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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 = 7,
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 Superseded by v4 below.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")
}
}
// v5: a feed with a literal empty <guid>/<id> element (confirmed live: a Mother
// Jones entry) produced an ArticleEntity with id = "" -- FeedParser fell back to
// itemLink only when the guid was null, not when it was blank. An empty-string
// primary key broke Navigation Compose's route matching and crashed on tap. The
// parser is fixed for future fetches; this cleans out any row already on-device
// with the bad id so it doesn't keep crashing. It'll come back with a real,
// hash-based id on the next fetch of that feed.
private val MIGRATION_4_5 = object : Migration(4, 5) {
override fun migrate(db: SupportSQLiteDatabase) {
db.execSQL("DELETE FROM articles WHERE trim(id) = ''")
}
}
// v6: added FeedEntity.folder (OPML category, for grouping the feed list). A plain
// ADD COLUMN is safe here (unlike v3->v4) since folder is a genuinely new field with
// no prior column it needs to replace/rebuild around.
private val MIGRATION_5_6 = object : Migration(5, 6) {
override fun migrate(db: SupportSQLiteDatabase) {
db.execSQL("ALTER TABLE feeds ADD COLUMN folder TEXT")
}
}
// v7: this app now upgrades http:// feed URLs to https:// at add/import time (see
// AddFeedScreen.preferHttps), but that only ever runs on the way IN -- feeds already
// subscribed to before this change stay http:// forever otherwise. Android blocks
// cleartext by default (targetSdk 28+), so every one of these was failing every fetch
// ("CLEARTEXT communication ... not permitted"). Checked live (curl) which of this
// user's http feeds actually serve valid content over https and rewrite just those --
// three hosts genuinely have no usable HTTPS (no TLS listener at all, a broken TLS
// handshake, or a certificate that doesn't match the hostname) and are deliberately
// left alone, since switching them would just trade one permanent failure for another.
private val MIGRATION_6_7 = object : Migration(6, 7) {
override fun migrate(db: SupportSQLiteDatabase) {
val httpToHttps = mapOf(
"http://blog.cryptographyengineering.com/feeds/posts/default" to
"https://blog.cryptographyengineering.com/feeds/posts/default",
"http://mybiasedcoin.blogspot.com/feeds/posts/default?alt=rss" to
"https://mybiasedcoin.blogspot.com/feeds/posts/default?alt=rss",
"http://processalgebra.blogspot.com/feeds/posts/default?alt=rss" to
"https://processalgebra.blogspot.com/feeds/posts/default?alt=rss",
"http://www.rowetel.com/blog/?feed=rss2" to
"https://www.rowetel.com/blog/?feed=rss2",
"http://www.thecodelesscode.com/rss" to
"https://www.thecodelesscode.com/rss",
// This one's own https endpoint redirects through an insecure (http)
// feedburner hop before landing on real content -- point straight at
// feedburner's own https endpoint instead of a URL that would still fail
// cleartext-blocked partway through the redirect chain.
"http://www.divingforpearlsblog.com/feeds/posts/default" to
"https://feeds.feedburner.com/blogspot/sjomU"
)
for ((oldUrl, newUrl) in httpToHttps) {
db.execSQL("UPDATE articles SET feedId = ? WHERE feedId = ?", arrayOf(newUrl, oldUrl))
db.execSQL("UPDATE feeds SET id = ? WHERE id = ?", arrayOf(newUrl, oldUrl))
}
}
}
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, MIGRATION_4_5, MIGRATION_5_6, MIGRATION_6_7).build().also { instance = it }
}
}
}
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