server/storage/message_store.go

236 lines
6.7 KiB
Go

package storage
import (
"cwtch.im/cwtch/protocol/groups"
"database/sql"
"encoding/base64"
"fmt"
"git.openprivacy.ca/openprivacy/log"
"sync"
)
// MessageStoreInterface defines an interface to interact with a store of cwtch messages.
type MessageStoreInterface interface {
AddMessage(groups.EncryptedGroupMessage)
FetchMessages() []*groups.EncryptedGroupMessage
MessagesCount() int
FetchMessagesFrom(signature []byte) []*groups.EncryptedGroupMessage
SetMessageCap(newcap int)
Close()
}
// SqliteMessageStore is an sqlite3 backed message store
type SqliteMessageStore struct {
incMessageCounterFn func()
messageCap int
messageCount int
countLock sync.Mutex
database *sql.DB
// Some prepared queries...
preparedInsertStatement *sql.Stmt // A Stmt is safe for concurrent use by multiple goroutines.
preparedFetchFromQuery *sql.Stmt
preparedFetchQuery *sql.Stmt
preparedCountQuery *sql.Stmt
preparedPruneStatement *sql.Stmt
}
// Close closes the underlying sqlite3 database to further changes
func (s *SqliteMessageStore) Close() {
s.preparedInsertStatement.Close()
s.preparedFetchFromQuery.Close()
s.database.Close()
}
func (s *SqliteMessageStore) SetMessageCap(newcap int) {
s.countLock.Lock()
defer s.countLock.Unlock()
s.messageCap = newcap
s.checkPruneMessages()
}
// AddMessage implements the MessageStoreInterface AddMessage for sqlite message store
func (s *SqliteMessageStore) AddMessage(message groups.EncryptedGroupMessage) {
if s.incMessageCounterFn != nil {
s.incMessageCounterFn()
}
// ignore this clearly invalid message...
if len(message.Signature) == 0 {
return
}
stmt, err := s.preparedInsertStatement.Exec(base64.StdEncoding.EncodeToString(message.Signature), base64.StdEncoding.EncodeToString(message.Ciphertext))
if err != nil {
log.Errorf("%v %q", stmt, err)
return
}
s.countLock.Lock()
defer s.countLock.Unlock()
s.messageCount++
s.checkPruneMessages()
}
func (s *SqliteMessageStore) checkPruneMessages() {
if s.messageCap != -1 && s.messageCount > s.messageCap {
log.Debugf("Message Count: %d / Message Cap: %d, message cap exceeded, pruning oldest 10%...", s.messageCount, s.messageCap)
// Delete 10% of messages (and any overage if the cap was adjusted lower)
delCount := (s.messageCount - s.messageCap) + s.messageCap/10
stmt, err := s.preparedPruneStatement.Exec(delCount)
if err != nil {
log.Errorf("%v %q", stmt, err)
}
s.messageCount -= delCount
}
}
func (s *SqliteMessageStore) MessagesCount() int {
rows, err := s.preparedCountQuery.Query()
if err != nil {
log.Errorf("%v", err)
return -1
}
defer rows.Close()
result := rows.Next()
if !result {
return -1
}
var rownum int
err = rows.Scan(&rownum)
if err != nil {
log.Errorf("error fetching rows: %v", err)
return -1
}
return rownum
}
// FetchMessages implements the MessageStoreInterface FetchMessages for sqlite message store
func (s *SqliteMessageStore) FetchMessages() []*groups.EncryptedGroupMessage {
rows, err := s.preparedFetchQuery.Query()
if err != nil {
log.Errorf("%v", err)
return nil
}
defer rows.Close()
return s.compileRows(rows)
}
// FetchMessagesFrom implements the MessageStoreInterface FetchMessagesFrom for sqlite message store
func (s *SqliteMessageStore) FetchMessagesFrom(signature []byte) []*groups.EncryptedGroupMessage {
// If signature is empty then treat this as a complete sync request
if len(signature) == 0 {
return s.FetchMessages()
}
rows, err := s.preparedFetchFromQuery.Query(base64.StdEncoding.EncodeToString(signature))
if err != nil {
log.Errorf("%v", err)
return nil
}
defer rows.Close()
messages := s.compileRows(rows)
// if we don't have *any* messages then either the signature next existed
// or the server purged it...either way treat this as a full sync...
if len(messages) < 1 {
return s.FetchMessages()
}
return messages
}
func (s *SqliteMessageStore) compileRows(rows *sql.Rows) []*groups.EncryptedGroupMessage {
var messages []*groups.EncryptedGroupMessage
for rows.Next() {
var id int
var signature string
var ciphertext string
err := rows.Scan(&id, &signature, &ciphertext)
if err != nil {
log.Errorf("Error fetching row %v", err)
}
rawSignature, _ := base64.StdEncoding.DecodeString(signature)
rawCiphertext, _ := base64.StdEncoding.DecodeString(ciphertext)
messages = append(messages, &groups.EncryptedGroupMessage{
Signature: rawSignature,
Ciphertext: rawCiphertext,
})
}
return messages
}
// InitializeSqliteMessageStore creates a database `dbfile` with the necessary tables (if it doesn't already exist)
// and returns an open database
func InitializeSqliteMessageStore(dbfile string, messageCap int, incMessageCounterFn func()) (*SqliteMessageStore, error) {
db, err := sql.Open("sqlite3", dbfile)
if err != nil {
log.Errorf("database %v cannot be created or opened %v", dbfile, err)
return nil, fmt.Errorf("database %v cannot be created or opened: %v", dbfile, err)
}
sqlStmt := `CREATE TABLE IF NOT EXISTS messages (id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, signature TEXT UNIQUE NOT NULL, ciphertext TEXT NOT NULL);`
_, err = db.Exec(sqlStmt)
if err != nil {
db.Close()
log.Errorf("%q: %s", err, sqlStmt)
return nil, fmt.Errorf("%s: %q", sqlStmt, err)
}
log.Infof("Database Initialized")
slms := new(SqliteMessageStore)
slms.database = db
slms.incMessageCounterFn = incMessageCounterFn
slms.messageCap = messageCap
sqlStmt = `INSERT INTO messages(signature, ciphertext) values (?,?);`
stmt, err := slms.database.Prepare(sqlStmt)
if err != nil {
log.Errorf("%q: %s", err, sqlStmt)
return nil, fmt.Errorf("%s: %q", sqlStmt, err)
}
slms.preparedInsertStatement = stmt
sqlStmt = "SELECT id, signature,ciphertext from messages"
query, err := slms.database.Prepare(sqlStmt)
if err != nil {
log.Errorf("%q: %s", err, sqlStmt)
return nil, fmt.Errorf("%s: %q", sqlStmt, err)
}
slms.preparedFetchQuery = query
sqlStmt = "SELECT id, signature,ciphertext FROM messages WHERE id>=(SELECT id FROM messages WHERE signature=(?));"
query, err = slms.database.Prepare(sqlStmt)
if err != nil {
log.Errorf("%q: %s", err, sqlStmt)
return nil, fmt.Errorf("%s: %q", sqlStmt, err)
}
slms.preparedFetchFromQuery = query
sqlStmt = "SELECT COUNT(*) from messages"
stmt, err = slms.database.Prepare(sqlStmt)
if err != nil {
log.Errorf("%q: %s", err, sqlStmt)
return nil, fmt.Errorf("%s: %q", sqlStmt, err)
}
slms.preparedCountQuery = stmt
sqlStmt = "DELETE FROM messages WHERE id IN (SELECT id FROM messages ORDER BY id ASC LIMIT (?))"
stmt, err = slms.database.Prepare(sqlStmt)
if err != nil {
log.Errorf("%q: %s", err, sqlStmt)
return nil, fmt.Errorf("%s: %q", sqlStmt, err)
}
slms.preparedPruneStatement = stmt
slms.messageCount = slms.MessagesCount()
slms.checkPruneMessages()
return slms, nil
}