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41 lines
877 B
Go
41 lines
877 B
Go
package string
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import (
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"github.com/nalgeon/redka/internal/core"
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"github.com/nalgeon/redka/internal/redis"
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)
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// Returns the previous string value of a key after setting it to a new value.
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// GETSET key value
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// https://redis.io/commands/getset
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type GetSet struct {
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redis.BaseCmd
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key string
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value []byte
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}
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func ParseGetSet(b redis.BaseCmd) (*GetSet, error) {
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cmd := &GetSet{BaseCmd: b}
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if len(cmd.Args()) != 2 {
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return cmd, redis.ErrInvalidArgNum
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}
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cmd.key = string(cmd.Args()[0])
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cmd.value = cmd.Args()[1]
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return cmd, nil
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}
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func (cmd *GetSet) Run(w redis.Writer, red redis.Redka) (any, error) {
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out, err := red.Str().SetWith(cmd.key, cmd.value).Run()
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if err != nil {
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w.WriteError(cmd.Error(err))
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return nil, err
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}
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if out.Created {
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// no previous value
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w.WriteNull()
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return core.Value(nil), nil
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}
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w.WriteBulk(out.Prev)
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return out.Prev, nil
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}
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