initial webapp

internal/web/state.go

@@ -0,0 +1,33 @@
+package web
+
+import "sync"
+
+// State holds the last rendered report table and row count produced by the
+// upload handler. The web app is single-user and in-memory, but net/http runs
+// handlers concurrently, so reads and writes are guarded by an RWMutex.
+type State struct {
+	mu    sync.RWMutex
+	table string
+	rows  int
+}
+
+// NewState returns an empty State with no rendered table.
+func NewState() *State {
+	return &State{}
+}
+
+// Set replaces the stored rendered table string and row count.
+func (s *State) Set(table string, rows int) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.table = table
+	s.rows = rows
+}
+
+// Get returns the current rendered table string and row count. The returned
+// values are zero-valued when no upload has happened yet.
+func (s *State) Get() (string, int) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	return s.table, s.rows
+}