mirror of https://github.com/jlelse/GoBlog
39 lines
1.0 KiB
Go
39 lines
1.0 KiB
Go
package main
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import (
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"database/sql"
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"time"
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"golang.org/x/sync/singleflight"
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)
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func cachePersistently(key string, data []byte) error {
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date, _ := toLocal(time.Now().String())
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_, err := appDb.exec("insert or replace into persistent_cache(key, data, date) values(@key, @data, @date)", sql.Named("key", key), sql.Named("data", data), sql.Named("date", date))
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return err
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}
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var persistentCacheGroup singleflight.Group
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func retrievePersistentCache(key string) (data []byte, err error) {
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d, err, _ := persistentCacheGroup.Do(key, func() (interface{}, error) {
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if row, err := appDb.queryRow("select data from persistent_cache where key = @key", sql.Named("key", key)); err == sql.ErrNoRows {
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return nil, nil
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} else if err != nil {
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return nil, err
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} else {
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err = row.Scan(&data)
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return data, err
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}
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})
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if err != nil {
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return nil, err
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}
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return d.([]byte), nil
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}
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func clearPersistentCache(pattern string) error {
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_, err := appDb.exec("delete from persistent_cache where key like @pattern", sql.Named("pattern", pattern))
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return err
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}
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