Golang File.Remove方法代码示例

func (db *DB) recoverJournal() error {
	// Get all tables and sort it by file number.
	journalFiles_, err := db.s.getFiles(storage.TypeJournal)
	if err != nil {
		return err
	}
	journalFiles := files(journalFiles_)
	journalFiles.sort()

	// Discard older journal.
	prev := -1
	for i, file := range journalFiles {
		if file.Num() >= db.s.stJournalNum {
			if prev >= 0 {
				i--
				journalFiles[i] = journalFiles[prev]
			}
			journalFiles = journalFiles[i:]
			break
		} else if file.Num() == db.s.stPrevJournalNum {
			prev = i
		}
	}

	var jr *journal.Reader
	var of storage.File
	var mem *memdb.DB
	batch := new(Batch)
	cm := newCMem(db.s)
	buf := new(util.Buffer)
	// Options.
	strict := db.s.o.GetStrict(opt.StrictJournal)
	checksum := db.s.o.GetStrict(opt.StrictJournalChecksum)
	writeBuffer := db.s.o.GetWriteBuffer()
	recoverJournal := func(file storage.File) error {
		db.logf("[email protected] recovering @%d", file.Num())
		reader, err := file.Open()
		if err != nil {
			return err
		}
		defer reader.Close()

		// Create/reset journal reader instance.
		if jr == nil {
			jr = journal.NewReader(reader, dropper{db.s, file}, strict, checksum)
		} else {
			jr.Reset(reader, dropper{db.s, file}, strict, checksum)
		}

		// Flush memdb and remove obsolete journal file.
		if of != nil {
			if mem.Len() > 0 {
				if err := cm.flush(mem, 0); err != nil {
					return err
				}
			}
			if err := cm.commit(file.Num(), db.seq); err != nil {
				return err
			}
			cm.reset()
			of.Remove()
			of = nil
		}

		// Replay journal to memdb.
		mem.Reset()
		for {
			r, err := jr.Next()
			if err != nil {
				if err == io.EOF {
					break
				}
				return err
			}

			buf.Reset()
			if _, err := buf.ReadFrom(r); err != nil {
				if err == io.ErrUnexpectedEOF {
					continue
				} else {
					return err
				}
			}
			if err := batch.decode(buf.Bytes()); err != nil {
				return err
			}
			if err := batch.memReplay(mem); err != nil {
				return err
			}

			// Save sequence number.
			db.seq = batch.seq + uint64(batch.len())

			// Flush it if large enough.
			if mem.Size() >= writeBuffer {
				if err := cm.flush(mem, 0); err != nil {
					return err
				}
				mem.Reset()
			}
//.........这里部分代码省略.........

func (db *DB) recoverJournal() error {
	// Get all journals and sort it by file number.
	allJournalFiles, err := db.s.getFiles(storage.TypeJournal)
	if err != nil {
		return err
	}
	files(allJournalFiles).sort()

	// Journals that will be recovered.
	var recJournalFiles []storage.File
	for _, jf := range allJournalFiles {
		if jf.Num() >= db.s.stJournalNum || jf.Num() == db.s.stPrevJournalNum {
			recJournalFiles = append(recJournalFiles, jf)
		}
	}

	var (
		of  storage.File // Obsolete file.
		rec = &sessionRecord{}
	)

	// Recover journals.
	if len(recJournalFiles) > 0 {
		db.logf("[email protected] F·%d", len(recJournalFiles))

		// Mark file number as used.
		db.s.markFileNum(recJournalFiles[len(recJournalFiles)-1].Num())

		var (
			// Options.
			strict      = db.s.o.GetStrict(opt.StrictJournal)
			checksum    = db.s.o.GetStrict(opt.StrictJournalChecksum)
			writeBuffer = db.s.o.GetWriteBuffer()

			jr    *journal.Reader
			mdb   = memdb.New(db.s.icmp, writeBuffer)
			buf   = &util.Buffer{}
			batch = &Batch{}
		)

		for _, jf := range recJournalFiles {
			db.logf("[email protected] recovering @%d", jf.Num())

			fr, err := jf.Open()
			if err != nil {
				return err
			}

			// Create or reset journal reader instance.
			if jr == nil {
				jr = journal.NewReader(fr, dropper{db.s, jf}, strict, checksum)
			} else {
				jr.Reset(fr, dropper{db.s, jf}, strict, checksum)
			}

			// Flush memdb and remove obsolete journal file.
			if of != nil {
				if mdb.Len() > 0 {
					if _, err := db.s.flushMemdb(rec, mdb, -1); err != nil {
						fr.Close()
						return err
					}
				}

				rec.setJournalNum(jf.Num())
				rec.setSeqNum(db.seq)
				if err := db.s.commit(rec); err != nil {
					fr.Close()
					return err
				}
				rec.resetAddedTables()

				of.Remove()
				of = nil
			}

			// Replay journal to memdb.
			mdb.Reset()
			for {
				r, err := jr.Next()
				if err != nil {
					if err == io.EOF {
						break
					}

					fr.Close()
					return errors.SetFile(err, jf)
				}

				buf.Reset()
				if _, err := buf.ReadFrom(r); err != nil {
					if err == io.ErrUnexpectedEOF {
						// This is error returned due to corruption, with strict == false.
						continue
					}

					fr.Close()
					return errors.SetFile(err, jf)
				}
				if err := batch.memDecodeAndReplay(db.seq, buf.Bytes(), mdb); err != nil {
//.........这里部分代码省略.........

func (h *dbCorruptHarness) corrupt(ft storage.FileType, offset, n int) {
	p := &h.dbHarness
	t := p.t

	var file storage.File
	ff, _ := p.stor.GetFiles(ft)
	for _, f := range ff {
		if file == nil || f.Num() > file.Num() {
			file = f
		}
	}
	if file == nil {
		t.Fatalf("no such file with type %q", ft)
	}

	r, err := file.Open()
	if err != nil {
		t.Fatal("cannot open file: ", err)
	}
	x, err := r.Seek(0, 2)
	if err != nil {
		t.Fatal("cannot query file size: ", err)
	}
	m := int(x)
	if _, err := r.Seek(0, 0); err != nil {
		t.Fatal(err)
	}

	if offset < 0 {
		if -offset > m {
			offset = 0
		} else {
			offset = m + offset
		}
	}
	if offset > m {
		offset = m
	}
	if offset+n > m {
		n = m - offset
	}

	buf := make([]byte, m)
	_, err = io.ReadFull(r, buf)
	if err != nil {
		t.Fatal("cannot read file: ", err)
	}
	r.Close()

	for i := 0; i < n; i++ {
		buf[offset+i] ^= 0x80
	}

	err = file.Remove()
	if err != nil {
		t.Fatal("cannot remove old file: ", err)
	}
	w, err := file.Create()
	if err != nil {
		t.Fatal("cannot create new file: ", err)
	}
	_, err = w.Write(buf)
	if err != nil {
		t.Fatal("cannot write new file: ", err)
	}
	w.Close()
}

func (d *DB) recoverJournal() error {
	s := d.s

	ff0, err := s.getFiles(storage.TypeJournal)
	if err != nil {
		return err
	}
	ff1 := files(ff0)
	ff1.sort()
	ff2 := make([]storage.File, 0, len(ff1))
	for _, file := range ff1 {
		if file.Num() >= s.stJournalNum || file.Num() == s.stPrevJournalNum {
			s.markFileNum(file.Num())
			ff2 = append(ff2, file)
		}
	}

	var jr *journal.Reader
	var of storage.File
	var mem *memdb.DB
	batch := new(Batch)
	cm := newCMem(s)
	buf := new(util.Buffer)
	// Options.
	strict := s.o.GetStrict(opt.StrictJournal)
	checksum := s.o.GetStrict(opt.StrictJournalChecksum)
	writeBuffer := s.o.GetWriteBuffer()
	recoverJournal := func(file storage.File) error {
		s.logf("[email protected] recovering @%d", file.Num())
		reader, err := file.Open()
		if err != nil {
			return err
		}
		defer reader.Close()
		if jr == nil {
			jr = journal.NewReader(reader, dropper{s, file}, strict, checksum)
		} else {
			jr.Reset(reader, dropper{s, file}, strict, checksum)
		}
		if of != nil {
			if mem.Len() > 0 {
				if err := cm.flush(mem, 0); err != nil {
					return err
				}
			}
			if err := cm.commit(file.Num(), d.seq); err != nil {
				return err
			}
			cm.reset()
			of.Remove()
			of = nil
		}
		// Reset memdb.
		mem.Reset()
		for {
			r, err := jr.Next()
			if err != nil {
				if err == io.EOF {
					break
				}
				return err
			}
			buf.Reset()
			if _, err := buf.ReadFrom(r); err != nil {
				if strict {
					return err
				}
				continue
			}
			if err := batch.decode(buf.Bytes()); err != nil {
				return err
			}
			if err := batch.memReplay(mem); err != nil {
				return err
			}
			d.seq = batch.seq + uint64(batch.len())
			if mem.Size() >= writeBuffer {
				// Large enough, flush it.
				if err := cm.flush(mem, 0); err != nil {
					return err
				}
				// Reset memdb.
				mem.Reset()
			}
		}
		of = file
		return nil
	}
	// Recover all journals.
	if len(ff2) > 0 {
		s.logf("[email protected] F·%d", len(ff2))
		mem = memdb.New(s.icmp, writeBuffer)
		for _, file := range ff2 {
			if err := recoverJournal(file); err != nil {
				return err
			}
		}
		// Flush the last journal.
		if mem.Len() > 0 {
			if err := cm.flush(mem, 0); err != nil {
//.........这里部分代码省略.........