nmon/internal/backup/backup_inventory.go

package backup

import (
	"context"
	"fmt"
	"os"
	"path/filepath"

	"github.com/v10networks/nmon/internal/store"
)

// addInventory archives the inventory: a VACUUM INTO copy on SQLite (counted by opening that copy, so the
// numbers describe the archived data), the JSON-lines export elsewhere.
func addInventory(ctx context.Context, o *Options, aw *archiveWriter, m *Manifest, scratch string) error {
	m.Dialect = o.Store.Dialect()
	var err error
	if m.Dialect == store.DriverSQLite {
		err = snapshotSQLite(ctx, o, aw, m, scratch)
	} else {
		err = exportJSONL(ctx, o, aw, m, scratch)
	}
	if err != nil {
		return fmt.Errorf("backup: inventory: %w", err)
	}
	return nil
}

func snapshotSQLite(ctx context.Context, o *Options, aw *archiveWriter, m *Manifest, scratch string) error {
	snap := filepath.Join(scratch, inventoryDB)
	if err := o.Store.SnapshotInto(ctx, snap); err != nil {
		return err
	}
	cp, err := store.Open(ctx, store.DriverSQLite, snap, nil, o.Clock)
	if err != nil {
		return err
	}
	defer func() { _ = cp.Close() }() // read-only use of the copy
	if m.Rows, err = cp.RowCounts(ctx); err != nil {
		return err
	}
	if m.Rollup, err = cp.RollupCheckpoints(ctx); err != nil {
		return err
	}
	m.Inventory = inventoryDB
	return aw.addFile(inventoryDB, snap)
}

func exportJSONL(ctx context.Context, o *Options, aw *archiveWriter, m *Manifest, scratch string) error {
	path := filepath.Join(scratch, inventoryJSONL)
	f, err := os.Create(path)
	if err != nil {
		return err
	}
	counts, err := o.Store.ExportJSONL(ctx, f)
	if cerr := f.Close(); err == nil {
		err = cerr
	}
	if err != nil {
		return err
	}
	m.Rows = counts
	if m.Rollup, err = o.Store.RollupCheckpoints(ctx); err != nil {
		return err
	}
	m.Inventory = inventoryJSONL
	return aw.addFile(inventoryJSONL, path)
}