forked from anchore/go-rpmdb
/
sqlite3.go
83 lines (67 loc) · 1.55 KB
/
sqlite3.go
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package sqlite3
import (
"bytes"
"database/sql"
"encoding/binary"
"os"
dbi "github.com/meghfossa/go-rpmdb/pkg/db"
"golang.org/x/xerrors"
_ "modernc.org/sqlite"
)
type SQLite3 struct {
*sql.DB
}
var (
// https://www.sqlite.org/fileformat.html
SQLite3_HeaderMagic = []byte("SQLite format 3\x00")
ErrorInvalidSQLite3 = xerrors.Errorf("invalid or unsupported SQLite3 format")
)
func Open(path string) (*SQLite3, error) {
file, err := os.Open(path)
if err != nil {
return nil, err
}
defer file.Close()
b := make([]byte, 16)
if err = binary.Read(file, binary.LittleEndian, b); err != nil {
return nil, xerrors.Errorf("binary read error: %w", err)
}
if !bytes.Equal(b, SQLite3_HeaderMagic) {
return nil, ErrorInvalidSQLite3
}
db, err := sql.Open("sqlite", path)
if err != nil {
return nil, xerrors.Errorf("failed to open sqlite3: %w", err)
}
return &SQLite3{db}, nil
}
func (db *SQLite3) Read() <-chan dbi.Entry {
entries := make(chan dbi.Entry)
go func() {
defer close(entries)
rows, err := db.Query("SELECT blob FROM Packages")
if err != nil {
entries <- dbi.Entry{
Err: xerrors.Errorf("failed to SELECT query: %w", err),
}
}
if err := db.Close(); err != nil {
entries <- dbi.Entry{
Err: xerrors.Errorf("failed to close DB: %w", err),
}
}
for rows.Next() {
var blob string
if err := rows.Scan(&blob); err != nil {
entries <- dbi.Entry{
Err: xerrors.Errorf("failed to Scan Row: %w", err),
}
}
entries <- dbi.Entry{
Value: []byte(blob),
Err: nil,
}
}
}()
return entries
}