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-rw-r--r--source3/tdb/tdb.c244
-rw-r--r--source3/tdb/tdbtest.c39
2 files changed, 251 insertions, 32 deletions
diff --git a/source3/tdb/tdb.c b/source3/tdb/tdb.c
index 87c145cb8c..8266cb4b4d 100644
--- a/source3/tdb/tdb.c
+++ b/source3/tdb/tdb.c
@@ -325,6 +325,196 @@ static int rec_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
return 0;
}
+/* read a freelist record and check for simple errors */
+static int rec_free_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
+{
+ if (tdb_read(tdb, offset, (char *)rec, sizeof(*rec)) == -1) return -1;
+ if (rec->magic != TDB_FREE_MAGIC) {
+#if TDB_DEBUG
+ printf("bad magic 0x%08x at offset %d\n",
+ rec->magic, offset);
+#endif
+ tdb->ecode = TDB_ERR_CORRUPT;
+ return -1;
+ }
+ if (tdb_oob(tdb, rec->next) != 0) {
+ return -1;
+ }
+ return 0;
+}
+
+/* Add an element into the (sorted) freelist. Merge adjacent records
+ if neccessary. */
+
+static int tdb_free(TDB_CONTEXT *tdb, tdb_off rec_offset, struct list_struct *rec)
+{
+ tdb_off curr_offset = 0;
+ struct list_struct curr_rec;
+
+ /* Set rec as free. */
+ rec->magic = TDB_FREE_MAGIC;
+ rec->next = 0;
+
+ tdb_lock(tdb, -1, F_WRLCK);
+
+ /* Find the correct place for this offset in the freelist. */
+
+ if (ofs_read(tdb, FREELIST_TOP, &curr_offset) == -1) {
+ goto fail;
+ }
+
+ /* Special case 1 - no freelist. */
+ if (curr_offset == 0) {
+ if (rec_write(tdb, rec_offset, rec) == -1)
+ goto fail;
+
+ if (ofs_write(tdb, FREELIST_TOP, &rec_offset) == -1) {
+ tdb->ecode = TDB_ERR_CORRUPT;
+ goto fail;
+ }
+
+#if TDB_DEBUG_FREE
+ {
+ extern void tdb_printfreelist(TDB_CONTEXT *);
+
+ tdb_printfreelist(tdb);
+ }
+#endif
+ tdb_unlock(tdb, -1);
+ return 0;
+ }
+
+ /* Special case 2 - rec should be inserted at start of freelist. */
+ if (rec_offset < curr_offset) {
+
+ /* Link the record being freed into the freelist. */
+ rec->next = curr_offset;
+
+ /* Check for merge with first record. */
+ if (rec_offset + rec->rec_len + sizeof(struct list_struct) == curr_offset ) {
+
+ /* Read the first freelist record. */
+ if (rec_free_read(tdb, curr_offset, &curr_rec) == -1) {
+ goto fail;
+ }
+
+ rec->rec_len += (curr_rec.rec_len + sizeof(struct list_struct));
+ rec->next = curr_rec.next;
+ }
+
+ /* Write out the new record. */
+ if (rec_write(tdb, rec_offset, rec) == -1)
+ goto fail;
+
+ /* Insert at the start of the freelist. */
+ if (ofs_write(tdb, FREELIST_TOP, &rec_offset) == -1) {
+ tdb->ecode = TDB_ERR_CORRUPT;
+ goto fail;
+ }
+
+#if TDB_DEBUG_FREE
+ {
+ extern void tdb_printfreelist(TDB_CONTEXT *);
+
+ tdb_printfreelist(tdb);
+ }
+#endif
+ tdb_unlock(tdb, -1);
+ return 0;
+ }
+
+ /* Find the correct place to insert into the freelist. */
+
+ /* Read the first freelist record. */
+ if (rec_free_read(tdb, curr_offset, &curr_rec) == -1) {
+ goto fail;
+ }
+
+ while ( curr_rec.next && (rec_offset > curr_rec.next)) {
+
+ curr_offset = curr_rec.next;
+
+ if (tdb_read(tdb, curr_offset, (char *)&curr_rec, sizeof(struct list_struct)) == -1) {
+ goto fail;
+ }
+
+ if (curr_rec.magic != TDB_FREE_MAGIC) {
+#if TDB_DEBUG
+ printf("bad magic in freelist 0x%08x at offset %d\n",
+ curr_rec.magic, curr_offset);
+#endif
+ tdb->ecode = TDB_ERR_CORRUPT;
+ goto fail;
+ }
+ }
+
+ /* Link the record being freed into the freelist. */
+ rec->next = curr_rec.next;
+ curr_rec.next = rec_offset;
+
+ /* Check for merge with previous record. */
+
+ if (curr_offset + curr_rec.rec_len + sizeof(struct list_struct) == rec_offset) {
+ /* Merge with previous. */
+ curr_rec.rec_len += (rec->rec_len + sizeof(struct list_struct));
+ curr_rec.next = rec->next;
+ rec_offset = curr_offset;
+ *rec = curr_rec;
+ }
+
+
+ /* Check for merge with next record. */
+ if (rec_offset + rec->rec_len + sizeof(struct list_struct) == rec->next ) {
+ struct list_struct next_rec;
+
+ if (rec_free_read(tdb, rec->next, &next_rec) == -1) {
+ goto fail;
+ }
+
+ /* Merge with next. */
+ rec->rec_len += (next_rec.rec_len + sizeof(struct list_struct));
+ rec->next = next_rec.next;
+ }
+
+ /* At this point rec_offset is the offset of the
+ new free record, and rec points at the new record to write. */
+
+#if TDB_DEBUG_FREE
+ printf("tdb free: writing record of size %x at offset %x\n",
+ rec->rec_len, rec_offset );
+#endif
+
+ /* Write the new record. */
+ if (rec_write(tdb, rec_offset, rec) == -1) {
+ tdb->ecode = TDB_ERR_CORRUPT;
+ goto fail;
+ }
+
+ /* Now link into the freelist. */
+ if (rec_offset != curr_offset) {
+ if (rec_write(tdb, curr_offset, &curr_rec) == -1) {
+ tdb->ecode = TDB_ERR_CORRUPT;
+ goto fail;
+ }
+ }
+
+#if TDB_DEBUG_FREE
+ {
+ extern void tdb_printfreelist(TDB_CONTEXT *);
+
+ tdb_printfreelist(tdb);
+ }
+#endif
+
+ tdb_unlock(tdb, -1);
+ return 0;
+
+ fail:
+
+ tdb_unlock(tdb, -1);
+ return -1;
+}
+
/* expand the database at least length bytes by expanding the
underlying file and doing the mmap again if necessary */
static int tdb_expand(TDB_CONTEXT *tdb, tdb_off length)
@@ -346,17 +536,9 @@ static int tdb_expand(TDB_CONTEXT *tdb, tdb_off length)
length = ((tdb->map_size + length + TDB_PAGE_SIZE) & ~(TDB_PAGE_SIZE - 1)) - tdb->map_size;
/* expand the file itself */
- if (!(tdb->flags & TDB_INTERNAL)) {
+ if (!(tdb->flags & TDB_INTERNAL)) {
lseek(tdb->fd, tdb->map_size + length - 1, SEEK_SET);
if (write(tdb->fd, &b, 1) != 1) goto fail;
- }
-
- /* form a new freelist record */
- offset = FREELIST_TOP;
- rec.rec_len = length - sizeof(rec);
- rec.magic = TDB_FREE_MAGIC;
- if (ofs_read(tdb, offset, &rec.next) == -1) {
- goto fail;
}
#if HAVE_MMAP
@@ -368,25 +550,24 @@ static int tdb_expand(TDB_CONTEXT *tdb, tdb_off length)
tdb->map_size += length;
- if (tdb->flags & TDB_INTERNAL) {
+ if (tdb->flags & TDB_INTERNAL) {
tdb->map_ptr = realloc(tdb->map_ptr, tdb->map_size);
- }
-
- /* write it out */
- if (rec_write(tdb, tdb->map_size - length, &rec) == -1) {
- goto fail;
}
+ /* form a new freelist record */
+ memset(&rec,'\0',sizeof(rec));
+ rec.rec_len = length - sizeof(rec);
+
/* link it into the free list */
- ptr = tdb->map_size - length;
- if (ofs_write(tdb, offset, &ptr) == -1) goto fail;
+ offset = tdb->map_size - length;
+ if (tdb_free(tdb, offset, &rec) == -1) goto fail;
#if HAVE_MMAP
- if (!(tdb->flags & TDB_NOMMAP)) {
+ if (!(tdb->flags & TDB_NOMMAP)) {
tdb->map_ptr = (void *)mmap(NULL, tdb->map_size,
PROT_READ|PROT_WRITE,
MAP_SHARED | MAP_FILE, tdb->fd, 0);
- }
+ }
#endif
tdb_unlock(tdb, -1);
@@ -470,6 +651,15 @@ static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length)
/* all done - return the new record offset */
tdb_unlock(tdb, -1);
+
+#if TDB_DEBUG_FREE
+ {
+ extern void tdb_printfreelist(TDB_CONTEXT *);
+ printf("tdb_allocate: offset %x, size %x\n", rec_ptr, rec.rec_len);
+
+ tdb_printfreelist(tdb);
+ }
+#endif
return rec_ptr;
}
@@ -978,23 +1168,13 @@ int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key)
}
}
tdb_unlock(tdb, BUCKET(hash));
- tdb_lock(tdb, -1, F_WRLCK);
+
/* and recover the space */
- offset = FREELIST_TOP;
- if (ofs_read(tdb, offset, &rec.next) == -1) {
- goto fail2;
- }
- rec.magic = TDB_FREE_MAGIC;
- if (rec_write(tdb, rec_ptr, &rec) == -1) {
+ if (tdb_free(tdb, rec_ptr, &rec) == -1)
goto fail2;
- }
- if (ofs_write(tdb, offset, &rec_ptr) == -1) {
- goto fail2;
- }
/* yipee - all done */
free(data);
- tdb_unlock(tdb, -1);
return 0;
}
@@ -1016,7 +1196,6 @@ int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key)
fail2:
if (data) free(data);
- tdb_unlock(tdb, -1);
return -1;
}
@@ -1324,6 +1503,7 @@ void tdb_printfreelist(TDB_CONTEXT *tdb)
return;
}
+ printf("freelist top=[0x%08x]\n", rec_ptr );
while (rec_ptr) {
if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec)) == -1) {
return;
diff --git a/source3/tdb/tdbtest.c b/source3/tdb/tdbtest.c
index 67580f9067..9e636eef83 100644
--- a/source3/tdb/tdbtest.c
+++ b/source3/tdb/tdbtest.c
@@ -177,6 +177,43 @@ static int traverse_fn(TDB_CONTEXT *db, TDB_DATA key, TDB_DATA dbuf, void *state
return 0;
}
+static void merge_test()
+{
+ int klen, dlen;
+ int i;
+ char keys[5][2];
+ TDB_DATA key, data;
+
+ for (i = 0; i < 5; i++) {
+ sprintf(keys[i], "%d", i);
+ key.dptr = keys[i];
+ key.dsize = 2;
+
+ data.dptr = "test";
+ data.dsize = 4;
+
+ if (tdb_store(db, key, data, TDB_REPLACE) != 0) {
+ fatal("tdb_store failed");
+ }
+ }
+
+ key.dptr = keys[0];
+ tdb_delete(db, key);
+ tdb_printfreelist(db);
+ key.dptr = keys[4];
+ tdb_delete(db, key);
+ tdb_printfreelist(db);
+ key.dptr = keys[2];
+ tdb_delete(db, key);
+ tdb_printfreelist(db);
+ key.dptr = keys[1];
+ tdb_delete(db, key);
+ tdb_printfreelist(db);
+ key.dptr = keys[3];
+ tdb_delete(db, key);
+ tdb_printfreelist(db);
+}
+
int main(int argc, char *argv[])
{
int i, seed=0;
@@ -201,6 +238,8 @@ int main(int argc, char *argv[])
printf("gdbm got %.2f ops/sec\n", i/end_timer());
#endif
+ merge_test();
+
srand(seed);
start_timer();
for (i=0;i<loops;i++) addrec_db();
generated by cgit (git 2.34.1) at 2024-07-12 12:54:25 +0000