More memory-efficient packages state hash calculation. (001ae198) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/policy/role/RoleServicePlatformHelperImpl.java

+85 −40

Original line number	Diff line number	Diff line
		@@ -34,7 +34,6 @@ import android.text.TextUtils;
		import android.util.ArrayMap;
		import android.util.ArraySet;
		import android.util.AtomicFile;
		import android.util.PackageUtils;
		import android.util.Slog;
		import android.util.Xml;

		@@ -43,15 +42,18 @@ import com.android.internal.util.CollectionUtils;
		import com.android.server.LocalServices;
		import com.android.server.role.RoleServicePlatformHelper;

		import libcore.util.HexEncoding;

		import org.xmlpull.v1.XmlPullParser;
		import org.xmlpull.v1.XmlPullParserException;

		import java.io.ByteArrayOutputStream;
		import java.io.DataOutputStream;
		import java.io.File;
		import java.io.FileInputStream;
		import java.io.FileNotFoundException;
		import java.io.IOException;
		import java.nio.charset.StandardCharsets;
		import java.security.MessageDigest;
		import java.security.NoSuchAlgorithmException;
		import java.util.Collections;
		import java.util.List;
		import java.util.Map;
		@@ -300,45 +302,88 @@ public class RoleServicePlatformHelperImpl implements RoleServicePlatformHelper
		public String computePackageStateHash(@UserIdInt int userId) {
		PackageManagerInternal packageManagerInternal = LocalServices.getService(
		PackageManagerInternal.class);
		ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
		DataOutputStream dataOutputStream = new DataOutputStream(byteArrayOutputStream);
		final MessageDigestUtils md = new MessageDigestUtils();

		packageManagerInternal.forEachInstalledPackage(pkg -> {
		try {
		dataOutputStream.writeUTF(pkg.getPackageName());
		dataOutputStream.writeLong(pkg.getLongVersionCode());
		dataOutputStream.writeInt(packageManagerInternal.getApplicationEnabledState(
		pkg.getPackageName(), userId));
		md.writeString(pkg.getPackageName());
		md.writeLong(pkg.getLongVersionCode());
		md.writeInt(packageManagerInternal.getApplicationEnabledState(pkg.getPackageName(),
		userId));

		final List<String> requestedPermissions = pkg.getRequestedPermissions();
		final int requestedPermissionsSize = requestedPermissions.size();
		dataOutputStream.writeInt(requestedPermissionsSize);
		md.writeInt(requestedPermissionsSize);
		for (int i = 0; i < requestedPermissionsSize; i++) {
		dataOutputStream.writeUTF(requestedPermissions.get(i));
		md.writeString(requestedPermissions.get(i));
		}

		final ArraySet<String> enabledComponents =
		packageManagerInternal.getEnabledComponents(pkg.getPackageName(), userId);
		final ArraySet<String> enabledComponents = packageManagerInternal.getEnabledComponents(
		pkg.getPackageName(), userId);
		final int enabledComponentsSize = CollectionUtils.size(enabledComponents);
		dataOutputStream.writeInt(enabledComponentsSize);
		md.writeInt(enabledComponentsSize);
		for (int i = 0; i < enabledComponentsSize; i++) {
		dataOutputStream.writeUTF(enabledComponents.valueAt(i));
		md.writeString(enabledComponents.valueAt(i));
		}

		final ArraySet<String> disabledComponents =
		packageManagerInternal.getDisabledComponents(pkg.getPackageName(), userId);
		final int disabledComponentsSize = CollectionUtils.size(disabledComponents);
		for (int i = 0; i < disabledComponentsSize; i++) {
		dataOutputStream.writeUTF(disabledComponents.valueAt(i));
		md.writeString(disabledComponents.valueAt(i));
		}

		for (final Signature signature : pkg.getSigningDetails().getSignatures()) {
		dataOutputStream.write(signature.toByteArray());
		}
		} catch (IOException e) {
		// Never happens for ByteArrayOutputStream and DataOutputStream.
		throw new AssertionError(e);
		md.writeBytes(signature.toByteArray());
		}
		}, userId);
		return PackageUtils.computeSha256Digest(byteArrayOutputStream.toByteArray());

		return md.getDigestAsString();
		}

		private static class MessageDigestUtils {
		private final byte[] mBuffer = new byte[8];
		private final MessageDigest mMessageDigest;

		MessageDigestUtils() {
		try {
		mMessageDigest = MessageDigest.getInstance("SHA256");
		} catch (NoSuchAlgorithmException e) {
		/* can't happen */
		throw new RuntimeException("Failed to create MessageDigest", e);
		}
		}

		@NonNull
		String getDigestAsString() {
		return HexEncoding.encodeToString(mMessageDigest.digest(), true /* uppercase */);
		}

		void writeBytes(@NonNull byte[] bytes) {
		mMessageDigest.update(bytes);
		}

		void writeString(@NonNull String s) {
		mMessageDigest.update(s.getBytes(StandardCharsets.UTF_8));
		}

		void writeLong(long v) {
		mBuffer[0] = (byte) (v >>> 56);
		mBuffer[1] = (byte) (v >>> 48);
		mBuffer[2] = (byte) (v >>> 40);
		mBuffer[3] = (byte) (v >>> 32);
		mBuffer[4] = (byte) (v >>> 24);
		mBuffer[5] = (byte) (v >>> 16);
		mBuffer[6] = (byte) (v >>> 8);
		mBuffer[7] = (byte) (v >>> 0);
		mMessageDigest.update(mBuffer, 0, 8);
		}

		void writeInt(int v) {
		mBuffer[0] = (byte) (v >>> 24);
		mBuffer[1] = (byte) (v >>> 16);
		mBuffer[2] = (byte) (v >>> 8);
		mBuffer[3] = (byte) (v >>> 0);
		mMessageDigest.update(mBuffer, 0, 4);
		}
		}
		}