SchemaBundle.java
/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.room.migration.bundle;
import androidx.annotation.RestrictTo;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.TypeAdapter;
import com.google.gson.TypeAdapterFactory;
import com.google.gson.annotations.SerializedName;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonWriter;
import java.io.Closeable;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
/**
* Data class that holds the information about a database schema export.
*
* @hide
*/
@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP_PREFIX)
public class SchemaBundle implements SchemaEquality<SchemaBundle> {
@SerializedName("formatVersion")
private int mFormatVersion;
@SerializedName("database")
private DatabaseBundle mDatabase;
private static final Gson GSON;
private static final String CHARSET = "UTF-8";
public static final int LATEST_FORMAT = 1;
static {
GSON = new GsonBuilder()
.setPrettyPrinting()
.disableHtmlEscaping()
.registerTypeAdapterFactory(new EntityTypeAdapterFactory())
.create();
}
public SchemaBundle(int formatVersion, DatabaseBundle database) {
mFormatVersion = formatVersion;
mDatabase = database;
}
@SuppressWarnings("unused")
public int getFormatVersion() {
return mFormatVersion;
}
public DatabaseBundle getDatabase() {
return mDatabase;
}
/**
* @hide
*/
@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP_PREFIX)
public static SchemaBundle deserialize(InputStream fis)
throws UnsupportedEncodingException {
InputStreamReader is = new InputStreamReader(fis, CHARSET);
try {
return GSON.fromJson(is, SchemaBundle.class);
} finally {
safeClose(is);
safeClose(fis);
}
}
/**
* @hide
*/
@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP_PREFIX)
public static void serialize(SchemaBundle bundle, File file) throws IOException {
FileOutputStream fos = new FileOutputStream(file, false);
OutputStreamWriter osw = new OutputStreamWriter(fos, CHARSET);
try {
GSON.toJson(bundle, osw);
} finally {
safeClose(osw);
safeClose(fos);
}
}
private static void safeClose(Closeable closeable) {
if (closeable != null) {
try {
closeable.close();
} catch (Throwable ignored) {
}
}
}
@Override
public boolean isSchemaEqual(SchemaBundle other) {
return SchemaEqualityUtil.checkSchemaEquality(mDatabase, other.mDatabase)
&& mFormatVersion == other.mFormatVersion;
}
private static class EntityTypeAdapterFactory implements TypeAdapterFactory {
EntityTypeAdapterFactory() {
}
@Override
@SuppressWarnings("unchecked")
public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
if (!EntityBundle.class.isAssignableFrom(type.getRawType())) {
return null;
}
TypeAdapter<JsonElement> jsonElementAdapter = gson.getAdapter(JsonElement.class);
TypeAdapter<EntityBundle> entityBundleAdapter = gson.getDelegateAdapter(this,
TypeToken.get(EntityBundle.class));
TypeAdapter<FtsEntityBundle> ftsEntityBundleAdapter = gson.getDelegateAdapter(this,
TypeToken.get(FtsEntityBundle.class));
return (TypeAdapter<T>) new EntityTypeAdapter(
jsonElementAdapter, entityBundleAdapter, ftsEntityBundleAdapter);
}
private static class EntityTypeAdapter extends TypeAdapter<EntityBundle> {
private final TypeAdapter<JsonElement> mJsonElementAdapter;
private final TypeAdapter<EntityBundle> mEntityBundleAdapter;
private final TypeAdapter<FtsEntityBundle> mFtsEntityBundleAdapter;
EntityTypeAdapter(
TypeAdapter<JsonElement> jsonElementAdapter,
TypeAdapter<EntityBundle> entityBundleAdapter,
TypeAdapter<FtsEntityBundle> ftsEntityBundleAdapter) {
this.mJsonElementAdapter = jsonElementAdapter;
this.mEntityBundleAdapter = entityBundleAdapter;
this.mFtsEntityBundleAdapter = ftsEntityBundleAdapter;
}
@Override
public void write(JsonWriter out, EntityBundle value) throws IOException {
if (value instanceof FtsEntityBundle) {
mFtsEntityBundleAdapter.write(out, (FtsEntityBundle) value);
} else {
mEntityBundleAdapter.write(out, value);
}
}
@Override
public EntityBundle read(JsonReader in) throws IOException {
JsonObject jsonObject = mJsonElementAdapter.read(in).getAsJsonObject();
if (jsonObject.has("ftsVersion")) {
return mFtsEntityBundleAdapter.fromJsonTree(jsonObject);
} else {
return mEntityBundleAdapter.fromJsonTree(jsonObject);
}
}
}
}
}