status-im/status-go

package currency

import (
    "context"
    "database/sql"
)

type DB struct {
    db *sql.DB
}

func NewCurrencyDB(sqlDb *sql.DB) *DB {
    return &DB{
        db: sqlDb,
    }
}

func getCachedFormatsFromDBRows(rows *sql.Rows) (FormatPerSymbol, error) {
    formats := make(FormatPerSymbol)

    for rows.Next() {
        var format Format
        if err := rows.Scan(&format.Symbol, &format.DisplayDecimals, &format.StripTrailingZeroes); err != nil {
            return nil, err
        }

        formats[format.Symbol] = format
    }

    return formats, nil
}

func (cdb *DB) GetCachedFormats() (FormatPerSymbol, error) {
    rows, err := cdb.db.Query("SELECT symbol, display_decimals, strip_trailing_zeroes FROM currency_format_cache")
    if err != nil {
        return nil, err
    }
    defer rows.Close()

    return getCachedFormatsFromDBRows(rows)
}

func (cdb *DB) UpdateCachedFormats(formats FormatPerSymbol) error {
    tx, err := cdb.db.BeginTx(context.Background(), &sql.TxOptions{})
    if err != nil {
        return err
    }

    defer func() {
        if err == nil {
            err = tx.Commit()
            return
        }
        // don't shadow original error
        _ = tx.Rollback()
    }()

    insert, err := tx.Prepare(`INSERT OR REPLACE INTO currency_format_cache
                (symbol, display_decimals, strip_trailing_zeroes)
                VALUES
                (?, ?, ?)`)
    if err != nil {
        return err
    }

    for _, format := range formats {
        _, err = insert.Exec(format.Symbol, format.DisplayDecimals, format.StripTrailingZeroes)
        if err != nil {
            return err
        }
    }
    return nil
}