示例#1
0
func (f *wfile) Close() error {
	if rem := f.Chunker.Remaining(); len(rem) > 0 {
		if len(f.chunks) == 0 {
			// Store the file inline. Data is uint32 + len(metadata) + uint32 + rem
			total := 4 + len(f.metadata) + 4 + len(rem)
			data := make([]byte, total)
			out := putMetadata(data, f.metadata)
			// 0 chunks indicates the data is inline
			littleEndian.PutUint32(out, uint32(0))
			copy(out[4:], rem)
			id := f.id
			wfilesPool.Put(f)
			return f.drv.files.Put(internal.StringToBytes(id), data, nil)
		}
		if err := f.Chunker.Flush(); err != nil {
			return err
		}
	}
	if err := f.flushBatch(); err != nil {
		return err
	}
	// Reserve uint32 + len(metadata) + n sha1 hashes + n uint32 + 1 uint32 (for the chunk count)
	total := 4 + len(f.metadata) + (len(f.chunks) * (sha1.Size + 4)) + 4
	data := make([]byte, total)
	out := putMetadata(data, f.metadata)
	littleEndian.PutUint32(out, uint32(len(f.chunks)))
	pos := 4
	for _, chunk := range f.chunks {
		littleEndian.PutUint32(out[pos:], uint32(len(chunk)))
		pos += 4
		n := copy(out[pos:], chunk)
		pos += n
	}
	id := f.id
	wfilesPool.Put(f)
	return f.drv.files.Put(internal.StringToBytes(id), data, nil)
}
示例#2
0
文件: db.go 项目: rainycape/gondola
func (d *DB) preparedStmt(s string) *sql.Stmt {
	// Don't bother making a prepared statement if
	// the transaction is non-nil, since the current
	// implementation of d.tx.Stmt() (as of Go 1.8 freeze)
	// will end up parsing the query string again. Given
	// that tx prepared statements won't be valid once
	// the transaction goes away, we'll most likely end
	// up parsing twice for one execution.
	//
	// XXX: Also, sqlite has some issues with prepared stmts
	// and transactions. TestMigrations in gnd.la/orm wouldn't
	// pass because the connection which created the 1st
	// "migration "table was incorrectly in a transaction and when
	// creating the table for the 1st migration (BadMigration1),
	// the inspection would return that no table was present.
	// Eventually, the table would appear and some other part
	// of the test would fail.
	//
	// TLDR: Make sure the sqlite tests pass if you remove the following
	// check
	if d.tx != nil {
		return nil
	}
	key := crc32.ChecksumIEEE(internal.StringToBytes(s))
	d.mu.RLock()
	cached, ok := d.cache[key]
	d.mu.RUnlock()
	if ok && cached.sql == s {
		if d.tx != nil {
			return d.tx.Stmt(cached.stmt)
		}
		return cached.stmt
	}
	stmt, _ := d.sqlDb.Prepare(s)
	if stmt == nil {
		// Let the non-prepared method report the error
		return nil
	}
	d.mu.Lock()
	if d.cache == nil {
		d.cache = make(map[uint32]cacheEntry)
	}
	d.cache[key] = cacheEntry{sql: s, stmt: stmt}
	d.mu.Unlock()
	if d.tx != nil {
		return d.tx.Stmt(stmt)
	}
	return stmt
}
示例#3
0
func (d *leveldbDriver) Open(id string) (driver.RFile, error) {
	value, err := d.files.Get(internal.StringToBytes(id), nil)
	if err != nil {
		if err == leveldb.ErrNotFound {
			return nil, fmt.Errorf("file %s not found", id)
		}
		return nil, err
	}
	metaLen := int(littleEndian.Uint32(value))
	value = value[4:]
	metadata := value[:metaLen]
	value = value[metaLen:]
	count := int(littleEndian.Uint32(value))
	value = value[4:]
	if count == 0 {
		// Data is inline
		return &rfile{metadata: metadata, chunks: [][]byte{value}}, nil
	}
	pos := 0
	chunks := make([][]byte, count)
	for ii := 0; ii < count; ii++ {
		size := int(littleEndian.Uint32(value[pos:]))
		pos += 4
		key := value[pos : pos+size]
		chunk, err := d.chunks.Get(key, nil)
		if err != nil {
			if err == leveldb.ErrNotFound {
				return nil, fmt.Errorf("chunk %s in file %s not found", hex.EncodeToString(key), id)
			}
			return nil, err
		}
		chunks[ii] = chunk
		pos += size
	}
	return &rfile{metadata: metadata, chunks: chunks}, nil
}