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Exposed, an ORM framework for Kotlin
package org.jetbrains.exposed.dao
import org.jetbrains.exposed.dao.id.EntityID
import org.jetbrains.exposed.dao.id.IdTable
import org.jetbrains.exposed.sql.*
import org.jetbrains.exposed.sql.transactions.transactionScope
import java.util.*
import kotlin.collections.HashMap
import kotlin.collections.HashSet
/** The current [EntityCache] for [this][Transaction] scope, or a new instance if none exists. */
val Transaction.entityCache: EntityCache by transactionScope { EntityCache(this) }
/**
* Class responsible for the storage of [Entity] instances in a specific [transaction].
*/
@Suppress("UNCHECKED_CAST")
class EntityCache(private val transaction: Transaction) {
private var flushingEntities = false
private var initializingEntities: LinkedIdentityHashSet> = LinkedIdentityHashSet()
internal val pendingInitializationLambdas = IdentityHashMap, MutableList<(Entity<*>) -> Unit>>()
/** The mapping of [IdTable]s to associated [Entity] instances (as a mapping of entity id values to entities). */
val data = LinkedHashMap, MutableMap>>()
internal val inserts = LinkedHashMap, MutableSet>>()
private val updates = LinkedHashMap, MutableSet>>()
internal val referrers = HashMap, MutableMap, SizedIterable<*>>>()
/**
* The amount of entities to store in this [EntityCache] per [Entity] class.
*
* By default, this value is configured by `DatabaseConfig.maxEntitiesToStoreInCachePerEntity`,
* which defaults to storing all entities.
*
* On setting a new value, all data stored in the cache will be adjusted to the new size. If the new value
* is less than the current cache size by N, the first N entities stored will be removed. If the new value
* is greater than the current cache size, the adjusted cache will only be filled with more entities after
* they are retrieved, for example by calling [EntityClass.all].
*
* @sample org.jetbrains.exposed.sql.tests.shared.entities.EntityCacheTests.changeEntityCacheMaxEntitiesToStoreInMiddleOfTransaction
*/
var maxEntitiesToStore = transaction.db.config.maxEntitiesToStoreInCachePerEntity
set(value) {
val diff = value - field
field = value
if (diff < 0) {
data.values.forEach { map ->
val sizeExceed = map.size - value
if (sizeExceed > 0) {
val iterator = map.iterator()
repeat(sizeExceed) {
iterator.next()
iterator.remove()
}
}
}
}
}
private fun getMap(f: EntityClass<*, *>): MutableMap> = getMap(f.table)
private fun getMap(table: IdTable<*>): MutableMap> = data.getOrPut(table) {
LimitedHashMap()
}
/**
* Returns a [SizedIterable] containing all child [Entity] instances that reference the parent entity with
* the provided [sourceId] using the specified [key] column.
*
* @sample org.jetbrains.exposed.sql.tests.shared.entities.EntityTests.preloadReferrersOnAnEntity
*/
fun > getReferrers(sourceId: EntityID<*>, key: Column<*>): SizedIterable? {
return referrers[key]?.get(sourceId) as? SizedIterable
}
/**
* Returns a [SizedIterable] containing all child [Entity] instances that reference the parent entity with
* the provided [sourceId] using the specified [key] column.
*
* If either the [key] column is not present or a value does not exist for the parent entity, the default [refs]
* will be called and its result will be put into the map under the given keys and the call result returned.
*/
fun > getOrPutReferrers(sourceId: EntityID<*>, key: Column<*>, refs: () -> SizedIterable): SizedIterable {
return referrers.getOrPut(key) { HashMap() }.getOrPut(sourceId) { LazySizedCollection(refs()) } as SizedIterable
}
/**
* Searches this [EntityCache] for an [Entity] by its [EntityID] value using its associated [EntityClass] as the key.
*
* @return The entity that has this wrapped id value, or `null` if no entity was found.
*/
fun , T : Entity> find(f: EntityClass, id: EntityID): T? =
getMap(f)[id.value] as T?
?: inserts[f.table]?.firstOrNull { it.id == id } as? T
?: initializingEntities.firstOrNull { it.klass == f && it.id == id } as? T
/**
* Gets all [Entity] instances in this [EntityCache] that match the associated [EntityClass].
*
* @sample org.jetbrains.exposed.sql.tests.shared.entities.EntityCacheTests.testPerTransactionEntityCacheLimit
*/
fun , T : Entity> findAll(f: EntityClass): Collection = getMap(f).values as Collection
/** Stores the specified [Entity] in this [EntityCache] using its associated [EntityClass] as the key. */
fun , T : Entity> store(f: EntityClass, o: T) {
getMap(f)[o.id.value] = o
}
/**
* Stores the specified [Entity] in this [EntityCache].
*
* The [EntityClass] associated with this entity will be inferred based on its [Entity.klass] property.
*/
fun store(o: Entity<*>) {
getMap(o.klass.table)[o.id.value] = o
}
/** Removes the specified [Entity] from this [EntityCache] using its associated [table] as the key. */
fun , T : Entity> remove(table: IdTable, o: T) {
getMap(table).remove(o.id.value)
}
internal fun addNotInitializedEntityToQueue(entity: Entity<*>) {
require(initializingEntities.add(entity)) { "Entity ${entity::class.simpleName} already in initialization process" }
}
internal fun finishEntityInitialization(entity: Entity<*>) {
require(initializingEntities.lastOrNull() == entity) {
"Can't finish initialization for entity ${entity::class.simpleName} - the initialization order is broken"
}
initializingEntities.remove(entity)
}
internal fun isEntityInInitializationState(entity: Entity<*>) = entity in initializingEntities
/** Stores the specified [Entity] in this [EntityCache] as scheduled to be inserted into the database. */
fun , T : Entity> scheduleInsert(f: EntityClass, o: T) {
inserts.getOrPut(f.table) { LinkedIdentityHashSet() }.add(o as Entity<*>)
}
/** Stores the specified [Entity] in this [EntityCache] as scheduled to be updated in the database. */
fun , T : Entity> scheduleUpdate(f: EntityClass, o: T) {
updates.getOrPut(f.table) { LinkedIdentityHashSet() }.add(o as Entity<*>)
}
/** Sends all pending inserts and updates for all [Entity] instances in this [EntityCache] to the database. */
fun flush() {
val toFlush = when {
inserts.isEmpty() && updates.isEmpty() -> emptyList()
inserts.isNotEmpty() && updates.isNotEmpty() -> inserts.keys + updates.keys
inserts.isNotEmpty() -> inserts.keys
else -> updates.keys
}
flush(toFlush)
}
private fun updateEntities(idTable: IdTable<*>) {
val update = updates.remove(idTable) ?: return
if (update.isEmpty()) return
val updatedEntities = HashSet>()
val batch = EntityBatchUpdate(update.first().klass)
for (entity in update) {
if (entity.flush(batch)) {
check(entity.klass !is ImmutableEntityClass<*, *>) { "Update on immutable entity ${entity.javaClass.simpleName} ${entity.id}" }
updatedEntities.add(entity)
}
}
executeAsPartOfEntityLifecycle {
batch.execute(transaction)
}
updatedEntities.forEach {
transaction.registerChange(it.klass, it.id, EntityChangeType.Updated)
}
}
/**
* Sends all pending inserts and updates for [Entity] instances in this [EntityCache] to the database.
*
* The only entities that will be flushed are those that can be associated with any of the specified [tables].
*/
fun flush(tables: Iterable>) {
if (flushingEntities) return
try {
flushingEntities = true
val insertedTables = inserts.keys
val updateBeforeInsert = SchemaUtils.sortTablesByReferences(insertedTables).filterIsInstance>()
updateBeforeInsert.forEach(::updateEntities)
SchemaUtils.sortTablesByReferences(tables).filterIsInstance>().forEach(::flushInserts)
val updateTheRestTables = tables - updateBeforeInsert
for (t in updateTheRestTables) {
updateEntities(t)
}
if (insertedTables.isNotEmpty()) {
removeTablesReferrers(insertedTables, true)
}
} finally {
flushingEntities = false
}
}
internal fun removeTablesReferrers(tables: Collection, isInsert: Boolean) {
val insertedTablesSet = tables.toSet()
val columnsToInvalidate = tables.flatMapTo(hashSetOf()) { it.columns.mapNotNull { it.takeIf { it.referee != null } } }
columnsToInvalidate.forEach {
referrers.remove(it)
}
referrers.keys.filter { refColumn ->
when {
isInsert -> false
refColumn.referee?.table in insertedTablesSet -> true
refColumn.table.columns.any { it.referee?.table in tables } -> true
else -> false
}
}.forEach {
referrers.remove(it)
}
}
internal fun flushInserts(table: IdTable<*>) {
var toFlush: List> = inserts.remove(table)?.toList().orEmpty()
while (toFlush.isNotEmpty()) {
val partition = toFlush.partition {
it.writeValues.none {
val (key, value) = it
key.referee == table.id && value is EntityID<*> && value._value == null
}
}
toFlush = partition.first
val ids = executeAsPartOfEntityLifecycle {
table.batchInsert(toFlush) { entry ->
for ((c, v) in entry.writeValues) {
this[c] = v
}
}
}
for ((entry, genValues) in toFlush.zip(ids)) {
if (entry.id._value == null) {
val id = genValues[table.id]
entry.id._value = id._value
entry.writeValues[entry.klass.table.id as Column] = id
}
genValues.fieldIndex.keys.forEach { key ->
entry.writeValues[key as Column] = genValues[key]
}
entry.storeWrittenValues()
store(entry)
transaction.registerChange(entry.klass, entry.id, EntityChangeType.Created)
pendingInitializationLambdas[entry]?.forEach { it(entry) }
}
toFlush = partition.second
}
transaction.alertSubscribers()
}
/**
* Clears this [EntityCache] of all stored data, including any reference mappings.
*
* @param flush By default, pending inserts and updates for all cached entities will first be sent to the
* database. If this is set to `false`, any pending operations will not be flushed and will be removed as well.
* @sample org.jetbrains.exposed.sql.tests.shared.entities.EntityCacheTests.changeEntityCacheMaxEntitiesToStoreInMiddleOfTransaction
*/
fun clear(flush: Boolean = true) {
if (flush) flush()
data.clear()
inserts.clear()
updates.clear()
clearReferrersCache()
}
/** Clears this [EntityCache] of stored data that maps cached parent entities to their referencing child entities. */
fun clearReferrersCache() {
referrers.clear()
}
private inner class LimitedHashMap : LinkedHashMap() {
override fun removeEldestEntry(eldest: MutableMap.MutableEntry?): Boolean {
return size > maxEntitiesToStore
}
}
companion object {
/**
* Clears the internal cache of any [created] entity that can be associated
* with an [ImmutableCachedEntityClass].
*/
fun invalidateGlobalCaches(created: List>) {
created.asSequence().mapNotNull { it.klass as? ImmutableCachedEntityClass<*, *> }.distinct().forEach {
it.expireCache()
}
}
}
}
/**
* Sends all pending [Entity] inserts and updates stored in this transaction's [EntityCache] to the database.
*
* @return A list of all new entities that were stored as scheduled for insert.
* @sample org.jetbrains.exposed.sql.tests.shared.entities.EntityTests.testInsertChildWithFlush
*/
fun Transaction.flushCache(): List> {
with(entityCache) {
val newEntities = inserts.flatMap { it.value }
flush()
return newEntities
}
}
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