EntityRowAdapter.kt
/*
* Copyright (C) 2016 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.XCodeBlock
import androidx.room.compiler.codegen.XFunSpec
import androidx.room.compiler.codegen.XTypeName
import androidx.room.ext.AndroidTypeNames
import androidx.room.ext.ArrayLiteral
import androidx.room.ext.CommonTypeNames
import androidx.room.ext.RoomMemberNames
import androidx.room.solver.CodeGenScope
import androidx.room.vo.ColumnIndexVar
import androidx.room.vo.Entity
import androidx.room.vo.columnNames
import androidx.room.writer.EntityCursorConverterWriter
class EntityRowAdapter(val entity: Entity) : QueryMappedRowAdapter(entity.type) {
override val mapping = EntityMapping(entity)
private lateinit var functionSpec: XFunSpec
private var cursorDelegateVarName: String? = null
private val indexAdapter = object : IndexAdapter {
private var indexVars: List<ColumnIndexVar>? = null
override fun onCursorReady(cursorVarName: String, scope: CodeGenScope) {
indexVars = entity.columnNames.map { columnName ->
ColumnIndexVar(
column = columnName,
indexVar = XCodeBlock.of(
scope.language,
"%M(%L, %S)",
RoomMemberNames.CURSOR_UTIL_GET_COLUMN_INDEX,
cursorVarName,
columnName
).toString()
)
}
}
override fun getIndexVars() = indexVars ?: emptyList()
}
override fun onCursorReady(
cursorVarName: String,
scope: CodeGenScope,
indices: List<ColumnIndexVar>
) {
// Check if given indices are the default ones, i.e. onCursorReady() was called without
// an indices argument and these are the default parameter ones, which means a wrapped
// cursor is not needed since the generated entity cursor converter has access to the
// original cursor.
if (indices.isNotEmpty() && indices != indexAdapter.getIndexVars()) {
// Due to entity converter code being shared and using Cursor.getColumnIndex() we can't
// generate code that uses the mapping directly. Instead we create a wrapped Cursor that is
// solely used in the shared converter method and whose getColumnIndex() is overridden
// to return the resolved column index.
cursorDelegateVarName = scope.getTmpVar("_wrappedCursor")
val entityColumnNamesParam = ArrayLiteral(
scope.language,
CommonTypeNames.STRING,
*entity.columnNames.toTypedArray()
)
val entityColumnIndicesParam = ArrayLiteral(
scope.language,
XTypeName.PRIMITIVE_INT,
*indices.map { it.indexVar }.toTypedArray()
)
scope.builder.addLocalVariable(
checkNotNull(cursorDelegateVarName),
AndroidTypeNames.CURSOR,
assignExpr = XCodeBlock.of(
scope.language,
"%M(%L, %L, %L)",
RoomMemberNames.CURSOR_UTIL_WRAP_MAPPED_COLUMNS,
cursorVarName,
entityColumnNamesParam,
entityColumnIndicesParam
)
)
}
functionSpec = scope.writer.getOrCreateFunction(EntityCursorConverterWriter(entity))
}
override fun convert(outVarName: String, cursorVarName: String, scope: CodeGenScope) {
scope.builder.addStatement(
"%L = %N(%L)",
outVarName, functionSpec, cursorDelegateVarName ?: cursorVarName
)
}
override fun getDefaultIndexAdapter() = indexAdapter
data class EntityMapping(val entity: Entity) : Mapping() {
override val usedColumns: List<String> = entity.columnNames
}
}