mirror of https://github.com/jackc/pgx.git
MsgReader no longer uses double buffering
Jack Christensen
parent
78b8e0b6f2
commit
b25aea5c52
167
conn.go
167
conn.go
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@ -14,7 +14,6 @@ import (
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"fmt"
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log "gopkg.in/inconshreveable/log15.v2"
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"io"
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"io/ioutil"
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"net"
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"net/url"
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"os"
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@ -52,8 +51,8 @@ type Conn struct {
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conn net.Conn // the underlying TCP or unix domain socket connection
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reader *bufio.Reader // buffered reader to improve read performance
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wbuf [1024]byte
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buf *bytes.Buffer // work buffer to avoid constant alloc and dealloc
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bufSize int // desired size of buf
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buf *bytes.Buffer
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bufSize int
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Pid int32 // backend pid
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SecretKey int32 // key to use to send a cancel query message to the server
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RuntimeParams map[string]string // parameters that have been reported by the server
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@ -65,6 +64,7 @@ type Conn struct {
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causeOfDeath error
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logger log.Logger
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qr QueryResult
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mr MsgReader
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}
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type PreparedStatement struct {
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@ -197,6 +197,7 @@ func Connect(config ConnConfig) (c *Conn, err error) {
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}
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c.reader = bufio.NewReader(c.conn)
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c.mr.reader = c.reader
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msg := newStartupMessage()
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msg.options["user"] = c.config.User
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@ -209,7 +210,7 @@ func Connect(config ConnConfig) (c *Conn, err error) {
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for {
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var t byte
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var r *MessageReader
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var r *MsgReader
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t, r, err = c.rxMsg()
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if err != nil {
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return nil, err
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@ -348,9 +349,9 @@ func (c *Conn) SelectValueTo(w io.Writer, sql string, arguments ...interface{})
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for {
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var t byte
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var bodySize int32
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var r *MsgReader
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t, bodySize, err = c.rxMsgHeader()
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t, r, err = c.rxMsg()
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if err != nil {
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return err
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}
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@ -363,19 +364,12 @@ func (c *Conn) SelectValueTo(w io.Writer, sql string, arguments ...interface{})
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}
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if softErr != nil {
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c.rxMsgBody(bodySize) // Read and discard rest of message
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// Read and discard rest of message
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continue
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}
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softErr = c.rxDataRowValueTo(w, bodySize)
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softErr = c.rxDataRowValueTo(w, r)
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} else {
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var body *bytes.Buffer
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body, err = c.rxMsgBody(bodySize)
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if err != nil {
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return err
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}
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r := (*MessageReader)(body)
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switch t {
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case readyForQuery:
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c.rxReadyForQuery(r)
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@ -392,44 +386,20 @@ func (c *Conn) SelectValueTo(w io.Writer, sql string, arguments ...interface{})
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}
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}
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func (c *Conn) rxDataRowValueTo(w io.Writer, bodySize int32) (err error) {
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b := make([]byte, 2)
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_, err = io.ReadFull(c.reader, b)
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if err != nil {
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c.die(err)
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return
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}
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columnCount := int16(binary.BigEndian.Uint16(b))
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func (c *Conn) rxDataRowValueTo(w io.Writer, r *MsgReader) error {
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columnCount := r.ReadInt16()
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if columnCount != 1 {
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// Read the rest of the data row so it can be discarded
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if _, err = io.CopyN(ioutil.Discard, c.reader, int64(bodySize-2)); err != nil {
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c.die(err)
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return
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}
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err = UnexpectedColumnCountError{ExpectedCount: 1, ActualCount: columnCount}
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return
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return UnexpectedColumnCountError{ExpectedCount: 1, ActualCount: columnCount}
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}
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b = make([]byte, 4)
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_, err = io.ReadFull(c.reader, b)
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if err != nil {
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c.die(err)
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return
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}
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valueSize := int32(binary.BigEndian.Uint32(b))
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valueSize := r.ReadInt32()
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if valueSize == -1 {
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err = errors.New("SelectValueTo cannot handle null")
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return
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return errors.New("SelectValueTo cannot handle null")
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}
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_, err = io.CopyN(w, c.reader, int64(valueSize))
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if err != nil {
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c.die(err)
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}
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r.CopyN(w, valueSize)
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return
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return r.Err()
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}
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// Prepare creates a prepared statement with name and sql. sql can contain placeholders
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@ -475,7 +445,7 @@ func (c *Conn) Prepare(name, sql string) (ps *PreparedStatement, err error) {
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for {
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var t byte
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var r *MessageReader
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var r *MsgReader
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t, r, err := c.rxMsg()
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if err != nil {
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return nil, err
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@ -563,7 +533,7 @@ func (c *Conn) WaitForNotification(timeout time.Duration) (*Notification, error)
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}
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var t byte
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var r *MessageReader
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var r *MsgReader
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if t, r, err = c.rxMsg(); err == nil {
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if err = c.processContextFreeMsg(t, r); err != nil {
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return nil, err
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@ -653,12 +623,12 @@ func (rr *RowReader) ReadDate(qr *QueryResult) time.Time {
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}
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func (rr *RowReader) ReadString(qr *QueryResult) string {
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_, size, ok := qr.NextColumn()
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fd, size, ok := qr.NextColumn()
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if !ok {
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return ""
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}
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return qr.mr.ReadString(size)
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return decodeText(qr, fd, size)
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}
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func (rr *RowReader) ReadValue(qr *QueryResult) interface{} {
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@ -671,7 +641,7 @@ func (rr *RowReader) ReadValue(qr *QueryResult) interface{} {
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if vt, present := ValueTranscoders[fd.DataType]; present && vt.Decode != nil {
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return vt.Decode(qr, fd, size)
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} else {
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return qr.mr.ReadString(size)
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return decodeText(qr, fd, size)
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}
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} else {
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return nil
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@ -681,7 +651,7 @@ func (rr *RowReader) ReadValue(qr *QueryResult) interface{} {
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type QueryResult struct {
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pool *ConnPool
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conn *Conn
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mr *MessageReader
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mr *MsgReader
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fields []FieldDescription
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rowCount int
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columnIdx int
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@ -693,7 +663,7 @@ func (qr *QueryResult) FieldDescriptions() []FieldDescription {
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return qr.fields
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}
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func (qr *QueryResult) MessageReader() *MessageReader {
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func (qr *QueryResult) MsgReader() *MsgReader {
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return qr.mr
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}
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@ -771,8 +741,8 @@ func (qr *QueryResult) NextRow() bool {
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qr.close()
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return false
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case dataRow:
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fieldCount := int(r.ReadInt16())
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if fieldCount != len(qr.fields) {
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fieldCount := r.ReadInt16()
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if int(fieldCount) != len(qr.fields) {
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qr.Fatal(ProtocolError(fmt.Sprintf("Row description field count (%v) and data row field count (%v) do not match", len(qr.fields), fieldCount)))
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return false
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}
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@ -803,7 +773,6 @@ func (qr *QueryResult) NextColumn() (*FieldDescription, int32, bool) {
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fd := &qr.fields[qr.columnIdx]
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qr.columnIdx++
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size := qr.mr.ReadInt32()
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return fd, size, true
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}
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@ -965,7 +934,7 @@ func (c *Conn) Exec(sql string, arguments ...interface{}) (commandTag CommandTag
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for {
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var t byte
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var r *MessageReader
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var r *MsgReader
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t, r, err = c.rxMsg()
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if err != nil {
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return commandTag, err
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@ -1040,7 +1009,7 @@ func (c *Conn) transaction(isoLevel string, f func() bool) (committed bool, err
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// Processes messages that are not exclusive to one context such as
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// authentication or query response. The response to these messages
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// is the same regardless of when they occur.
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func (c *Conn) processContextFreeMsg(t byte, r *MessageReader) (err error) {
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func (c *Conn) processContextFreeMsg(t byte, r *MsgReader) (err error) {
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switch t {
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case 'S':
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c.rxParameterStatus(r)
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@ -1050,69 +1019,28 @@ func (c *Conn) processContextFreeMsg(t byte, r *MessageReader) (err error) {
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case noticeResponse:
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return nil
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case notificationResponse:
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return c.rxNotificationResponse(r)
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c.rxNotificationResponse(r)
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return nil
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default:
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return fmt.Errorf("Received unknown message type: %c", t)
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}
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}
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func (c *Conn) rxMsg() (t byte, r *MessageReader, err error) {
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var bodySize int32
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t, bodySize, err = c.rxMsgHeader()
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if err != nil {
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return
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}
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var body *bytes.Buffer
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if body, err = c.rxMsgBody(bodySize); err != nil {
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return
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}
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r = (*MessageReader)(body)
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return
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}
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func (c *Conn) rxMsgHeader() (t byte, bodySize int32, err error) {
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func (c *Conn) rxMsg() (t byte, r *MsgReader, err error) {
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if !c.alive {
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return 0, 0, DeadConnError
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return 0, nil, DeadConnError
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}
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t, err = c.reader.ReadByte()
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t, err = c.mr.rxMsg()
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if err != nil {
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c.die(err)
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return 0, 0, err
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}
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b := make([]byte, 4)
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_, err = io.ReadFull(c.reader, b)
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if err != nil {
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c.die(err)
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return 0, 0, err
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return t, &c.mr, err
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}
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bodySize = int32(binary.BigEndian.Uint32(b))
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bodySize -= 4 // remove self from size
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return t, bodySize, err
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}
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func (c *Conn) rxMsgBody(bodySize int32) (*bytes.Buffer, error) {
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if !c.alive {
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return nil, DeadConnError
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}
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buf := c.getBuf()
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_, err := io.CopyN(buf, c.reader, int64(bodySize))
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if err != nil {
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c.die(err)
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return nil, err
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}
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return buf, nil
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}
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func (c *Conn) rxAuthenticationX(r *MessageReader) (err error) {
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code := r.ReadInt32()
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switch code {
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func (c *Conn) rxAuthenticationX(r *MsgReader) (err error) {
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switch r.ReadInt32() {
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case 0: // AuthenticationOk
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case 3: // AuthenticationCleartextPassword
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err = c.txPasswordMessage(c.config.Password)
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@ -1133,13 +1061,13 @@ func hexMD5(s string) string {
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return hex.EncodeToString(hash.Sum(nil))
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}
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func (c *Conn) rxParameterStatus(r *MessageReader) {
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func (c *Conn) rxParameterStatus(r *MsgReader) {
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key := r.ReadCString()
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value := r.ReadCString()
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c.RuntimeParams[key] = value
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}
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func (c *Conn) rxErrorResponse(r *MessageReader) (err PgError) {
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func (c *Conn) rxErrorResponse(r *MsgReader) (err PgError) {
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for {
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switch r.ReadByte() {
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case 'S':
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@ -1159,16 +1087,16 @@ func (c *Conn) rxErrorResponse(r *MessageReader) (err PgError) {
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}
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}
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func (c *Conn) rxBackendKeyData(r *MessageReader) {
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func (c *Conn) rxBackendKeyData(r *MsgReader) {
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c.Pid = r.ReadInt32()
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c.SecretKey = r.ReadInt32()
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}
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func (c *Conn) rxReadyForQuery(r *MessageReader) {
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func (c *Conn) rxReadyForQuery(r *MsgReader) {
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c.TxStatus = r.ReadByte()
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}
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func (c *Conn) rxRowDescription(r *MessageReader) (fields []FieldDescription) {
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func (c *Conn) rxRowDescription(r *MsgReader) (fields []FieldDescription) {
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fieldCount := r.ReadInt16()
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fields = make([]FieldDescription, fieldCount)
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for i := int16(0); i < fieldCount; i++ {
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@ -1184,26 +1112,26 @@ func (c *Conn) rxRowDescription(r *MessageReader) (fields []FieldDescription) {
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return
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}
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func (c *Conn) rxParameterDescription(r *MessageReader) (parameters []Oid) {
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func (c *Conn) rxParameterDescription(r *MsgReader) (parameters []Oid) {
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parameterCount := r.ReadInt16()
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parameters = make([]Oid, 0, parameterCount)
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for i := int16(0); i < parameterCount; i++ {
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parameters = append(parameters, r.ReadOid())
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}
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return
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}
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func (c *Conn) rxCommandComplete(r *MessageReader) string {
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func (c *Conn) rxCommandComplete(r *MsgReader) string {
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return r.ReadCString()
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}
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func (c *Conn) rxNotificationResponse(r *MessageReader) (err error) {
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func (c *Conn) rxNotificationResponse(r *MsgReader) {
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n := new(Notification)
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n.Pid = r.ReadInt32()
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n.Channel = r.ReadCString()
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n.Payload = r.ReadCString()
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c.notifications = append(c.notifications, n)
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return
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}
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func (c *Conn) startTLS() (err error) {
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@ -1280,12 +1208,7 @@ func (c *Conn) txPasswordMessage(password string) (err error) {
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// its internal byte array, check on the size and create a new bytes.Buffer so the
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// old one can get GC'ed
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func (c *Conn) getBuf() *bytes.Buffer {
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c.buf.Reset()
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if cap(c.buf.Bytes()) > c.bufSize {
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c.logger.Debug(fmt.Sprintf("c.buf (%d) is larger than c.bufSize (%d) -- resetting", cap(c.buf.Bytes()), c.bufSize))
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c.buf = bytes.NewBuffer(make([]byte, 0, c.bufSize))
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}
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return c.buf
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return &bytes.Buffer{}
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}
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func (c *Conn) die(err error) {
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@ -51,7 +51,7 @@ func decodePoint(qr *pgx.QueryResult, fd *pgx.FieldDescription, size int32) Poin
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switch fd.FormatCode {
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case pgx.TextFormatCode:
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s := qr.MessageReader().ReadString(size)
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s := qr.MsgReader().ReadString(size)
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match := pointRegexp.FindStringSubmatch(s)
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if match == nil {
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qr.Fatal(pgx.ProtocolError(fmt.Sprintf("Received invalid point: %v", s)))
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@ -1,47 +0,0 @@
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package pgx
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import (
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"bytes"
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"encoding/binary"
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)
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// MessageReader is a helper that reads values from a PostgreSQL message.
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type MessageReader bytes.Buffer
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func (r *MessageReader) ReadByte() (b byte) {
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b, _ = (*bytes.Buffer)(r).ReadByte()
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return
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}
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func (r *MessageReader) ReadInt16() (n int16) {
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b := (*bytes.Buffer)(r).Next(2)
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return int16(binary.BigEndian.Uint16(b))
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}
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func (r *MessageReader) ReadInt32() (n int32) {
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b := (*bytes.Buffer)(r).Next(4)
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return int32(binary.BigEndian.Uint32(b))
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}
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func (r *MessageReader) ReadInt64() (n int64) {
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b := (*bytes.Buffer)(r).Next(8)
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return int64(binary.BigEndian.Uint64(b))
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}
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func (r *MessageReader) ReadOid() (oid Oid) {
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b := (*bytes.Buffer)(r).Next(4)
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return Oid(binary.BigEndian.Uint32(b))
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}
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// ReadString reads a null terminated string
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func (r *MessageReader) ReadCString() (s string) {
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b, _ := (*bytes.Buffer)(r).ReadBytes(0)
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return string(b[:len(b)-1])
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}
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// ReadString reads count bytes and returns as string
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func (r *MessageReader) ReadString(count int32) (s string) {
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size := int(count)
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b := (*bytes.Buffer)(r).Next(size)
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return string(b)
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}
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@ -0,0 +1,197 @@
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package pgx
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import (
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"bufio"
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"encoding/binary"
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"errors"
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"io"
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"io/ioutil"
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)
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// MsgReader is a helper that reads values from a PostgreSQL message.
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type MsgReader struct {
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reader *bufio.Reader
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buf [128]byte
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msgBytesRemaining int32
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err error
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}
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// Err returns any error that the MsgReader has experienced
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func (r *MsgReader) Err() error {
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return r.err
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}
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// Fatal tells r that a Fatal error has occurred
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func (r *MsgReader) Fatal(err error) {
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||||
r.err = err
|
||||
}
|
||||
|
||||
// rxMsg reads the type and size of the next message.
|
||||
func (r *MsgReader) rxMsg() (t byte, err error) {
|
||||
if r.err != nil {
|
||||
return 0, err
|
||||
}
|
||||
|
||||
if r.msgBytesRemaining > 0 {
|
||||
io.CopyN(ioutil.Discard, r.reader, int64(r.msgBytesRemaining))
|
||||
}
|
||||
|
||||
t, err = r.reader.ReadByte()
|
||||
b := r.buf[0:4]
|
||||
_, err = io.ReadFull(r.reader, b)
|
||||
r.msgBytesRemaining = int32(binary.BigEndian.Uint32(b)) - 4
|
||||
return t, err
|
||||
}
|
||||
|
||||
func (r *MsgReader) ReadByte() byte {
|
||||
if r.err != nil {
|
||||
return 0
|
||||
}
|
||||
|
||||
r.msgBytesRemaining -= 1
|
||||
if r.msgBytesRemaining < 0 {
|
||||
r.Fatal(errors.New("read past end of message"))
|
||||
return 0
|
||||
}
|
||||
|
||||
b, err := r.reader.ReadByte()
|
||||
if err != nil {
|
||||
r.Fatal(err)
|
||||
return 0
|
||||
}
|
||||
|
||||
return b
|
||||
}
|
||||
|
||||
func (r *MsgReader) ReadInt16() int16 {
|
||||
if r.err != nil {
|
||||
return 0
|
||||
}
|
||||
|
||||
r.msgBytesRemaining -= 2
|
||||
if r.msgBytesRemaining < 0 {
|
||||
r.Fatal(errors.New("read past end of message"))
|
||||
return 0
|
||||
}
|
||||
|
||||
b := r.buf[0:2]
|
||||
_, err := io.ReadFull(r.reader, b)
|
||||
if err != nil {
|
||||
r.Fatal(err)
|
||||
return 0
|
||||
}
|
||||
|
||||
return int16(binary.BigEndian.Uint16(b))
|
||||
}
|
||||
|
||||
func (r *MsgReader) ReadInt32() int32 {
|
||||
if r.err != nil {
|
||||
return 0
|
||||
}
|
||||
|
||||
r.msgBytesRemaining -= 4
|
||||
if r.msgBytesRemaining < 0 {
|
||||
r.Fatal(errors.New("read past end of message"))
|
||||
return 0
|
||||
}
|
||||
|
||||
b := r.buf[0:4]
|
||||
_, err := io.ReadFull(r.reader, b)
|
||||
if err != nil {
|
||||
r.Fatal(err)
|
||||
return 0
|
||||
}
|
||||
|
||||
return int32(binary.BigEndian.Uint32(b))
|
||||
}
|
||||
|
||||
func (r *MsgReader) ReadInt64() int64 {
|
||||
if r.err != nil {
|
||||
return 0
|
||||
}
|
||||
|
||||
r.msgBytesRemaining -= 8
|
||||
if r.msgBytesRemaining < 0 {
|
||||
r.Fatal(errors.New("read past end of message"))
|
||||
return 0
|
||||
}
|
||||
|
||||
b := r.buf[0:8]
|
||||
_, err := io.ReadFull(r.reader, b)
|
||||
if err != nil {
|
||||
r.Fatal(err)
|
||||
return 0
|
||||
}
|
||||
|
||||
return int64(binary.BigEndian.Uint64(b))
|
||||
}
|
||||
|
||||
func (r *MsgReader) ReadOid() Oid {
|
||||
return Oid(r.ReadInt32())
|
||||
}
|
||||
|
||||
// ReadCString reads a null terminated string
|
||||
func (r *MsgReader) ReadCString() string {
|
||||
if r.err != nil {
|
||||
return ""
|
||||
}
|
||||
|
||||
b, err := r.reader.ReadBytes(0)
|
||||
if err != nil {
|
||||
r.Fatal(err)
|
||||
return ""
|
||||
}
|
||||
|
||||
r.msgBytesRemaining -= int32(len(b))
|
||||
if r.msgBytesRemaining < 0 {
|
||||
r.Fatal(errors.New("read past end of message"))
|
||||
return ""
|
||||
}
|
||||
|
||||
return string(b[0 : len(b)-1])
|
||||
}
|
||||
|
||||
// ReadString reads count bytes and returns as string
|
||||
func (r *MsgReader) ReadString(count int32) string {
|
||||
if r.err != nil {
|
||||
return ""
|
||||
}
|
||||
|
||||
r.msgBytesRemaining -= count
|
||||
if r.msgBytesRemaining < 0 {
|
||||
r.Fatal(errors.New("read past end of message"))
|
||||
return ""
|
||||
}
|
||||
|
||||
var b []byte
|
||||
if count <= int32(len(r.buf)) {
|
||||
b = r.buf[0:int(count)]
|
||||
} else {
|
||||
b = make([]byte, int(count))
|
||||
}
|
||||
|
||||
_, err := io.ReadFull(r.reader, b)
|
||||
if err != nil {
|
||||
r.Fatal(err)
|
||||
return ""
|
||||
}
|
||||
|
||||
return string(b)
|
||||
}
|
||||
|
||||
func (r *MsgReader) CopyN(w io.Writer, count int32) {
|
||||
if r.err != nil {
|
||||
return
|
||||
}
|
||||
|
||||
r.msgBytesRemaining -= count
|
||||
if r.msgBytesRemaining < 0 {
|
||||
r.Fatal(errors.New("read past end of message"))
|
||||
return
|
||||
}
|
||||
|
||||
_, err := io.CopyN(w, r.reader, int64(count))
|
||||
if err != nil {
|
||||
r.Fatal(err)
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue