Initial commit: stats-gateway gRPC service + dashboard + CLI

internal/storage/sqlite.go

@@ -0,0 +1,114 @@
+package storage
+
+import (
+	"context"
+	"database/sql"
+	"embed"
+	"fmt"
+	"time"
+
+	"github.com/bergabruh/stats-gateway/internal/probes"
+	_ "github.com/mattn/go-sqlite3"
+)
+
+//go:embed migrations/*.sql
+var migrations embed.FS
+
+// tsLayout is RFC3339 with fixed 9-digit nanosecond fraction. Lexical
+// ordering of formatted strings preserves chronological order — unlike
+// time.RFC3339Nano which strips trailing zeros (".1Z" lex-sorts after
+// ".100000001Z" because 'Z' > '0'). SQLite TEXT columns are compared
+// lexically, so this matters for QueryRange boundaries.
+const tsLayout = "2006-01-02T15:04:05.000000000Z07:00"
+
+// Store wraps a SQLite database for probe sample persistence.
+type Store struct {
+	db *sql.DB
+}
+
+// Open opens (or creates) the SQLite database at path and runs migrations.
+func Open(path string) (*Store, error) {
+	db, err := sql.Open("sqlite3", path+"?_journal_mode=WAL&_busy_timeout=5000")
+	if err != nil {
+		return nil, err
+	}
+	s := &Store{db: db}
+	if err := s.migrate(); err != nil {
+		return nil, fmt.Errorf("migrate: %w", err)
+	}
+	return s, nil
+}
+
+// Close closes the underlying database.
+func (s *Store) Close() error { return s.db.Close() }
+
+func (s *Store) migrate() error {
+	body, err := migrations.ReadFile("migrations/001_init.sql")
+	if err != nil {
+		return err
+	}
+	_, err = s.db.Exec(string(body))
+	return err
+}
+
+// InsertSample stores a probe result for the given node.
+func (s *Store) InsertSample(ctx context.Context, node string, r *probes.Result) error {
+	_, err := s.db.ExecContext(ctx, `
+		INSERT INTO samples (node, ts, http_latency_ms, tcp_rtt_ms, dns_resolve_ms, tls_handshake_ms, throughput_kbps)
+		VALUES (?, ?, ?, ?, ?, ?, ?)
+	`, node, r.Timestamp.Format(tsLayout),
+		r.HTTPLatencyMs, r.TCPRttMs, r.DNSResolveMs, r.TLSHandshakeMs, r.ThroughputKbps)
+	return err
+}
+
+// QueryRecent returns up to limit samples for node ordered by ts DESC.
+// If since is zero, no lower bound is applied. If node is empty, all nodes are returned.
+func (s *Store) QueryRecent(ctx context.Context, node string, limit int, since time.Time) ([]probes.Result, error) {
+	q := `SELECT node, ts, http_latency_ms, tcp_rtt_ms, dns_resolve_ms, tls_handshake_ms, throughput_kbps
+	      FROM samples WHERE 1=1`
+	args := []any{}
+	if node != "" {
+		q += ` AND node = ?`
+		args = append(args, node)
+	}
+	if !since.IsZero() {
+		q += ` AND ts >= ?`
+		args = append(args, since.Format(tsLayout))
+	}
+	q += ` ORDER BY ts DESC LIMIT ?`
+	args = append(args, limit)
+
+	return s.scanSamples(ctx, q, args...)
+}
+
+// QueryRange returns samples for [since, until). Used by Aggregate (Task 5).
+func (s *Store) QueryRange(ctx context.Context, node string, since, until time.Time) ([]probes.Result, error) {
+	q := `SELECT node, ts, http_latency_ms, tcp_rtt_ms, dns_resolve_ms, tls_handshake_ms, throughput_kbps
+	      FROM samples WHERE ts >= ? AND ts < ?`
+	args := []any{since.Format(tsLayout), until.Format(tsLayout)}
+	if node != "" {
+		q += ` AND node = ?`
+		args = append(args, node)
+	}
+	q += ` ORDER BY ts ASC`
+	return s.scanSamples(ctx, q, args...)
+}
+
+func (s *Store) scanSamples(ctx context.Context, q string, args ...any) ([]probes.Result, error) {
+	rows, err := s.db.QueryContext(ctx, q, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []probes.Result
+	for rows.Next() {
+		var ts string
+		var r probes.Result
+		if err := rows.Scan(&r.Node, &ts, &r.HTTPLatencyMs, &r.TCPRttMs, &r.DNSResolveMs, &r.TLSHandshakeMs, &r.ThroughputKbps); err != nil {
+			return nil, err
+		}
+		r.Timestamp, _ = time.Parse(tsLayout, ts)
+		out = append(out, r)
+	}
+	return out, rows.Err()
+}