Reduce nesting in message loops

scan-io
Jack Christensen 2014-06-17 16:39:44 -05:00
parent 928612917d
commit 5fe3dd7ecf
1 changed files with 133 additions and 111 deletions

244
conn.go
View File

@ -211,27 +211,28 @@ func Connect(config ConnConfig) (c *Conn, err error) {
for {
var t byte
var r *MessageReader
if t, r, err = c.rxMsg(); err == nil {
switch t {
case backendKeyData:
c.rxBackendKeyData(r)
case authenticationX:
if err = c.rxAuthenticationX(r); err != nil {
return nil, err
}
case readyForQuery:
c.rxReadyForQuery(r)
c.logger = c.logger.New("pid", c.Pid)
c.logger.Info("Connection established")
return c, nil
default:
if err = c.processContextFreeMsg(t, r); err != nil {
return nil, err
}
}
} else {
t, r, err = c.rxMsg()
if err != nil {
return nil, err
}
switch t {
case backendKeyData:
c.rxBackendKeyData(r)
case authenticationX:
if err = c.rxAuthenticationX(r); err != nil {
return nil, err
}
case readyForQuery:
c.rxReadyForQuery(r)
c.logger = c.logger.New("pid", c.Pid)
c.logger.Info("Connection established")
return c, nil
default:
if err = c.processContextFreeMsg(t, r); err != nil {
return nil, err
}
}
}
}
@ -305,31 +306,36 @@ func (c *Conn) selectFunc(sql string, onDataRow func(*DataRowReader) error, argu
return
}
var softErr error
for {
if t, r, rxErr := c.rxMsg(); rxErr == nil {
switch t {
case readyForQuery:
c.rxReadyForQuery(r)
return
case rowDescription:
fields = c.rxRowDescription(r)
case dataRow:
if err == nil {
var drr *DataRowReader
drr, err = newDataRowReader(r, fields)
if err == nil {
err = onDataRow(drr)
}
}
case commandComplete:
case bindComplete:
default:
if e := c.processContextFreeMsg(t, r); e != nil && err == nil {
err = e
var t byte
var r *MessageReader
t, r, err = c.rxMsg()
if err != nil {
return err
}
switch t {
case readyForQuery:
c.rxReadyForQuery(r)
return softErr
case rowDescription:
fields = c.rxRowDescription(r)
case dataRow:
if softErr == nil {
var drr *DataRowReader
drr, softErr = newDataRowReader(r, fields)
if softErr == nil {
softErr = onDataRow(drr)
}
}
} else {
return rxErr
case commandComplete:
case bindComplete:
default:
if e := c.processContextFreeMsg(t, r); e != nil && softErr == nil {
softErr = e
}
}
}
}
@ -456,44 +462,50 @@ func (c *Conn) SelectValueTo(w io.Writer, sql string, arguments ...interface{})
}
var numRowsFound int64
var softErr error
for {
if t, bodySize, rxErr := c.rxMsgHeader(); rxErr == nil {
if t == dataRow {
numRowsFound++
var t byte
var bodySize int32
if numRowsFound > 1 {
err = NotSingleRowError{RowCount: numRowsFound}
}
t, bodySize, err = c.rxMsgHeader()
if err != nil {
return err
}
if err != nil {
c.rxMsgBody(bodySize) // Read and discard rest of message
continue
}
if t == dataRow {
numRowsFound++
err = c.rxDataRowValueTo(w, bodySize)
} else {
var body *bytes.Buffer
if body, rxErr = c.rxMsgBody(bodySize); rxErr == nil {
r := newMessageReader(body)
switch t {
case readyForQuery:
c.rxReadyForQuery(r)
return
case rowDescription:
case commandComplete:
case bindComplete:
default:
if e := c.processContextFreeMsg(t, r); e != nil && err == nil {
err = e
}
}
} else {
return rxErr
if numRowsFound > 1 {
softErr = NotSingleRowError{RowCount: numRowsFound}
}
if softErr != nil {
c.rxMsgBody(bodySize) // Read and discard rest of message
continue
}
softErr = c.rxDataRowValueTo(w, bodySize)
} else {
var body *bytes.Buffer
body, err = c.rxMsgBody(bodySize)
if err != nil {
return err
}
r := newMessageReader(body)
switch t {
case readyForQuery:
c.rxReadyForQuery(r)
return softErr
case rowDescription:
case commandComplete:
case bindComplete:
default:
if e := c.processContextFreeMsg(t, r); e != nil && softErr == nil {
softErr = e
}
}
} else {
return rxErr
}
}
}
@ -610,32 +622,37 @@ func (c *Conn) Prepare(name, sql string) (err error) {
ps := preparedStatement{Name: name}
var softErr error
for {
if t, r, rxErr := c.rxMsg(); rxErr == nil {
switch t {
case parseComplete:
case parameterDescription:
ps.ParameterOids = c.rxParameterDescription(r)
case rowDescription:
ps.FieldDescriptions = c.rxRowDescription(r)
for i := range ps.FieldDescriptions {
oid := ps.FieldDescriptions[i].DataType
if ValueTranscoders[oid] != nil && ValueTranscoders[oid].DecodeBinary != nil {
ps.FieldDescriptions[i].FormatCode = 1
}
}
case noData:
case readyForQuery:
c.rxReadyForQuery(r)
c.preparedStatements[name] = &ps
return
default:
if e := c.processContextFreeMsg(t, r); e != nil && err == nil {
err = e
var t byte
var r *MessageReader
t, r, err := c.rxMsg()
if err != nil {
return err
}
switch t {
case parseComplete:
case parameterDescription:
ps.ParameterOids = c.rxParameterDescription(r)
case rowDescription:
ps.FieldDescriptions = c.rxRowDescription(r)
for i := range ps.FieldDescriptions {
oid := ps.FieldDescriptions[i].DataType
if ValueTranscoders[oid] != nil && ValueTranscoders[oid].DecodeBinary != nil {
ps.FieldDescriptions[i].FormatCode = 1
}
}
} else {
return rxErr
case noData:
case readyForQuery:
c.rxReadyForQuery(r)
c.preparedStatements[name] = &ps
return softErr
default:
if e := c.processContextFreeMsg(t, r); e != nil && softErr == nil {
softErr = e
}
}
}
}
@ -844,24 +861,29 @@ func (c *Conn) Execute(sql string, arguments ...interface{}) (commandTag Command
return
}
var softErr error
for {
if t, r, rxErr := c.rxMsg(); rxErr == nil {
switch t {
case readyForQuery:
c.rxReadyForQuery(r)
return
case rowDescription:
case dataRow:
case bindComplete:
case commandComplete:
commandTag = CommandTag(r.ReadCString())
default:
if e := c.processContextFreeMsg(t, r); e != nil && err == nil {
err = e
}
var t byte
var r *MessageReader
t, r, err = c.rxMsg()
if err != nil {
return commandTag, err
}
switch t {
case readyForQuery:
c.rxReadyForQuery(r)
return commandTag, softErr
case rowDescription:
case dataRow:
case bindComplete:
case commandComplete:
commandTag = CommandTag(r.ReadCString())
default:
if e := c.processContextFreeMsg(t, r); e != nil && softErr == nil {
softErr = e
}
} else {
return "", rxErr
}
}
}