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package org.terst.feedreader.data
import android.content.Context
import androidx.room.Database
import androidx.room.Room
import androidx.room.RoomDatabase
import androidx.sqlite.db.SupportSQLiteDatabase
import androidx.room.migration.Migration
@Database(
entities = [FeedEntity::class, ArticleEntity::class, FilterRuleEntity::class],
version = 4,
exportSchema = false
)
abstract class AppDatabase : RoomDatabase() {
abstract fun feedDao(): FeedDao
abstract fun articleDao(): ArticleDao
abstract fun filterRuleDao(): FilterRuleDao
companion object {
@Volatile private var instance: AppDatabase? = null
// v2: added ArticleEntity.imageUrl (thumbnail support). Real migrations,
// not fallbackToDestructiveMigration, since this app already has real
// subscriptions/read-state on-device during active development --
// wiping the DB on every schema tweak would mean re-importing OPML
// and losing read history each time.
private val MIGRATION_1_2 = object : Migration(1, 2) {
override fun migrate(db: SupportSQLiteDatabase) {
db.execSQL("ALTER TABLE articles ADD COLUMN imageUrl TEXT")
}
}
// v3: added FeedEntity.readerModeDisabled (per-feed reader-mode opt-out, paired with
// an auto-extract-on-thin-content heuristic). Superseded by v4 below.
private val MIGRATION_2_3 = object : Migration(2, 3) {
override fun migrate(db: SupportSQLiteDatabase) {
db.execSQL("ALTER TABLE feeds ADD COLUMN readerModeDisabled INTEGER NOT NULL DEFAULT 0")
}
}
// v4: replaced readerModeDisabled with readerModeEnabled -- reader mode is no longer
// ever auto-triggered by a content-length heuristic (that's what kept "auto-switching"
// kottke articles even after the v3 opt-out); it's now a plain per-feed opt-in, set
// only by explicitly tapping the reader-mode toggle. Starts everyone fresh at off
// rather than trying to translate the old opt-out semantics, which don't map cleanly
// onto "opt in". A plain ADD COLUMN + leaving the old one in place (as v1->v2 and
// v2->v3 do) crashes here: Room's post-migration validation requires the table's
// columns to match FeedEntity's fields EXACTLY, and readerModeDisabled isn't a field
// anymore -- confirmed live ("Migration didn't properly handle: feeds"). SQLite has no
// DROP COLUMN on the versions bundled with older Android, so this rebuilds the table
// instead: create with the new shape, copy the columns that still exist, swap in.
private val MIGRATION_3_4 = object : Migration(3, 4) {
override fun migrate(db: SupportSQLiteDatabase) {
db.execSQL(
"""
CREATE TABLE feeds_new (
id TEXT NOT NULL PRIMARY KEY,
title TEXT NOT NULL,
siteUrl TEXT,
lastFetchedAt INTEGER,
etag TEXT,
lastModified TEXT,
lastError TEXT,
readerModeEnabled INTEGER NOT NULL DEFAULT 0
)
""".trimIndent()
)
db.execSQL(
"""
INSERT INTO feeds_new (id, title, siteUrl, lastFetchedAt, etag, lastModified, lastError)
SELECT id, title, siteUrl, lastFetchedAt, etag, lastModified, lastError FROM feeds
""".trimIndent()
)
db.execSQL("DROP TABLE feeds")
db.execSQL("ALTER TABLE feeds_new RENAME TO feeds")
}
}
fun get(context: Context): AppDatabase = instance ?: synchronized(this) {
instance ?: Room.databaseBuilder(
context.applicationContext,
AppDatabase::class.java,
"feedreader.db"
).addMigrations(MIGRATION_1_2, MIGRATION_2_3, MIGRATION_3_4).build().also { instance = it }
}
}
}
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