Example #1
0
File: dbm.go Project: pmezard/exp
// Verify attempts to find any structural errors in DB wrt the organization of
// it as defined by lldb.Allocator. 'bitmap' is a scratch pad for necessary
// bookkeeping and will grow to at most to DB size/128 (0,78%). Any problems
// found are reported to 'log' except non verify related errors like disk read
// fails etc. If 'log' returns false or the error doesn't allow to (reliably)
// continue, the verification process is stopped and an error is returned from
// the Verify function. Passing a nil log works like providing a log function
// always returning false. Any non-structural errors, like for instance Filer
// read errors, are NOT reported to 'log', but returned as the Verify's return
// value, because Verify cannot proceed in such cases. Verify returns nil only
// if it fully completed verifying DB without detecting any error.
//
// It is recommended to limit the number reported problems by returning false
// from 'log' after reaching some limit. Huge and corrupted DB can produce an
// overwhelming error report dataset.
//
// The verifying process will scan the whole DB at least 3 times (a trade
// between processing space and time consumed). It doesn't read the content of
// free blocks above the head/tail info bytes. If the 3rd phase detects lost
// free space, then a 4th scan (a faster one) is performed to precisely report
// all of them.
//
// Statistics are returned via 'stats' if non nil. The statistics are valid
// only if Verify succeeded, ie. it didn't reported anything to log and it
// returned a nil error.
func (db *DB) Verify(log func(error) bool, stats *lldb.AllocStats) (err error) {
	bitmapf, err := fileutil.TempFile(".", "verifier", ".tmp")
	if err != nil {
		return
	}

	defer func() {
		tn := bitmapf.Name()
		bitmapf.Close()
		os.Remove(tn)
	}()

	bitmap := lldb.NewSimpleFileFiler(bitmapf)

	if err = db.enter(); err != nil {
		return
	}

	defer func() {
		if e := recover(); e != nil {
			err = fmt.Errorf("%v", e)
		}
		db.leave(&err)
	}()

	return db.alloc.Verify(bitmap, log, stats)
}
Example #2
0
File: dbm.go Project: pmezard/exp
// CreateTemp creates a new temporary DB in the directory dir with a basename
// beginning with prefix and name ending in suffix. If dir is the empty string,
// CreateTemp uses the default directory for temporary files (see os.TempDir).
// Multiple programs calling CreateTemp simultaneously will not choose the same
// file name for the DB. The caller can use Name() to find the pathname of the
// DB file. It is the caller's responsibility to remove the file when no longer
// needed.
//
// For the meaning of opts please see documentation of Options.
func CreateTemp(dir, prefix, suffix string, opts *Options) (db *DB, err error) {
	f, err := fileutil.TempFile(dir, prefix, suffix)
	if err != nil {
		return
	}

	return create(f, lldb.NewSimpleFileFiler(f), opts, false)
}
Example #3
0
File: kv.go Project: miffa/kv
// CreateTemp creates a new temporary DB in the directory dir with a basename
// beginning with prefix and name ending in suffix. If dir is the empty string,
// CreateTemp uses the default directory for temporary files (see os.TempDir).
// Multiple programs calling CreateTemp simultaneously will not choose the same
// file name for the DB. The caller can use Name() to find the pathname of the
// DB file. It is the caller's responsibility to remove the file when no longer
// needed.
//
// For the meaning of opts please see documentation of Options.
func CreateTemp(dir, prefix, suffix string, opts *Options) (db *DB, err error) {
	opts = opts.clone()
	opts._ACID = _ACIDFull
	f, err := fileutil.TempFile(dir, prefix, suffix)
	if err != nil {
		return
	}

	return create(lldb.NewSimpleFileFiler(f), opts, false)
}