Store each ticket in its own DB bucket.

**NOTE: This contains a backwards incompatible database migration, so if you plan to test it, please make a copy of your database first.**

Moves tickets from a single database bucket containing JSON encoded strings, to a bucket for each ticket.

This change is to preemptively deal with scaling issues seen with databases containing tens of thousands of tickets.

background/background.go

@@ -548,7 +548,7 @@ func checkWalletConsistency() {
 	}
 }
 
-func findOldestHeight(tickets []database.Ticket) int64 {
+func findOldestHeight(tickets []*database.Ticket) int64 {
 	var oldestHeight int64
 	for _, ticket := range tickets {
 		// skip unconfirmed tickets

database/database.go

@@ -85,6 +85,16 @@ func writeHotBackupFile(db *bolt.DB) error {
 	return err
 }
 
+func int64ToBytes(i int64) []byte {
+	bytes := make([]byte, 8)
+	binary.LittleEndian.PutUint64(bytes, uint64(i))
+	return bytes
+}
+
+func bytesToInt64(bytes []byte) int64 {
+	return int64(binary.LittleEndian.Uint64(bytes))
+}
+
 func uint32ToBytes(i uint32) []byte {
 	bytes := make([]byte, 4)
 	binary.LittleEndian.PutUint32(bytes, i)

database/database_upgrades.go

@@ -16,16 +16,41 @@ const (
 	// need to keep these, and they take up a lot of space.
 	removeOldFeeTxVersion = 2
 
+	// ticketBucketVersion changes the way tickets are stored. Previously they
+	// were stored as JSON encoded strings in a single bucket. This upgrade
+	// moves each ticket into its own bucket and does away with JSON encoding.
+	ticketBucketVersion = 3
+
 	// latestVersion is the latest version of the database that is understood by
 	// vspd. Databases with recorded versions higher than this will fail to open
 	// (meaning any upgrades prevent reverting to older software).
-	latestVersion = removeOldFeeTxVersion
+	latestVersion = ticketBucketVersion
 )
 
 // upgrades maps between old database versions and the upgrade function to
 // upgrade the database to the next version.
 var upgrades = []func(tx *bolt.DB) error{
-	initialVersion: removeOldFeeTxUpgrade,
+	initialVersion:        removeOldFeeTxUpgrade,
+	removeOldFeeTxVersion: ticketBucketUpgrade,
+}
+
+// v1Ticket has the json tags required to unmarshal tickets stored in the
+// v1 database format.
+type v1Ticket struct {
+	Hash              string            `json:"hsh"`
+	PurchaseHeight    int64             `json:"phgt"`
+	CommitmentAddress string            `json:"cmtaddr"`
+	FeeAddressIndex   uint32            `json:"faddridx"`
+	FeeAddress        string            `json:"faddr"`
+	FeeAmount         int64             `json:"famt"`
+	FeeExpiration     int64             `json:"fexp"`
+	Confirmed         bool              `json:"conf"`
+	VotingWIF         string            `json:"vwif"`
+	VoteChoices       map[string]string `json:"vchces"`
+	FeeTxHex          string            `json:"fhex"`
+	FeeTxHash         string            `json:"fhsh"`
+	FeeTxStatus       FeeStatus         `json:"fsts"`
+	Outcome           TicketOutcome     `json:"otcme"`
 }
 
 // Upgrade will update the database to the latest known version.