feat(gemini-web): Add conversation affinity selector

internal/provider/gemini-web/conversation/index.go

@@ -0,0 +1,187 @@
+package conversation
+
+import (
+	"encoding/json"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	bolt "go.etcd.io/bbolt"
+)
+
+const (
+	bucketMatches    = "matches"
+	defaultIndexFile = "gemini-web-index.bolt"
+)
+
+// MatchRecord stores persisted mapping metadata for a conversation prefix.
+type MatchRecord struct {
+	AccountLabel string   `json:"account_label"`
+	Metadata     []string `json:"metadata,omitempty"`
+	PrefixLen    int      `json:"prefix_len"`
+	UpdatedAt    int64    `json:"updated_at"`
+}
+
+// MatchResult combines a persisted record with the hash that produced it.
+type MatchResult struct {
+	Hash   string
+	Record MatchRecord
+	Model  string
+}
+
+var (
+	indexOnce sync.Once
+	indexDB   *bolt.DB
+	indexErr  error
+)
+
+func openIndex() (*bolt.DB, error) {
+	indexOnce.Do(func() {
+		path := indexPath()
+		if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+			indexErr = err
+			return
+		}
+		db, err := bolt.Open(path, 0o600, &bolt.Options{Timeout: 2 * time.Second})
+		if err != nil {
+			indexErr = err
+			return
+		}
+		indexDB = db
+	})
+	return indexDB, indexErr
+}
+
+func indexPath() string {
+	wd, err := os.Getwd()
+	if err != nil || wd == "" {
+		wd = "."
+	}
+	return filepath.Join(wd, "conv", defaultIndexFile)
+}
+
+// StoreMatch persists or updates a conversation hash mapping.
+func StoreMatch(hash string, record MatchRecord) error {
+	if strings.TrimSpace(hash) == "" {
+		return errors.New("gemini-web conversation: empty hash")
+	}
+	db, err := openIndex()
+	if err != nil {
+		return err
+	}
+	record.UpdatedAt = time.Now().UTC().Unix()
+	payload, err := json.Marshal(record)
+	if err != nil {
+		return err
+	}
+	return db.Update(func(tx *bolt.Tx) error {
+		bucket, err := tx.CreateBucketIfNotExists([]byte(bucketMatches))
+		if err != nil {
+			return err
+		}
+		return bucket.Put([]byte(hash), payload)
+	})
+}
+
+// LookupMatch retrieves a stored mapping.
+func LookupMatch(hash string) (MatchRecord, bool, error) {
+	db, err := openIndex()
+	if err != nil {
+		return MatchRecord{}, false, err
+	}
+	var record MatchRecord
+	err = db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(bucketMatches))
+		if bucket == nil {
+			return nil
+		}
+		raw := bucket.Get([]byte(hash))
+		if len(raw) == 0 {
+			return nil
+		}
+		return json.Unmarshal(raw, &record)
+	})
+	if err != nil {
+		return MatchRecord{}, false, err
+	}
+	if record.AccountLabel == "" || record.PrefixLen <= 0 {
+		return MatchRecord{}, false, nil
+	}
+	return record, true, nil
+}
+
+// RemoveMatch deletes a mapping for the given hash.
+func RemoveMatch(hash string) error {
+	db, err := openIndex()
+	if err != nil {
+		return err
+	}
+	return db.Update(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(bucketMatches))
+		if bucket == nil {
+			return nil
+		}
+		return bucket.Delete([]byte(hash))
+	})
+}
+
+// RemoveMatchesByLabel removes all entries associated with the specified label.
+func RemoveMatchesByLabel(label string) error {
+	label = strings.TrimSpace(label)
+	if label == "" {
+		return nil
+	}
+	db, err := openIndex()
+	if err != nil {
+		return err
+	}
+	return db.Update(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(bucketMatches))
+		if bucket == nil {
+			return nil
+		}
+		cursor := bucket.Cursor()
+		for k, v := cursor.First(); k != nil; k, v = cursor.Next() {
+			if len(v) == 0 {
+				continue
+			}
+			var record MatchRecord
+			if err := json.Unmarshal(v, &record); err != nil {
+				_ = bucket.Delete(k)
+				continue
+			}
+			if strings.EqualFold(strings.TrimSpace(record.AccountLabel), label) {
+				if err := bucket.Delete(k); err != nil {
+					return err
+				}
+			}
+		}
+		return nil
+	})
+}
+
+// StoreConversation updates all hashes representing the provided conversation snapshot.
+func StoreConversation(label, model string, msgs []Message, metadata []string) error {
+	label = strings.TrimSpace(label)
+	if label == "" || len(msgs) == 0 {
+		return nil
+	}
+	hashes := BuildStorageHashes(model, msgs)
+	if len(hashes) == 0 {
+		return nil
+	}
+	for _, h := range hashes {
+		rec := MatchRecord{
+			AccountLabel: label,
+			Metadata:     append([]string(nil), metadata...),
+			PrefixLen:    h.PrefixLen,
+		}
+		if err := StoreMatch(h.Hash, rec); err != nil {
+			return err
+		}
+	}
+	return nil
+}