server: Make registration implicit

uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/sync/AbstractSyncServer.kt

@@ -20,15 +20,6 @@
 package org.isoron.uhabits.core.sync
 
 interface AbstractSyncServer {
-    /**
-     * Generates and returns a new sync key, which can be used to store and retrive
-     * data.
-     *
-     * @throws ServiceUnavailable If key cannot be generated at this time, for example,
-     *      due to insufficient server resources, temporary server maintenance or network problems.
-     */
-    suspend fun register(): String
-
     /**
      * Replaces data for a given sync key.
      *

uhabits-server/src/main/kotlin/org/isoron/uhabits/server/app/RegistrationModule.kt

@@ -1,39 +0,0 @@
-/*
- * Copyright (C) 2016-2021 Álinson Santos Xavier <git@axavier.org>
- *
- * This file is part of Loop Habit Tracker.
- *
- * Loop Habit Tracker 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 of the License, or (at your
- * option) any later version.
- *
- * Loop Habit Tracker 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 this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-package org.isoron.uhabits.server.app
-
-import io.ktor.application.call
-import io.ktor.http.HttpStatusCode
-import io.ktor.response.respond
-import io.ktor.routing.Routing
-import io.ktor.routing.post
-import org.isoron.uhabits.core.sync.RegisterReponse
-import org.isoron.uhabits.core.sync.ServiceUnavailable
-
-fun Routing.registration(app: SyncApplication) {
-    post("/register") {
-        try {
-            val key = app.server.register()
-            call.respond(HttpStatusCode.OK, RegisterReponse(key))
-        } catch (e: ServiceUnavailable) {
-            call.respond(HttpStatusCode.ServiceUnavailable)
-        }
-    }
-}

uhabits-server/src/main/kotlin/org/isoron/uhabits/server/app/StorageModule.kt

@@ -49,8 +49,6 @@ fun Routing.storage(app: SyncApplication) {
             try {
                 app.server.put(key, data)
                 call.respond(HttpStatusCode.OK)
-            } catch (e: KeyNotFoundException) {
-                call.respond(HttpStatusCode.NotFound)
             } catch (e: EditConflictException) {
                 call.respond(HttpStatusCode.Conflict)
             }

uhabits-server/src/main/kotlin/org/isoron/uhabits/server/app/SyncApplication.kt

@@ -26,8 +26,8 @@ import io.ktor.features.ContentNegotiation
 import io.ktor.features.DefaultHeaders
 import io.ktor.jackson.jackson
 import io.ktor.routing.routing
-import org.isoron.uhabits.server.sync.Repository
 import org.isoron.uhabits.core.sync.AbstractSyncServer
+import org.isoron.uhabits.server.sync.Repository
 import org.isoron.uhabits.server.sync.RepositorySyncServer
 import java.nio.file.Path
 import java.nio.file.Paths
@@ -48,7 +48,6 @@ class SyncApplication(
             jackson { }
         }
         routing {
-            registration(this@SyncApplication)
             storage(this@SyncApplication)
             metrics(this@SyncApplication)
         }

uhabits-server/src/main/kotlin/org/isoron/uhabits/server/sync/RepositorySyncServer.kt

@@ -24,8 +24,6 @@ import org.isoron.uhabits.core.sync.AbstractSyncServer
 import org.isoron.uhabits.core.sync.EditConflictException
 import org.isoron.uhabits.core.sync.KeyNotFoundException
 import org.isoron.uhabits.core.sync.SyncData
-import java.util.Random
-import kotlin.streams.asSequence
 
 /**
  * An AbstractSyncServer that stores all data in a [Repository].
@@ -40,21 +38,13 @@ class RepositorySyncServer(
         .labelNames("method")
         .register()
 
-    override suspend fun register(): String {
-        requestsCounter.labels("register").inc()
-        val key = generateKey()
-        repo.put(key, SyncData(0, ""))
-        return key
-    }
-
     override suspend fun put(key: String, newData: SyncData) {
         requestsCounter.labels("put").inc()
-        if (!repo.contains(key)) {
+        if (repo.contains(key)) {
-            throw KeyNotFoundException()
+            val prevData = repo.get(key)
-        }
+            if (newData.version != prevData.version + 1) {
-        val prevData = repo.get(key)
+                throw EditConflictException()
-        if (newData.version != prevData.version + 1) {
+            }
-            throw EditConflictException()
         }
         repo.put(key, newData)
     }
@@ -74,20 +64,4 @@ class RepositorySyncServer(
         }
         return repo.get(key).version
     }
-
-    private fun generateKey(): String {
-        while (true) {
-            val key = randomString(64)
-            if (!repo.contains(key))
-                return key
-        }
-    }
-
-    private fun randomString(length: Long): String {
-        val chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
-        return Random().ints(length, 0, chars.length)
-            .asSequence()
-            .map(chars::get)
-            .joinToString("")
-    }
 }

uhabits-server/src/test/kotlin/org/isoron/uhabits/server/app/RegistrationModuleTest.kt

@@ -1,51 +0,0 @@
-/*
- * Copyright (C) 2016-2021 Álinson Santos Xavier <git@axavier.org>
- *
- * This file is part of Loop Habit Tracker.
- *
- * Loop Habit Tracker 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 of the License, or (at your
- * option) any later version.
- *
- * Loop Habit Tracker 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 this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-package org.isoron.uhabits.server.app
-
-import com.nhaarman.mockitokotlin2.whenever
-import io.ktor.http.HttpMethod
-import io.ktor.http.HttpStatusCode
-import io.ktor.server.testing.handleRequest
-import io.ktor.server.testing.withTestApplication
-import kotlinx.coroutines.runBlocking
-import org.isoron.uhabits.core.sync.ServiceUnavailable
-import org.junit.Test
-import kotlin.test.assertEquals
-
-class RegistrationModuleTest : BaseApplicationTest() {
-    @Test
-    fun `when register succeeds should return generated key`(): Unit = runBlocking {
-        whenever(server.register()).thenReturn("ABCDEF")
-        withTestApplication(app()) {
-            val call = handleRequest(HttpMethod.Post, "/register")
-            assertEquals(HttpStatusCode.OK, call.response.status())
-            assertEquals("{\"key\":\"ABCDEF\"}", call.response.content)
-        }
-    }
-
-    @Test
-    fun `when registration is unavailable should return 503`(): Unit = runBlocking {
-        whenever(server.register()).thenThrow(ServiceUnavailable())
-        withTestApplication(app()) {
-            val call = handleRequest(HttpMethod.Post, "/register")
-            assertEquals(HttpStatusCode.ServiceUnavailable, call.response.status())
-        }
-    }
-}

uhabits-server/src/test/kotlin/org/isoron/uhabits/server/app/StorageModuleTest.kt

@@ -87,16 +87,6 @@ class StorageModuleTest : BaseApplicationTest() {
         }
     }
 
-    @Test
-    fun `when put with invalid key should return 404`(): Unit = runBlocking {
-        whenever(server.put("k1", data1)).thenThrow(KeyNotFoundException())
-        withTestApplication(app()) {
-            handlePut("/db/k1", data1).apply {
-                assertEquals(HttpStatusCode.NotFound, response.status())
-            }
-        }
-    }
-
     @Test
     fun `when put with invalid version should return 409 and current data`(): Unit = runBlocking {
         whenever(server.put("k1", data1)).thenThrow(EditConflictException())

uhabits-server/src/test/kotlin/org/isoron/uhabits/server/sync/RepositorySyncServerTest.kt

@@ -32,13 +32,10 @@ class RepositorySyncServerTest {
 
     private val tempdir = Files.createTempDirectory("db")
     private val server = RepositorySyncServer(Repository(tempdir))
-    private val key = runBlocking { server.register() }
+    private val key = "abcdefgh"
 
     @Test
     fun testUsage(): Unit = runBlocking {
-        val data0 = SyncData(0, "")
-        assertEquals(server.getData(key), data0)
-
         val data1 = SyncData(1, "Hello world")
         server.put(key, data1)
         assertEquals(server.getData(key), data1)
@@ -54,9 +51,5 @@ class RepositorySyncServerTest {
         assertFailsWith<KeyNotFoundException> {
             server.getData("INVALID")
         }
-
-        assertFailsWith<KeyNotFoundException> {
-            server.put("INVALID", data0)
-        }
     }
 }