Improve backup export perf by using better batching.

core-util/src/main/java/org/signal/core/util/SqlUtil.kt

@@ -154,6 +154,17 @@ object SqlUtil {
     }.toTypedArray()
   }
 
+  @JvmStatic
+  fun buildArgs(objects: Collection<Any?>): Array<String> {
+    return objects.map {
+      when (it) {
+        null -> throw NullPointerException("Cannot have null arg!")
+        is DatabaseId -> it.serialize()
+        else -> it.toString()
+      }
+    }.toTypedArray()
+  }
+
   @JvmStatic
   fun buildArgs(argument: Long): Array<String> {
     return arrayOf(argument.toString())
@@ -290,6 +301,20 @@ object SqlUtil {
     }
   }
 
+  /**
+   * A convenient way of making queries that are _equivalent_ to `WHERE [column] IN (?, ?, ..., ?)`
+   * Under the hood, it uses JSON1 functions which can both be surprisingly faster than normal (?, ?, ?) lists, as well as removes the [MAX_QUERY_ARGS] limit.
+   * This means chunking isn't necessary for any practical collection length.
+   */
+  @JvmStatic
+  fun buildFastCollectionQuery(
+    column: String,
+    values: Collection<Any?>
+  ): Query {
+    require(!values.isEmpty()) { "Must have values!" }
+    return Query("$column IN (SELECT e.value FROM json_each(?) e)", arrayOf(jsonEncode(buildArgs(values))))
+  }
+
   /**
    * A convenient way of making queries in the form: WHERE [column] IN (?, ?, ..., ?)
    *
@@ -453,6 +478,11 @@ object SqlUtil {
     return null
   }
 
+  /** Simple encoding of a string array as a json array */
+  private fun jsonEncode(strings: Array<String>): String {
+    return strings.joinToString(prefix = "[", postfix = "]", separator = ",") { "\"$it\"" }
+  }
+
   class Query(val where: String, val whereArgs: Array<String>) {
     infix fun and(other: Query): Query {
       return if (where.isNotEmpty() && other.where.isNotEmpty()) {

core-util/src/test/java/org/signal/core/util/SqlUtilTest.java

@@ -170,6 +170,22 @@ public final class SqlUtilTest {
     assertTrue(results.isEmpty());
   }
 
+  @Test
+  public void buildFastCollectionQuery_single() {
+    SqlUtil.Query updateQuery = SqlUtil.buildFastCollectionQuery("a", Arrays.asList(1));
+
+    assertEquals("a IN (SELECT e.value FROM json_each(?) e)", updateQuery.getWhere());
+    assertArrayEquals(new String[] { "[\"1\"]" }, updateQuery.getWhereArgs());
+  }
+
+  @Test
+  public void buildFastCollectionQuery_multiple() {
+    SqlUtil.Query updateQuery = SqlUtil.buildFastCollectionQuery("a", Arrays.asList(1, 2, 3));
+
+    assertEquals("a IN (SELECT e.value FROM json_each(?) e)", updateQuery.getWhere());
+    assertArrayEquals(new String[] { "[\"1\",\"2\",\"3\"]" }, updateQuery.getWhereArgs());
+  }
+
   @Test
   public void buildCustomCollectionQuery_single_singleBatch() {
     List<String[]> args = new ArrayList<>();