Drop some optional arrays in the fetchspec

The empty array has no relevant overhead in Swift, just use that and make code simpler. Affects: - `fetchAttributeNames` - `sortOrderings` - `prefetchingRelationshipKeyPathes`
ZeeQL · Dec 5, 2024 · 6e83e77 · 6e83e77
1 parent 251e93d
commit 6e83e77
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Showing 12 changed files with 109 additions and 136 deletions.
diff --git a/Sources/ZeeQL/Access/AccessDataSourceFinders.swift b/Sources/ZeeQL/Access/AccessDataSourceFinders.swift
@@ -3,7 +3,7 @@
 //  ZeeQL
 //
 //  Created by Helge Heß on 22.08.19.
-//  Copyright © 2019 ZeeZide GmbH. All rights reserved.
+//  Copyright © 2019-2024 ZeeZide GmbH. All rights reserved.
 //
 
 public extension AccessDataSource {
@@ -206,8 +206,8 @@ public extension AccessDataSource { // Finders
 
     var fs = try fetchSpecificationForFetch()
     fs.qualifier     = and(q, auxiliaryQualifier)
-    fs.sortOrderings = nil /* no sorting, makes DB faster */
-    fs.fetchLimit    = 1   /* we just want to find one record */
+    fs.sortOrderings = [] /* no sorting, makes DB faster */
+    fs.fetchLimit    = 1  /* we just want to find one record */
     return fs
   }
 

diff --git a/Sources/ZeeQL/Access/ActiveDataSource.swift b/Sources/ZeeQL/Access/ActiveDataSource.swift
@@ -139,7 +139,7 @@ open class ActiveDataSource<Object: ActiveRecordType>: AccessDataSource<Object>,
     var cfs = fs
     cfs.fetchesReadOnly     = true
     cfs.fetchAttributeNames = pkeys
-    cfs.prefetchingRelationshipKeyPathes = nil
+    cfs.prefetchingRelationshipKeyPathes = []
 
     let pkeyAttrs = pkeys.compactMap { entity[attribute: $0] }
     assert(pkeyAttrs.count == pkeys.count, "could not lookup all pkeys!")
@@ -177,7 +177,7 @@ open class ActiveDataSource<Object: ActiveRecordType>: AccessDataSource<Object>,
       // The idea is that this preserves the WHERE part of the query, including
       // relationships.
       var cfs = fs
-      cfs.sortOrderings = nil // no need to sort
+      cfs.sortOrderings = [] // no need to sort
 
       // hm, well, OK.
       cfs.fetchLimit  = 1 // TBD: could use '2' to detect query issues

diff --git a/Sources/ZeeQL/Access/AdaptorChannel.swift b/Sources/ZeeQL/Access/AdaptorChannel.swift
@@ -369,8 +369,8 @@ public extension AdaptorChannel { // MARK: - Operations
       attributes = attrs
     }
     else if let entity = e {
-      if let fs = fs, let an = fs.fetchAttributeNames {
-        attributes = entity.attributesWithNames(an)
+      if let fs = fs, !fs.fetchAttributeNames.isEmpty {
+        attributes = entity.attributesWithNames(fs.fetchAttributeNames)
       }
       else {
         attributes = entity.attributes

diff --git a/Sources/ZeeQL/Access/DatabaseChannel.swift b/Sources/ZeeQL/Access/DatabaseChannel.swift
@@ -1186,9 +1186,7 @@ open class TypedDatabaseChannel<ObjectType> : DatabaseChannelBase,
     _ ec: ObjectTrackingContext? = nil
   ) throws
   {
-    guard let prefetchRelPathes = fs.prefetchingRelationshipKeyPathes,
-          !prefetchRelPathes.isEmpty else
-    {
+    guard !fs.prefetchingRelationshipKeyPathes.isEmpty else {
       /* simple case, no prefetches */
       return try primarySelectObjectsWithFetchSpecification(fs, ec)
     }
@@ -1273,7 +1271,8 @@ open class TypedDatabaseChannel<ObjectType> : DatabaseChannelBase,
 
     do {
       try fetchRelationships(fs.entity, entityName,
-                             prefetchRelPathes, baseObjects, ec)
+                             fs.prefetchingRelationshipKeyPathes,
+                             baseObjects, ec)
     }
     catch {
       cancelFetch()
@@ -1347,9 +1346,7 @@ open class DatabaseChannel : DatabaseChannelBase, IteratorProtocol {
                                                               = nil)
                 throws
   {
-    guard let prefetchRelPathes = fs.prefetchingRelationshipKeyPathes,
-          !prefetchRelPathes.isEmpty
-     else {
+    guard !fs.prefetchingRelationshipKeyPathes.isEmpty else {
       /* simple case, no prefetches */
       return try primarySelectObjectsWithFetchSpecification(fs, ec)
     }
@@ -1425,7 +1422,8 @@ open class DatabaseChannel : DatabaseChannelBase, IteratorProtocol {
 
     do {
       try fetchRelationships(fs.entity, entityName,
-                             prefetchRelPathes, baseObjects, ec)
+                             fs.prefetchingRelationshipKeyPathes,
+                             baseObjects, ec)
     }
     catch {
       cancelFetch()

diff --git a/Sources/ZeeQL/Access/ModelLoader.swift b/Sources/ZeeQL/Access/ModelLoader.swift
@@ -320,9 +320,8 @@ open class CoreDataModelLoader : ModelLoader {
     }
     else { limit = nil }
 
-    let sos   : [ SortOrdering ]? = nil
     var fs = ModelFetchSpecification(entity: entity, qualifier: q,
-                                     sortOrderings: sos, limit: limit)
+                                     sortOrderings: [], limit: limit)
 
     fs.usesDistinct = boolValue(attrs["returnDistinctResults"])
 
@@ -356,30 +355,19 @@ open class CoreDataModelLoader : ModelLoader {
     for xml in xml.childElementsWithName("ordering") {
       // `<ordering key="name" />` (multiple are possible!)
       guard let ordering = loadSortOrdering(from: xml) else { continue }
-      if fs.sortOrderings == nil { fs.sortOrderings = [] }
-      fs.sortOrderings?.append(ordering)
+      fs.sortOrderings.append(ordering)
     }
 
     if let v = attrs["attributes"]?.split(separator: ","), !v.isEmpty {
-      if fs.fetchAttributeNames == nil {
-        fs.fetchAttributeNames = v.map(String.init)
-      }
-      else {
-        fs.fetchAttributeNames?.append(contentsOf: v.map(String.init))
-      }
+      fs.fetchAttributeNames.append(contentsOf: v.map(String.init))
     }
     for xml in xml.childElementsWithName("attributes") {
       // <attributes>objectId,permissions</attributes>
       guard let v = xml.textContent?.split(separator: ","), !v.isEmpty else {
         assertionFailure("<attributes> tag w/o content?")
         continue
       }
-      if fs.fetchAttributeNames == nil {
-        fs.fetchAttributeNames = v.map(String.init)
-      }
-      else {
-        fs.fetchAttributeNames?.append(contentsOf: v.map(String.init))
-      }
+      fs.fetchAttributeNames.append(contentsOf: v.map(String.init))
     }
     if let xml = xml.firstChildElementWithName("qualifier") {
       // <qualifier>(principalId IN $authIds) AND (objectId IN $ids)</qualifier>

diff --git a/Sources/ZeeQL/Access/TypedFetchSpecification.swift b/Sources/ZeeQL/Access/TypedFetchSpecification.swift
@@ -42,9 +42,9 @@ public struct TypedFetchSpecification<Object: DatabaseObject>
     return nil
   }
 
-  public var fetchAttributeNames : [ String ]?
+  public var fetchAttributeNames = [ String ]()
   public var qualifier           : Qualifier?
-  public var sortOrderings       : [ SortOrdering ]?
+  public var sortOrderings       = [ SortOrdering ]()
   public var fetchLimit          : Int?
   public var fetchOffset         : Int?
   public var hints               = [ String : Any ]()
@@ -55,14 +55,14 @@ public struct TypedFetchSpecification<Object: DatabaseObject>
   public var fetchesRawRows      = false
   public var fetchesReadOnly     = false
   public var requiresAllQualifierBindingVariables = false
-  public var prefetchingRelationshipKeyPathes : [ String ]?
+  public var prefetchingRelationshipKeyPathes = [ String ]()
 
   @inlinable
-  public init(entityName    : String?           = nil,
-              qualifier     : Qualifier?        = nil,
-              sortOrderings : [ SortOrdering ]? = nil,
-              limit         : Int?              = nil,
-              prefetch      : [ String ]?       = nil,
+  public init(entityName    : String?          = nil,
+              qualifier     : Qualifier?       = nil,
+              sortOrderings : [ SortOrdering ] = [],
+              limit         : Int?             = nil,
+              prefetch      : [ String ]       = [],
               requiresAllQualifierBindingVariables: Bool = false)
   {
     self._entityName   = entityName
@@ -76,10 +76,10 @@ public struct TypedFetchSpecification<Object: DatabaseObject>
 
   @inlinable
   public init(entity        : Entity,
-              qualifier     : Qualifier?        = nil,
-              sortOrderings : [ SortOrdering ]? = nil,
-              limit         : Int?              = nil,
-              prefetch      : [ String ]?       = nil,
+              qualifier     : Qualifier?       = nil,
+              sortOrderings : [ SortOrdering ] = [],
+              limit         : Int?             = nil,
+              prefetch      : [ String ]       = [],
               requiresAllQualifierBindingVariables: Bool = false)
   {
     self._entity       = entity
@@ -94,9 +94,9 @@ public struct TypedFetchSpecification<Object: DatabaseObject>
   /// Initialize w/ a qualifier string.
   public init(entity        : Entity,
               _ q           : String,
-              sortOrderings : [ SortOrdering ]? = nil,
-              limit         : Int?              = nil,
-              prefetch      : [ String ]?       = nil)
+              sortOrderings : [ SortOrdering ] = [],
+              limit         : Int?             = nil,
+              prefetch      : [ String ]       = [])
   {
     self._entity       = entity
     self.qualifier     = qualifierWith(format: q)

diff --git a/Sources/ZeeQL/Control/ArrayDataSource.swift b/Sources/ZeeQL/Control/ArrayDataSource.swift
@@ -66,9 +66,9 @@ open class ArrayDataSource<Object: SwiftObject> : DataSource<Object>,
       }
 
 
-      if let sos = fs.sortOrderings, !sos.isEmpty {
+      if !fs.sortOrderings.isEmpty {
         // TODO: sort
-        log.warn("not applying sort orderings", self, sos)
+        log.warn("not applying sort orderings", self, fs.sortOrderings)
       }
 
       let count       = filtered.count

diff --git a/Sources/ZeeQL/Control/EntityType+Builder.swift b/Sources/ZeeQL/Control/EntityType+Builder.swift
@@ -9,11 +9,9 @@ public extension EntityType {
   // TBD: maybe rename, 'select' should run the actual select, right?
 
   @inlinable
-  static func select(_ attributes: String...)
-              -> FetchSpecification
-  {
+  static func select(_ attributes: String...) -> FetchSpecification {
     var fs = ModelFetchSpecification(entity: Self.entity)
-    fs.fetchAttributeNames = attributes.isEmpty ? nil : attributes
+    fs.fetchAttributeNames = attributes
     return fs
   }
 
@@ -57,7 +55,7 @@ public extension TypedEntityType where Self: DatabaseObject {
               -> TypedFetchSpecification<Self>
   {
     var fs = TypedFetchSpecification<Self>(entity: Self.entity)
-    fs.fetchAttributeNames = attributes.isEmpty ? nil : attributes
+    fs.fetchAttributeNames = attributes
     return fs
   }
 

diff --git a/Sources/ZeeQL/Control/FetchSpecification+Builder.swift b/Sources/ZeeQL/Control/FetchSpecification+Builder.swift
@@ -96,13 +96,8 @@ public extension FetchSpecification {
   {
     transform {
       if clear { $0.prefetchingRelationshipKeyPathes = [] }
-      if $0.prefetchingRelationshipKeyPathes == nil {
-        $0.prefetchingRelationshipKeyPathes = [ path ]
-      }
-      else {
-        $0.prefetchingRelationshipKeyPathes?.append(path)
-        $0.prefetchingRelationshipKeyPathes?.append(contentsOf: more)
-      }
+      $0.prefetchingRelationshipKeyPathes.append(path)
+      $0.prefetchingRelationshipKeyPathes.append(contentsOf: more)
     }
   }
   @inlinable
@@ -114,14 +109,8 @@ public extension FetchSpecification {
     //         `fs.prefetch(Person.e.company.addresses)`
     transform {
       if clear { $0.prefetchingRelationshipKeyPathes = [] }
-      if $0.prefetchingRelationshipKeyPathes == nil {
-        $0.prefetchingRelationshipKeyPathes = [ path.name ]
-      }
-      else {
-        $0.prefetchingRelationshipKeyPathes?.append(path.name)
-        $0.prefetchingRelationshipKeyPathes?
-          .append(contentsOf: more.map(\.name))
-      }
+      $0.prefetchingRelationshipKeyPathes.append(path.name)
+      $0.prefetchingRelationshipKeyPathes.append(contentsOf: more.map(\.name))
     }
   }
 
@@ -131,22 +120,22 @@ public extension FetchSpecification {
   @inlinable
   func order(by: SortOrdering, _ e: SortOrdering...) -> Self {
     transform {
-      if let old = $0.sortOrderings { $0.sortOrderings = old + [ by ] + e }
-      else                          { $0.sortOrderings = [ by ] + e }
+      $0.sortOrderings.append(by)
+      $0.sortOrderings.append(contentsOf: e)
     }
   }
 
   @inlinable
   func order(by: String, _ e: String...) -> Self {
     transform {
-      var ops = [ SortOrdering ]()
-      if let p = SortOrdering.parse(by) { ops += p }
+      if let p = SortOrdering.parse(by) { $0.sortOrderings += p }
+      else { assertionFailure("Could not parse order string")}
       for by in e {
-        if let p = SortOrdering.parse(by) { ops += p }
+        if let p = SortOrdering.parse(by) {
+          $0.sortOrderings.append(contentsOf: p)
+        }
+        else { assertionFailure("Could not parse order string")}
       }
-
-      if let old = $0.sortOrderings { $0.sortOrderings = old + ops }
-      else                          { $0.sortOrderings = ops }
     }
   }
 }
@@ -188,8 +177,7 @@ public extension DatabaseFetchSpecification
       for key in repeat each key {
         let attribute = Object.e[keyPath: key]
         let so = SortOrdering(key: AttributeKey(attribute), selector: selector)
-        if $0.sortOrderings == nil { $0.sortOrderings = [ so ] }
-        else { $0.sortOrderings?.append(so) }
+        $0.sortOrderings.append(so)
       }
     }
   }
@@ -219,7 +207,7 @@ public extension DatabaseFetchSpecification
       if clear { $0.prefetchingRelationshipKeyPathes = [] }
       for relationship in repeat each relationship {
         let relationship = Object.e[keyPath: relationship]
-        $0.prefetchingRelationshipKeyPathes?.append(relationship.name)
+        $0.prefetchingRelationshipKeyPathes.append(relationship.name)
       }
     }
   }
@@ -233,7 +221,7 @@ public extension DatabaseFetchSpecification
       if clear { $0.prefetchingRelationshipKeyPathes = [] }
       for relationship in repeat each relationship {
         let relationship = Object.e[keyPath: relationship]
-        $0.prefetchingRelationshipKeyPathes?.append(relationship.name)
+        $0.prefetchingRelationshipKeyPathes.append(relationship.name)
       }
     }
   }
@@ -247,7 +235,7 @@ public extension DatabaseFetchSpecification
       if clear { $0.prefetchingRelationshipKeyPathes = [] }
       for relationship in repeat each relationship {
         let relationship = Object.e[keyPath: relationship]
-        $0.prefetchingRelationshipKeyPathes?.append(relationship.name)
+        $0.prefetchingRelationshipKeyPathes.append(relationship.name)
       }
     }
   }
@@ -257,17 +245,19 @@ public extension DatabaseFetchSpecification
 
 public extension FetchSpecification {
 
+  @inlinable
   static func select<T: EntityType>(_ attributes: String..., from: T.Type)
               -> FetchSpecification
   {
     var fs = ModelFetchSpecification(entity: from.entity)
-    fs.fetchAttributeNames = attributes.isEmpty ? nil : attributes
+    fs.fetchAttributeNames = attributes
     return fs
   }
 
 
   // MARK: - Ordering
 
+  @inlinable
   func order(by    : Attribute...,
              asc   : Attribute? = nil,
              desc  : Attribute? = nil,
@@ -277,35 +267,28 @@ public extension FetchSpecification {
   {
     var fs = self
 
-    var ops = [ SortOrdering ]()
-
     for by in by {
       let so = SortOrdering(key: AttributeKey(by), selector: .CompareAscending)
-      ops.append(so)
+      fs.sortOrderings.append(so)
     }
     if let by = asc {
       let so = SortOrdering(key: AttributeKey(by), selector: .CompareAscending)
-      ops.append(so)
+      fs.sortOrderings.append(so)
     }
     if let by = desc {
       let so = SortOrdering(key: AttributeKey(by), selector: .CompareDescending)
-      ops.append(so)
+      fs.sortOrderings.append(so)
     }
     if let by = iasc {
       let so = SortOrdering(key: AttributeKey(by),
                             selector: .CompareCaseInsensitiveAscending)
-      ops.append(so)
+      fs.sortOrderings.append(so)
     }
     if let by = idesc {
       let so = SortOrdering(key: AttributeKey(by),
                             selector: .CompareCaseInsensitiveDescending)
-      ops.append(so)
+      fs.sortOrderings.append(so)
     }
-
-    guard !ops.isEmpty else { return self }
-
-    if let old = fs.sortOrderings { fs.sortOrderings = old + ops }
-    else                          { fs.sortOrderings = ops       }
     return fs
   }
 }