Handle resource changes when the resources is already evicted from cache

Also fix a logical flaw in the cache resizer that made it too aggressive. After this I haven't been able to reproduce #11988, but I need to look closer.

Closes #11973
Updates #11988

hugolib/content_map_page.go

@@ -1018,14 +1018,6 @@ func (h *HugoSites) resolveAndClearStateForIdentities(
 					b = cachebuster(s)
 				}
 
-				if b {
-					identity.WalkIdentitiesShallow(v, func(level int, id identity.Identity) bool {
-						// Add them to the change set so we can reset any page that depends on them.
-						changes = append(changes, id)
-						return false
-					})
-				}
-
 				return b
 			}
 
@@ -1037,6 +1029,15 @@ func (h *HugoSites) resolveAndClearStateForIdentities(
 		}
 	}
 
+	// Drain the the cache eviction stack.
+	evicted := h.Deps.MemCache.DrainEvictedIdentities()
+	if len(evicted) < 200 {
+		changes = append(changes, evicted...)
+	} else {
+		// Mass eviction, we might as well invalidate everything.
+		changes = []identity.Identity{identity.GenghisKhan}
+	}
+
 	// Remove duplicates
 	seen := make(map[identity.Identity]bool)
 	var n int

hugolib/hugo_sites.go

@@ -99,6 +99,8 @@ type HugoSites struct {
 
 	*fatalErrorHandler
 	*buildCounters
+	// Tracks invocations of the Build method.
+	buildCounter atomic.Uint64
 }
 
 // ShouldSkipFileChangeEvent allows skipping filesystem event early before
@@ -420,10 +422,9 @@ func (cfg *BuildCfg) shouldRender(p *pageState) bool {
 		return false
 	}
 
-	fastRenderMode := cfg.RecentlyVisited.Len() > 0
+	fastRenderMode := p.s.Conf.FastRenderMode()
 
-	if !fastRenderMode {
-		// Not in fast render mode or first time render.
+	if !fastRenderMode || p.s.h.buildCounter.Load() == 0 {
 		return shouldRender
 	}
 

hugolib/hugo_sites_build.go

@@ -57,6 +57,9 @@ import (
 func (h *HugoSites) Build(config BuildCfg, events ...fsnotify.Event) error {
 	infol := h.Log.InfoCommand("build")
 	defer loggers.TimeTrackf(infol, time.Now(), nil, "")
+	defer func() {
+		h.buildCounter.Add(1)
+	}()
 
 	if h.Deps == nil {
 		panic("must have deps")
@@ -769,8 +772,9 @@ func (h *HugoSites) processPartial(ctx context.Context, l logg.LevelLogger, conf
 			}
 		case files.ComponentFolderAssets:
 			logger.Println("Asset changed", pathInfo.Path())
-			r, _ := h.ResourceSpec.ResourceCache.Get(context.Background(), dynacache.CleanKey(pathInfo.Base()))
+
 			var hasID bool
+			r, _ := h.ResourceSpec.ResourceCache.Get(context.Background(), dynacache.CleanKey(pathInfo.Base()))
 			identity.WalkIdentitiesShallow(r, func(level int, rid identity.Identity) bool {
 				hasID = true
 				changes = append(changes, rid)