Golang bufio.NewReaderSize函数代码示例

// startCommand starts up a command and creates a stdin pipe and a buffered
// stdout & stderr pipes, wrapped in a wrappedCmd. The stdout buffer will be of stdoutBufSize
// bytes.
func startCommand(command string, args ...string) (*wrappedCmd, error) {
	cmd := exec.Command(command, args...)
	stdout, err := cmd.StdoutPipe()
	if err != nil {
		return nil, err
	}
	stderr, err := cmd.StderrPipe()
	if err != nil {
		return nil, err
	}

	stdin, err := cmd.StdinPipe()
	if err != nil {
		return nil, err
	}

	tracerx.Printf("run_command: %s %s", command, strings.Join(args, " "))
	if err := cmd.Start(); err != nil {
		return nil, err
	}

	return &wrappedCmd{
		stdin,
		bufio.NewReaderSize(stdout, stdoutBufSize),
		bufio.NewReaderSize(stderr, stdoutBufSize),
		cmd,
	}, nil
}

func (c *RedisCmd) parseRESP() (interface{}, error) {
	//reader := bytes.NewReader(c.data)
	//bufio 的 NewReader Size默认值比reader大的话，会reset多损耗性能
	//br := bufio.NewReaderSize(reader, reader.Len())
	if c.r == nil {
		c.r = bytes.NewReader(c.data)
		c.br = bufio.NewReaderSize(c.r, c.r.Len())
	} else {
		c.r.Reset(c.data)
		//reset并不能扩充buffer的大小，所以用buffered并不能得出剩余数据的大小，而仅仅是buff里面还未读出来的，可能还有部分
		//数据在c.r中
		//c.br.Reset(c.r)
		c.br = bufio.NewReaderSize(c.r, c.r.Len())
	}
	if resp, neededDataLen, err := parseRESP(c.br); err != nil {
		if err == ErrUnexpectedRESPEOF || err == ErrBufferFullRESP {
			//数据还没收完
		}
		c.neededDataLen = neededDataLen
		return nil, err
	} else {
		c.neededDataLen = 0
		return resp, nil
	}
}

// *****************************************************************************
// CREATION OF INDEX FILE
// *****************************************************************************
func (g *YIndex) CreateIndexFiles() (int, error) {
	count := 0
	// -------------------------------------------------------------------------
	// OPEN AN INPUT FILE
	// -------------------------------------------------------------------------
	fi, err := os.Open(g.InputFileName)
	if err != nil {
		return count, errors.New(
			fmt.Sprintf("Cannot open file <%s>.", g.InputFileName),
		)
	}
	bfi := bufio.NewReaderSize(fi, 1*1024*1024)
	defer fi.Close()

	// -------------------------------------------------------------------------
	// CREATE MAIN INDEXING FILE
	// -------------------------------------------------------------------------
	fo1, err := os.Create(g.InputFileName + ".yidx1")
	if err != nil {
		return count, errors.New(
			fmt.Sprintf("Cannot create main indexing file <%s.yidx1>.",
				g.InputFileName+".yidx1"),
		)
	}
	bfo1 := bufio.NewWriter(fo1)

	count, err = g.createIndexFile1(bfi, bfo1)
	if err != nil {
		return count, err
	}
	fo1.Close()

	// -------------------------------------------------------------------------
	// CREATE DOUBLE INDEXING FILE (THISFILE WILL BE LOADED INTO MEMORY)
	// -------------------------------------------------------------------------
	fi1, err := os.Open(g.InputFileName + ".yidx1")
	if err != nil {
		return count, errors.New(
			fmt.Sprintf("Cannot read main indexing file <%s>.",
				g.InputFileName+".yidx1"),
		)
	}
	bfi1 := bufio.NewReaderSize(fi1, 1*1024*1024)
	defer fi1.Close()

	fo2, err := os.Create(g.InputFileName + ".yidx2")
	if err != nil {
		return count, errors.New(
			fmt.Sprintf("Cannot create double indexing file <%s>.",
				g.InputFileName+".yidx2"),
		)
	}
	bfo2 := bufio.NewWriter(fo2)
	count, err = g.createIndexFile2(bfi1, bfo2)
	if err != nil {
		return count, err
	}
	fo2.Close()
	return count, nil
}

func main() {
	Log.SetHandler(log15.StderrHandler)
	flagConnect := flag.String("connect", os.Getenv("BRUNO_ID"), "database connection string")
	flagCharset := flag.String("charset", term.GetTTYEncodingName(), "input charset of the csv")
	flagTruncate := flag.Bool("truncate", false, "truncate table?")
	flagSep := flag.String("sep", ";", "csv field separator")
	flag.Parse()

	var enc encoding.Encoding
	if *flagCharset != "" {
		enc = text.GetEncoding(*flagCharset)
		if enc == nil {
			Log.Error("unknown charset " + *flagCharset)
			os.Exit(1)
		}
	}

	db, err := sql.Open("ora", *flagConnect)
	if err != nil {
		Log.Crit("connect to db", "dsn", *flagConnect, "error", err)
		os.Exit(1)
	}
	defer db.Close()

	fh, err := os.Open(flag.Arg(0))
	if err != nil {
		Log.Crit("open csv", "file", flag.Arg(0), "error", err)
		os.Exit(1)
	}
	defer fh.Close()
	r := io.Reader(fh)
	if enc != nil {
		Log.Debug("NewReader", "encoding", enc)
		r = text.NewReader(bufio.NewReaderSize(r, 1<<20), enc)
	}

	if *flagTruncate {
		if _, err = db.Exec("TRUNCATE TABLE " + flag.Arg(1)); err != nil {
			Log.Error("TRUNCATE", "table", flag.Arg(1), "error", err)
			os.Exit(1)
		}
	}
	if os.Getenv("GOMAXPROCS") == "" {
		Log.Info("Setting GOMAXPROCS", "numCPU", runtime.NumCPU())
		runtime.GOMAXPROCS(runtime.NumCPU())
	}

	cr := csv.NewReader(bufio.NewReaderSize(r, 16<<20))
	cr.Comma = ([]rune(*flagSep))[0]
	cr.TrimLeadingSpace = true
	cr.LazyQuotes = true
	if err := load(db, flag.Arg(1), cr); err != nil {
		Log.Error("load", "error", err)
		os.Exit(2)
	}
}

// handleConnection wraps the in and out connection endpoints for transfer between them.
func handleConnection(clientConn net.Conn, serverConn net.Conn, txHandlers []func([]byte), rxHandlers []func([]byte)) {
	clientReader := bufio.NewReaderSize(clientConn, 8192)
	clientWriter := bufio.NewWriterSize(clientConn, 8192)

	serverReader := bufio.NewReaderSize(serverConn, 8192)
	serverWriter := bufio.NewWriterSize(serverConn, 8192)

	go pipeReaderToWriter(clientReader, serverWriter, txHandlers)
	go pipeReaderToWriter(serverReader, clientWriter, rxHandlers)
}

func TestPeek(t *testing.T) {
	p := make([]byte, 10)
	// string is 16 (minReadBufferSize) long.
	buf := bufio.NewReaderSize(strings.NewReader("abcdefghijklmnop"), minReadBufferSize)
	if s, err := buf.Peek(1); string(s) != "a" || err != nil {
		t.Fatalf("want %q got %q, err=%v", "a", string(s), err)
	}
	if s, err := buf.Peek(4); string(s) != "abcd" || err != nil {
		t.Fatalf("want %q got %q, err=%v", "abcd", string(s), err)
	}
	if _, err := buf.Peek(32); err != bufio.ErrBufferFull {
		t.Fatalf("want ErrBufFull got %v", err)
	}
	if _, err := buf.Read(p[0:3]); string(p[0:3]) != "abc" || err != nil {
		t.Fatalf("want %q got %q, err=%v", "abc", string(p[0:3]), err)
	}
	if s, err := buf.Peek(1); string(s) != "d" || err != nil {
		t.Fatalf("want %q got %q, err=%v", "d", string(s), err)
	}
	if s, err := buf.Peek(2); string(s) != "de" || err != nil {
		t.Fatalf("want %q got %q, err=%v", "de", string(s), err)
	}
	if _, err := buf.Read(p[0:3]); string(p[0:3]) != "def" || err != nil {
		t.Fatalf("want %q got %q, err=%v", "def", string(p[0:3]), err)
	}
	if s, err := buf.Peek(4); string(s) != "ghij" || err != nil {
		t.Fatalf("want %q got %q, err=%v", "ghij", string(s), err)
	}
	if _, err := buf.Read(p[0:]); string(p[0:]) != "ghijklmnop" || err != nil {
		t.Fatalf("want %q got %q, err=%v", "ghijklmnop", string(p[0:minReadBufferSize]), err)
	}
	if s, err := buf.Peek(0); string(s) != "" || err != nil {
		t.Fatalf("want %q got %q, err=%v", "", string(s), err)
	}
	if _, err := buf.Peek(1); err != io.EOF {
		t.Fatalf("want EOF got %v", err)
	}

	// Test for issue 3022, not exposing a reader's error on a successful Peek.
	buf = bufio.NewReaderSize(dataAndEOFReader("abcd"), 32)
	if s, err := buf.Peek(2); string(s) != "ab" || err != nil {
		t.Errorf(`Peek(2) on "abcd", EOF = %q, %v; want "ab", nil`, string(s), err)
	}
	if s, err := buf.Peek(4); string(s) != "abcd" || err != nil {
		t.Errorf(`Peek(4) on "abcd", EOF = %q, %v; want "abcd", nil`, string(s), err)
	}
	if n, err := buf.Read(p[0:5]); string(p[0:n]) != "abcd" || err != nil {
		t.Fatalf("Read after peek = %q, %v; want abcd, EOF", p[0:n], err)
	}
	if n, err := buf.Read(p[0:1]); string(p[0:n]) != "" || err != io.EOF {
		t.Fatalf(`second Read after peek = %q, %v; want "", EOF`, p[0:n], err)
	}
}

func (cmd *cmdSync) SendPSyncCmd(master, passwd string) (pipe.Reader, int64) {
	c := openNetConn(master, passwd)
	br := bufio.NewReaderSize(c, ReaderBufferSize)
	bw := bufio.NewWriterSize(c, WriterBufferSize)

	runid, offset, wait := sendPSyncFullsync(br, bw)
	log.Infof("psync runid = %s offset = %d, fullsync", runid, offset)

	var nsize int64
	for nsize == 0 {
		select {
		case nsize = <-wait:
			if nsize == 0 {
				log.Info("+")
			}
		case <-time.After(time.Second):
			log.Info("-")
		}
	}

	piper, pipew := pipe.NewSize(ReaderBufferSize)

	go func() {
		defer pipew.Close()
		p := make([]byte, 8192)
		for rdbsize := int(nsize); rdbsize != 0; {
			rdbsize -= iocopy(br, pipew, p, rdbsize)
		}
		for {
			n, err := cmd.PSyncPipeCopy(c, br, bw, offset, pipew)
			if err != nil {
				log.PanicErrorf(err, "psync runid = %s, offset = %d, pipe is broken", runid, offset)
			}
			offset += n
			for {
				time.Sleep(time.Second)
				c = openNetConnSoft(master, passwd)
				if c != nil {
					log.Infof("psync reopen connection, offset = %d", offset)
					break
				} else {
					log.Infof("psync reopen connection, failed")
				}
			}
			authPassword(c, passwd)
			br = bufio.NewReaderSize(c, ReaderBufferSize)
			bw = bufio.NewWriterSize(c, WriterBufferSize)
			sendPSyncContinue(br, bw, runid, offset)
		}
	}()
	return piper, nsize
}

func TestNewReaderSizeIdempotent(t *testing.T) {
	const BufSize = 1000
	b := bufio.NewReaderSize(bytes.NewBufferString("hello world"), BufSize)
	// Does it recognize itself?
	b1 := bufio.NewReaderSize(b, BufSize)
	if b1 != b {
		t.Error("bufio.NewReaderSize did not detect underlying Reader")
	}
	// Does it wrap if existing buffer is too small?
	b2 := bufio.NewReaderSize(b, 2*BufSize)
	if b2 == b {
		t.Error("bufio.NewReaderSize did not enlarge buffer")
	}
}

// Return a buffered reader from an io.Reader
// If f == "-", then it will attempt to read from os.Stdin.
// If the file is gzipped, it will be read as such.
func Buf(r io.Reader) *Reader {
	b := bufio.NewReaderSize(r, getSize())
	var rdr *gzip.Reader
	if is, err := IsGzip(b); err != nil && err != io.EOF {
		log.Fatal(err)
	} else if is {
		rdr, err = gzip.NewReader(b)
		if err != nil {
			log.Fatal(err)
		}
		b = bufio.NewReaderSize(rdr, getSize())
	}
	return &Reader{b, r, rdr}
}

// this method returns an array or responses that client has to handle
// considering adding error to the reply type but i don't know if we really need it
// response can contain nil's!
func (client *Client) executeAnyArrayCommand(command []byte) ([]*Reply, error) {
	_, err := client.runCommand(command)

	if err != nil {
		return nil, err
	}

	reader := bufio.NewReaderSize(client.connection, bufSize)
	result, err := readResponse(reader)

	if err != nil {
		return nil, err
	}

	if res, ok := result.Response.([]interface{}); ok {

		result_array := make([]*Reply, len(res))

		for i, elem := range res {
			origin, _ := elem.(*Reply)
			result_array[i] = origin
		}
		return result_array, nil

	} else {
		return nil, errors.New("Internal reddan error, unexpected response type")
	}

}

func (client *Client) executeStringArrayCommand(command []byte) ([]string, error) {
	_, err := client.runCommand(command)

	if err != nil {
		return nil, err
	}

	reader := bufio.NewReaderSize(client.connection, bufSize)
	result, err := readResponse(reader)

	if err != nil {
		return nil, err
	}

	if res, ok := result.Response.([]interface{}); ok {

		result_array := make([]string, len(res))

		// TODO requires work on errors and refactor
		for i, elem := range res {
			origin, _ := elem.(*Reply) // change _ to ok and refactor Array responses
			el := origin.Response.([]byte)
			result_array[i] = string(el)
		}
		return result_array, nil

	} else {
		return nil, errors.New("Internal reddan error, unexpected response type")
	}

}

func (s *ProxyServer) handleClient(w http.ResponseWriter, r *http.Request) error {
	ip, _, _ := net.SplitHostPort(r.RemoteAddr)
	cs := &Session{ip: ip, enc: json.NewEncoder(w)}
	defer r.Body.Close()
	connbuff := bufio.NewReaderSize(r.Body, MaxReqSize)

	for {
		data, isPrefix, err := connbuff.ReadLine()
		if isPrefix {
			log.Printf("Socket flood detected")
			return errors.New("Socket flood")
		} else if err == io.EOF {
			break
		}

		if len(data) > 1 {
			var req JSONRpcReq
			err = json.Unmarshal(data, &req)
			if err != nil {
				log.Printf("Malformed request: %v", err)
				return err
			}
			cs.handleMessage(s, r, &req)
		}
	}
	return nil
}

func (s *Server) newConn(rwc net.Conn) (c *conn, err error) {
	c = new(conn)
	c.server = s
	c.conn = rwc
	c.rwc = bufio.NewReadWriter(bufio.NewReaderSize(rwc, 1048576), bufio.NewWriter(rwc))
	return c, nil
}

// Creates and opens a new connection to server per ConnectionSpec.
// The new connection is wrapped by a new connHdl with its bufio.Reader
// delegating to the net.Conn's reader. 
//
func newConnHdl (spec *ConnectionSpec) (hdl *connHdl, err os.Error) {
	here := "newConnHdl";

	if hdl = new(connHdl); hdl == nil { 
		return nil, withNewError (fmt.Sprintf("%s(): failed to allocate connHdl", here));
	}
	addr := fmt.Sprintf("%s:%d", spec.host, spec.port); 
	raddr, e:= net.ResolveTCPAddr(addr); 
	if e != nil {
		return nil, withNewError (fmt.Sprintf("%s(): failed to resolve remote address %s", here, addr));
	}	
	conn, e:= net.DialTCP(TCP, nil, raddr);
	switch {
		case e != nil:
			err = withOsError (fmt.Sprintf("%s(): could not open connection", here), e);
		case conn == nil:
			err = withNewError (fmt.Sprintf("%s(): net.Dial returned nil, nil (?)", here));
		default:
			configureConn(conn, spec);
			hdl.spec = spec;
			hdl.conn = conn;
			bufsize := 4096;
			hdl.reader, e = bufio.NewReaderSize(conn, bufsize);
			if e != nil {
				err = withNewError (fmt.Sprintf("%s(): bufio.NewReaderSize (%d) error", here, bufsize));
			}
			else {
				if debug() {log.Stdout("[Go-Redis] Opened SynchConnection connection to ", addr);}
			}
	}
	return hdl, err;
}

func sbclBin(path string) string {
	u := uname_m() + "-" + uname()
	condPrintf(1, "open %s\n", path)
	in, err := os.Open(path)
	if err != nil {
		panic(err)
	}
	defer in.Close()
	r := bufio.NewReaderSize(in, 4096)
	doc, err := html.Parse(r)
	if err != nil {
		panic(err)
	}
	var f func(n *html.Node) string
	f = func(n *html.Node) string {
		if n.Type == html.ElementNode && n.Data == "a" {
			for _, attr := range n.Attr {
				if k, v := attr.Key, attr.Val; k == "href" && (v[len(v)-3:] == "bz2" || v[len(v)-3:] == "msi") && strings.Index(v, u) != -1 {
					return strings.Split(v, "-")[1]
				}
			}
		}
		for c := n.FirstChild; c != nil; c = c.NextSibling {
			if result := f(c); result != "" {
				return result
			}
		}
		return ""
	}
	return f(doc)
}