Separated out version of dir remove/append for non-entries

This allows updates to directories without needing to allocate an entry
struct for every call.
This commit is contained in:
Christopher Haster
2018-03-15 20:32:00 -05:00
parent 362b0bbe45
commit 03b262b1e8

197
lfs.c
View File

@@ -677,15 +677,14 @@ relocate:
return 0;
}
static int lfs_dir_append(lfs_t *lfs, lfs_dir_t *dir,
lfs_entry_t *entry, struct lfs_region *regions) {
static int lfs_dir_append_(lfs_t *lfs, lfs_dir_t *dir,
lfs_off_t *off, lfs_size_t size, struct lfs_region *regions) {
// check if we fit, if top bit is set we do not and move on
while (true) {
if ((0x7fffffff & dir->d.size) + lfs_entry_size(entry)
<= lfs->cfg->block_size) {
entry->off = dir->d.size - 4;
if ((0x7fffffff & dir->d.size) + size <= lfs->cfg->block_size) {
*off = dir->d.size - 4;
for (struct lfs_region *r = regions; r; r = r->next) {
r->off += entry->off;
r->off += *off;
}
return lfs_dir_commit(lfs, dir, regions);
@@ -701,9 +700,9 @@ static int lfs_dir_append(lfs_t *lfs, lfs_dir_t *dir,
dir->d.tail[0] = olddir.d.tail[0];
dir->d.tail[1] = olddir.d.tail[1];
entry->off = dir->d.size - 4;
*off = dir->d.size - 4;
for (struct lfs_region *r = regions; r; r = r->next) {
r->off += entry->off;
r->off += *off;
}
err = lfs_dir_commit(lfs, dir, regions);
@@ -724,89 +723,10 @@ static int lfs_dir_append(lfs_t *lfs, lfs_dir_t *dir,
}
}
static int lfs_dir_update(lfs_t *lfs, lfs_dir_t *dir,
lfs_entry_t *entry, struct lfs_region *regions) {
lfs_off_t oldoff = entry->off; // <- TODO rm me?
lfs_ssize_t diff = 0;
for (struct lfs_region *r = regions; r; r = r->next) {
diff += r->diff;
}
// do we still fit?
if ((0x7fffffff & dir->d.size) + diff <= lfs->cfg->block_size) {
for (struct lfs_region *r = regions; r; r = r->next) {
r->off += entry->off;
}
int err = lfs_dir_commit(lfs, dir, regions);
if (err) {
return err;
}
} else {
lfs_dir_t olddir = *dir;
lfs_off_t oldoff = entry->off;
lfs_size_t oldsize = lfs_entry_size(entry) - diff;
// mark as moving
entry->d.type |= LFS_STRUCT_MOVED;
int err = lfs_dir_commit(lfs, &olddir,
&(struct lfs_region){
oldoff, 0,
lfs_commit_mem, &entry->d.type, 1});
if (err) {
return err;
}
// append updated entry
entry->d.type &= LFS_STRUCT_MOVED;
err = lfs_dir_append(lfs, dir, entry,
&(struct lfs_region){
0, +lfs_entry_size(entry),
lfs_commit_disk, &(struct lfs_commit_disk){
olddir.pair[0], entry->off, regions}, oldsize});
if (err) {
return err;
}
// remove old entry
err = lfs_dir_commit(lfs, &olddir,
&(struct lfs_region){
oldoff, -oldsize,
lfs_commit_mem, NULL, 0});
if (err) {
return err;
}
}
// TODO move to dir_commit?
// TODO this doesn't work...
// shift over any files/directories that are affected
for (lfs_file_t *f = lfs->files; f; f = f->next) {
if (lfs_paircmp(f->pair, dir->pair) == 0) {
if (f->poff == oldoff) {
f->poff = entry->off;
} else if (f->poff > entry->off) {
f->poff += diff;
}
}
}
for (lfs_dir_t *d = lfs->dirs; d; d = d->next) {
if (lfs_paircmp(d->pair, dir->pair) == 0) {
if (d->off > entry->off) {
d->off += diff;
d->pos += diff;
}
}
}
return 0;
}
static int lfs_dir_remove(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
static int lfs_dir_remove_(lfs_t *lfs, lfs_dir_t *dir,
lfs_off_t off, lfs_size_t size) {
// check if we should just drop the directory block
if ((dir->d.size & 0x7fffffff) == sizeof(dir->d)+4
+ lfs_entry_size(entry)) {
if ((dir->d.size & 0x7fffffff) == sizeof(dir->d)+4 + size) {
lfs_dir_t pdir;
int res = lfs_pred(lfs, dir->pair, &pdir);
if (res < 0) {
@@ -824,7 +744,7 @@ static int lfs_dir_remove(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
// shift out the entry
int err = lfs_dir_commit(lfs, dir,
&(struct lfs_region){
entry->off, -lfs_entry_size(entry),
off, -size,
lfs_commit_mem, NULL, 0});
if (err) {
return err;
@@ -833,11 +753,61 @@ static int lfs_dir_remove(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
// shift over any files/directories that are affected
for (lfs_file_t *f = lfs->files; f; f = f->next) {
if (lfs_paircmp(f->pair, dir->pair) == 0) {
if (f->poff == entry->off) {
if (f->poff == off) {
f->pair[0] = 0xffffffff;
f->pair[1] = 0xffffffff;
} else if (f->poff > entry->off) {
f->poff -= lfs_entry_size(entry);
} else if (f->poff > off) {
f->poff -= size;
}
}
}
for (lfs_dir_t *d = lfs->dirs; d; d = d->next) {
if (lfs_paircmp(d->pair, dir->pair) == 0) {
if (d->off > off) {
d->off -= size;
d->pos -= size;
}
}
}
return 0;
}
static int lfs_dir_append(lfs_t *lfs, lfs_dir_t *dir,
lfs_entry_t *entry, struct lfs_region *regions) {
return lfs_dir_append_(lfs, dir,
&entry->off, lfs_entry_size(entry), regions);
}
static int lfs_dir_remove(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
return lfs_dir_remove_(lfs, dir,
entry->off, lfs_entry_size(entry));
}
static int lfs_dir_update(lfs_t *lfs, lfs_dir_t *dir,
lfs_entry_t *entry, struct lfs_region *regions) {
lfs_ssize_t diff = 0;
for (struct lfs_region *r = regions; r; r = r->next) {
diff += r->diff;
}
// do we still fit?
if ((0x7fffffff & dir->d.size) + diff <= lfs->cfg->block_size) {
for (struct lfs_region *r = regions; r; r = r->next) {
r->off += entry->off;
}
int err = lfs_dir_commit(lfs, dir, regions);
if (err) {
return err;
}
// shift over any files/directories that are affected
for (lfs_file_t *f = lfs->files; f; f = f->next) {
if (lfs_paircmp(f->pair, dir->pair) == 0) {
if (f->poff > entry->off) {
f->poff += diff;
}
}
}
@@ -845,11 +815,46 @@ static int lfs_dir_remove(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
for (lfs_dir_t *d = lfs->dirs; d; d = d->next) {
if (lfs_paircmp(d->pair, dir->pair) == 0) {
if (d->off > entry->off) {
d->off -= lfs_entry_size(entry);
d->pos -= lfs_entry_size(entry);
d->off += diff;
d->pos += diff;
}
}
}
} else {
lfs_dir_t olddir = *dir;
lfs_off_t oldoff = entry->off;
lfs_size_t oldsize = lfs_entry_size(entry) - diff;
// mark as moving
entry->d.type |= LFS_STRUCT_MOVED;
int err = lfs_dir_commit(lfs, &olddir,
&(struct lfs_region){
oldoff, 0,
lfs_commit_mem, &entry->d.type, 1});
if (err) {
return err;
}
entry->d.type &= LFS_STRUCT_MOVED;
// append updated entry
err = lfs_dir_append(lfs, dir, entry,
&(struct lfs_region){
0, +lfs_entry_size(entry),
lfs_commit_disk, &(struct lfs_commit_disk){
olddir.pair[0], entry->off, regions}, oldsize});
if (err) {
return err;
}
// remove old entry
err = lfs_dir_remove_(lfs, dir, oldoff, oldsize);
if (err) {
return err;
}
// TODO remove file under file?
// TODO need to shift entries?
}
return 0;
}