server: Add lite-version config

Enabling the lite-version allows to prune block details
to allow syncing fast until what the light wallet needs.

server/app/com/xsn/explorer/config/ExplorerConfig.scala

@@ -7,15 +7,28 @@ import play.api.Configuration
 trait ExplorerConfig {
 
   def genesisBlock: Blockhash
+
+  def liteVersionConfig: ExplorerConfig.LiteVersionConfig
 }
 
-class PlayExplorerConfig @Inject() (config: Configuration) extends ExplorerConfig {
+object ExplorerConfig {
 
-  override val genesisBlock:  Blockhash = {
-    Blockhash
-      .from(config.get[String]("explorer.genesisBlock"))
-      .getOrElse(throw new RuntimeException("The given genesisBlock is incorrect"))
-  }
+  case class LiteVersionConfig(enabled: Boolean, syncTransactionsFromBlock: Int)
 
-}
+  class Play @Inject() (config: Configuration) extends ExplorerConfig {
+
+    override val genesisBlock: Blockhash = {
+      Blockhash
+          .from(config.get[String]("explorer.genesisBlock"))
+          .getOrElse(throw new RuntimeException("The given genesisBlock is incorrect"))
+    }
 
+    override def liteVersionConfig: LiteVersionConfig = {
+      val inner = config.get[Configuration]("explorer.liteVersion")
+      val enabled = inner.get[Boolean]("enabled")
+      val syncTransactionsFromBlock = inner.get[Int]("syncTransactionsFromBlock")
+
+      LiteVersionConfig(enabled, syncTransactionsFromBlock)
+    }
+  }
+}

server/app/com/xsn/explorer/data/anorm/dao/AddressTransactionDetailsPostgresDAO.scala

@@ -3,11 +3,16 @@ package com.xsn.explorer.data.anorm.dao
 import java.sql.Connection
 
 import anorm._
+import com.xsn.explorer.config.ExplorerConfig
 import com.xsn.explorer.data.anorm.parsers.TransactionParsers._
 import com.xsn.explorer.models.persisted.{AddressTransactionDetails, Transaction}
 import com.xsn.explorer.models.values.TransactionId
+import javax.inject.Inject
+import org.slf4j.LoggerFactory
 
-class AddressTransactionDetailsPostgresDAO {
+class AddressTransactionDetailsPostgresDAO @Inject() (explorerConfig: ExplorerConfig) {
+
+  private val logger = LoggerFactory.getLogger(this.getClass)
 
   def batchInsertDetails(transaction: Transaction.HasIO)(implicit conn: Connection): Option[Unit] = {
     val outputAddressValueList = for {
@@ -66,9 +71,12 @@ class AddressTransactionDetailsPostgresDAO {
           params.tail: _*
         )
 
-        val success = batch.execute().forall(_ == 1)
+        val result = batch.execute()
+        val success = result.forall(_ == 1)
+
+        if (success ||
+            explorerConfig.liteVersionConfig.enabled) {
 
-        if (success) {
           Some(())
         } else {
           None

server/app/com/xsn/explorer/data/anorm/dao/TransactionInputPostgresDAO.scala

@@ -3,12 +3,14 @@ package com.xsn.explorer.data.anorm.dao
 import java.sql.Connection
 
 import anorm._
+import com.xsn.explorer.config.ExplorerConfig
 import com.xsn.explorer.data.anorm.parsers.TransactionParsers._
 import com.xsn.explorer.models.persisted.Transaction
 import com.xsn.explorer.models.values.{Address, TransactionId}
+import javax.inject.Inject
 import org.slf4j.LoggerFactory
 
-class TransactionInputPostgresDAO {
+class TransactionInputPostgresDAO @Inject() (explorerConfig: ExplorerConfig) {
 
   private val logger = LoggerFactory.getLogger(this.getClass)
 
@@ -41,8 +43,11 @@ class TransactionInputPostgresDAO {
           params.tail: _*
         )
 
-        val success = batch.execute().forall(_ == 1)
-        if (success) {
+        val result = batch.execute()
+        val success = result.forall(_ == 1)
+        if (success ||
+            explorerConfig.liteVersionConfig.enabled) {
+
           Some(inputs)
         } else {
           None

server/app/com/xsn/explorer/data/anorm/dao/TransactionOutputPostgresDAO.scala

@@ -3,12 +3,14 @@ package com.xsn.explorer.data.anorm.dao
 import java.sql.Connection
 
 import anorm._
+import com.xsn.explorer.config.ExplorerConfig
 import com.xsn.explorer.data.anorm.parsers.TransactionParsers._
 import com.xsn.explorer.models.persisted.Transaction
 import com.xsn.explorer.models.values.{Address, TransactionId}
+import javax.inject.Inject
 import org.slf4j.LoggerFactory
 
-class TransactionOutputPostgresDAO {
+class TransactionOutputPostgresDAO @Inject() (explorerConfig: ExplorerConfig) {
 
   private val logger = LoggerFactory.getLogger(this.getClass)
 
@@ -68,9 +70,11 @@ class TransactionOutputPostgresDAO {
         )
 
         val success = batch.execute().forall(_ == 1)
-        if (success) {
+        if (success ||
+            explorerConfig.liteVersionConfig.enabled) {
+
           Some(outputs)
-        } else {
+        } else{
           None
         }
     }
@@ -145,7 +149,9 @@ class TransactionOutputPostgresDAO {
         """.stripMargin
         ).executeUpdate()
 
-        if (result == inputs.size) {
+        if (result == inputs.size ||
+            explorerConfig.liteVersionConfig.enabled) {
+
           Option(())
         } else {
           None

server/app/com/xsn/explorer/data/anorm/dao/TransactionPostgresDAO.scala

@@ -6,6 +6,7 @@ import anorm._
 import com.alexitc.playsonify.models.ordering.{FieldOrdering, OrderingCondition}
 import com.alexitc.playsonify.models.pagination.{Count, Limit, PaginatedQuery}
 import com.alexitc.playsonify.sql.FieldOrderingSQLInterpreter
+import com.xsn.explorer.config.ExplorerConfig
 import com.xsn.explorer.data.anorm.parsers.TransactionParsers._
 import com.xsn.explorer.models._
 import com.xsn.explorer.models.fields.TransactionField
@@ -15,6 +16,7 @@ import javax.inject.Inject
 import org.slf4j.LoggerFactory
 
 class TransactionPostgresDAO @Inject() (
+    explorerConfig: ExplorerConfig,
     transactionInputDAO: TransactionInputPostgresDAO,
     transactionOutputDAO: TransactionOutputPostgresDAO,
     tposContractDAO: TPoSContractDAO,
@@ -65,7 +67,11 @@ class TransactionPostgresDAO @Inject() (
   private def spend(transactions: List[Transaction.HasIO])(implicit conn: Connection): Unit = {
     val spendResult = transactions.map { tx => transactionOutputDAO.batchSpend(tx.id, tx.inputs) }
 
-    assert(spendResult.forall(_.isDefined), "Spending inputs batch failed")
+    if (explorerConfig.liteVersionConfig.enabled) {
+      ()
+    } else {
+      assert(spendResult.forall(_.isDefined), "Spending inputs batch failed")
+    }
   }
 
   private def closeContracts(transactions: List[Transaction.HasIO])(implicit conn: Connection): Unit = {

server/app/com/xsn/explorer/modules/ConfigModule.scala

@@ -8,6 +8,6 @@ class ConfigModule extends AbstractModule {
   override def configure(): Unit = {
     bind(classOf[RPCConfig]).to(classOf[PlayRPCConfig])
     bind(classOf[LedgerSynchronizerConfig]).to(classOf[LedgerSynchronizerPlayConfig])
-    bind(classOf[ExplorerConfig]).to(classOf[PlayExplorerConfig])
+    bind(classOf[ExplorerConfig]).to(classOf[ExplorerConfig.Play])
   }
 }

server/app/com/xsn/explorer/services/LedgerSynchronizerService.scala

@@ -2,6 +2,7 @@ package com.xsn.explorer.services
 
 import com.alexitc.playsonify.core.FutureOr.Implicits.{FutureOps, OptionOps}
 import com.alexitc.playsonify.core.{ApplicationResult, FutureApplicationResult}
+import com.xsn.explorer.config.ExplorerConfig
 import com.xsn.explorer.data.async.{BlockFutureDataHandler, LedgerFutureDataHandler}
 import com.xsn.explorer.errors.BlockNotFoundError
 import com.xsn.explorer.models._
@@ -16,6 +17,7 @@ import org.slf4j.LoggerFactory
 import scala.concurrent.{ExecutionContext, Future}
 
 class LedgerSynchronizerService @Inject() (
+    explorerConfig: ExplorerConfig,
     xsnService: XSNService,
     blockService: BlockService,
     transactionCollectorService: TransactionCollectorService,
@@ -172,7 +174,14 @@ class LedgerSynchronizerService @Inject() (
     val result = for {
       rpcBlock <- xsnService.getBlock(blockhash).toFutureOr
     } yield {
-      rpcBlock
+      if (explorerConfig.liteVersionConfig.enabled &&
+          rpcBlock.height.int < explorerConfig.liteVersionConfig.syncTransactionsFromBlock) {
+
+        // lite version, ignore transactions
+        rpcBlock.copy(transactions = List.empty)
+      } else {
+        rpcBlock
+      }
     }
 
     result.toFuture

server/conf/application.conf

@@ -42,7 +42,7 @@ rpc {
 synchronizer {
   enabled = true
   initialDelay = "10 seconds"
-  interval = "1 minute"
+  interval = "1 minutes"
 
   enabled = ${?XSN_SYNCHRONIZER_ENABLED}
 }
@@ -110,4 +110,19 @@ externalService.dispatcher {
 explorer {
   genesisBlock = "00000c822abdbb23e28f79a49d29b41429737c6c7e15df40d1b1f1b35907ae34"
   genesisBlock = ${?EXPLORER_GENESIS_BLOCK}
+
+  liteVersion {
+    # Enabling the lite explorer, starts syncing the block details only, the transactions and
+    # its related details are synced only on blocks having height >= syncTransactionsFromBlock
+    #
+    # This is useful to support our light wallet, assuming that all its addresses are new (hence, old details aren't important).
+    #
+    # This also implies that some consistency checks are removed, you are required to drop some foreign keys manually.
+    #
+    # Updating these values on an existing explorer is likely to need to rebuilt the database from scratch.
+    enabled = false
+    enabled = ${?EXPLORER_LITE_VERSION_ENABLED}
+
+    syncTransactionsFromBlock = 0
+  }
 }

server/test/com/xsn/explorer/helpers/Config.scala

@@ -0,0 +1,13 @@
+package com.xsn.explorer.helpers
+
+import com.xsn.explorer.config.ExplorerConfig
+import com.xsn.explorer.models.values.Blockhash
+
+object Config {
+  val explorerConfig = new ExplorerConfig {
+
+    override def genesisBlock: Blockhash = Blockhash.from("00000c822abdbb23e28f79a49d29b41429737c6c7e15df40d1b1f1b35907ae34").get
+
+    override def liteVersionConfig: ExplorerConfig.LiteVersionConfig = ExplorerConfig.LiteVersionConfig(enabled = false, 0)
+  }
+}

server/test/com/xsn/explorer/helpers/DataHandlerObjects.scala

@@ -7,12 +7,15 @@ import play.api.db.Database
 
 trait DataHandlerObjects {
 
+  import Config.explorerConfig
+
   lazy val fieldOrderingSQLInterpreter = new FieldOrderingSQLInterpreter
-  lazy val transactionInputDAO = new TransactionInputPostgresDAO
-  lazy val transactionOutputDAO = new TransactionOutputPostgresDAO
-  lazy val addressTransactionDetailsDAO = new AddressTransactionDetailsPostgresDAO
+  lazy val transactionInputDAO = new TransactionInputPostgresDAO(explorerConfig)
+  lazy val transactionOutputDAO = new TransactionOutputPostgresDAO(explorerConfig)
+  lazy val addressTransactionDetailsDAO = new AddressTransactionDetailsPostgresDAO(explorerConfig)
   lazy val tposContractDAO = new TPoSContractDAO
   lazy val transactionPostgresDAO = new TransactionPostgresDAO(
+    explorerConfig,
     transactionInputDAO,
     transactionOutputDAO,
     tposContractDAO,

server/test/com/xsn/explorer/services/LedgerSynchronizerServiceSpec.scala

@@ -227,6 +227,7 @@ class LedgerSynchronizerServiceSpec extends PostgresDataHandlerSpec with BeforeA
       new TransactionFutureDataHandler(transactionDataHandler)(Executors.databaseEC)
     )
     new LedgerSynchronizerService(
+      Config.explorerConfig,
       xsnService,
       blockService,
       transactionCollectorService,

server/test/com/xsn/explorer/services/XSNServiceRPCImplSpec.scala

@@ -33,6 +33,8 @@ class XSNServiceRPCImplSpec extends WordSpec {
 
   val explorerConfig = new ExplorerConfig {
     override def genesisBlock: Blockhash = Blockhash.from("00000c822abdbb23e28f79a49d29b41429737c6c7e15df40d1b1f1b35907ae34").get
+
+    override def liteVersionConfig: ExplorerConfig.LiteVersionConfig = ???
   }
 
   val request = mock[WSRequest]