Adding PerResourceLocalChangeFetcher (google#2257)

* adding per resource change fetcher

* Reverting fhir application change

* spotless corrections

* review comments

engine/src/androidTest/java/com/google/android/fhir/db/impl/DatabaseImplTest.kt

@@ -233,6 +233,23 @@ class DatabaseImplTest {
  assertThat(database.getLocalChanges(ResourceType.Encounter, patient.logicalId)).isEmpty()
  }
 
+ @Test
+ fun getAllChangesForEarliestChangedResource_withMultipleChanges_shouldReturnFirstChange() =
+ runBlocking {
+ val patient: Patient = readFromFile(Patient::class.java, "/date_test_patient.json")
+ database.insert(patient)
+ database.insert(TEST_PATIENT_2)
+ database.update(
+ TEST_PATIENT_1.copy().apply { gender = Enumerations.AdministrativeGender.FEMALE },
+ )
+ assertThat(
+ database.getAllChangesForEarliestChangedResource().all {
+ it.resourceId.equals(TEST_PATIENT_1.logicalId)
+ },
+ )
+ .isTrue()
+ }
+
  @Test
  fun clearDatabase_shouldClearAllTablesData() = runBlocking {
  val patient: Patient = readFromFile(Patient::class.java, "/date_test_patient.json")

engine/src/main/java/com/google/android/fhir/db/Database.kt

@@ -105,6 +105,12 @@ internal interface Database {
  */
  suspend fun getAllLocalChanges(): List<LocalChange>
 
+ /**
+ * Retrieves all [LocalChange]s for the [Resource] which has the [LocalChange] with the oldest
+ * [LocalChange.timestamp]
+ */
+ suspend fun getAllChangesForEarliestChangedResource(): List<LocalChange>
+
  /** Retrieves the count of [LocalChange]s stored in the database. */
  suspend fun getLocalChangesCount(): Int
 

engine/src/main/java/com/google/android/fhir/db/impl/DatabaseImpl.kt

@@ -228,6 +228,10 @@ internal class DatabaseImpl(
  return db.withTransaction { localChangeDao.getLocalChangesCount() }
  }
 
+ override suspend fun getAllChangesForEarliestChangedResource(): List<LocalChange> {
+ return localChangeDao.getAllChangesForEarliestChangedResource().map { it.toLocalChange() }
+ }
+
  override suspend fun deleteUpdates(token: LocalChangeToken) {
  db.withTransaction { localChangeDao.discardLocalChanges(token) }
  }

engine/src/main/java/com/google/android/fhir/db/impl/dao/LocalChangeDao.kt

@@ -206,6 +206,20 @@ internal abstract class LocalChangeDao {
  resourceId: String,
  ): List<LocalChangeEntity>
 
+ @Query(
+ """
+ SELECT * 
+ FROM LocalChangeEntity 
+ WHERE resourceUuid = (
+ SELECT resourceUuid 
+ FROM LocalChangeEntity 
+ ORDER BY timestamp ASC 
+ LIMIT 1)
+ ORDER BY timestamp ASC
+ """,
+ )
+ abstract suspend fun getAllChangesForEarliestChangedResource(): List<LocalChangeEntity>
+
  class InvalidLocalChangeException(message: String?) : Exception(message)
 }
 

engine/src/main/java/com/google/android/fhir/sync/upload/LocalChangeFetcher.kt

@@ -71,6 +71,25 @@ internal class AllChangesLocalChangeFetcher(
  SyncUploadProgress(database.getLocalChangesCount(), total)
 }
 
+internal class PerResourceLocalChangeFetcher(
+ private val database: Database,
+) : LocalChangeFetcher {
+
+ override var total by Delegates.notNull<Int>()
+
+ suspend fun initTotalCount() {
+ total = database.getLocalChangesCount()
+ }
+
+ override suspend fun hasNext(): Boolean = database.getLocalChangesCount().isNotZero()
+
+ override suspend fun next(): List<LocalChange> =
+ database.getAllChangesForEarliestChangedResource()
+
+ override suspend fun getProgress(): SyncUploadProgress =
+ SyncUploadProgress(database.getLocalChangesCount(), total)
+}
+
 /** Represents the mode in which local changes should be fetched. */
 sealed class LocalChangesFetchMode {
  object AllChanges : LocalChangesFetchMode()
@@ -88,6 +107,8 @@ internal object LocalChangeFetcherFactory {
  when (mode) {
  is LocalChangesFetchMode.AllChanges ->
  AllChangesLocalChangeFetcher(database).apply { initTotalCount() }
+ is LocalChangesFetchMode.PerResource ->
+ PerResourceLocalChangeFetcher(database).apply { initTotalCount() }
  else -> throw NotImplementedError("$mode is not implemented yet.")
  }
 }

engine/src/test/java/com/google/android/fhir/sync/upload/AllChangesLocalChangeFetcherTest.kt → engine/src/test/java/com/google/android/fhir/sync/upload/fetcher/AllChangesLocalChangeFetcherTest.kt

@@ -14,10 +14,12 @@
  * limitations under the License.
  */
 
-package com.google.android.fhir.sync.upload
+package com.google.android.fhir.sync.upload.fetcher
 
 import androidx.test.core.app.ApplicationProvider
 import com.google.android.fhir.FhirServices
+import com.google.android.fhir.sync.upload.AllChangesLocalChangeFetcher
+import com.google.android.fhir.sync.upload.SyncUploadProgress
 import com.google.common.truth.Truth.assertThat
 import java.util.Date
 import kotlinx.coroutines.test.runTest

engine/src/test/java/com/google/android/fhir/sync/upload/fetcher/PerResourceLocalChangeFetcherTest.kt

@@ -0,0 +1,114 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http:https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.fhir.sync.upload.fetcher
+
+import androidx.test.core.app.ApplicationProvider
+import com.google.android.fhir.FhirServices
+import com.google.android.fhir.LocalChange
+import com.google.android.fhir.logicalId
+import com.google.android.fhir.sync.upload.PerResourceLocalChangeFetcher
+import com.google.common.truth.Truth.assertThat
+import java.util.Date
+import kotlinx.coroutines.test.runTest
+import org.hl7.fhir.r4.model.Enumerations
+import org.hl7.fhir.r4.model.Meta
+import org.hl7.fhir.r4.model.Patient
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+class PerResourceLocalChangeFetcherTest {
+
+ private val services =
+ FhirServices.builder(ApplicationProvider.getApplicationContext()).inMemory().build()
+ private val database = services.database
+
+ @Test
+ fun `fetcher is created correctly`() = runTest {
+ database.insert(TEST_PATIENT_1, TEST_PATIENT_2)
+ database.update(
+ TEST_PATIENT_1.copy().apply { gender = Enumerations.AdministrativeGender.FEMALE },
+ )
+ val fetcher = PerResourceLocalChangeFetcher(database).apply { initTotalCount() }
+
+ assertThat(fetcher.getProgress().initialTotal).isEqualTo(3)
+ }
+
+ @Test
+ fun `hasNext returns correct value`() = runTest {
+ database.insert(TEST_PATIENT_1, TEST_PATIENT_2)
+ database.update(
+ TEST_PATIENT_1.copy().apply { gender = Enumerations.AdministrativeGender.FEMALE },
+ )
+ val fetcher = PerResourceLocalChangeFetcher(database).apply { initTotalCount() }
+
+ assertThat(fetcher.hasNext()).isTrue()
+ database.deleteUpdates(listOf(TEST_PATIENT_1))
+ assertThat(fetcher.hasNext()).isTrue()
+ database.deleteUpdates(listOf(TEST_PATIENT_2))
+ assertThat(fetcher.hasNext()).isFalse()
+ }
+
+ @Test
+ fun `next returns correct set of changes in the right order`() = runTest {
+ database.insert(TEST_PATIENT_1, TEST_PATIENT_2)
+ database.update(
+ TEST_PATIENT_1.copy().apply { gender = Enumerations.AdministrativeGender.FEMALE },
+ )
+ val fetcher = PerResourceLocalChangeFetcher(database).apply { initTotalCount() }
+
+ val firstSetOfChanges = fetcher.next()
+ database.deleteUpdates(listOf(TEST_PATIENT_1))
+ val secondSetOfChanges = fetcher.next()
+ database.deleteUpdates(listOf(TEST_PATIENT_2))
+
+ assertThat(firstSetOfChanges.size).isEqualTo(2)
+ with(firstSetOfChanges[0]) {
+ assertThat(type).isEqualTo(LocalChange.Type.INSERT)
+ assertThat(resourceId).isEqualTo(TEST_PATIENT_1.logicalId)
+ }
+
+ with(firstSetOfChanges[1]) {
+ assertThat(type).isEqualTo(LocalChange.Type.UPDATE)
+ assertThat(resourceId).isEqualTo(TEST_PATIENT_1.logicalId)
+ }
+
+ assertThat(secondSetOfChanges.size).isEqualTo(1)
+ with(secondSetOfChanges[0]) {
+ assertThat(type).isEqualTo(LocalChange.Type.INSERT)
+ assertThat(resourceId).isEqualTo(TEST_PATIENT_2.logicalId)
+ }
+ }
+
+ companion object {
+ private const val TEST_PATIENT_1_ID = "test_patient_1"
+ private var TEST_PATIENT_1 =
+ Patient().apply {
+ id = TEST_PATIENT_1_ID
+ gender = Enumerations.AdministrativeGender.MALE
+ }
+
+ private const val TEST_PATIENT_2_ID = "test_patient_2"
+ private var TEST_PATIENT_2 =
+ Patient().apply {
+ id = TEST_PATIENT_2_ID
+ gender = Enumerations.AdministrativeGender.MALE
+ meta = Meta().apply { lastUpdated = Date() }
+ }
+ }
+}