Merge "Perform SQL comment scanning with a manual parser" into main (50288883) · Commits · e / os / android_frameworks_base

core/java/android/database/DatabaseUtils.java

+65 −5

Original line number	Diff line number	Diff line
		@@ -22,6 +22,7 @@ import android.compat.annotation.UnsupportedAppUsage;
		import android.content.ContentValues;
		import android.content.Context;
		import android.content.OperationApplicationException;
		import android.database.sqlite.Flags;
		import android.database.sqlite.SQLiteAbortException;
		import android.database.sqlite.SQLiteConstraintException;
		import android.database.sqlite.SQLiteDatabase;
		@@ -1609,7 +1610,7 @@ public class DatabaseUtils {
		* 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 getSqlStatementPrefixExtended(String sql) {
		private static String getSqlStatementPrefixExtendedRegex(String sql) {
		Matcher m = sPrefixPattern.matcher(sql);
		if (m.lookingAt()) {
		return m.group(PREFIX_GROUP_NUM).toUpperCase(Locale.ROOT);
		@@ -1618,6 +1619,61 @@ public class DatabaseUtils {
		}
		}

		/**
		* Return the index of the first character past comments and whitespace. -1 is returned if
		* a comment is malformed.
		*/
		private static int getSqlStatementPrefixOffset(String s) {
		final int limit = s.length() - 2;
		if (limit < 0) return -1;
		int i = 0;
		while (i < limit) {
		final char c = s.charAt(i);
		if (c <= ' ') {
		// This behavior conforms to String.trim(), which is used by the legacy Android
		// SQL prefix logic. This test is not unicode-aware. Notice that it accepts the
		// null character as whitespace even though the null character will terminate the
		// SQL string in native code.
		i++;
		} else if (c == '-') {
		if (s.charAt(i+1) != '-') return i;
		i = s.indexOf('\n', i+2);
		if (i < 0) return -1;
		i++;
		} else if (c == '/') {
		if (s.charAt(i+1) != '*') return i;
		i++;
		do {
		i = s.indexOf('*', i+1);
		if (i < 0) return -1;
		i++;
		} while (s.charAt(i) != '/');
		i++;
		} else {
		return i;
		}
		}
		return -1;
		}

		/**
		* Scan past leading comments without using the Java regex routines.
		*/
		private static String getSqlStatementPrefixExtendedNoRegex(String sql) {
		int n = getSqlStatementPrefixOffset(sql);
		if (n < 0) {
		// Bad comment syntax.
		return null;
		}
		final int end = sql.length();
		if (n > end) {
		// Bad scanning. This indicates a programming error.
		return null;
		}
		final int eos = Math.min(n+3, end);
		return sql.substring(n, eos);
		}

		/**
		* Return the extended statement type for the SQL statement. This is not a public API and it
		* can return values that are not publicly visible.
		@@ -1663,12 +1719,16 @@ 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(getSqlStatementPrefixExtended(sql), sql);
		type = categorizeStatement(getSqlStatementPrefixExtendedRegex(sql), sql);
		}
		return type;
		}
		}

		/**
		* Convert an extended statement type to a public SQL statement type value.

core/java/android/database/sqlite/flags.aconfig

+8 −0

Original line number	Diff line number	Diff line
		@@ -17,3 +17,11 @@ flag {
		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"
		}

core/tests/coretests/src/android/database/DatabaseUtilsTest.java

+5 −1

Original line number	Diff line number	Diff line
		@@ -78,7 +78,8 @@ public class DatabaseUtilsTest {
		final int sel = STATEMENT_SELECT;
		assertEquals(sel, getSqlStatementType("SELECT"));
		assertEquals(sel, getSqlStatementType(" SELECT"));
		assertEquals(sel, getSqlStatementType(" \n SELECT"));
		assertEquals(sel, getSqlStatementType(" \n\r\f\t SELECT"));
		assertEquals(sel, getSqlStatementType(" \n\r\f\t SEL"));

		final int upd = STATEMENT_UPDATE;
		assertEquals(upd, getSqlStatementType("UPDATE"));
		@@ -95,6 +96,9 @@ public class DatabaseUtilsTest {
		assertEquals(othr, getSqlStatementType("SE LECT"));
		assertEquals(othr, getSqlStatementType("-- cmt\n SE"));
		assertEquals(othr, getSqlStatementType("WITH"));
		assertEquals(othr, getSqlStatementType("-"));
		assertEquals(othr, getSqlStatementType("--"));
		assertEquals(othr, getSqlStatementType("/ foo */ SEL"));

		// Verify that leading line-comments are skipped.
		assertEquals(sel, getSqlStatementType("-- cmt\n SELECT"));