From 07a65e0bb5b4efcb838ad82888864d8a61850a67 Mon Sep 17 00:00:00 2001
From: InsanusMokrassar <ovsyannikov.alexey95@gmail.com>
Date: Sun, 22 Nov 2020 23:19:16 +0600
Subject: [PATCH] fixes

---
 .../repos/DatabaseCoroutineContext.kt         |  4 +--
 .../micro_utils/repos/DatabaseTransactions.kt | 34 ++++++++++++++++++-
 .../AndroidSQLStandardVersionsRepoProxy.kt    | 10 +++---
 3 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/DatabaseCoroutineContext.kt b/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/DatabaseCoroutineContext.kt
index 8a2932eb0fe..b99835e5972 100644
--- a/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/DatabaseCoroutineContext.kt
+++ b/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/DatabaseCoroutineContext.kt
@@ -1,6 +1,6 @@
 package dev.inmo.micro_utils.repos
 
-import kotlinx.coroutines.newSingleThreadContext
+import kotlinx.coroutines.Dispatchers
 import kotlin.coroutines.CoroutineContext
 
-val DatabaseCoroutineContext: CoroutineContext = newSingleThreadContext("db-context")
+val DatabaseCoroutineContext: CoroutineContext = Dispatchers.IO
diff --git a/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/DatabaseTransactions.kt b/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/DatabaseTransactions.kt
index 2f2c5e21f1e..6d7821d20ca 100644
--- a/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/DatabaseTransactions.kt
+++ b/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/DatabaseTransactions.kt
@@ -3,10 +3,42 @@ package dev.inmo.micro_utils.repos
 import android.database.sqlite.SQLiteDatabase
 import dev.inmo.micro_utils.coroutines.safely
 import kotlinx.coroutines.*
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 import java.util.concurrent.Executors
 import kotlin.coroutines.CoroutineContext
 import kotlin.coroutines.coroutineContext
 
+private object ContextsPool {
+    private val contexts = mutableListOf<CoroutineContext>()
+    private val mutex = Mutex(locked = false)
+    private val freeContexts = mutableListOf<CoroutineContext>()
+
+    suspend fun acquireContext(): CoroutineContext {
+        return mutex.withLock {
+            freeContexts.removeFirstOrNull() ?: Executors.newSingleThreadExecutor().asCoroutineDispatcher().also {
+                contexts.add(it)
+            }
+        }
+    }
+
+    suspend fun freeContext(context: CoroutineContext) {
+        return mutex.withLock {
+            if (context in contexts && context !in freeContexts) {
+                freeContexts.add(context)
+            }
+        }
+    }
+
+    suspend fun <T> use(block: suspend (CoroutineContext) -> T): T = acquireContext().let {
+        try {
+            block(it)
+        } finally {
+            freeContext(it)
+        }
+    }
+}
+
 class TransactionContext(
     val databaseContext: CoroutineContext
 ): CoroutineContext.Element {
@@ -20,7 +52,7 @@ suspend fun <T> SQLiteDatabase.transaction(block: suspend SQLiteDatabase.() -> T
         withContext(it.databaseContext) {
             block()
         }
-    } ?: Executors.newSingleThreadExecutor().asCoroutineDispatcher().let { context ->
+    } ?: ContextsPool.use { context ->
         withContext(TransactionContext(context) + context) {
             beginTransaction()
             safely(
diff --git a/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/versions/AndroidSQLStandardVersionsRepoProxy.kt b/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/versions/AndroidSQLStandardVersionsRepoProxy.kt
index 81d31449a9b..d52d9e9ddad 100644
--- a/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/versions/AndroidSQLStandardVersionsRepoProxy.kt
+++ b/repos/common/src/main/kotlin/dev/inmo/micro_utils/repos/versions/AndroidSQLStandardVersionsRepoProxy.kt
@@ -32,11 +32,11 @@ class AndroidSQLStandardVersionsRepoProxy(
         }
     }
 
-    override suspend fun getTableVersion(tableName: String): Int? = database.writableTransaction {
+    override suspend fun getTableVersion(table: String): Int? = database.writableTransaction {
         select(
             tableName,
             selection = "$tableNameColumnName=?",
-            selectionArgs = arrayOf(tableName),
+            selectionArgs = arrayOf(table),
             limit = limitClause(1)
         ).use {
             if (it.moveToFirst()) {
@@ -47,16 +47,16 @@ class AndroidSQLStandardVersionsRepoProxy(
         }
     }
 
-    override suspend fun updateTableVersion(tableName: String, version: Int) {
+    override suspend fun updateTableVersion(table: String, version: Int) {
         database.writableTransaction {
             val updated = update(
                 tableName,
                 contentValuesOf(tableVersionColumnName to version),
                 "$tableNameColumnName=?",
-                arrayOf(version.toString())
+                arrayOf(table)
             ) > 0
             if (!updated) {
-                insert(tableName, null, contentValuesOf(tableNameColumnName to tableName, tableVersionColumnName to version))
+                insert(tableName, null, contentValuesOf(tableNameColumnName to table, tableVersionColumnName to version))
             }
         }
     }