2023-10-25 15:11:37 -07:00

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//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2023 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
extension String {
// Ideally we'd entirely de-duplicate this code with serializeString()'s, but at the moment there's a noticeable performance regression when doing so.
func serializedForJSON(withoutEscapingSlashes: Bool) -> String {
var bytes = [UInt8]()
bytes.reserveCapacity(self.utf8.count + 2)
bytes.append(._quote)
var mutStr = self
mutStr.withUTF8 {
var cursor = $0.baseAddress!
let end = $0.baseAddress! + $0.count
var mark = cursor
while cursor < end {
let escapeString: String
switch cursor.pointee {
case ._quote:
escapeString = "\\\""
break
case ._backslash:
escapeString = "\\\\"
break
case ._slash where !withoutEscapingSlashes:
escapeString = "\\/"
break
case 0x8:
escapeString = "\\b"
break
case 0xc:
escapeString = "\\f"
break
case ._newline:
escapeString = "\\n"
break
case ._return:
escapeString = "\\r"
break
case ._tab:
escapeString = "\\t"
break
case 0x0...0xf:
escapeString = "\\u000\(String(cursor.pointee, radix: 16))"
break
case 0x10...0x1f:
escapeString = "\\u00\(String(cursor.pointee, radix: 16))"
break
default:
// Accumulate this byte
cursor += 1
continue
}
// Append accumulated bytes
if cursor > mark {
bytes.append(contentsOf: UnsafeBufferPointer(start: mark, count: cursor-mark))
}
bytes.append(contentsOf: escapeString.utf8)
cursor += 1
mark = cursor // Start accumulating bytes starting after this escaped byte.
}
// Append accumulated bytes
if cursor > mark {
bytes.append(contentsOf: UnsafeBufferPointer(start: mark, count: cursor-mark))
}
}
bytes.append(._quote)
return String(unsafeUninitializedCapacity: bytes.count) {
_ = $0.initialize(from: bytes)
return bytes.count
}
}
}
extension JSONReference {
static func number(from num: some (FixedWidthInteger & CustomStringConvertible)) -> JSONReference {
return .number(num.description)
}
static func number<T: BinaryFloatingPoint & CustomStringConvertible>(from float: T, with options: JSONEncoder.NonConformingFloatEncodingStrategy, for codingPathNode: _JSONCodingPathNode, _ additionalKey: (some CodingKey)? = Optional<_JSONKey>.none) throws -> JSONReference {
guard !float.isNaN, !float.isInfinite else {
if case .convertToString(let posInfString, let negInfString, let nanString) = options {
switch float {
case T.infinity:
return .string(posInfString)
case -T.infinity:
return .string(negInfString)
default:
// must be nan in this case
return .string(nanString)
}
}
let path = codingPathNode.path(with: additionalKey)
throw EncodingError.invalidValue(float, .init(
codingPath: path,
debugDescription: "Unable to encode \(T.self).\(float) directly in JSON."
))
}
var string = float.description
if string.hasSuffix(".0") {
string.removeLast(2)
}
return .number(string)
}
}
internal struct JSONWriter {
// Structures with container nesting deeper than this limit are not valid.
private static let maximumRecursionDepth = 512
private var indent = 0
private let pretty: Bool
#if FOUNDATION_FRAMEWORK
// https://github.com/apple/swift-foundation/issues/284
private let sortedKeys: Bool
#endif
private let withoutEscapingSlashes: Bool
var data = Data()
init(options: WritingOptions) {
pretty = options.contains(.prettyPrinted)
#if FOUNDATION_FRAMEWORK
// https://github.com/apple/swift-foundation/issues/284
sortedKeys = options.contains(.sortedKeys)
#endif
withoutEscapingSlashes = options.contains(.withoutEscapingSlashes)
data = Data()
}
mutating func serializeJSON(_ value: JSONReference, depth: Int = 0) throws {
switch value.backing {
case .string(let str):
try serializeString(str)
case .bool(let boolValue):
writer(boolValue.description)
case .number(let numberStr):
writer(numberStr)
case .array(let array):
try serializeArray(array, depth: depth + 1)
case .nonPrettyDirectArray(let arrayRepresentation):
writer(arrayRepresentation)
case .directArray(let strings):
try serializePreformattedStringArray(strings, depth: depth + 1)
case .object(let object):
try serializeObject(object, depth: depth + 1)
case .null:
serializeNull()
}
}
@inline(__always)
mutating func writer(_ string: StaticString) {
string.withUTF8Buffer {
data.append($0.baseAddress.unsafelyUnwrapped, count: $0.count)
}
}
@inline(__always)
mutating func writer(_ string: String) {
var localString = string
localString.withUTF8 {
data.append($0.baseAddress.unsafelyUnwrapped, count: $0.count)
}
}
@inline(__always)
mutating func writer(ascii: UInt8) {
data.append(ascii)
}
@inline(__always)
mutating func writer(pointer: UnsafePointer<UInt8>, count: Int) {
data.append(pointer, count: count)
}
mutating func serializeString(_ str: String) throws {
writer("\"")
var mutStr = str
mutStr.withUTF8 {
var cursor = $0.baseAddress!
let end = $0.baseAddress! + $0.count
var mark = cursor
while cursor < end {
let escapeString: String
switch cursor.pointee {
case ._quote:
escapeString = "\\\""
break
case ._backslash:
escapeString = "\\\\"
break
case ._slash where !withoutEscapingSlashes:
escapeString = "\\/"
break
case 0x8:
escapeString = "\\b"
break
case 0xc:
escapeString = "\\f"
break
case ._newline:
escapeString = "\\n"
break
case ._return:
escapeString = "\\r"
break
case ._tab:
escapeString = "\\t"
break
case 0x0...0xf:
escapeString = "\\u000\(String(cursor.pointee, radix: 16))"
break
case 0x10...0x1f:
escapeString = "\\u00\(String(cursor.pointee, radix: 16))"
break
default:
// Accumulate this byte
cursor += 1
continue
}
// Append accumulated bytes
if cursor > mark {
writer(pointer: mark, count: cursor-mark)
}
writer(escapeString)
cursor += 1
mark = cursor // Start accumulating bytes starting after this escaped byte.
}
// Append accumulated bytes
if cursor > mark {
writer(pointer: mark, count: cursor-mark)
}
}
writer("\"")
}
mutating func serializeArray(_ array: [JSONReference], depth: Int) throws {
guard depth < Self.maximumRecursionDepth else {
throw JSONError.tooManyNestedArraysOrDictionaries()
}
writer("[")
if pretty {
writer("\n")
incIndent()
}
var first = true
for elem in array {
if first {
first = false
} else if pretty {
writer(",\n")
} else {
writer(",")
}
if pretty {
writeIndent()
}
try serializeJSON(elem, depth: depth)
}
if pretty {
writer("\n")
decAndWriteIndent()
}
writer("]")
}
mutating func serializePreformattedStringArray(_ array: [String], depth: Int) throws {
guard depth < Self.maximumRecursionDepth else {
throw JSONError.tooManyNestedArraysOrDictionaries()
}
writer("[")
if pretty {
writer("\n")
incIndent()
}
var first = true
for elem in array {
if first {
first = false
} else if pretty {
writer(",\n")
} else {
writer(",")
}
if pretty {
writeIndent()
}
// Do NOT call `serializeString` here! The input strings have already been formatted exactly as they need to be for direct JSON output, including any requisite quotes or escaped characters for strings.
writer(elem)
}
if pretty {
writer("\n")
decAndWriteIndent()
}
writer("]")
}
mutating func serializeObject(_ dict: [String:JSONReference], depth: Int) throws {
guard depth < Self.maximumRecursionDepth else {
throw JSONError.tooManyNestedArraysOrDictionaries()
}
writer("{")
if pretty {
writer("\n")
incIndent()
if dict.count > 0 {
writeIndent()
}
}
var first = true
func serializeObjectElement(key: String, value: JSONReference, depth: Int) throws {
if first {
first = false
} else if pretty {
writer(",\n")
writeIndent()
} else {
writer(",")
}
try serializeString(key)
pretty ? writer(" : ") : writer(":")
try serializeJSON(value, depth: depth)
}
#if FOUNDATION_FRAMEWORK && !NO_LOCALIZATION
if sortedKeys {
// TODO: Until we have a solution for sorting like Locale.system in FoundationEssentials or with the help of FoundationLocalization, this comparison requires bridging back to NSString. To avoid the extreme overhead of bridging the strings on every comparison, we'll do it up front instead.
// https://github.com/apple/swift-foundation/issues/284
let nsKeysAndValues = dict.map {
(key: $0.key as NSString, value: $0.value)
}
let elems = nsKeysAndValues.sorted(by: { a, b in
let options: String.CompareOptions = [.numeric, .caseInsensitive, .forcedOrdering]
let range = NSMakeRange(0, a.key.length)
let locale = Locale.system
return a.key.compare(b.key as String, options: options, range: range, locale: locale) == .orderedAscending
})
for elem in elems {
try serializeObjectElement(key: elem.key as String, value: elem.value, depth: depth)
}
} else {
for (key, value) in dict {
try serializeObjectElement(key: key, value: value, depth: depth)
}
}
#else
for (key, value) in dict {
try serializeObjectElement(key: key, value: value, depth: depth)
}
#endif // FOUNDATION_FRAMEWORK
if pretty {
writer("\n")
decAndWriteIndent()
}
writer("}")
}
mutating func serializeNull() {
writer("null")
}
mutating func incIndent() {
indent += 1
}
mutating func incAndWriteIndent() {
indent += 1
writeIndent()
}
mutating func decAndWriteIndent() {
indent -= 1
writeIndent()
}
mutating func writeIndent() {
switch indent {
case 0: break
case 1: writer(" ")
case 2: writer(" ")
case 3: writer(" ")
case 4: writer(" ")
case 5: writer(" ")
case 6: writer(" ")
case 7: writer(" ")
case 8: writer(" ")
case 9: writer(" ")
case 10: writer(" ")
default:
for _ in 0..<indent {
writer(" ")
}
}
}
}
// MARK: - WritingOptions
extension JSONWriter {
#if FOUNDATION_FRAMEWORK
typealias WritingOptions = JSONSerialization.WritingOptions
#else
struct WritingOptions : OptionSet, Sendable {
let rawValue: UInt
init(rawValue: UInt) {
self.rawValue = rawValue
}
/// Specifies that the output uses white space and indentation to make the resulting data more readable.
static let prettyPrinted = WritingOptions(rawValue: 1 << 0)
/// Specifies that the output sorts keys in lexicographic order.
static let sortedKeys = WritingOptions(rawValue: 1 << 1)
/// Specifies that the parser should allow top-level objects that arent arrays or dictionaries.
static let fragmentsAllowed = WritingOptions(rawValue: 1 << 2)
/// Specifies that the output doesnt prefix slash characters with escape characters.
static let withoutEscapingSlashes = WritingOptions(rawValue: 1 << 3)
}
#endif // FOUNDATION_FRAMEWORK
}