api,db: add page attributes and thread locking

api/page_get.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"database/sql"
+)
+
+func pageGet(domain string, path string) (page, error) {
+	// path can be empty
+	if domain == "" {
+		return page{}, errorMissingField
+	}
+
+	statement := `
+		SELECT isLocked
+		FROM pages
+		WHERE domain=$1 AND path=$2;
+	`
+	row := db.QueryRow(statement, domain, path)
+
+	p := page{Domain: domain, Path: path}
+	if err := row.Scan(&p.IsLocked); err != nil {
+		if err == sql.ErrNoRows {
+			// If there haven't been any comments, there won't be a record for this
+			// page. The sane thing to do is return defaults.
+			// TODO: the defaults are hard-coded in two places: here and the schema
+			p.IsLocked = false
+		} else {
+			logger.Errorf("error scanning page: %v", err)
+			return page{}, errorInternal
+		}
+	}
+
+	return p, nil
+}