Don't crash if creating a cache directory fails (#1657)

* Don't crash if creating a cache directory fails

I'd previously attempted to recover when writes fail,
but I missed this case.

* Track an API change

---------

Co-authored-by: Jesse Wilson <jwilson@squareup.com>

Author: swankjesse

zipline-loader/api/android/zipline-loader.api

@@ -102,6 +102,7 @@ public final class app/cash/zipline/loader/SignatureAlgorithmId : java/lang/Enum
 }
 
 public final class app/cash/zipline/loader/ZiplineCache : java/io/Closeable {
+	public synthetic fun <init> (Lapp/cash/sqldelight/db/SqlDriver;Lapp/cash/zipline/loader/internal/cache/Database;Lokio/FileSystem;Lokio/Path;JLapp/cash/zipline/loader/LoaderEventListener;ZLkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public fun close ()V
 }
 

zipline-loader/api/jvm/zipline-loader.api

@@ -102,6 +102,7 @@ public final class app/cash/zipline/loader/SignatureAlgorithmId : java/lang/Enum
 }
 
 public final class app/cash/zipline/loader/ZiplineCache : java/io/Closeable {
+	public synthetic fun <init> (Lapp/cash/sqldelight/db/SqlDriver;Lapp/cash/zipline/loader/internal/cache/Database;Lokio/FileSystem;Lokio/Path;JLapp/cash/zipline/loader/LoaderEventListener;ZLkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public fun close ()V
 }
 

zipline-loader/src/androidMain/kotlin/app/cash/zipline/loader/internal/cache/databaseAndroid.kt

@@ -23,10 +23,10 @@ import app.cash.sqldelight.db.SqlSchema
 import app.cash.sqldelight.driver.android.AndroidSqliteDriver
 import okio.Path
 
-internal actual class SqlDriverFactory(
+internal class AndroidSqliteDriverFactory(
   private val context: Context,
-) {
-  actual fun create(path: Path, schema: SqlSchema<QueryResult.Value<Unit>>): SqlDriver {
+) : SqlDriverFactory {
+  override fun create(path: Path, schema: SqlSchema<QueryResult.Value<Unit>>): SqlDriver {
     validateDbPath(path)
     return AndroidSqliteDriver(
       schema = schema,

zipline-loader/src/androidMain/kotlin/app/cash/zipline/loader/loaderAndroid.kt

@@ -16,7 +16,7 @@
 package app.cash.zipline.loader
 
 import android.content.Context
-import app.cash.zipline.loader.internal.cache.SqlDriverFactory
+import app.cash.zipline.loader.internal.cache.AndroidSqliteDriverFactory
 import okio.FileSystem
 import okio.Path
 
@@ -28,7 +28,7 @@ fun ZiplineCache(
   loaderEventListener: LoaderEventListener,
 ): ZiplineCache {
   return ZiplineCache(
-    sqlDriverFactory = SqlDriverFactory(context),
+    sqlDriverFactory = AndroidSqliteDriverFactory(context),
     fileSystem = fileSystem,
     directory = directory,
     maxSizeInBytes = maxSizeInBytes,

zipline-loader/src/commonMain/kotlin/app/cash/zipline/loader/NullSqlDriver.kt

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2025 Cash App
+ *
+ * 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://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 app.cash.zipline.loader
+
+import app.cash.sqldelight.Query
+import app.cash.sqldelight.db.QueryResult
+import app.cash.sqldelight.db.SqlCursor
+import app.cash.sqldelight.db.SqlDriver
+import app.cash.sqldelight.db.SqlPreparedStatement
+import okio.IOException
+
+/**
+ * A SQL Driver that always throws [IOException]. Used this when creating a driver fails, such as
+ * when the disk is full.
+ */
+internal class NullSqlDriver : SqlDriver {
+  override fun <R> executeQuery(
+    identifier: Int?,
+    sql: String,
+    mapper: (SqlCursor) -> QueryResult<R>,
+    parameters: Int,
+    binders: (SqlPreparedStatement.() -> Unit)?,
+  ) = throw IOException("NullSqlDriver")
+
+  override fun execute(
+    identifier: Int?,
+    sql: String,
+    parameters: Int,
+    binders: (SqlPreparedStatement.() -> Unit)?,
+  ) = throw IOException("NullSqlDriver")
+
+  override fun newTransaction() = throw IOException("NullSqlDriver")
+
+  override fun currentTransaction() = throw IOException("NullSqlDriver")
+
+  override fun addListener(vararg queryKeys: String, listener: Query.Listener) = Unit
+
+  override fun removeListener(vararg queryKeys: String, listener: Query.Listener) = Unit
+
+  override fun notifyListeners(vararg queryKeys: String) = Unit
+
+  override fun close() = Unit
+}

zipline-loader/src/commonMain/kotlin/app/cash/zipline/loader/ZiplineCache.kt

@@ -27,7 +27,6 @@ import okio.ByteString.Companion.decodeHex
 import okio.Closeable
 import okio.FileNotFoundException
 import okio.FileSystem
-import okio.IOException
 import okio.Path
 
 /**
@@ -44,15 +43,15 @@ import okio.Path
  * If multiple threads in a single process operate on a cache instance simultaneously, downloads may
  * be repeated but no thread will be blocked.
  */
-class ZiplineCache internal constructor(
+class ZiplineCache private constructor(
   private val driver: SqlDriver,
   private val database: Database,
   private val fileSystem: FileSystem,
   private val directory: Path,
   private val maxSizeInBytes: Long,
   private val loaderEventListener: LoaderEventListener,
+  private var hasWriteFailures: Boolean,
 ) : Closeable {
-  private var hasWriteFailures = false
 
   /*
    * Files are named by their SHA-256 hashes. We use a SQLite database for file metadata: which
@@ -192,7 +191,7 @@ class ZiplineCache internal constructor(
       fileSystem.read(path) {
         readByteString()
       }
-    } catch (e: FileNotFoundException) {
+    } catch (_: FileNotFoundException) {
       null // Might have been pruned while we were trying to read?
     }
 
@@ -201,19 +200,14 @@ class ZiplineCache internal constructor(
       try {
         fileSystem.delete(path)
         database.filesQueries.delete(metadata.id)
-      } catch (ignored: Exception) {
+      } catch (_: Exception) {
       }
       return null
     }
 
     return result
   }
 
-  internal fun pin(applicationName: String, sha256: ByteString) {
-    val fileId = database.filesQueries.get(sha256.hex()).executeAsOneOrNull()?.id ?: return
-    createPinIfNotExists(applicationName, fileId)
-  }
-
   internal fun unpin(applicationName: String, sha256: ByteString) {
     val fileId = database.filesQueries.get(sha256.hex()).executeAsOneOrNull()?.id ?: return
     database.pinsQueries.delete_pin(applicationName, fileId)
@@ -361,11 +355,11 @@ class ZiplineCache internal constructor(
   }
 
   private fun createPinIfNotExists(
-    application_name: String,
-    file_id: Long,
+    applicationName: String,
+    fileId: Long,
   ) {
-    database.pinsQueries.get_pin(file_id, application_name).executeAsOneOrNull()
-      ?: database.pinsQueries.create_pin(file_id, application_name)
+    database.pinsQueries.get_pin(fileId, applicationName).executeAsOneOrNull()
+      ?: database.pinsQueries.create_pin(fileId, applicationName)
   }
 
   /**
@@ -414,7 +408,7 @@ class ZiplineCache internal constructor(
    *
    * It will also delete dirty files that were open when the previous run completed.
    */
-  internal fun initialize() {
+  private fun initialize() {
     try {
       deleteDirtyFiles()
       prune()
@@ -459,9 +453,7 @@ class ZiplineCache internal constructor(
   /** Returns the number of pins in the cache DB. */
   internal fun countPins() = database.pinsQueries.count().executeAsOne().toInt()
 
-  private fun path(metadata: Files): Path {
-    return directory / "entry-${metadata.id}.bin"
-  }
+  private fun path(metadata: Files): Path = directory / "entry-${metadata.id}.bin"
 
   /**
    * Update file record freshAt timestamp to reflect that the manifest is still seen as fresh.
@@ -490,26 +482,35 @@ class ZiplineCache internal constructor(
       loaderEventListener.cacheStorageFailed(applicationName, e)
     }
   }
-}
 
-internal fun ZiplineCache(
-  sqlDriverFactory: SqlDriverFactory,
-  fileSystem: FileSystem,
-  directory: Path,
-  maxSizeInBytes: Long,
-  loaderEventListener: LoaderEventListener,
-): ZiplineCache {
-  fileSystem.createDirectories(directory, mustCreate = false)
-  val driver: SqlDriver = sqlDriverFactory.create(directory / "zipline.db", Database.Schema)
-  val database = createDatabase(driver = driver)
-  val cache = ZiplineCache(
-    driver = driver,
-    database = database,
-    fileSystem = fileSystem,
-    directory = directory,
-    maxSizeInBytes = maxSizeInBytes,
-    loaderEventListener = loaderEventListener,
-  )
-  cache.initialize()
-  return cache
+  internal companion object {
+    internal operator fun invoke(
+      sqlDriverFactory: SqlDriverFactory,
+      fileSystem: FileSystem,
+      directory: Path,
+      maxSizeInBytes: Long,
+      loaderEventListener: LoaderEventListener,
+    ): ZiplineCache {
+      val (driver, hasWriteFailures) = try {
+        fileSystem.createDirectories(directory, mustCreate = false)
+        sqlDriverFactory.create(directory / "zipline.db", Database.Schema) to false
+      } catch (e: Exception) {
+        loaderEventListener.cacheStorageFailed(null, e)
+        NullSqlDriver() to true
+      }
+
+      val database = createDatabase(driver = driver)
+      val cache = ZiplineCache(
+        driver = driver,
+        database = database,
+        fileSystem = fileSystem,
+        directory = directory,
+        maxSizeInBytes = maxSizeInBytes,
+        loaderEventListener = loaderEventListener,
+        hasWriteFailures = hasWriteFailures,
+      )
+      cache.initialize()
+      return cache
+    }
+  }
 }

zipline-loader/src/commonMain/kotlin/app/cash/zipline/loader/internal/cache/database.kt

@@ -21,7 +21,7 @@ import app.cash.sqldelight.db.SqlDriver
 import app.cash.sqldelight.db.SqlSchema
 import okio.Path
 
-internal expect class SqlDriverFactory {
+internal interface SqlDriverFactory {
   /**
    * Create a SqlDriver to be used in creating and managing a SqlLite instance on disk.
    *
@@ -39,11 +39,9 @@ internal fun validateDbPath(path: Path) {
   }
 }
 
-internal fun createDatabase(driver: SqlDriver): Database {
-  return Database(
+internal fun createDatabase(driver: SqlDriver): Database = Database(
     driver,
     filesAdapter = Files.Adapter(
       file_stateAdapter = EnumColumnAdapter(),
     ),
   )
-}

zipline-loader/src/commonTest/kotlin/app/cash/zipline/loader/internal/cache/CacheFaultsTester.kt

@@ -18,6 +18,7 @@ package app.cash.zipline.loader.internal.cache
 import app.cash.sqldelight.db.QueryResult
 import app.cash.sqldelight.db.SqlDriver
 import app.cash.sqldelight.db.SqlPreparedStatement
+import app.cash.sqldelight.db.SqlSchema
 import app.cash.zipline.ZiplineManifest
 import app.cash.zipline.loader.LoaderEventListener
 import app.cash.zipline.loader.ZiplineCache
@@ -94,7 +95,7 @@ class CacheFaultsTester {
    * https://www.sqlite.org/tempfiles.html
    */
   val fileNames: List<String>
-    get() = fileSystem.list(directory)
+    get() = (fileSystem.listOrNull(directory) ?: listOf())
       .map { it.name }
       .filterNot { it.startsWith("zipline.db-") }
 
@@ -104,22 +105,9 @@ class CacheFaultsTester {
    */
   var storageFailureCount = 0
 
-  init {
-    fileSystem.createDirectories(directory)
-  }
-
   suspend fun withCache(block: suspend Session.() -> Unit) {
-    val driver = LimitWritesSqlDriver(
-      testSqlDriverFactory().create(
-        path = directory / "zipline.db",
-        schema = Database.Schema,
-      ),
-    )
-    val database = createDatabase(driver)
-
     val cache = ZiplineCache(
-      driver = driver,
-      database = database,
+      sqlDriverFactory = LimitWritesSqlDriverFactory(),
       fileSystem = LimitWritesFileSystem(fileSystem),
       directory = directory,
       maxSizeInBytes = cacheSize,
@@ -131,7 +119,6 @@ class CacheFaultsTester {
     )
 
     try {
-      cache.initialize()
       Session(cache).block()
     } finally {
       cache.close()
@@ -197,6 +184,13 @@ class CacheFaultsTester {
   private inner class LimitWritesFileSystem(
     delegate: FileSystem,
   ) : ForwardingFileSystem(delegate) {
+    override fun createDirectory(dir: Path, mustCreate: Boolean) {
+      fileSystemWriteCount++
+      if (fileSystemWriteCount >= fileSystemWriteLimit) throw IOException("write limit exceeded")
+
+      super.createDirectory(dir, mustCreate)
+    }
+
     override fun sink(file: Path, mustCreate: Boolean): Sink {
       fileSystemWriteCount++
       if (fileSystemWriteCount >= fileSystemWriteLimit) throw IOException("write limit exceeded")
@@ -229,6 +223,25 @@ class CacheFaultsTester {
     }
   }
 
+  private inner class LimitWritesSqlDriverFactory : SqlDriverFactory {
+    override fun create(
+      path: Path,
+      schema: SqlSchema<QueryResult.Value<Unit>>,
+    ): SqlDriver {
+      fileSystemWriteCount++
+      if (fileSystemWriteCount >= fileSystemWriteLimit) {
+        throw SqlFaultException("write limit exceeded")
+      }
+
+      return LimitWritesSqlDriver(
+        testSqlDriverFactory().create(
+          path = directory / "zipline.db",
+          schema = Database.Schema,
+        ),
+      )
+    }
+  }
+
   private inner class LimitWritesSqlDriver(
     private val delegate: SqlDriver,
   ) : SqlDriver by delegate {