diff --git a/AUTHORS b/AUTHORS index 806b5b121..5ce4f7eca 100644 --- a/AUTHORS +++ b/AUTHORS @@ -73,6 +73,7 @@ Shuode Li Soroush Pour Stan Putrya Stanley Gunawan +Steven Hartland Thomas Wodarek Tom Jenkinson Xiangyu Hu @@ -90,3 +91,4 @@ Keybase Inc. Percona LLC Pivotal Inc. Stripe Inc. +Multiplay Ltd. diff --git a/auth.go b/auth.go index 14f678a87..fec7040d4 100644 --- a/auth.go +++ b/auth.go @@ -360,13 +360,15 @@ func (mc *mysqlConn) handleAuthResult(oldAuthData []byte, plugin string) error { pubKey := mc.cfg.pubKey if pubKey == nil { // request public key from server - data := mc.buf.takeSmallBuffer(4 + 1) + data, err := mc.buf.takeSmallBuffer(4 + 1) + if err != nil { + return err + } data[4] = cachingSha2PasswordRequestPublicKey mc.writePacket(data) // parse public key - data, err := mc.readPacket() - if err != nil { + if data, err = mc.readPacket(); err != nil { return err } diff --git a/buffer.go b/buffer.go index eb4748bf4..19486bd6f 100644 --- a/buffer.go +++ b/buffer.go @@ -22,17 +22,17 @@ const defaultBufSize = 4096 // The buffer is similar to bufio.Reader / Writer but zero-copy-ish // Also highly optimized for this particular use case. type buffer struct { - buf []byte + buf []byte // buf is a byte buffer who's length and capacity are equal. nc net.Conn idx int length int timeout time.Duration } +// newBuffer allocates and returns a new buffer. func newBuffer(nc net.Conn) buffer { - var b [defaultBufSize]byte return buffer{ - buf: b[:], + buf: make([]byte, defaultBufSize), nc: nc, } } @@ -105,43 +105,56 @@ func (b *buffer) readNext(need int) ([]byte, error) { return b.buf[offset:b.idx], nil } -// returns a buffer with the requested size. +// takeBuffer returns a buffer with the requested size. // If possible, a slice from the existing buffer is returned. // Otherwise a bigger buffer is made. // Only one buffer (total) can be used at a time. -func (b *buffer) takeBuffer(length int) []byte { +func (b *buffer) takeBuffer(length int) ([]byte, error) { if b.length > 0 { - return nil + return nil, ErrBusyBuffer } // test (cheap) general case first - if length <= defaultBufSize || length <= cap(b.buf) { - return b.buf[:length] + if length <= cap(b.buf) { + return b.buf[:length], nil } if length < maxPacketSize { b.buf = make([]byte, length) - return b.buf + return b.buf, nil } - return make([]byte, length) + + // buffer is larger than we want to store. + return make([]byte, length), nil } -// shortcut which can be used if the requested buffer is guaranteed to be -// smaller than defaultBufSize +// takeSmallBuffer is shortcut which can be used if length is +// known to be smaller than defaultBufSize. // Only one buffer (total) can be used at a time. -func (b *buffer) takeSmallBuffer(length int) []byte { +func (b *buffer) takeSmallBuffer(length int) ([]byte, error) { if b.length > 0 { - return nil + return nil, ErrBusyBuffer } - return b.buf[:length] + return b.buf[:length], nil } // takeCompleteBuffer returns the complete existing buffer. // This can be used if the necessary buffer size is unknown. +// cap and len of the returned buffer will be equal. // Only one buffer (total) can be used at a time. -func (b *buffer) takeCompleteBuffer() []byte { +func (b *buffer) takeCompleteBuffer() ([]byte, error) { + if b.length > 0 { + return nil, ErrBusyBuffer + } + return b.buf, nil +} + +// store stores buf, an updated buffer, if its suitable to do so. +func (b *buffer) store(buf []byte) error { if b.length > 0 { - return nil + return ErrBusyBuffer + } else if cap(buf) <= maxPacketSize && cap(buf) > cap(b.buf) { + b.buf = buf[:cap(buf)] } - return b.buf + return nil } diff --git a/connection.go b/connection.go index 20aa50910..fc4ec7597 100644 --- a/connection.go +++ b/connection.go @@ -182,10 +182,10 @@ func (mc *mysqlConn) interpolateParams(query string, args []driver.Value) (strin return "", driver.ErrSkip } - buf := mc.buf.takeCompleteBuffer() - if buf == nil { + buf, err := mc.buf.takeCompleteBuffer() + if err != nil { // can not take the buffer. Something must be wrong with the connection - errLog.Print(ErrBusyBuffer) + errLog.Print(err) return "", ErrInvalidConn } buf = buf[:0] diff --git a/driver.go b/driver.go index 67126355c..9f4967087 100644 --- a/driver.go +++ b/driver.go @@ -50,7 +50,7 @@ func RegisterDial(net string, dial DialFunc) { // Open new Connection. // See https://github.com/go-sql-driver/mysql#dsn-data-source-name for how -// the DSN string is formated +// the DSN string is formatted func (d MySQLDriver) Open(dsn string) (driver.Conn, error) { var err error diff --git a/packets.go b/packets.go index 9ed640850..cfcfff360 100644 --- a/packets.go +++ b/packets.go @@ -51,7 +51,7 @@ func (mc *mysqlConn) readPacket() ([]byte, error) { mc.sequence++ // packets with length 0 terminate a previous packet which is a - // multiple of (2^24)−1 bytes long + // multiple of (2^24)-1 bytes long if pktLen == 0 { // there was no previous packet if prevData == nil { @@ -286,10 +286,10 @@ func (mc *mysqlConn) writeHandshakeResponsePacket(authResp []byte, plugin string } // Calculate packet length and get buffer with that size - data := mc.buf.takeSmallBuffer(pktLen + 4) - if data == nil { + data, err := mc.buf.takeSmallBuffer(pktLen + 4) + if err != nil { // cannot take the buffer. Something must be wrong with the connection - errLog.Print(ErrBusyBuffer) + errLog.Print(err) return errBadConnNoWrite } @@ -367,10 +367,10 @@ func (mc *mysqlConn) writeHandshakeResponsePacket(authResp []byte, plugin string // http://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::AuthSwitchResponse func (mc *mysqlConn) writeAuthSwitchPacket(authData []byte) error { pktLen := 4 + len(authData) - data := mc.buf.takeSmallBuffer(pktLen) - if data == nil { + data, err := mc.buf.takeSmallBuffer(pktLen) + if err != nil { // cannot take the buffer. Something must be wrong with the connection - errLog.Print(ErrBusyBuffer) + errLog.Print(err) return errBadConnNoWrite } @@ -387,10 +387,10 @@ func (mc *mysqlConn) writeCommandPacket(command byte) error { // Reset Packet Sequence mc.sequence = 0 - data := mc.buf.takeSmallBuffer(4 + 1) - if data == nil { + data, err := mc.buf.takeSmallBuffer(4 + 1) + if err != nil { // cannot take the buffer. Something must be wrong with the connection - errLog.Print(ErrBusyBuffer) + errLog.Print(err) return errBadConnNoWrite } @@ -406,10 +406,10 @@ func (mc *mysqlConn) writeCommandPacketStr(command byte, arg string) error { mc.sequence = 0 pktLen := 1 + len(arg) - data := mc.buf.takeBuffer(pktLen + 4) - if data == nil { + data, err := mc.buf.takeBuffer(pktLen + 4) + if err != nil { // cannot take the buffer. Something must be wrong with the connection - errLog.Print(ErrBusyBuffer) + errLog.Print(err) return errBadConnNoWrite } @@ -427,10 +427,10 @@ func (mc *mysqlConn) writeCommandPacketUint32(command byte, arg uint32) error { // Reset Packet Sequence mc.sequence = 0 - data := mc.buf.takeSmallBuffer(4 + 1 + 4) - if data == nil { + data, err := mc.buf.takeSmallBuffer(4 + 1 + 4) + if err != nil { // cannot take the buffer. Something must be wrong with the connection - errLog.Print(ErrBusyBuffer) + errLog.Print(err) return errBadConnNoWrite } @@ -883,7 +883,7 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error { const minPktLen = 4 + 1 + 4 + 1 + 4 mc := stmt.mc - // Determine threshould dynamically to avoid packet size shortage. + // Determine threshold dynamically to avoid packet size shortage. longDataSize := mc.maxAllowedPacket / (stmt.paramCount + 1) if longDataSize < 64 { longDataSize = 64 @@ -893,15 +893,17 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error { mc.sequence = 0 var data []byte + var err error if len(args) == 0 { - data = mc.buf.takeBuffer(minPktLen) + data, err = mc.buf.takeBuffer(minPktLen) } else { - data = mc.buf.takeCompleteBuffer() + data, err = mc.buf.takeCompleteBuffer() + // In this case the len(data) == cap(data) which is used to optimise the flow below. } - if data == nil { + if err != nil { // cannot take the buffer. Something must be wrong with the connection - errLog.Print(ErrBusyBuffer) + errLog.Print(err) return errBadConnNoWrite } @@ -927,7 +929,7 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error { pos := minPktLen var nullMask []byte - if maskLen, typesLen := (len(args)+7)/8, 1+2*len(args); pos+maskLen+typesLen >= len(data) { + if maskLen, typesLen := (len(args)+7)/8, 1+2*len(args); pos+maskLen+typesLen >= cap(data) { // buffer has to be extended but we don't know by how much so // we depend on append after all data with known sizes fit. // We stop at that because we deal with a lot of columns here @@ -936,10 +938,11 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error { copy(tmp[:pos], data[:pos]) data = tmp nullMask = data[pos : pos+maskLen] + // No need to clean nullMask as make ensures that. pos += maskLen } else { nullMask = data[pos : pos+maskLen] - for i := 0; i < maskLen; i++ { + for i := range nullMask { nullMask[i] = 0 } pos += maskLen @@ -1076,7 +1079,10 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error { // In that case we must build the data packet with the new values buffer if valuesCap != cap(paramValues) { data = append(data[:pos], paramValues...) - mc.buf.buf = data + if err = mc.buf.store(data); err != nil { + errLog.Print(err) + return errBadConnNoWrite + } } pos += len(paramValues)