further optimize transaction storage by comparing dataHash field

if the dataHash field of the transaction that needs storage matches one
from the database (retrieved by profile id and ledger id), then simply
update the generation of the transaction in the database (and its
accounts)

since this is the common case (refreshing transaction list -- most of
the transactions are expected to be unchanged) this saves big time

diff --git a/app/src/main/java/net/ktnx/mobileledger/dao/TransactionDAO.java b/app/src/main/java/net/ktnx/mobileledger/dao/TransactionDAO.java
index 31319f34b9f2be522273b3a5ade9a74f2ecdc3b9..8f238183549bbc33b392540728ca4632d736cf89 100644 (file)
--- a/app/src/main/java/net/ktnx/mobileledger/dao/TransactionDAO.java
+++ b/app/src/main/java/net/ktnx/mobileledger/dao/TransactionDAO.java
@@ -32,6 +32,7 @@ import net.ktnx.mobileledger.db.Transaction;
 import net.ktnx.mobileledger.db.TransactionAccount;
 import net.ktnx.mobileledger.db.TransactionWithAccounts;
 import net.ktnx.mobileledger.utils.Logger;
+import net.ktnx.mobileledger.utils.Misc;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -128,6 +129,18 @@ public abstract class TransactionDAO extends BaseDAO<Transaction> {
 
     @Query("SELECT * FROM transactions where profile_id = :profileId AND ledger_id = :ledgerId")
     public abstract Transaction getByLedgerId(long profileId, long ledgerId);
+
+    @Query("UPDATE transactions SET generation = :newGeneration WHERE id = :transactionId")
+    public abstract int updateGeneration(long transactionId, long newGeneration);
+
+    @Query("UPDATE transaction_accounts SET generation = :newGeneration WHERE transaction_id = " +
+           ":transactionId")
+    public abstract int updateAccountsGeneration(long transactionId, long newGeneration);
+    @androidx.room.Transaction
+    public void updateGenerationWithAccounts(long transactionId, long newGeneration) {
+        updateGeneration(transactionId, newGeneration);
+        updateAccountsGeneration(transactionId, newGeneration);
+    }
     public long getGenerationSync(long profileId) {
         TransactionGenerationContainer result = getGenerationPOJOSync(profileId);
 
@@ -160,8 +173,14 @@ public abstract class TransactionDAO extends BaseDAO<Transaction> {
         Transaction transaction = rec.transaction;
         Transaction existing = getByLedgerId(transaction.getProfileId(), transaction.getLedgerId());
         if (existing != null) {
+            if (Misc.equalStrings(transaction.getDataHash(), existing.getDataHash())) {
+                updateGenerationWithAccounts(existing.getId(), rec.transaction.getGeneration());
+                return;
+            }
+
             existing.copyDataFrom(transaction);
             updateSync(existing);
+
             transaction = existing;
         }
         else