1 files changed, 89 insertions, 0 deletions
diff --git a/wallet/src/commonMain/kotlin/net/taler/lib/wallet/Db.kt b/wallet/src/commonMain/kotlin/net/taler/lib/wallet/Db.kt
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+++ b/wallet/src/commonMain/kotlin/net/taler/lib/wallet/Db.kt
@@ -0,0 +1,89 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2020 Taler Systems S.A.
+ *
+ * GNU Taler is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ * A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.lib.wallet
+
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import net.taler.lib.wallet.exchange.DenominationRecord
+import net.taler.lib.wallet.exchange.ExchangeRecord
+
+internal interface Db {
+    suspend fun put(exchange: ExchangeRecord)
+    suspend fun listExchanges(): List<ExchangeRecord>
+    suspend fun getExchangeByBaseUrl(baseUrl: String): ExchangeRecord?
+    suspend fun deleteExchangeByBaseUrl(baseUrl: String)
+    suspend fun put(denomination: DenominationRecord)
+    suspend fun getDenominationsByBaseUrl(baseUrl: String): List<DenominationRecord>
+    suspend fun <T> transaction(function: suspend Db.() -> T): T
+}
+
+internal expect class DbFactory() {
+    fun openDb(): Db
+}
+
+internal class FakeDb : Db {
+
+    private data class Data(
+        val exchanges: HashMap<String, ExchangeRecord> = HashMap(),
+        val denominations: HashMap<String, ArrayList<DenominationRecord>> = HashMap()
+    )
+
+    private var data = Data()
+    private val mutex = Mutex(false)
+
+    override suspend fun put(exchange: ExchangeRecord) {
+        data.exchanges[exchange.baseUrl] = exchange
+    }
+
+    override suspend fun listExchanges(): List<ExchangeRecord> {
+        return data.exchanges.values.toList()
+    }
+
+    override suspend fun getExchangeByBaseUrl(baseUrl: String): ExchangeRecord? {
+        return data.exchanges[baseUrl]
+    }
+
+    override suspend fun deleteExchangeByBaseUrl(baseUrl: String) {
+        data.exchanges.remove(baseUrl)
+    }
+
+    override suspend fun put(denomination: DenominationRecord): Unit = mutex.withLock("transaction") {
+        val list = data.denominations[denomination.exchangeBaseUrl] ?: {
+            val newList = ArrayList<DenominationRecord>()
+            data.denominations[denomination.exchangeBaseUrl] = newList
+            newList
+        }()
+        val index = list.indexOfFirst { it.denomPub == denomination.denomPub }
+        if (index == -1) list.add(denomination)
+        else list[index] = denomination
+    }
+
+    override suspend fun getDenominationsByBaseUrl(baseUrl: String): List<DenominationRecord> {
+        return data.denominations[baseUrl] ?: emptyList()
+    }
+
+    override suspend fun <T> transaction(function: suspend Db.() -> T): T = mutex.withLock("transaction") {
+        val dataCopy = data.copy()
+        return@withLock try {
+            function()
+        } catch (e: Throwable) {
+            data = dataCopy
+            throw e
+        }
+    }
+
+}