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Improves performance for the swift library by using structs + a storage class (#5835)

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This commit is contained in:
mustiikhalil
2020-04-02 22:55:30 +03:00
committed by GitHub
parent 925fab6b15
commit a83caf5910
12 changed files with 467 additions and 445 deletions
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69
swift/Sources/FlatBuffers/FlatBufferBuilder.swift
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@@ -1,6 +1,6 @@
import Foundation
public final class FlatBufferBuilder {
public struct FlatBufferBuilder {
/// Vtables used in the buffer are stored in here, so they would be written later in EndTable
private var _vtable: [UInt32] = []
@@ -72,7 +72,7 @@ public final class FlatBufferBuilder {
}
/// Clears the buffer and the builder from it's data
public func clear() {
mutating public func clear() {
_minAlignment = 0
isNested = false
_bb.clear()
@@ -80,7 +80,7 @@ public final class FlatBufferBuilder {
}
/// Removes all the offsets from the VTable
public func clearOffsets() {
mutating public func clearOffsets() {
_vtable = []
}
@@ -90,7 +90,7 @@ public final class FlatBufferBuilder {
/// - Parameters:
/// - table: offset for the table
/// - fields: Array of all the important fields to be serialized
public func require(table: Offset<UOffset>, fields: [Int32]) {
mutating public func require(table: Offset<UOffset>, fields: [Int32]) {
for field in fields {
let start = _bb.capacity - Int(table.o)
let startTable = start - Int(_bb.read(def: Int32.self, position: start))
@@ -104,7 +104,7 @@ public final class FlatBufferBuilder {
/// - offset: Offset of the table
/// - fileId: Takes the fileId
/// - prefix: if false it wont add the size of the buffer
public func finish<T>(offset: Offset<T>, fileId: String, addPrefix prefix: Bool = false) {
mutating public func finish<T>(offset: Offset<T>, fileId: String, addPrefix prefix: Bool = false) {
let size = MemoryLayout<UOffset>.size
preAlign(len: size + (prefix ? size : 0) + FileIdLength, alignment: _minAlignment)
assert(fileId.count == FileIdLength, "Flatbuffers requires file id to be 4")
@@ -116,7 +116,7 @@ public final class FlatBufferBuilder {
/// - Parameters:
/// - offset: Offset of the table
/// - prefix: if false it wont add the size of the buffer
public func finish<T>(offset: Offset<T>, addPrefix prefix: Bool = false) {
mutating public func finish<T>(offset: Offset<T>, addPrefix prefix: Bool = false) {
notNested()
let size = MemoryLayout<UOffset>.size
preAlign(len: size + (prefix ? size : 0), alignment: _minAlignment)
@@ -130,7 +130,7 @@ public final class FlatBufferBuilder {
///
/// The function will fatalerror if called while there is another object being serialized
/// - Parameter numOfFields: Number of elements to be written to the buffer
public func startTable(with numOfFields: Int) -> UOffset {
mutating public func startTable(with numOfFields: Int) -> UOffset {
notNested()
isNested = true
_vtable = [UInt32](repeating: 0, count: numOfFields)
@@ -145,7 +145,7 @@ public final class FlatBufferBuilder {
/// 2GB,
/// - Parameter startOffset:Start point of the object written
/// - returns: The root of the table
public func endTable(at startOffset: UOffset) -> UOffset {
mutating public func endTable(at startOffset: UOffset) -> UOffset {
assert(isNested, "Calling endtable without calling starttable")
let sizeofVoffset = MemoryLayout<VOffset>.size
let vTableOffset = push(element: SOffset(0))
@@ -203,13 +203,13 @@ public final class FlatBufferBuilder {
// MARK: - Builds Buffer
/// asserts to see if the object is not nested
fileprivate func notNested() {
@usableFromInline mutating internal func notNested() {
assert(!isNested, "Object serialization must not be nested")
}
/// Changes the minimuim alignment of the buffer
/// - Parameter size: size of the current alignment
fileprivate func minAlignment(size: Int) {
@usableFromInline mutating internal func minAlignment(size: Int) {
if size > _minAlignment {
_minAlignment = size
}
@@ -219,7 +219,7 @@ public final class FlatBufferBuilder {
/// - Parameters:
/// - bufSize: Current size of the buffer + the offset of the object to be written
/// - elementSize: Element size
fileprivate func padding(bufSize: UInt32, elementSize: UInt32) -> UInt32 {
@usableFromInline mutating internal func padding(bufSize: UInt32, elementSize: UInt32) -> UInt32 {
((~bufSize) &+ 1) & (elementSize - 1)
}
@@ -227,7 +227,7 @@ public final class FlatBufferBuilder {
/// - Parameters:
/// - len:Length of the object
/// - alignment: Alignment type
fileprivate func preAlign(len: Int, alignment: Int) {
@usableFromInline mutating internal func preAlign(len: Int, alignment: Int) {
minAlignment(size: alignment)
_bb.fill(padding: padding(bufSize: _bb.size + UOffset(len), elementSize: UOffset(alignment)))
}
@@ -236,13 +236,13 @@ public final class FlatBufferBuilder {
/// - Parameters:
/// - len: Length of the object
/// - type: Type of the object to be written
fileprivate func preAlign<T: Scalar>(len: Int, type: T.Type) {
@usableFromInline mutating internal func preAlign<T: Scalar>(len: Int, type: T.Type) {
preAlign(len: len, alignment: MemoryLayout<T>.size)
}
/// Refers to an object that's written in the buffer
/// - Parameter off: the objects index value
fileprivate func refer(to off: UOffset) -> UOffset {
@usableFromInline mutating internal func refer(to off: UOffset) -> UOffset {
let size = MemoryLayout<UOffset>.size
preAlign(len: size, alignment: size)
return _bb.size - off + UInt32(size)
@@ -252,14 +252,14 @@ public final class FlatBufferBuilder {
/// - Parameters:
/// - offset: The offset of the element witten
/// - position: The position of the element
fileprivate func track(offset: UOffset, at position: VOffset) {
@usableFromInline mutating internal func track(offset: UOffset, at position: VOffset) {
_vtable[Int(position)] = offset
}
// MARK: - Vectors
/// Starts a vector of length and Element size
public func startVector(_ len: Int, elementSize: Int) {
mutating public func startVector(_ len: Int, elementSize: Int) {
notNested()
isNested = true
preAlign(len: len * elementSize, type: UOffset.self)
@@ -270,7 +270,7 @@ public final class FlatBufferBuilder {
///
/// The current function will fatalError if startVector is called before serializing the vector
/// - Parameter len: Length of the buffer
public func endVector(len: Int) -> UOffset {
mutating public func endVector(len: Int) -> UOffset {
assert(isNested, "Calling endVector without calling startVector")
isNested = false
return push(element: Int32(len))
@@ -279,7 +279,7 @@ public final class FlatBufferBuilder {
/// Creates a vector of type Scalar in the buffer
/// - Parameter elements: elements to be written into the buffer
/// - returns: Offset of the vector
public func createVector<T: Scalar>(_ elements: [T]) -> Offset<UOffset> {
mutating public func createVector<T: Scalar>(_ elements: [T]) -> Offset<UOffset> {
return createVector(elements, size: elements.count)
}
@@ -287,7 +287,7 @@ public final class FlatBufferBuilder {
/// - Parameter elements: Elements to be written into the buffer
/// - Parameter size: Count of elements
/// - returns: Offset of the vector
public func createVector<T: Scalar>(_ elements: [T], size: Int) -> Offset<UOffset> {
mutating public func createVector<T: Scalar>(_ elements: [T], size: Int) -> Offset<UOffset> {
let size = size
startVector(size, elementSize: MemoryLayout<T>.size)
_bb.push(elements: elements)
@@ -297,7 +297,7 @@ public final class FlatBufferBuilder {
/// Creates a vector of type Enums in the buffer
/// - Parameter elements: elements to be written into the buffer
/// - returns: Offset of the vector
public func createVector<T: Enum>(_ elements: [T]) -> Offset<UOffset> {
mutating public func createVector<T: Enum>(_ elements: [T]) -> Offset<UOffset> {
return createVector(elements, size: elements.count)
}
@@ -305,7 +305,7 @@ public final class FlatBufferBuilder {
/// - Parameter elements: Elements to be written into the buffer
/// - Parameter size: Count of elements
/// - returns: Offset of the vector
public func createVector<T: Enum>(_ elements: [T], size: Int) -> Offset<UOffset> {
mutating public func createVector<T: Enum>(_ elements: [T], size: Int) -> Offset<UOffset> {
let size = size
startVector(size, elementSize: T.byteSize)
for e in elements.lazy.reversed() {
@@ -317,7 +317,7 @@ public final class FlatBufferBuilder {
/// Creates a vector of type Offsets in the buffer
/// - Parameter offsets:Array of offsets of type T
/// - returns: Offset of the vector
public func createVector<T>(ofOffsets offsets: [Offset<T>]) -> Offset<UOffset> {
mutating public func createVector<T>(ofOffsets offsets: [Offset<T>]) -> Offset<UOffset> {
createVector(ofOffsets: offsets, len: offsets.count)
}
@@ -325,7 +325,7 @@ public final class FlatBufferBuilder {
/// - Parameter elements: Array of offsets of type T
/// - Parameter size: Count of elements
/// - returns: Offset of the vector
public func createVector<T>(ofOffsets offsets: [Offset<T>], len: Int) -> Offset<UOffset> {
mutating public func createVector<T>(ofOffsets offsets: [Offset<T>], len: Int) -> Offset<UOffset> {
startVector(len, elementSize: MemoryLayout<Offset<T>>.size)
for o in offsets.lazy.reversed() {
push(element: o)
@@ -336,7 +336,7 @@ public final class FlatBufferBuilder {
/// Creates a vector of Strings
/// - Parameter str: a vector of strings that will be written into the buffer
/// - returns: Offset of the vector
public func createVector(ofStrings str: [String]) -> Offset<UOffset> {
mutating public func createVector(ofStrings str: [String]) -> Offset<UOffset> {
var offsets: [Offset<String>] = []
for s in str {
offsets.append(create(string: s))
@@ -351,7 +351,7 @@ public final class FlatBufferBuilder {
/// - structs: An array of UnsafeMutableRawPointer
/// - type: Type of the struct being written
/// - returns: Offset of the vector
public func createVector<T: Readable>(structs: [UnsafeMutableRawPointer],
mutating public func createVector<T: Readable>(structs: [UnsafeMutableRawPointer],
type: T.Type) -> Offset<UOffset> {
startVector(structs.count * T.size, elementSize: T.alignment)
for i in structs.lazy.reversed() {
@@ -368,7 +368,7 @@ public final class FlatBufferBuilder {
/// - type: Type of the element to be serialized
/// - returns: Offset of the Object
@discardableResult
public func create<T: Readable>(struct s: UnsafeMutableRawPointer,
mutating public func create<T: Readable>(struct s: UnsafeMutableRawPointer,
type: T.Type) -> Offset<UOffset> {
let size = T.size
preAlign(len: size, alignment: T.alignment)
@@ -380,7 +380,7 @@ public final class FlatBufferBuilder {
///
/// The function fatalErrors if we pass an offset that is out of range
/// - Parameter o: offset
public func add(structOffset o: UOffset) {
mutating public func add(structOffset o: UOffset) {
guard Int(o) < _vtable.count else { fatalError("Out of the table range") }
_vtable[Int(o)] = _bb.size
}
@@ -390,7 +390,7 @@ public final class FlatBufferBuilder {
/// Insets a string into the buffer using UTF8
/// - Parameter str: String to be serialized
/// - returns: The strings offset in the buffer
public func create(string str: String) -> Offset<String> {
mutating public func create(string str: String) -> Offset<String> {
let len = str.count
notNested()
preAlign(len: len + 1, type: UOffset.self)
@@ -405,7 +405,7 @@ public final class FlatBufferBuilder {
/// The function checks the stringOffsetmap if it's seen a similar string before
/// - Parameter str: String to be serialized
/// - returns: The strings offset in the buffer
public func createShared(string str: String) -> Offset<String> {
mutating public func createShared(string str: String) -> Offset<String> {
if let offset = stringOffsetMap[str] {
return offset
}
@@ -420,7 +420,7 @@ public final class FlatBufferBuilder {
/// - Parameters:
/// - offset: Offset of another object to be written
/// - position: The predefined position of the object
public func add<T>(offset: Offset<T>, at position: VOffset) {
mutating public func add<T>(offset: Offset<T>, at position: VOffset) {
if offset.isEmpty {
track(offset: 0, at: position)
return
@@ -432,7 +432,7 @@ public final class FlatBufferBuilder {
/// - Parameter o: Offset
/// - returns: Position of the offset
@discardableResult
public func push<T>(element o: Offset<T>) -> UOffset {
mutating public func push<T>(element o: Offset<T>) -> UOffset {
push(element: refer(to: o.o))
}
@@ -444,7 +444,7 @@ public final class FlatBufferBuilder {
/// - element: Element to insert
/// - def: Default value for that element
/// - position: The predefined position of the element
public func add<T: Scalar>(element: T, def: T, at position: VOffset) {
mutating public func add<T: Scalar>(element: T, def: T, at position: VOffset) {
if (element == def && !serializeDefaults) {
track(offset: 0, at: position)
return
@@ -458,7 +458,7 @@ public final class FlatBufferBuilder {
/// - condition: Condition to insert
/// - def: Default condition
/// - position: The predefined position of the element
public func add(condition: Bool, def: Bool, at position: VOffset) {
mutating public func add(condition: Bool, def: Bool, at position: VOffset) {
if (condition == def && !serializeDefaults) {
track(offset: 0, at: position)
return
@@ -471,12 +471,13 @@ public final class FlatBufferBuilder {
/// - Parameter element: Element to insert
/// - returns: Postion of the Element
@discardableResult
public func push<T: Scalar>(element: T) -> UOffset {
mutating public func push<T: Scalar>(element: T) -> UOffset {
preAlign(len: MemoryLayout<T>.size,
alignment: MemoryLayout<T>.size)
_bb.push(value: element, len: MemoryLayout<T>.size)
return _bb.size
}
}
extension FlatBufferBuilder: CustomDebugStringConvertible {