DatabaseVerifier.kt

/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * 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 androidx.room.verifier

import androidx.room.processor.Context
import androidx.room.vo.DatabaseView
import androidx.room.vo.Entity
import androidx.room.vo.EntityOrView
import androidx.room.vo.FtsEntity
import androidx.room.vo.FtsOptions
import androidx.room.vo.Warning
import columnInfo
import org.sqlite.JDBC
import org.sqlite.SQLiteJDBCLoader
import java.io.File
import java.sql.Connection
import java.sql.SQLException
import java.util.regex.Pattern
import javax.lang.model.element.Element

/**
 * Builds an in-memory version of the database and verifies the queries against it.
 * This class is also used to resolve the return types.
 */
class DatabaseVerifier private constructor(
    val connection: Connection,
    val context: Context,
    entities: List<Entity>,
    views: List<DatabaseView>
) {
    val entitiesAndViews: List<EntityOrView> = entities + views

    companion object {
        private const val CONNECTION_URL = "jdbc:sqlite::memory:"

        /**
         * Taken from:
         * https://github.com/robolectric/robolectric/blob/master/shadows/framework/
         * src/main/java/org/robolectric/shadows/ShadowSQLiteConnection.java#L94
         *
         * This is actually not accurate because it might swap anything since it does not parse
         * SQL. That being said, for the verification purposes, it does not matter and clearly
         * much easier than parsing and rebuilding the query.
         */
        private val COLLATE_LOCALIZED_UNICODE_PATTERN = Pattern.compile(
            "\s+COLLATE\s+(LOCALIZED|UNICODE)", Pattern.CASE_INSENSITIVE
        )

        init {
            verifyTempDir()
            // Synchronize on a bootstrap loaded class so that parallel runs of Room in the same JVM
            // with isolated class loaders (such as the Gradle daemon) don't conflict with each
            // other when extracting the native library. SQLiteJDBCLoader already handles
            // multiple library versions, process isolation and multiple class loaders by using
            // UUID named library files.
            synchronized(System::class.java) {
                SQLiteJDBCLoader.initialize() // extract and loads native library
                JDBC.isValidURL(CONNECTION_URL) // dummy call to register driver
            }
        }

        private fun verifyTempDir() {
            val defaultTempDir = System.getProperty("java.io.tmpdir")
            val tempDir = System.getProperty("org.sqlite.tmpdir", defaultTempDir)
            checkNotNull(tempDir) {
                "Room needs the java.io.tmpdir or org.sqlite.tmpdir system property to be set to " +
                        "setup SQLite."
            }
            File(tempDir).also {
                check(
                    it.isDirectory &&
                            (it.exists() || it.mkdirs()) &&
                            it.canRead() &&
                            it.canWrite()
                ) {
                    "The temp dir [$tempDir] needs to be a directory, must be readable, writable " +
                            "and allow executables. Please, provide a temporary directory that " +
                            "fits the requirements via the 'org.sqlite.tmpdir' property."
                }
            }
        }

        /**
         * Tries to create a verifier but returns null if it cannot find the driver.
         */
        fun create(
            context: Context,
            element: Element,
            entities: List<Entity>,
            views: List<DatabaseView>
        ): DatabaseVerifier? {
            try {
                val connection = JDBC.createConnection(CONNECTION_URL, java.util.Properties())
                return DatabaseVerifier(connection, context, entities, views)
            } catch (ex: Exception) {
                context.logger.w(
                    Warning.CANNOT_CREATE_VERIFICATION_DATABASE, element,
                    DatabaseVerificationErrors.cannotCreateConnection(ex)
                )
                return null
            }
        }
    }

    init {
        entities.forEach { entity ->
            val stmt = connection.createStatement()
            val createTableQuery = if (entity is FtsEntity &&
                !FtsOptions.defaultTokenizers.contains(entity.ftsOptions.tokenizer)
            ) {
                // Custom FTS tokenizer used, use create statement without custom tokenizer
                // since the DB used for verification probably doesn't have the tokenizer.
                entity.getCreateTableQueryWithoutTokenizer()
            } else {
                entity.createTableQuery
            }
            try {
                stmt.executeUpdate(stripLocalizeCollations(createTableQuery))
            } catch (e: SQLException) {
                context.logger.e(entity.element, "${e.message}")
            }
            entity.indices.forEach {
                stmt.executeUpdate(it.createQuery(entity.tableName))
            }
        }
        views.forEach { view ->
            val stmt = connection.createStatement()
            try {
                stmt.executeUpdate(stripLocalizeCollations(view.createViewQuery))
            } catch (e: SQLException) {
                context.logger.e(view.element, "${e.message}")
            }
        }
    }

    fun analyze(sql: String): QueryResultInfo {
        return try {
            val stmt = connection.prepareStatement(stripLocalizeCollations(sql))
            QueryResultInfo(stmt.columnInfo())
        } catch (ex: SQLException) {
            QueryResultInfo(emptyList(), ex)
        }
    }

    private fun stripLocalizeCollations(sql: String) =
        COLLATE_LOCALIZED_UNICODE_PATTERN.matcher(sql).replaceAll(" COLLATE NOCASE")

    fun closeConnection(context: Context) {
        if (!connection.isClosed) {
            try {
                connection.close()
            } catch (t: Throwable) {
                // ignore.
                context.logger.d("failed to close the database connection ${t.message}")
            }
        }
    }
}