From 7106d5a6e7585dce5fdd552cca30063dd352dc23 Mon Sep 17 00:00:00 2001 From: René 'Necoro' Neumann Date: Mon, 22 Feb 2021 22:54:43 +0100 Subject: Split cache and feed packages --- internal/feed/cache/cache_v1.go | 323 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 323 insertions(+) create mode 100644 internal/feed/cache/cache_v1.go (limited to 'internal/feed/cache/cache_v1.go') diff --git a/internal/feed/cache/cache_v1.go b/internal/feed/cache/cache_v1.go new file mode 100644 index 0000000..d754b00 --- /dev/null +++ b/internal/feed/cache/cache_v1.go @@ -0,0 +1,323 @@ +package cache + +import ( + "crypto/sha256" + "encoding/base64" + "encoding/hex" + "fmt" + "strconv" + "strings" + "time" + + "github.com/google/uuid" + + "github.com/Necoro/feed2imap-go/internal/feed" + "github.com/Necoro/feed2imap-go/pkg/log" + "github.com/Necoro/feed2imap-go/pkg/util" +) + +const ( + v1Version Version = 1 + startFeedId uint64 = 1 +) + +type feedId uint64 + +func (id feedId) String() string { + return strconv.FormatUint(uint64(id), 16) +} + +func idFromString(s string) feedId { + id, _ := strconv.ParseUint(s, 16, 64) + return feedId(id) +} + +type v1Cache struct { + Ids map[feed.Descriptor]feedId + NextId uint64 + Feeds map[feedId]*cachedFeed +} + +type cachedFeed struct { + feed *feed.Feed + id feedId // not saved, has to be set on loading + LastCheck time.Time + currentCheck time.Time + NumFailures int // can't be named `Failures` b/c it'll collide with the interface + Items []cachedItem + newItems []cachedItem +} + +type itemHash [sha256.Size]byte + +func (h itemHash) String() string { + return hex.EncodeToString(h[:]) +} + +type cachedItem struct { + Guid string + Title string + Link string + Date time.Time + UpdatedCache time.Time + Hash itemHash + ID uuid.UUID +} + +func (item cachedItem) String() string { + return fmt.Sprintf(`{ + ID: %s + Title: %q + Guid: %q + Link: %q + Date: %s + Hash: %s +}`, + base64.RawURLEncoding.EncodeToString(item.ID[:]), + item.Title, item.Guid, item.Link, util.TimeFormat(item.Date), item.Hash) +} + +func (cf *cachedFeed) Checked(withFailure bool) { + cf.currentCheck = time.Now() + if withFailure { + cf.NumFailures++ + } else { + cf.NumFailures = 0 + } +} + +func (cf *cachedFeed) Commit() { + if cf.newItems != nil { + cf.Items = cf.newItems + cf.newItems = nil + } + cf.LastCheck = cf.currentCheck +} + +func (cf *cachedFeed) Failures() int { + return cf.NumFailures +} + +func (cf *cachedFeed) Last() time.Time { + return cf.LastCheck +} + +func (cf *cachedFeed) Feed() *feed.Feed { + return cf.feed +} + +func (cache *v1Cache) Version() Version { + return v1Version +} + +func (cache *v1Cache) Info() string { + b := strings.Builder{} + for descr, id := range cache.Ids { + b.WriteString(fmt.Sprintf("%3s: %s (%s)\n", id.String(), descr.Name, descr.Url)) + } + return b.String() +} + +func (cache *v1Cache) SpecificInfo(i interface{}) string { + id := idFromString(i.(string)) + + b := strings.Builder{} + feed := cache.Feeds[id] + + for descr, fId := range cache.Ids { + if id == fId { + b.WriteString(descr.Name) + b.WriteString(" -- ") + b.WriteString(descr.Url) + b.WriteByte('\n') + break + } + } + + b.WriteString(fmt.Sprintf(` +Last Check: %s +Num Failures: %d +Num Items: %d +`, + util.TimeFormat(feed.LastCheck), + feed.NumFailures, + len(feed.Items))) + + for _, item := range feed.Items { + b.WriteString("\n--------------------\n") + b.WriteString(item.String()) + } + return b.String() +} + +func newV1Cache() *v1Cache { + cache := v1Cache{ + Ids: map[feed.Descriptor]feedId{}, + Feeds: map[feedId]*cachedFeed{}, + NextId: startFeedId, + } + return &cache +} + +func (cache *v1Cache) transformToCurrent() (Impl, error) { + return cache, nil +} + +func (cache *v1Cache) getItem(id feedId) *cachedFeed { + feed, ok := cache.Feeds[id] + if !ok { + feed = &cachedFeed{} + cache.Feeds[id] = feed + } + feed.id = id + return feed +} + +func (cache *v1Cache) cachedFeed(f *feed.Feed) CachedFeed { + fDescr := f.Descriptor() + id, ok := cache.Ids[fDescr] + if !ok { + var otherId feed.Descriptor + changed := false + for otherId, id = range cache.Ids { + if otherId.Name == fDescr.Name { + log.Warnf("Feed %s seems to have changed URLs: new '%s', old '%s'. Updating.", + fDescr.Name, fDescr.Url, otherId.Url) + changed = true + break + } else if otherId.Url == fDescr.Url { + log.Warnf("Feed with URL '%s' seems to have changed its name: new '%s', old '%s'. Updating.", + fDescr.Url, fDescr.Name, otherId.Name) + changed = true + break + } + } + if changed { + delete(cache.Ids, otherId) + } else { + id = feedId(cache.NextId) + cache.NextId++ + } + + cache.Ids[fDescr] = id + } + + cf := cache.getItem(id) + cf.feed = f + f.SetExtID(id) + return cf +} + +func newCachedItem(item *feed.Item) cachedItem { + var ci cachedItem + + ci.ID = item.ID + ci.Title = item.Item.Title + ci.Link = item.Item.Link + if item.DateParsed() != nil { + ci.Date = *item.DateParsed() + } + ci.Guid = item.Item.GUID + + contentByte := []byte(item.Item.Description + item.Item.Content) + ci.Hash = sha256.Sum256(contentByte) + + return ci +} + +func (item *cachedItem) similarTo(other *cachedItem, ignoreHash bool) bool { + return other.Title == item.Title && + other.Link == item.Link && + other.Date.Equal(item.Date) && + (ignoreHash || other.Hash == item.Hash) +} + +func (cf *cachedFeed) deleteItem(index int) { + copy(cf.Items[index:], cf.Items[index+1:]) + cf.Items[len(cf.Items)-1] = cachedItem{} + cf.Items = cf.Items[:len(cf.Items)-1] +} + +func (cf *cachedFeed) Filter(items []feed.Item, ignoreHash, alwaysNew bool) []feed.Item { + if len(items) == 0 { + return items + } + + cacheItems := make(map[cachedItem]*feed.Item, len(items)) + for idx := range items { + // remove complete duplicates on the go + cacheItems[newCachedItem(&items[idx])] = &items[idx] + } + log.Debugf("%d items after deduplication", len(cacheItems)) + + filtered := make([]feed.Item, 0, len(items)) + cacheadd := make([]cachedItem, 0, len(items)) + app := func(item *feed.Item, ci cachedItem, oldIdx *int) { + if oldIdx != nil { + item.UpdateOnly = true + prevId := cf.Items[*oldIdx].ID + ci.ID = prevId + item.ID = prevId + log.Debugf("oldIdx: %d, prevId: %s, item.id: %s", *oldIdx, prevId, item.Id()) + cf.deleteItem(*oldIdx) + } + filtered = append(filtered, *item) + cacheadd = append(cacheadd, ci) + } + +CACHE_ITEMS: + for ci, item := range cacheItems { + log.Debugf("Now checking %s", ci) + + if ci.Guid != "" { + for idx, oldItem := range cf.Items { + if oldItem.Guid == ci.Guid { + log.Debugf("Guid matches with: %s", oldItem) + if !oldItem.similarTo(&ci, ignoreHash) { + item.AddReason("guid (upd)") + app(item, ci, &idx) + } else { + log.Debugf("Similar, ignoring item %s", base64.RawURLEncoding.EncodeToString(oldItem.ID[:])) + } + + continue CACHE_ITEMS + } + } + + log.Debug("Found no matching GUID, including.") + item.AddReason("guid") + app(item, ci, nil) + continue + } + + for idx, oldItem := range cf.Items { + if oldItem.similarTo(&ci, ignoreHash) { + log.Debugf("Similarity matches, ignoring: %s", oldItem) + continue CACHE_ITEMS + } + + if oldItem.Link == ci.Link { + if alwaysNew { + log.Debugf("Link matches, but `always-new`.") + item.AddReason("always-new") + continue + } + log.Debugf("Link matches, updating: %s", oldItem) + item.AddReason("link (upd)") + app(item, ci, &idx) + + continue CACHE_ITEMS + } + } + + log.Debugf("No match found, inserting.") + item.AddReason("new") + app(item, ci, nil) + } + + log.Debugf("%d items after filtering", len(filtered)) + + cf.newItems = append(cacheadd, cf.Items...) + + return filtered +} -- cgit v1.2.3-54-g00ecf