initial commit

internal/collector/query.go

@@ -0,0 +1,159 @@
+package collector
+
+// Query combines filtering, sorting, and limiting into a single operation
+type Query struct {
+	Filter FilterOptions
+	Sort   SortOptions
+	Limit  int
+}
+
+// NewQuery creates a query with sensible defaults
+func NewQuery() *Query {
+	return &Query{
+		Filter: FilterOptions{},
+		Sort:   SortOptions{Field: SortByLport, Direction: SortAsc},
+		Limit:  0,
+	}
+}
+
+// WithFilter sets the filter options
+func (q *Query) WithFilter(f FilterOptions) *Query {
+	q.Filter = f
+	return q
+}
+
+// WithSort sets the sort options
+func (q *Query) WithSort(s SortOptions) *Query {
+	q.Sort = s
+	return q
+}
+
+// WithSortString parses and sets sort options from a string like "pid:desc"
+func (q *Query) WithSortString(s string) *Query {
+	q.Sort = ParseSortOptions(s)
+	return q
+}
+
+// WithLimit sets the maximum number of results
+func (q *Query) WithLimit(n int) *Query {
+	q.Limit = n
+	return q
+}
+
+// Proto filters by protocol
+func (q *Query) Proto(proto string) *Query {
+	q.Filter.Proto = proto
+	return q
+}
+
+// State filters by connection state
+func (q *Query) State(state string) *Query {
+	q.Filter.State = state
+	return q
+}
+
+// Process filters by process name (substring match)
+func (q *Query) Process(proc string) *Query {
+	q.Filter.Proc = proc
+	return q
+}
+
+// PID filters by process ID
+func (q *Query) PID(pid int) *Query {
+	q.Filter.Pid = pid
+	return q
+}
+
+// LocalPort filters by local port
+func (q *Query) LocalPort(port int) *Query {
+	q.Filter.Lport = port
+	return q
+}
+
+// RemotePort filters by remote port
+func (q *Query) RemotePort(port int) *Query {
+	q.Filter.Rport = port
+	return q
+}
+
+// IPv4Only filters to only IPv4 connections
+func (q *Query) IPv4Only() *Query {
+	q.Filter.IPv4 = true
+	q.Filter.IPv6 = false
+	return q
+}
+
+// IPv6Only filters to only IPv6 connections
+func (q *Query) IPv6Only() *Query {
+	q.Filter.IPv4 = false
+	q.Filter.IPv6 = true
+	return q
+}
+
+// Listening filters to only listening sockets
+func (q *Query) Listening() *Query {
+	q.Filter.State = "LISTEN"
+	return q
+}
+
+// Established filters to only established connections
+func (q *Query) Established() *Query {
+	q.Filter.State = "ESTABLISHED"
+	return q
+}
+
+// Contains filters by substring in process, local addr, or remote addr
+func (q *Query) Contains(s string) *Query {
+	q.Filter.Contains = s
+	return q
+}
+
+// Execute runs the query and returns results
+func (q *Query) Execute() ([]Connection, error) {
+	conns, err := GetConnections()
+	if err != nil {
+		return nil, err
+	}
+
+	return q.Apply(conns), nil
+}
+
+// Apply applies the query to a slice of connections
+func (q *Query) Apply(conns []Connection) []Connection {
+	result := FilterConnections(conns, q.Filter)
+	SortConnections(result, q.Sort)
+
+	if q.Limit > 0 && len(result) > q.Limit {
+		result = result[:q.Limit]
+	}
+
+	return result
+}
+
+// common pre-built queries
+
+// ListeningTCP returns a query for TCP listeners
+func ListeningTCP() *Query {
+	return NewQuery().Proto("tcp").Listening()
+}
+
+// ListeningAll returns a query for all listeners
+func ListeningAll() *Query {
+	return NewQuery().Listening()
+}
+
+// EstablishedTCP returns a query for established TCP connections
+func EstablishedTCP() *Query {
+	return NewQuery().Proto("tcp").Established()
+}
+
+// ByProcess returns a query filtered by process name
+func ByProcess(name string) *Query {
+	return NewQuery().Process(name)
+}
+
+// ByPort returns a query filtered by local port
+func ByPort(port int) *Query {
+	return NewQuery().LocalPort(port)
+}
+