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#include <camellia/fsutil.h>
#include <camellia/syscalls.h>
#include <shared/mem.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <user/lib/fs/dir.h>
struct node {
const char *name;
size_t namelen;
struct node *next;
char *buf;
size_t size, capacity;
};
struct node *root = NULL;
static struct node special_root = {
.size = 0,
};
static struct node *lookup(const char *path, size_t len) {
for (struct node *iter = root; iter; iter = iter->next) {
if (iter->namelen == len && !memcmp(path, iter->name, len))
return iter;
}
return NULL;
}
static struct node *tmpfs_open(const char *path, struct fs_wait_response *res) {
struct node *node;
if (res->len == 0) return NULL;
path++;
res->len--;
if (res->len == 0) return &special_root;
// no directory support (yet)
if (memchr(path, '/', res->len)) return NULL;
node = lookup(path, res->len);
if (!node && (res->flags & OPEN_CREATE)) {
node = malloc(sizeof *node);
memset(node, 0, sizeof *node);
char *namebuf = malloc(res->len + 1);
memcpy(namebuf, path, res->len);
namebuf[res->len] = '\0';
node->name = namebuf;
node->namelen = res->len;
node->next = root;
root = node;
}
return node;
}
int main(void) {
const size_t buflen = 4096;
char *buf = malloc(buflen);
struct fs_wait_response res;
struct node *ptr;
while (!_syscall_fs_wait(buf, buflen, &res)) {
switch (res.op) {
case VFSOP_OPEN:
ptr = tmpfs_open(buf, &res);
_syscall_fs_respond(ptr, ptr ? 0 : -1, 0);
break;
case VFSOP_READ:
ptr = (void*)res.id;
if (ptr == &special_root) {
struct dirbuild db;
dir_start(&db, res.offset, buf, buflen);
for (struct node *iter = root; iter; iter = iter->next)
dir_append(&db, iter->name);
_syscall_fs_respond(buf, dir_finish(&db), 0);
} else {
fs_normslice(&res.offset, &res.len, ptr->size, false);
_syscall_fs_respond(ptr->buf + res.offset, res.len, 0);
}
break;
case VFSOP_WRITE:
ptr = (void*)res.id;
if (ptr == &special_root) {
_syscall_fs_respond(NULL, -1, 0);
break;
}
if (res.len > 0 && !ptr->buf) {
ptr->buf = malloc(256);
if (!ptr->buf) {
_syscall_fs_respond(NULL, -1, 0);
break;
}
memset(ptr->buf, 0, 256);
ptr->capacity = 256;
}
fs_normslice(&res.offset, &res.len, ptr->size, true);
if (ptr->capacity <= res.offset + res.len) {
size_t newcap = 1;
while (newcap && newcap <= res.offset + res.len)
newcap *= 2;
if (!newcap) { /* overflow */
_syscall_fs_respond(NULL, -1, 0);
break;
}
ptr->capacity = newcap;
ptr->buf = realloc(ptr->buf, ptr->capacity);
}
memcpy(ptr->buf + res.offset, buf, res.len);
if ((res.flags & WRITE_TRUNCATE) || ptr->size < res.offset + res.len) {
ptr->size = res.offset + res.len;
}
_syscall_fs_respond(NULL, res.len, 0);
break;
case VFSOP_GETSIZE:
ptr = (void*)res.id;
if (ptr == &special_root) {
struct dirbuild db;
dir_start(&db, res.offset, NULL, buflen);
for (struct node *iter = root; iter; iter = iter->next)
dir_append(&db, iter->name);
_syscall_fs_respond(NULL, dir_finish(&db), 0);
} else {
_syscall_fs_respond(NULL, ptr->size, 0);
}
break;
default:
_syscall_fs_respond(NULL, -1, 0);
break;
}
}
return 1;
}
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