64 lines
1.8 KiB
Go
64 lines
1.8 KiB
Go
package mcfg
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import (
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"encoding/json"
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)
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// ParamValue describes a value for a parameter which has been parsed by a
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// Source.
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type ParamValue struct {
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Param
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Value json.RawMessage
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}
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// Source parses ParamValues out of a particular configuration source, given a
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// sorted set of possible Params to parse.
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//
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// Source should not return ParamValues which were not explicitly set to a value
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// by the configuration source.
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//
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// The returned []ParamValue may contain duplicates of the same Param's value.
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// in which case the later value takes precedence.
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type Source interface {
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Parse([]Param) ([]ParamValue, error)
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}
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// Sources combines together multiple Source instances into one. It will call
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// Parse on each element individually. Values from later Sources take precedence
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// over previous ones.
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type Sources []Source
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// Parse implements the method for the Source interface.
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func (ss Sources) Parse(params []Param) ([]ParamValue, error) {
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var pvs []ParamValue
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for _, s := range ss {
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innerPVs, err := s.Parse(params)
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if err != nil {
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return nil, err
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}
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pvs = append(pvs, innerPVs...)
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}
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return pvs, nil
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}
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// SourceMap implements the Source interface by mapping parameter names to
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// values for them. The names are comprised of the path and name of a Param
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// joined by "-" characters, i.e. `strings.Join(append(param.Path, param.Name),
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// "-")`. Values will be parsed in the same way that SourceEnv parses its
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// variables.
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type SourceMap map[string]string
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// Parse implements the method for the Source interface.
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func (m SourceMap) Parse(params []Param) ([]ParamValue, error) {
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pvs := make([]ParamValue, 0, len(m))
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for _, p := range params {
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if v, ok := m[p.fullName()]; ok {
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pvs = append(pvs, ParamValue{
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Param: p,
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Value: p.fuzzyParse(v),
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})
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}
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}
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return pvs, nil
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}
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