BaseObservableQueryResultBinder.kt
/*
* 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.solver.query.result
import androidx.room.compiler.codegen.CodeLanguage
import androidx.room.compiler.codegen.VisibilityModifier
import androidx.room.compiler.codegen.XCodeBlock
import androidx.room.compiler.codegen.XFunSpec
import androidx.room.compiler.codegen.XFunSpec.Builder.Companion.addStatement
import androidx.room.compiler.codegen.XMemberName.Companion.packageMember
import androidx.room.compiler.codegen.XPropertySpec
import androidx.room.compiler.codegen.XTypeSpec
import androidx.room.ext.AndroidTypeNames.CURSOR
import androidx.room.ext.RoomTypeNames
import androidx.room.solver.CodeGenScope
/**
* Base class for query result binders that observe the database. It includes common functionality
* like creating a finalizer to release the query or creating the actual adapter call code.
*/
abstract class BaseObservableQueryResultBinder(
adapter: QueryResultAdapter?
) : QueryResultBinder(adapter) {
protected fun XTypeSpec.Builder.createFinalizeMethod(roomSQLiteQueryVar: String) {
addFunction(
XFunSpec.builder(
language = language,
name = "finalize",
visibility = VisibilityModifier.PROTECTED,
// To 'override' finalize in Kotlin one does not use the 'override' keyword, but in
// Java the @Override is needed
isOverride = language == CodeLanguage.JAVA
).apply {
addStatement("%L.release()", roomSQLiteQueryVar)
}.build()
)
}
protected fun createRunQueryAndReturnStatements(
builder: XCodeBlock.Builder,
roomSQLiteQueryVar: String,
dbProperty: XPropertySpec,
inTransaction: Boolean,
scope: CodeGenScope,
cancellationSignalVar: String
) {
val transactionWrapper = if (inTransaction) {
builder.transactionWrapper(dbProperty.name)
} else {
null
}
val shouldCopyCursor = adapter?.shouldCopyCursor() == true
val outVar = scope.getTmpVar("_result")
val cursorVar = scope.getTmpVar("_cursor")
transactionWrapper?.beginTransactionWithControlFlow()
builder.apply {
addLocalVariable(
name = cursorVar,
typeName = CURSOR,
assignExpr = XCodeBlock.of(
language = language,
format = "%M(%N, %L, %L, %L)",
RoomTypeNames.DB_UTIL.packageMember("query"),
dbProperty,
roomSQLiteQueryVar,
if (shouldCopyCursor) "true" else "false",
cancellationSignalVar
)
)
beginControlFlow("try").apply {
val adapterScope = scope.fork()
adapter?.convert(outVar, cursorVar, adapterScope)
add(adapterScope.generate())
transactionWrapper?.commitTransaction()
addStatement("return %L", outVar)
}
nextControlFlow("finally").apply {
addStatement("%L.close()", cursorVar)
}
endControlFlow()
}
transactionWrapper?.endTransactionWithControlFlow()
}
}