2
0
Files
pgx/function_call.go
T
Martin Ashby 3d9a54f092 Fix unit test, it should return after any error is returned from Decode
function whether expected or not, rather than continue and try to
compare invalid decoded results.

Extend the unit test slightly to check the header.

Remove go-test/deep dependency in favour of standard library reflect
package.
2021-11-06 16:39:43 -05:00

105 lines
3.5 KiB
Go

package pgproto3
import (
"encoding/binary"
"encoding/json"
"github.com/jackc/pgio"
)
type FunctionCall struct {
Function uint32
ArgFormatCodes []uint16
Arguments [][]byte
ResultFormatCode uint16
}
// Frontend identifies this message as sendable by a PostgreSQL frontend.
func (*FunctionCall) Frontend() {}
// Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message
// type identifier and 4 byte message length.
func (dst *FunctionCall) Decode(src []byte) error {
*dst = FunctionCall{}
rp := 0
// Specifies the object ID of the function to call.
dst.Function = binary.BigEndian.Uint32(src[rp:])
rp += 4
// The number of argument format codes that follow (denoted C below).
// This can be zero to indicate that there are no arguments or that the arguments all use the default format (text);
// or one, in which case the specified format code is applied to all arguments;
// or it can equal the actual number of arguments.
nArgumentCodes := int(binary.BigEndian.Uint16(src[rp:]))
rp += 2
argumentCodes := make([]uint16, nArgumentCodes)
for i := 0; i < nArgumentCodes; i++ {
// The argument format codes. Each must presently be zero (text) or one (binary).
ac := binary.BigEndian.Uint16(src[rp:])
if ac != 0 && ac != 1 {
return &invalidMessageFormatErr{messageType: "FunctionCall"}
}
argumentCodes[i] = ac
rp += 2
}
dst.ArgFormatCodes = argumentCodes
// Specifies the number of arguments being supplied to the function.
nArguments := int(binary.BigEndian.Uint16(src[rp:]))
rp += 2
arguments := make([][]byte, nArguments)
for i := 0; i < nArguments; i++ {
// The length of the argument value, in bytes (this count does not include itself). Can be zero.
// As a special case, -1 indicates a NULL argument value. No value bytes follow in the NULL case.
argumentLength := int(binary.BigEndian.Uint32(src[rp:]))
rp += 4
if argumentLength == -1 {
arguments[i] = nil
} else {
// The value of the argument, in the format indicated by the associated format code. n is the above length.
argumentValue := src[rp : rp+argumentLength]
rp += argumentLength
arguments[i] = argumentValue
}
}
dst.Arguments = arguments
// The format code for the function result. Must presently be zero (text) or one (binary).
resultFormatCode := binary.BigEndian.Uint16(src[rp:])
if resultFormatCode != 0 && resultFormatCode != 1 {
return &invalidMessageFormatErr{messageType: "FunctionCall"}
}
dst.ResultFormatCode = resultFormatCode
return nil
}
// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
func (src *FunctionCall) Encode(dst []byte) []byte {
dst = append(dst, 'F')
sp := len(dst)
dst = pgio.AppendUint32(dst, 0) // Unknown length, set it at the end
dst = pgio.AppendUint32(dst, src.Function)
dst = pgio.AppendUint16(dst, uint16(len(src.ArgFormatCodes)))
for _, argFormatCode := range src.ArgFormatCodes {
dst = pgio.AppendUint16(dst, argFormatCode)
}
dst = pgio.AppendUint16(dst, uint16(len(src.Arguments)))
for _, argument := range src.Arguments {
if argument == nil {
dst = pgio.AppendInt32(dst, -1)
} else {
dst = pgio.AppendInt32(dst, int32(len(argument)))
dst = append(dst, argument...)
}
}
dst = pgio.AppendUint16(dst, src.ResultFormatCode)
pgio.SetInt32(dst[sp:], int32(len(dst[sp:])))
return dst
}
// MarshalJSON implements encoding/json.Marshaler.
func (src FunctionCall) MarshalJSON() ([]byte, error) {
return json.Marshal(struct {
Type string
}{
Type: "FunctionCall",
})
}