1 rizwank 1.1 /*--------------------------------------------------------------------------
 2             Trivial virtual file system for cabinet conformance test.
 3             --------------------------------------------------------------------------*/
 4             
 5             #include "tvfs.h"
 6             #include <string.h>
 7             
 8             /* This is extremely cheezy.  Everything is preallocated per file. */
 9             
10             #define MAXFILES 10
11             #define MAXHANDLES 10
12             #define MAXFNAME 255
13             #define MAXFLEN 65536
14             
15             struct tvfs_file {
16                    char fname[MAXFNAME];
17                    int bytes_used;
18                    char buf[MAXFLEN];
19             };
20             static struct tvfs_file *files[MAXFILES];
21             int nfiles = 0;
22 rizwank 1.1 
23             struct tvfs_fcb {
24                    int pos;
25                    int inode;
26             };
27             static struct tvfs_fcb *handles[MAXHANDLES];
28             int nhandles = 0;
29             
30             int tvfs_create(const char *fname, const char *buf, int len)
31             {
32                    int inode;
33                    struct tvfs_file *f;
34                    if (nfiles >= MAXFILES)
35                            return -1;
36             
37                    inode = nfiles++;
38                    f = calloc(sizeof(struct tvfs_file));
39                    strcpy(f->fname, fname);
40                    f->len = len;
41                    if (buf)
42                            memcpy(f->buf, buf, len);
43 rizwank 1.1        files[inode] = f;
44                    return inode;
45             }
46             
47             int tvfs_open(const char *fname, int flags, int mode)
48             {
49                    int h;
50                    int inode;
51                    /* Existing file? */
52                    for (inode=0; inode<nfiles; inode++) {
53                            if (!files[inode])
54                                    continue;
55                            if (strcmp(files[inode].fname, fname))
56                                    break;
57                    }
58                    if (inode == nfiles) {
59                            /* File did not exist */
60                            if ((flags & O_CREAT) == 0) {
61                                    /* ENOENT */
62                                    return -1;
63                            }
64 rizwank 1.1                inode = tvfs_create(fname, 0, 0);
65                    }
66                    h = nhandles++;
67                    handles[h].inode = inode;
68                    handles[h].pos = 0;
69                    return h;
70             }
71             
72             unsigned int tvfs_read(int h, void *buf, unsigned int len)
73             {
74                    int inode = handles[h].inode;
75                    int pos = handles[h].pos;
76             
77                    /* FIXME: handle edge cases */
78                    memcpy(buf, files[inode].buf, len);
79                    handles[h].pos += len;
80             
81                    return len;
82             }