zeus
79 lines
2.3 KiB
Swift
79 lines
2.3 KiB
Swift
/// A thread-unsafe database schema cache
|
|
struct DatabaseSchemaCache {
|
|
/// A cached value
|
|
///
|
|
/// We cache both hits and misses, because we often query both the temp
|
|
/// schema and the main schema: not remembering misses would have us
|
|
/// perform too many database queries.
|
|
enum Presence<T> {
|
|
/// Value does not exist in the schema.
|
|
case missing
|
|
|
|
/// Value exists in the schema.
|
|
case value(T)
|
|
|
|
var value: T? {
|
|
switch self {
|
|
case .missing: return nil
|
|
case let .value(value): return value
|
|
}
|
|
}
|
|
}
|
|
|
|
var schemaInfo: SchemaInfo?
|
|
private var tables: [String: Presence<TableInfo>] = [:]
|
|
private var primaryKeys: [String: Presence<PrimaryKeyInfo>] = [:]
|
|
private var columns: [String: Presence<[ColumnInfo]>] = [:]
|
|
private var indexes: [String: Presence<[IndexInfo]>] = [:]
|
|
private var foreignKeys: [String: Presence<[ForeignKeyInfo]>] = [:]
|
|
|
|
mutating func clear() {
|
|
tables = [:]
|
|
primaryKeys = [:]
|
|
columns = [:]
|
|
indexes = [:]
|
|
foreignKeys = [:]
|
|
schemaInfo = nil
|
|
}
|
|
|
|
func table(_ table: String) -> Presence<TableInfo>? {
|
|
tables[table]
|
|
}
|
|
|
|
mutating func set(tableInfo: Presence<TableInfo>, forTable table: String) {
|
|
tables[table] = tableInfo
|
|
}
|
|
|
|
func primaryKey(_ table: String) -> Presence<PrimaryKeyInfo>? {
|
|
primaryKeys[table]
|
|
}
|
|
|
|
mutating func set(primaryKey: Presence<PrimaryKeyInfo>, forTable table: String) {
|
|
primaryKeys[table] = primaryKey
|
|
}
|
|
|
|
func columns(in table: String) -> Presence<[ColumnInfo]>? {
|
|
columns[table]
|
|
}
|
|
|
|
mutating func set(columns: Presence<[ColumnInfo]>, forTable table: String) {
|
|
self.columns[table] = columns
|
|
}
|
|
|
|
func indexes(on table: String) -> Presence<[IndexInfo]>? {
|
|
indexes[table]
|
|
}
|
|
|
|
mutating func set(indexes: Presence<[IndexInfo]>, forTable table: String) {
|
|
self.indexes[table] = indexes
|
|
}
|
|
|
|
func foreignKeys(on table: String) -> Presence<[ForeignKeyInfo]>? {
|
|
foreignKeys[table]
|
|
}
|
|
|
|
mutating func set(foreignKeys: Presence<[ForeignKeyInfo]>, forTable table: String) {
|
|
self.foreignKeys[table] = foreignKeys
|
|
}
|
|
}
|