Initial commit

vendor/github.com/jackc/pgproto3/v2/function_call.go

@@ -0,0 +1,94 @@
+package pgproto3
+
+import (
+	"encoding/binary"
+	"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
+}