From c288760047f7b2fc37dd13e06bfab075ed604219 Mon Sep 17 00:00:00 2001
From: Mady Mellor <madym@google.com>
Date: Wed, 17 Jun 2020 16:47:19 -0700
Subject: [PATCH] Introduce versions to XML for bubbles persistence

Let's just drop previous versions... we could check
and update but this is very safe and technically
version 1.

Test: atest BubbleXmlHelperTest
Fixes: 159243080
Change-Id: Ia8a136c737bac638ab70398212e6387c3736eead
---
 .../systemui/bubbles/storage/BubbleXmlHelper.kt | 14 +++++++++++---
 .../bubbles/storage/BubbleXmlHelperTest.kt      | 17 ++++++++++++++++-
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/packages/SystemUI/src/com/android/systemui/bubbles/storage/BubbleXmlHelper.kt b/packages/SystemUI/src/com/android/systemui/bubbles/storage/BubbleXmlHelper.kt
index 66fff3386ae14..bf163a230affc 100644
--- a/packages/SystemUI/src/com/android/systemui/bubbles/storage/BubbleXmlHelper.kt
+++ b/packages/SystemUI/src/com/android/systemui/bubbles/storage/BubbleXmlHelper.kt
@@ -25,7 +25,11 @@ import java.io.InputStream
 import java.io.OutputStream
 import java.nio.charset.StandardCharsets
 
+// TODO: handle version changes gracefully
+private const val CURRENT_VERSION = 1
+
 private const val TAG_BUBBLES = "bs"
+private const val ATTR_VERSION = "v"
 private const val TAG_BUBBLE = "bb"
 private const val ATTR_USER_ID = "uid"
 private const val ATTR_PACKAGE = "pkg"
@@ -44,6 +48,7 @@ fun writeXml(stream: OutputStream, bubbles: List<BubbleEntity>) {
     serializer.setOutput(stream, StandardCharsets.UTF_8.name())
     serializer.startDocument(null, true)
     serializer.startTag(null, TAG_BUBBLES)
+    serializer.attribute(null, ATTR_VERSION, CURRENT_VERSION.toString())
     bubbles.forEach { b -> writeXmlEntry(serializer, b) }
     serializer.endTag(null, TAG_BUBBLES)
     serializer.endDocument()
@@ -79,9 +84,12 @@ fun readXml(stream: InputStream): List<BubbleEntity> {
     val parser: XmlPullParser = Xml.newPullParser()
     parser.setInput(stream, StandardCharsets.UTF_8.name())
     XmlUtils.beginDocument(parser, TAG_BUBBLES)
-    val outerDepth = parser.depth
-    while (XmlUtils.nextElementWithin(parser, outerDepth)) {
-        bubbles.add(readXmlEntry(parser) ?: continue)
+    val version = parser.getAttributeWithName(ATTR_VERSION)?.toInt()
+    if (version != null && version == CURRENT_VERSION) {
+        val outerDepth = parser.depth
+        while (XmlUtils.nextElementWithin(parser, outerDepth)) {
+            bubbles.add(readXmlEntry(parser) ?: continue)
+        }
     }
     return bubbles
 }
diff --git a/packages/SystemUI/tests/src/com/android/systemui/bubbles/storage/BubbleXmlHelperTest.kt b/packages/SystemUI/tests/src/com/android/systemui/bubbles/storage/BubbleXmlHelperTest.kt
index 81687c7fbe1a7..8cf4534ecdce2 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/bubbles/storage/BubbleXmlHelperTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/bubbles/storage/BubbleXmlHelperTest.kt
@@ -55,7 +55,7 @@ class BubbleXmlHelperTest : SysuiTestCase() {
     fun testReadXml() {
         val src = """
 <?xml version='1.0' encoding='utf-8' standalone='yes' ?>
-<bs>
+<bs v="1">
 <bb uid="0" pkg="com.example.messenger" sid="shortcut-1" key="k1" h="120" hid="0" />
 <bb uid="10" pkg="com.example.chat" sid="alice and bob" key="k2" h="0" hid="16537428" t="title" />
 <bb uid="0" pkg="com.example.messenger" sid="shortcut-2" key="k3" h="120" hid="0" />
@@ -64,4 +64,19 @@ class BubbleXmlHelperTest : SysuiTestCase() {
         val actual = readXml(ByteArrayInputStream(src.toByteArray(Charsets.UTF_8)))
         assertEquals("failed parsing bubbles from xml\n$src", bubbles, actual)
     }
+
+    // TODO: We should handle upgrades gracefully but this is v1
+    @Test
+    fun testUpgradeDropsPreviousData() {
+        val src = """
+<?xml version='1.0' encoding='utf-8' standalone='yes' ?>
+<bs>
+<bb uid="0" pkg="com.example.messenger" sid="shortcut-1" key="k1" h="120" hid="0" />
+<bb uid="10" pkg="com.example.chat" sid="alice and bob" key="k2" h="0" hid="16537428" t="title" />
+<bb uid="0" pkg="com.example.messenger" sid="shortcut-2" key="k3" h="120" hid="0" />
+</bs>
+        """.trimIndent()
+        val actual = readXml(ByteArrayInputStream(src.toByteArray(Charsets.UTF_8)))
+        assertEquals("failed parsing bubbles from xml\n$src", emptyList<BubbleEntity>(), actual)
+    }
 }
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