mirror of https://github.com/pressly/goose.git
67 lines
1.1 KiB
Go
67 lines
1.1 KiB
Go
package main
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import (
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"fmt"
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"log"
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"os"
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"path/filepath"
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)
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var downCmd = &Command{
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Name: "down",
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Usage: "",
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Summary: "Roll back the version by 1",
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Help: `down extended help here...`,
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}
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func downRun(cmd *Command, args ...string) {
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conf, err := MakeDBConf()
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if err != nil {
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log.Fatal(err)
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}
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current := getDBVersion(conf)
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previous, earliest := getPreviousVersion(conf.MigrationsDir, current)
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if current == 0 {
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fmt.Println("db is empty, can't go down.")
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return
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}
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// if we're at the earliest version, indicate that the
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// only available step is to roll back to an empty database
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if current == earliest {
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previous = 0
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}
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runMigrations(conf, conf.MigrationsDir, previous)
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}
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func getPreviousVersion(dirpath string, version int) (previous, earliest int) {
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previous = -1
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earliest = (1 << 31) - 1
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filepath.Walk(dirpath, func(name string, info os.FileInfo, err error) error {
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if v, e := numericComponent(name); e == nil {
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if v > previous && v < version {
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previous = v
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}
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if v < earliest {
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earliest = v
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}
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}
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return nil
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})
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return previous, earliest
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}
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func init() {
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downCmd.Run = downRun
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}
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