Initial commit

internal/handlers/preview_cache.go

@@ -0,0 +1,66 @@
+package handlers
+
+import (
+	"sync"
+	"time"
+
+	"veola/internal/apify"
+)
+
+// previewKey caches the *raw* apify result set (post-decode, post-merge,
+// pre-filter). Filters like min_price and exclude_keywords are applied after
+// the cache lookup so the operator can iterate on them without burning credits.
+type previewKey struct {
+	Queries, URL, Marketplace, ListingType, ActorIDs string
+	MaxResults                                       int
+}
+
+type previewEntry struct {
+	results []apify.UnifiedResult
+	source  string
+	stored  time.Time
+}
+
+type PreviewCache struct {
+	ttl     time.Duration
+	mu      sync.Mutex
+	entries map[previewKey]previewEntry
+}
+
+func NewPreviewCache(ttl time.Duration) *PreviewCache {
+	return &PreviewCache{
+		ttl:     ttl,
+		entries: make(map[previewKey]previewEntry),
+	}
+}
+
+func (c *PreviewCache) Get(k previewKey) ([]apify.UnifiedResult, string, bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	e, ok := c.entries[k]
+	if !ok {
+		return nil, "", false
+	}
+	if time.Since(e.stored) > c.ttl {
+		delete(c.entries, k)
+		return nil, "", false
+	}
+	return e.results, e.source, true
+}
+
+func (c *PreviewCache) Put(k previewKey, results []apify.UnifiedResult, source string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.entries[k] = previewEntry{results: results, source: source, stored: time.Now()}
+	if len(c.entries) > 64 {
+		c.evictExpired()
+	}
+}
+
+func (c *PreviewCache) evictExpired() {
+	for k, e := range c.entries {
+		if time.Since(e.stored) > c.ttl {
+			delete(c.entries, k)
+		}
+	}
+}