !           207:     strncpy (buf + 5 + 2*257, aino->comment ? aino->comment : "", 80);
        !           208:     buf[5 + 2 * 257 + 80] = '\0';
        !           209:     fwrite (buf, 1, sizeof buf, f);
        !           210:     aino->has_dbentry = aino->needs_dbentry;
        !           211: }
        !           212: 
        !           213: void fsdb_dir_writeback (a_inode *dir)
        !           214: {
        !           215:     FILE *f;
        !           216:     int changes_needed = 0;
        !           217:     a_inode *aino;
        !           218: 
        !           219:     /* First pass: clear dirty bits where unnecessary, and see if any work
        !           220:      * needs to be done.  */
        !           221:     for (aino = dir->child; aino; aino = aino->sibling) {
        !           222:        if (! aino->dirty)
        !           223:            continue;
        !           224:        aino->needs_dbentry = needs_dbentry (aino);
        !           225:        if (aino->needs_dbentry != aino->has_dbentry)
        !           226:            changes_needed = 1;
        !           227:        else if (! aino->needs_dbentry)
        !           228:            aino->dirty = 0;
        !           229:     }
        !           230:     if (! changes_needed)
        !           231:        return;
        !           232: 
        !           233:     f = get_fsdb (dir, "r+b");
        !           234:     if (f == 0) {
        !           235:        f = get_fsdb (dir, "w+b");
        !           236:        if (f == 0)
        !           237:            /* This shouldn't happen... */
        !           238:            return;
        !           239:     }
        !           240: 
        !           241:     for (aino = dir->child; aino; aino = aino->sibling) {
        !           242:        off_t pos;
        !           243: 
        !           244:        if (! aino->dirty)
        !           245:            continue;
        !           246:        aino->dirty = 0;
        !           247:        if (! aino->has_dbentry) {
        !           248:            fseek (f, 0, SEEK_END);
        !           249:            write_aino (f, aino);
        !           250:            continue;
        !           251:        }
        !           252: 
        !           253:        fseek (f, 0, SEEK_SET);
        !           254:        pos = 0;
        !           255:        for (;;) {
        !           256:            char buf[1 + 4 + 257 + 257 + 81];
        !           257:            if (fread (buf, 1, sizeof buf, f) < sizeof buf)
        !           258:                /* Can't happen... */
        !           259:                break;
        !           260:            if (strcmp (buf + 5, aino->aname) == 0) {
        !           261:                fseek (f, pos, SEEK_SET);
        !           262:                write_aino (f, aino);
        !           263:                break;
        !           264:            }
        !           265:            pos += sizeof buf;
        !           266:        }
        !           267:     }
        !           268:     fclose (f);
        !           269: }

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