Cleanup released sqlite flags

Remove the simple_sql_comment_scanner flag and any code that is
subsequently unreachable.  A few comments have been updated.

Remove the sqlite_allow_temp_tables flag.  Comments have been updated
to remove references to the flagging.

Flag: EXEMPT flag-cleanup
Test: atest
 * FrameworksCoreTests:android.database
 * CtsDatabaseTestCases
Bug: 347726805
Bug: 347725835
Change-Id: I56969e85e780c924a98700875253dd898452a608

4 files changed, 6 insertions, 81 deletions

diff --git a/core/java/android/database/DatabaseUtils.java b/core/java/android/database/DatabaseUtils.java
index 3c4307c63cf7..0d583dedeb74 100644
--- a/core/java/android/database/DatabaseUtils.java
+++ b/core/java/android/database/DatabaseUtils.java
@@ -48,8 +48,6 @@ import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 
 /**
  * Static utility methods for dealing with databases and {@link Cursor}s.
@@ -1577,49 +1575,6 @@ public class DatabaseUtils {
     }
 
     /**
-     * The legacy prefix matcher.
-     */
-    private static String getSqlStatementPrefixSimple(@NonNull String sql) {
-        sql = sql.trim();
-        if (sql.length() < 3) {
-            return null;
-        }
-        return sql.substring(0, 3).toUpperCase(Locale.ROOT);
-    }
-
-    /**
-     * A regular expression that matches the first three characters in a SQL statement, after
-     * skipping past comments and whitespace.  PREFIX_GROUP_NUM is the regex group that contains
-     * the matching prefix string.  If PREFIX_REGEX is changed, PREFIX_GROUP_NUM may require an
-     * update too.
-     */
-    private static final String PREFIX_REGEX =
-            "("                                         // Zero-or more...
-            + "\\s+"                                    //   Leading space
-            + "|"
-            + "--.*?\n"                                 //   Line comment
-            + "|"
-            + "/\\*[\\w\\W]*?\\*/"                      //   Block comment
-            + ")*"
-            + "(\\w\\w\\w)";                            // Three word-characters
-    private static final int PREFIX_GROUP_NUM = 2;
-    private static final Pattern sPrefixPattern = Pattern.compile(PREFIX_REGEX);
-
-    /**
-     * Return the three-letter prefix of a SQL statement, skipping past whitespace and comments.
-     * Comments either start with "--" and run to the end of the line or are C-style block
-     * comments.  The function returns null if a prefix could not be found.
-     */
-    private static String getSqlStatementPrefixExtendedRegex(String sql) {
-        Matcher m = sPrefixPattern.matcher(sql);
-        if (m.lookingAt()) {
-            return m.group(PREFIX_GROUP_NUM).toUpperCase(Locale.ROOT);
-        } else {
-            return null;
-        }
-    }
-
-    /**
      * Return the index of the first character past comments and whitespace.  -1 is returned if
      * a comment is malformed.
      */
@@ -1719,15 +1674,7 @@ public class DatabaseUtils {
      * @hide
      */
     public static int getSqlStatementTypeExtended(@NonNull String sql) {
-        if (Flags.simpleSqlCommentScanner()) {
-            return categorizeStatement(getSqlStatementPrefixExtendedNoRegex(sql), sql);
-        } else {
-            int type = categorizeStatement(getSqlStatementPrefixSimple(sql), sql);
-            if (type == STATEMENT_COMMENT) {
-                type = categorizeStatement(getSqlStatementPrefixExtendedRegex(sql), sql);
-            }
-            return type;
-        }
+      return categorizeStatement(getSqlStatementPrefixExtendedNoRegex(sql), sql);
     }
 
     /**
diff --git a/core/java/android/database/sqlite/SQLiteConnection.java b/core/java/android/database/sqlite/SQLiteConnection.java
index 914aa51e5314..d77e6280d19c 100644
--- a/core/java/android/database/sqlite/SQLiteConnection.java
+++ b/core/java/android/database/sqlite/SQLiteConnection.java
@@ -129,9 +129,6 @@ public final class SQLiteConnection implements CancellationSignal.OnCancelListen
     // Restrict this connection to read-only operations.
     private boolean mOnlyAllowReadOnlyOperations;
 
-    // Allow this connection to treat updates to temporary tables as read-only operations.
-    private boolean mAllowTempTableRetry = Flags.sqliteAllowTempTables();
-
     // The number of times attachCancellationSignal has been called.
     // Because SQLite statement execution can be reentrant, we keep track of how many
     // times we have attempted to attach a cancellation signal to the connection so that
@@ -1281,19 +1278,17 @@ public final class SQLiteConnection implements CancellationSignal.OnCancelListen
 
     /**
      * Verify that the statement is read-only, if the connection only allows read-only
-     * operations.  If the connection allows updates to temporary tables, then the statement is
-     * read-only if the only updates are to temporary tables.
+     * operations.  If the statement is not read-only, then check if the statement only modifies
+     * temp tables, in which case it is treated the same as a read-only statement and is allowed.
      * @param statement The statement to check.
      * @throws SQLiteException if the statement could update the database inside a read-only
      * transaction.
      */
     void throwIfStatementForbidden(PreparedStatement statement) {
         if (mOnlyAllowReadOnlyOperations && !statement.mReadOnly) {
-            if (mAllowTempTableRetry) {
-                statement.mReadOnly =
-                        nativeUpdatesTempOnly(mConnectionPtr, statement.mStatementPtr);
-                if (statement.mReadOnly) return;
-            }
+            statement.mReadOnly =
+                  nativeUpdatesTempOnly(mConnectionPtr, statement.mStatementPtr);
+            if (statement.mReadOnly) return;
 
             throw new SQLiteException("Cannot execute this statement because it "
                     + "might modify the database but the connection is read-only.");
diff --git a/core/java/android/database/sqlite/flags.aconfig b/core/java/android/database/sqlite/flags.aconfig
index 285f984faab7..d5a7db82d456 100644
--- a/core/java/android/database/sqlite/flags.aconfig
+++ b/core/java/android/database/sqlite/flags.aconfig
@@ -9,19 +9,3 @@ flag {
      description: "SQLite APIs held back for Android 15"
      bug: "279043253"
 }
-
-flag {
-     name: "sqlite_allow_temp_tables"
-     namespace: "system_performance"
-     is_fixed_read_only: true
-     description: "Permit updates to TEMP tables in read-only transactions"
-     bug: "317993835"
-}
-
-flag {
-     name: "simple_sql_comment_scanner"
-     namespace: "system_performance"
-     is_fixed_read_only: true
-     description: "Scan SQL comments by hand instead of with a regex"
-     bug: "329118560"
-}
diff --git a/core/tests/coretests/src/android/database/sqlite/SQLiteDatabaseTest.java b/core/tests/coretests/src/android/database/sqlite/SQLiteDatabaseTest.java
index 9d477094692a..d5479ea3310d 100644
--- a/core/tests/coretests/src/android/database/sqlite/SQLiteDatabaseTest.java
+++ b/core/tests/coretests/src/android/database/sqlite/SQLiteDatabaseTest.java
@@ -358,7 +358,6 @@ public class SQLiteDatabaseTest {
         assertTrue("ReadThread failed with errors: " + errors, errors.isEmpty());
     }
 
-    @RequiresFlagsEnabled(Flags.FLAG_SQLITE_ALLOW_TEMP_TABLES)
     @Test
     public void testTempTable() {
         boolean allowed;