Method structmap

gen/encode.go:173–277

(s *Struct)

}

func (e *encodeGen) structmap(s *Struct) {
	oeIdentPrefix := randIdent()

	var data []byte
	nfields := len(s.Fields)
	bm := bmask{
		bitlen:  nfields,
		varname: oeIdentPrefix + "Mask",
	}

	omitempty := s.AnyHasTagPart("omitempty")
	omitzero := s.AnyHasTagPart("omitzero")
	var closeZero bool
	var fieldNVar string
	if omitempty || omitzero {

		fieldNVar = oeIdentPrefix + "Len"

		e.p.printf("\n// check for omitted fields")
		e.p.printf("\n%s := uint32(%d)", fieldNVar, nfields)
		e.p.printf("\n%s", bm.typeDecl())
		e.p.printf("\n_ = %s", bm.varname)
		for i, sf := range s.Fields {
			if !e.p.ok() {
				return
			}
			if ize := sf.FieldElem.IfZeroExpr(); ize != "" && sf.HasTagPart("omitempty") {
				e.p.printf("\nif %s {", ize)
				e.p.printf("\n%s--", fieldNVar)
				e.p.printf("\n%s", bm.setStmt(i))
				e.p.printf("\n}")
			} else if sf.HasTagPart("omitzero") {
				e.p.printf("\nif %s.IsZero() {", sf.FieldElem.Varname())
				e.p.printf("\n%s--", fieldNVar)
				e.p.printf("\n%s", bm.setStmt(i))
				e.p.printf("\n}")
			}
		}

		e.p.printf("\n// variable map header, size %s", fieldNVar)
		e.p.varWriteMapHeader("en", fieldNVar, nfields)
		e.p.print("\nif err != nil { return }")
		if !e.p.ok() {
			return
		}

		// Skip block, if no fields are set.
		if nfields > 1 {
			e.p.printf("\n\n// skip if no fields are to be emitted")
			e.p.printf("\nif %s != 0 {", fieldNVar)
			closeZero = true
		}

	} else {

		// non-omit version
		data = msgp.AppendMapHeader(nil, uint32(nfields))
		e.p.printf("\n// map header, size %d", nfields)