diff options
Diffstat (limited to 'vendor/github.com/jackc/pgx/v5/pgproto3/frontend.go')
| -rw-r--r-- | vendor/github.com/jackc/pgx/v5/pgproto3/frontend.go | 468 |
1 files changed, 0 insertions, 468 deletions
diff --git a/vendor/github.com/jackc/pgx/v5/pgproto3/frontend.go b/vendor/github.com/jackc/pgx/v5/pgproto3/frontend.go deleted file mode 100644 index 056e547cd..000000000 --- a/vendor/github.com/jackc/pgx/v5/pgproto3/frontend.go +++ /dev/null @@ -1,468 +0,0 @@ -package pgproto3 - -import ( - "bytes" - "encoding/binary" - "errors" - "fmt" - "io" -) - -// Frontend acts as a client for the PostgreSQL wire protocol version 3. -type Frontend struct { - cr *chunkReader - w io.Writer - - // tracer is used to trace messages when Send or Receive is called. This means an outbound message is traced - // before it is actually transmitted (i.e. before Flush). It is safe to change this variable when the Frontend is - // idle. Setting and unsetting tracer provides equivalent functionality to PQtrace and PQuntrace in libpq. - tracer *tracer - - wbuf []byte - encodeError error - - // Backend message flyweights - authenticationOk AuthenticationOk - authenticationCleartextPassword AuthenticationCleartextPassword - authenticationMD5Password AuthenticationMD5Password - authenticationGSS AuthenticationGSS - authenticationGSSContinue AuthenticationGSSContinue - authenticationSASL AuthenticationSASL - authenticationSASLContinue AuthenticationSASLContinue - authenticationSASLFinal AuthenticationSASLFinal - backendKeyData BackendKeyData - bindComplete BindComplete - closeComplete CloseComplete - commandComplete CommandComplete - copyBothResponse CopyBothResponse - copyData CopyData - copyInResponse CopyInResponse - copyOutResponse CopyOutResponse - copyDone CopyDone - dataRow DataRow - emptyQueryResponse EmptyQueryResponse - errorResponse ErrorResponse - functionCallResponse FunctionCallResponse - noData NoData - noticeResponse NoticeResponse - notificationResponse NotificationResponse - parameterDescription ParameterDescription - parameterStatus ParameterStatus - parseComplete ParseComplete - readyForQuery ReadyForQuery - rowDescription RowDescription - portalSuspended PortalSuspended - - bodyLen int - maxBodyLen int // maxBodyLen is the maximum length of a message body in octets. If a message body exceeds this length, Receive will return an error. - msgType byte - partialMsg bool - authType uint32 -} - -// NewFrontend creates a new Frontend. -func NewFrontend(r io.Reader, w io.Writer) *Frontend { - cr := newChunkReader(r, 0) - return &Frontend{cr: cr, w: w} -} - -// Send sends a message to the backend (i.e. the server). The message is buffered until Flush is called. Any error -// encountered will be returned from Flush. -// -// Send can work with any FrontendMessage. Some commonly used message types such as Bind have specialized send methods -// such as SendBind. These methods should be preferred when the type of message is known up front (e.g. when building an -// extended query protocol query) as they may be faster due to knowing the type of msg rather than it being hidden -// behind an interface. -func (f *Frontend) Send(msg FrontendMessage) { - if f.encodeError != nil { - return - } - - prevLen := len(f.wbuf) - newBuf, err := msg.Encode(f.wbuf) - if err != nil { - f.encodeError = err - return - } - f.wbuf = newBuf - - if f.tracer != nil { - f.tracer.traceMessage('F', int32(len(f.wbuf)-prevLen), msg) - } -} - -// Flush writes any pending messages to the backend (i.e. the server). -func (f *Frontend) Flush() error { - if err := f.encodeError; err != nil { - f.encodeError = nil - f.wbuf = f.wbuf[:0] - return &writeError{err: err, safeToRetry: true} - } - - if len(f.wbuf) == 0 { - return nil - } - - n, err := f.w.Write(f.wbuf) - - const maxLen = 1024 - if len(f.wbuf) > maxLen { - f.wbuf = make([]byte, 0, maxLen) - } else { - f.wbuf = f.wbuf[:0] - } - - if err != nil { - return &writeError{err: err, safeToRetry: n == 0} - } - - return nil -} - -// Trace starts tracing the message traffic to w. It writes in a similar format to that produced by the libpq function -// PQtrace. -func (f *Frontend) Trace(w io.Writer, options TracerOptions) { - f.tracer = &tracer{ - w: w, - buf: &bytes.Buffer{}, - TracerOptions: options, - } -} - -// Untrace stops tracing. -func (f *Frontend) Untrace() { - f.tracer = nil -} - -// SendBind sends a Bind message to the backend (i.e. the server). The message is buffered until Flush is called. Any -// error encountered will be returned from Flush. -func (f *Frontend) SendBind(msg *Bind) { - if f.encodeError != nil { - return - } - - prevLen := len(f.wbuf) - newBuf, err := msg.Encode(f.wbuf) - if err != nil { - f.encodeError = err - return - } - f.wbuf = newBuf - - if f.tracer != nil { - f.tracer.traceBind('F', int32(len(f.wbuf)-prevLen), msg) - } -} - -// SendParse sends a Parse message to the backend (i.e. the server). The message is buffered until Flush is called. Any -// error encountered will be returned from Flush. -func (f *Frontend) SendParse(msg *Parse) { - if f.encodeError != nil { - return - } - - prevLen := len(f.wbuf) - newBuf, err := msg.Encode(f.wbuf) - if err != nil { - f.encodeError = err - return - } - f.wbuf = newBuf - - if f.tracer != nil { - f.tracer.traceParse('F', int32(len(f.wbuf)-prevLen), msg) - } -} - -// SendClose sends a Close message to the backend (i.e. the server). The message is buffered until Flush is called. Any -// error encountered will be returned from Flush. -func (f *Frontend) SendClose(msg *Close) { - if f.encodeError != nil { - return - } - - prevLen := len(f.wbuf) - newBuf, err := msg.Encode(f.wbuf) - if err != nil { - f.encodeError = err - return - } - f.wbuf = newBuf - - if f.tracer != nil { - f.tracer.traceClose('F', int32(len(f.wbuf)-prevLen), msg) - } -} - -// SendDescribe sends a Describe message to the backend (i.e. the server). The message is buffered until Flush is -// called. Any error encountered will be returned from Flush. -func (f *Frontend) SendDescribe(msg *Describe) { - if f.encodeError != nil { - return - } - - prevLen := len(f.wbuf) - newBuf, err := msg.Encode(f.wbuf) - if err != nil { - f.encodeError = err - return - } - f.wbuf = newBuf - - if f.tracer != nil { - f.tracer.traceDescribe('F', int32(len(f.wbuf)-prevLen), msg) - } -} - -// SendExecute sends an Execute message to the backend (i.e. the server). The message is buffered until Flush is called. -// Any error encountered will be returned from Flush. -func (f *Frontend) SendExecute(msg *Execute) { - if f.encodeError != nil { - return - } - - prevLen := len(f.wbuf) - newBuf, err := msg.Encode(f.wbuf) - if err != nil { - f.encodeError = err - return - } - f.wbuf = newBuf - - if f.tracer != nil { - f.tracer.TraceQueryute('F', int32(len(f.wbuf)-prevLen), msg) - } -} - -// SendSync sends a Sync message to the backend (i.e. the server). The message is buffered until Flush is called. Any -// error encountered will be returned from Flush. -func (f *Frontend) SendSync(msg *Sync) { - if f.encodeError != nil { - return - } - - prevLen := len(f.wbuf) - newBuf, err := msg.Encode(f.wbuf) - if err != nil { - f.encodeError = err - return - } - f.wbuf = newBuf - - if f.tracer != nil { - f.tracer.traceSync('F', int32(len(f.wbuf)-prevLen), msg) - } -} - -// SendQuery sends a Query message to the backend (i.e. the server). The message is buffered until Flush is called. Any -// error encountered will be returned from Flush. -func (f *Frontend) SendQuery(msg *Query) { - if f.encodeError != nil { - return - } - - prevLen := len(f.wbuf) - newBuf, err := msg.Encode(f.wbuf) - if err != nil { - f.encodeError = err - return - } - f.wbuf = newBuf - - if f.tracer != nil { - f.tracer.traceQuery('F', int32(len(f.wbuf)-prevLen), msg) - } -} - -// SendUnbufferedEncodedCopyData immediately sends an encoded CopyData message to the backend (i.e. the server). This method -// is more efficient than sending a CopyData message with Send as the message data is not copied to the internal buffer -// before being written out. The internal buffer is flushed before the message is sent. -func (f *Frontend) SendUnbufferedEncodedCopyData(msg []byte) error { - err := f.Flush() - if err != nil { - return err - } - - n, err := f.w.Write(msg) - if err != nil { - return &writeError{err: err, safeToRetry: n == 0} - } - - if f.tracer != nil { - f.tracer.traceCopyData('F', int32(len(msg)-1), &CopyData{}) - } - - return nil -} - -func translateEOFtoErrUnexpectedEOF(err error) error { - if err == io.EOF { - return io.ErrUnexpectedEOF - } - return err -} - -// Receive receives a message from the backend. The returned message is only valid until the next call to Receive. -func (f *Frontend) Receive() (BackendMessage, error) { - if !f.partialMsg { - header, err := f.cr.Next(5) - if err != nil { - return nil, translateEOFtoErrUnexpectedEOF(err) - } - - f.msgType = header[0] - - msgLength := int(binary.BigEndian.Uint32(header[1:])) - if msgLength < 4 { - return nil, fmt.Errorf("invalid message length: %d", msgLength) - } - - f.bodyLen = msgLength - 4 - if f.maxBodyLen > 0 && f.bodyLen > f.maxBodyLen { - return nil, &ExceededMaxBodyLenErr{f.maxBodyLen, f.bodyLen} - } - f.partialMsg = true - } - - msgBody, err := f.cr.Next(f.bodyLen) - if err != nil { - return nil, translateEOFtoErrUnexpectedEOF(err) - } - - f.partialMsg = false - - var msg BackendMessage - switch f.msgType { - case '1': - msg = &f.parseComplete - case '2': - msg = &f.bindComplete - case '3': - msg = &f.closeComplete - case 'A': - msg = &f.notificationResponse - case 'c': - msg = &f.copyDone - case 'C': - msg = &f.commandComplete - case 'd': - msg = &f.copyData - case 'D': - msg = &f.dataRow - case 'E': - msg = &f.errorResponse - case 'G': - msg = &f.copyInResponse - case 'H': - msg = &f.copyOutResponse - case 'I': - msg = &f.emptyQueryResponse - case 'K': - msg = &f.backendKeyData - case 'n': - msg = &f.noData - case 'N': - msg = &f.noticeResponse - case 'R': - var err error - msg, err = f.findAuthenticationMessageType(msgBody) - if err != nil { - return nil, err - } - case 's': - msg = &f.portalSuspended - case 'S': - msg = &f.parameterStatus - case 't': - msg = &f.parameterDescription - case 'T': - msg = &f.rowDescription - case 'V': - msg = &f.functionCallResponse - case 'W': - msg = &f.copyBothResponse - case 'Z': - msg = &f.readyForQuery - default: - return nil, fmt.Errorf("unknown message type: %c", f.msgType) - } - - err = msg.Decode(msgBody) - if err != nil { - return nil, err - } - - if f.tracer != nil { - f.tracer.traceMessage('B', int32(5+len(msgBody)), msg) - } - - return msg, nil -} - -// Authentication message type constants. -// See src/include/libpq/pqcomm.h for all -// constants. -const ( - AuthTypeOk = 0 - AuthTypeCleartextPassword = 3 - AuthTypeMD5Password = 5 - AuthTypeSCMCreds = 6 - AuthTypeGSS = 7 - AuthTypeGSSCont = 8 - AuthTypeSSPI = 9 - AuthTypeSASL = 10 - AuthTypeSASLContinue = 11 - AuthTypeSASLFinal = 12 -) - -func (f *Frontend) findAuthenticationMessageType(src []byte) (BackendMessage, error) { - if len(src) < 4 { - return nil, errors.New("authentication message too short") - } - f.authType = binary.BigEndian.Uint32(src[:4]) - - switch f.authType { - case AuthTypeOk: - return &f.authenticationOk, nil - case AuthTypeCleartextPassword: - return &f.authenticationCleartextPassword, nil - case AuthTypeMD5Password: - return &f.authenticationMD5Password, nil - case AuthTypeSCMCreds: - return nil, errors.New("AuthTypeSCMCreds is unimplemented") - case AuthTypeGSS: - return &f.authenticationGSS, nil - case AuthTypeGSSCont: - return &f.authenticationGSSContinue, nil - case AuthTypeSSPI: - return nil, errors.New("AuthTypeSSPI is unimplemented") - case AuthTypeSASL: - return &f.authenticationSASL, nil - case AuthTypeSASLContinue: - return &f.authenticationSASLContinue, nil - case AuthTypeSASLFinal: - return &f.authenticationSASLFinal, nil - default: - return nil, fmt.Errorf("unknown authentication type: %d", f.authType) - } -} - -// GetAuthType returns the authType used in the current state of the frontend. -// See SetAuthType for more information. -func (f *Frontend) GetAuthType() uint32 { - return f.authType -} - -func (f *Frontend) ReadBufferLen() int { - return f.cr.wp - f.cr.rp -} - -// SetMaxBodyLen sets the maximum length of a message body in octets. -// If a message body exceeds this length, Receive will return an error. -// This is useful for protecting against a corrupted server that sends -// messages with incorrect length, which can cause memory exhaustion. -// The default value is 0. -// If maxBodyLen is 0, then no maximum is enforced. -func (f *Frontend) SetMaxBodyLen(maxBodyLen int) { - f.maxBodyLen = maxBodyLen -} |