prime8dev

commit 4d5ac0f58f908dcda8320de4f335af448f49257e
parent 5cf9620370532ec0a210de7771fdbb108c68e011
Author: Damian Myrda <damian@prime8.dev>
Date:   Wed, 21 Oct 2026 18:39:13 +0000

fix(web): load the first project's readme on a cold cache

/projects rendered projects[0] straight from the list cache, which is bare after a deploy or TTL expiry, and the browser then cached "README not available" for an hour. Resolve it via GetProjectByID, keep the last good READMEs across cache expiry, and never cache a detail without a README.

Diffstat:
M
cmd/server/handlers/projects.go
 | 
25
++++++++++++++++++++-----
M
cmd/server/handlers/render.go
 | 
2
+-
M
internal/content/projects.go
 | 
37
++++++++++++++++++++++++++++++++++++-

3 files changed, 57 insertions(+), 7 deletions(-)
diff --git a/cmd/server/handlers/projects.go b/cmd/server/handlers/projects.go
@@ -30,15 +30,21 @@ func (h *Handler) ProjectsPageHandler(w http.ResponseWriter, r *http.Request) {
 
 	if id == "" {
 		if len(projects) > 0 {
-			applyProjectDetailData(&data, &projects[0])
+			// Resolve through GetProjectByID so a cold cache fetches the
+			// README synchronously instead of rendering "not available".
+			first := &projects[0]
+			if p, err := content.GetProjectByID(h.gitService, first.ID); err == nil && p != nil {
+				first = p
+			}
+			applyProjectDetailData(&data, first)
 		}
 
 		if utils.IsHTMXRequest(r) {
-			h.renderTemplate(w, r, "projects", data, fragmentCacheMaxAgeSeconds)
+			h.renderTemplate(w, r, "projects", data, detailMaxAge(data, fragmentCacheMaxAgeSeconds))
 			return
 		}
 
-		h.renderTemplate(w, r, "layout", data, fullPageCacheMaxAgeSeconds)
+		h.renderTemplate(w, r, "layout", data, detailMaxAge(data, fullPageCacheMaxAgeSeconds))
 		return
 	}
 
@@ -55,7 +61,16 @@ func (h *Handler) ProjectsPageHandler(w http.ResponseWriter, r *http.Request) {
 	data.SelectedProjectID = id
 	applyProjectDetailData(&data, project)
 
-	h.renderTemplate(w, r, "layout", data, fullPageCacheMaxAgeSeconds)
+	h.renderTemplate(w, r, "layout", data, detailMaxAge(data, fullPageCacheMaxAgeSeconds))
+}
+
+// detailMaxAge never lets a browser cache a page whose README failed to
+// load, so a transient fetch error isn't pinned for an hour.
+func detailMaxAge(data web.Data, maxAge int) int {
+	if data.Project != nil && strings.TrimSpace(string(data.ProjectReadme)) == "" {
+		return 0
+	}
+	return maxAge
 }
 
 func applyProjectDetailData(data *web.Data, project *config.Project) {
@@ -84,7 +99,7 @@ func (h *Handler) ProjectDetailHandler(w http.ResponseWriter, r *http.Request) {
 		ProjectReadme: template.HTML(project.HTML),
 	}
 
-	h.renderTemplate(w, r, "project_detail", data, fragmentCacheMaxAgeSeconds)
+	h.renderTemplate(w, r, "project_detail", data, detailMaxAge(data, fragmentCacheMaxAgeSeconds))
 }
 
 // ProjectRawHandler serves a file from HEAD of a public project's repo, so
diff --git a/cmd/server/handlers/render.go b/cmd/server/handlers/render.go
@@ -27,7 +27,7 @@ func (h *Handler) renderTemplate(w http.ResponseWriter, r *http.Request, name st
 	cacheEnabled := shouldCacheResponses()
 
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
-	if !cacheEnabled {
+	if !cacheEnabled || maxAgeSeconds == 0 {
 		applyNoCacheHeaders(w)
 	} else if maxAgeSeconds > 0 {
 		w.Header().Set("Cache-Control", fmt.Sprintf("public, max-age=%d", maxAgeSeconds))
diff --git a/internal/content/projects.go b/internal/content/projects.go
@@ -36,7 +36,7 @@ func LoadProjects(gitService *external.Git) ([]config.Project, error) {
 		}
 	}
 
-	projects := config.GetProjects()
+	projects := withLastGoodReadmes(config.GetProjects())
 	projectsCache.Set(projectsCacheKey, projects, projectsCacheTTL)
 	startProjectsRefresh(gitService)
 
@@ -62,6 +62,7 @@ func GetProjectByID(gitService *external.Git, id string) (*config.Project, error
 			if readme, err := fetchProjectReadme(gitService, projects[i]); err == nil {
 				projects[i].Markdown = readme.Markdown
 				projects[i].HTML = readme.HTML
+				rememberReadmes(projects[i : i+1])
 				projectsCache.Set(projectsCacheKey, cloneProjects(projects), projectsCacheTTL)
 			}
 		}
@@ -160,6 +161,40 @@ func startProjectsRefresh(gitService *external.Git) {
 			return
 		}
 
+		projects = withLastGoodReadmes(projects)
+		rememberReadmes(projects)
 		projectsCache.Set(projectsCacheKey, projects, projectsCacheTTL)
 	}()
 }
+
+// lastGoodReadmes outlives the projects cache, so an expired cache or a failed
+// refresh serves the previous README instead of "README not available".
+var (
+	lastGoodMu      sync.RWMutex
+	lastGoodReadmes = map[string]config.Project{}
+)
+
+func rememberReadmes(projects []config.Project) {
+	lastGoodMu.Lock()
+	defer lastGoodMu.Unlock()
+	for _, p := range projects {
+		if strings.TrimSpace(p.HTML) != "" {
+			lastGoodReadmes[p.ID] = config.Project{Markdown: p.Markdown, HTML: p.HTML}
+		}
+	}
+}
+
+func withLastGoodReadmes(projects []config.Project) []config.Project {
+	lastGoodMu.RLock()
+	defer lastGoodMu.RUnlock()
+	for i := range projects {
+		if strings.TrimSpace(projects[i].HTML) != "" {
+			continue
+		}
+		if good, ok := lastGoodReadmes[projects[i].ID]; ok {
+			projects[i].Markdown = good.Markdown
+			projects[i].HTML = good.HTML
+		}
+	}
+	return projects
+}