mirror of https://github.com/jlelse/GoBlog
44 lines
1.1 KiB
Go
44 lines
1.1 KiB
Go
package main
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import (
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"database/sql"
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"errors"
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)
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func (db *database) cachePersistently(key string, data []byte) error {
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if db == nil {
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return errors.New("database is nil")
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}
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_, err := db.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", utcNowString()))
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return err
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}
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func (db *database) retrievePersistentCache(key string) (data []byte, err error) {
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if db == nil {
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return nil, errors.New("database is nil")
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}
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d, err, _ := db.pc.Do(key, func() (interface{}, error) {
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if row, err := db.queryRow("select data from persistent_cache where key = @key", sql.Named("key", key)); 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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if errors.Is(err, sql.ErrNoRows) {
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return nil, nil
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}
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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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if d == nil {
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return nil, nil
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}
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return d.([]byte), nil
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}
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func (db *database) clearPersistentCache(pattern string) error {
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_, err := db.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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