func infoFromTags()

in parquet/schema/reflection.go [214:315]
98 lines of code
34 McCabe index (conditional complexity)

func infoFromTags(f reflect.StructTag) *taggedInfo {
	typeFromStr := func(v string) parquet.Type {
		t, err := format.TypeFromString(strings.ToUpper(v))
		if err != nil {
			panic(fmt.Errorf("invalid type specified: %s", v))
		}
		return parquet.Type(t)
	}

	repFromStr := func(v string) parquet.Repetition {
		r, err := format.FieldRepetitionTypeFromString(strings.ToUpper(v))
		if err != nil {
			panic(err)
		}
		return parquet.Repetition(r)
	}

	convertedFromStr := func(v string) ConvertedType {
		c, err := format.ConvertedTypeFromString(strings.ToUpper(v))
		if err != nil {
			panic(err)
		}
		return ConvertedType(c)
	}

	if ptags, ok := f.Lookup("parquet"); ok {
		info := newTaggedInfo()
		if ptags == "-" {
			info.Exclude = true
			return &info
		}
		for _, tag := range strings.Split(strings.Replace(ptags, "\t", "", -1), ",") {
			tag = strings.TrimSpace(tag)
			kv := strings.SplitN(tag, "=", 2)
			key := strings.TrimSpace(strings.ToLower(kv[0]))
			value := strings.TrimSpace(kv[1])

			switch key {
			case "name":
				info.Name = value
			case "type":
				info.Type = typeFromStr(value)
			case "keytype":
				info.KeyType = typeFromStr(value)
			case "valuetype":
				info.ValueType = typeFromStr(value)
			case "length":
				info.Length = int32FromType(value)
			case "keylength":
				info.KeyLength = int32FromType(value)
			case "valuelength":
				info.ValueLength = int32FromType(value)
			case "scale":
				info.Scale = int32FromType(value)
			case "keyscale":
				info.KeyScale = int32FromType(value)
			case "valuescale":
				info.ValueScale = int32FromType(value)
			case "precision":
				info.Precision = int32FromType(value)
			case "keyprecision":
				info.KeyPrecision = int32FromType(value)
			case "valueprecision":
				info.ValuePrecision = int32FromType(value)
			case "fieldid":
				info.FieldID = int32FromType(value)
			case "keyfieldid":
				info.KeyFieldID = int32FromType(value)
			case "valuefieldid":
				info.ValueFieldID = int32FromType(value)
			case "repetition":
				info.RepetitionType = repFromStr(value)
			case "valuerepetition":
				info.ValueRepetition = repFromStr(value)
			case "converted":
				info.Converted = convertedFromStr(value)
			case "keyconverted":
				info.KeyConverted = convertedFromStr(value)
			case "valueconverted":
				info.ValueConverted = convertedFromStr(value)
			case "logical":
				info.LogicalFields["type"] = value
			case "keylogical":
				info.KeyLogicalFields["type"] = value
			case "valuelogical":
				info.ValueLogicalFields["type"] = value
			default:
				switch {
				case strings.HasPrefix(key, "logical."):
					info.LogicalFields[strings.TrimPrefix(key, "logical.")] = value
				case strings.HasPrefix(key, "keylogical."):
					info.KeyLogicalFields[strings.TrimPrefix(key, "keylogical.")] = value
				case strings.HasPrefix(key, "valuelogical."):
					info.ValueLogicalFields[strings.TrimPrefix(key, "valuelogical.")] = value
				}
			}
		}
		info.UpdateLogicalTypes()
		return &info
	}
	return nil
}