| | | 1 | | using System.Collections; |
| | | 2 | | using System.Diagnostics.CodeAnalysis; |
| | | 3 | | using System.Threading; |
| | | 4 | | |
| | | 5 | | namespace NGql.Core.Abstractions; |
| | | 6 | | |
| | | 7 | | /// <summary> |
| | | 8 | | /// Array-backed ordered collection of child <see cref="FieldDefinition"/> instances. |
| | | 9 | | /// Uses linear scan for small counts and a lazy dictionary index for larger counts. |
| | | 10 | | /// Null <see cref="FieldDefinition._children"/> on a leaf node costs nothing — no allocation occurs |
| | | 11 | | /// until the first child is added. |
| | | 12 | | /// |
| | | 13 | | /// THREAD-SAFETY: Reads on small (no-index) collections are lock-free — readers do volatile loads |
| | | 14 | | /// of <see cref="_count"/> and <see cref="_items"/> and walk a contiguous array. Reads against the |
| | | 15 | | /// index, and all writes, take <see cref="_lock"/>. Writers publish updates with explicit volatile |
| | | 16 | | /// stores: the new slot is written before <see cref="_count"/> bumps, so any reader observing the |
| | | 17 | | /// new count is also guaranteed to see the corresponding initialized slot. |
| | | 18 | | /// |
| | | 19 | | /// The index threshold is intentionally moderate: tiny collections do not need an index, and avoiding |
| | | 20 | | /// it on the read fast-path eliminates lock acquisition for the common case (most query nodes have |
| | | 21 | | /// fewer than a dozen direct children). |
| | | 22 | | /// </summary> |
| | | 23 | | internal sealed class FieldChildren : IReadOnlyDictionary<string, FieldDefinition> |
| | | 24 | | { |
| | | 25 | | private const int InitialCapacity = 4; |
| | | 26 | | private const int IndexThreshold = 16; |
| | | 27 | | |
| | 146457 | 28 | | internal FieldChildren() |
| | | 29 | | { |
| | 146457 | 30 | | } |
| | | 31 | | |
| | | 32 | | /// <summary> |
| | | 33 | | /// Creates the collection pre-sized for a known child count, avoiding the grow-and-copy |
| | | 34 | | /// cycles of the default 4-slot start. Used by clone paths where the count is known upfront. |
| | | 35 | | /// </summary> |
| | 3945 | 36 | | internal FieldChildren(int capacity) |
| | 3945 | 37 | | => _items = new FieldDefinition[Math.Max(capacity, InitialCapacity)]; |
| | | 38 | | |
| | | 39 | | /// <summary>Backing storage. Written only under <see cref="_lock"/>; readers do a single volatile load.</summary> |
| | | 40 | | private FieldDefinition[]? _items; |
| | | 41 | | /// <summary>Number of valid entries in <see cref="_items"/>. Volatile-stored last on writes |
| | | 42 | | /// (release semantics) so readers observing the new value also see the corresponding slot.</summary> |
| | | 43 | | private int _count; |
| | | 44 | | /// <summary>Lazy lookup index, built when <see cref="_count"/> reaches <see cref="IndexThreshold"/>. |
| | | 45 | | /// Maps name to its SLOT INDEX in <see cref="_items"/> (not the <see cref="FieldDefinition"/> itself), |
| | | 46 | | /// so a hit gives both the current value (via <c>_items[slot]</c>) and the position needed for an |
| | | 47 | | /// in-place replace. All access (including reads) is guarded by <see cref="_lock"/> because |
| | | 48 | | /// <see cref="Dictionary{TKey,TValue}"/> is not safe for concurrent read+write. |
| | | 49 | | /// <para> |
| | | 50 | | /// <b>"Last occurrence wins" is the intended invariant for <see cref="AppendLocked"/> and |
| | | 51 | | /// <see cref="BuildIndexLocked"/>, but <see cref="ReplaceReference"/>'s linear-scan fallback |
| | | 52 | | /// (reached only for the rare same-name/different-alias collision the index cannot fully |
| | | 53 | | /// disambiguate) can re-point a name's slot at an EARLIER same-named sibling's position via |
| | | 54 | | /// <see cref="UpdateIndexKeyLocked"/>, technically breaking that invariant for the remainder of |
| | | 55 | | /// that name's entries.</b> No observable misbehavior is currently known: every caller that |
| | | 56 | | /// legitimately needs to distinguish same-named/different-alias siblings |
| | | 57 | | /// (<c>NGql.Core.Extensions.Helpers.FindExistingField(FieldChildren, FieldDefinition)</c>, |
| | | 58 | | /// <c>NGql.Core.Extensions.FieldDefinitionExtensions.FindChildByNameAndAlias</c>) already falls back to an exhausti |
| | | 59 | | /// scan rather than trusting a bare name-index hit as authoritative. Documented here rather than |
| | | 60 | | /// changed because a fix would need to touch the same re-bucketing/index machinery under active, |
| | | 61 | | /// separate revision — flag before altering. |
| | | 62 | | /// </para></summary> |
| | | 63 | | private Dictionary<string, int>? _index; |
| | 150402 | 64 | | private readonly object _lock = new(); |
| | | 65 | | |
| | | 66 | | // ── Counts ──────────────────────────────────────────────────────────────── |
| | | 67 | | |
| | 15 | 68 | | int IReadOnlyCollection<KeyValuePair<string, FieldDefinition>>.Count => Volatile.Read(ref _count); |
| | 566937 | 69 | | internal int Count => Volatile.Read(ref _count); |
| | | 70 | | |
| | | 71 | | // ── Span access ─────────────────────────────────────────────────────────── |
| | | 72 | | |
| | | 73 | | /// <summary>Returns a span over the items for zero-alloc iteration. |
| | | 74 | | /// Reads count first, then items — combined with the writer's items-then-count publication this |
| | | 75 | | /// guarantees the observed array contains every slot below the observed count.</summary> |
| | | 76 | | internal ReadOnlySpan<FieldDefinition> AsSpan() |
| | | 77 | | { |
| | 314316 | 78 | | var count = Volatile.Read(ref _count); |
| | 314316 | 79 | | var items = Volatile.Read(ref _items); |
| | 314316 | 80 | | return items == null ? ReadOnlySpan<FieldDefinition>.Empty : items.AsSpan(0, count); |
| | | 81 | | } |
| | | 82 | | |
| | | 83 | | // ── Lookup ──────────────────────────────────────────────────────────────── |
| | | 84 | | |
| | | 85 | | /// <summary>Find a child by name (case-insensitive). Returns null if not found.</summary> |
| | | 86 | | internal FieldDefinition? Find(ReadOnlySpan<char> name) |
| | | 87 | | { |
| | | 88 | | // Fast path: no index yet. Lock-free volatile snapshot + linear scan. |
| | 167442 | 89 | | if (Volatile.Read(ref _index) == null) |
| | | 90 | | { |
| | 163571 | 91 | | var count = Volatile.Read(ref _count); |
| | 163571 | 92 | | var items = Volatile.Read(ref _items); |
| | 312082 | 93 | | if (items == null) return null; |
| | 58626 | 94 | | for (int i = 0; i < count; i++) |
| | | 95 | | { |
| | 20412 | 96 | | if (name.Equals(items[i].Name.AsSpan(), StringComparison.OrdinalIgnoreCase)) |
| | 6159 | 97 | | return items[i]; |
| | | 98 | | } |
| | 8901 | 99 | | return null; |
| | | 100 | | } |
| | | 101 | | |
| | | 102 | | // Slow path: indexed lookup needs the lock since Dictionary is not concurrent-read-safe. |
| | | 103 | | // _index is monotone: once published non-null by BuildIndexLocked it never reverts, so |
| | | 104 | | // re-checking under the lock would be a dead branch. |
| | 3871 | 105 | | lock (_lock) |
| | | 106 | | { |
| | 3871 | 107 | | return TryGetIndexSlot(name, out var slot) ? _items![slot] : null; |
| | | 108 | | } |
| | 3871 | 109 | | } |
| | | 110 | | |
| | | 111 | | /// <summary>Find a child by name (case-insensitive). String overload avoids span/string round-tripping.</summary> |
| | | 112 | | internal FieldDefinition? Find(string name) |
| | | 113 | | { |
| | 13620 | 114 | | if (Volatile.Read(ref _index) == null) |
| | | 115 | | { |
| | 13500 | 116 | | var count = Volatile.Read(ref _count); |
| | 13500 | 117 | | var items = Volatile.Read(ref _items); |
| | 14721 | 118 | | if (items == null) return null; |
| | 31422 | 119 | | for (int i = 0; i < count; i++) |
| | | 120 | | { |
| | 14994 | 121 | | if (string.Equals(items[i].Name, name, StringComparison.OrdinalIgnoreCase)) |
| | 11562 | 122 | | return items[i]; |
| | | 123 | | } |
| | 717 | 124 | | return null; |
| | | 125 | | } |
| | | 126 | | |
| | 120 | 127 | | lock (_lock) |
| | | 128 | | { |
| | 120 | 129 | | return _index!.TryGetValue(name, out var slot) ? _items![slot] : null; |
| | | 130 | | } |
| | 120 | 131 | | } |
| | | 132 | | |
| | | 133 | | internal bool TryGetValue(ReadOnlySpan<char> name, [MaybeNullWhen(false)] out FieldDefinition value) |
| | | 134 | | { |
| | 155385 | 135 | | value = Find(name)!; |
| | 155385 | 136 | | return value != null; |
| | | 137 | | } |
| | | 138 | | |
| | | 139 | | internal bool TryGetValue(string name, [MaybeNullWhen(false)] out FieldDefinition value) |
| | | 140 | | { |
| | 2382 | 141 | | value = Find(name)!; |
| | 2382 | 142 | | return value != null; |
| | | 143 | | } |
| | | 144 | | |
| | | 145 | | bool IReadOnlyDictionary<string, FieldDefinition>.TryGetValue(string key, [MaybeNullWhen(false)] out FieldDefinition |
| | 366 | 146 | | => TryGetValue(key, out value); |
| | | 147 | | |
| | | 148 | | bool IReadOnlyDictionary<string, FieldDefinition>.ContainsKey(string key) |
| | 606 | 149 | | => Find(key) != null; |
| | | 150 | | |
| | | 151 | | FieldDefinition IReadOnlyDictionary<string, FieldDefinition>.this[string key] |
| | | 152 | | { |
| | | 153 | | get |
| | | 154 | | { |
| | 1863 | 155 | | var found = Find(key); |
| | 1863 | 156 | | return found ?? throw new KeyNotFoundException($"Key '{key}' not found."); |
| | | 157 | | } |
| | | 158 | | } |
| | | 159 | | |
| | | 160 | | // ── Mutation ────────────────────────────────────────────────────────────── |
| | | 161 | | |
| | | 162 | | /// <summary> |
| | | 163 | | /// Appends a new child. The caller must ensure the name does not already exist |
| | | 164 | | /// (use <see cref="Set(string,FieldDefinition)"/> when an update may be needed). |
| | | 165 | | /// </summary> |
| | | 166 | | internal void Append(FieldDefinition child) |
| | | 167 | | { |
| | 174351 | 168 | | lock (_lock) |
| | | 169 | | { |
| | 174351 | 170 | | AppendLocked(child); |
| | 174351 | 171 | | } |
| | 174351 | 172 | | } |
| | | 173 | | |
| | | 174 | | /// <summary>Adds or replaces a child by name (case-insensitive).</summary> |
| | | 175 | | internal void Set(string name, FieldDefinition child) |
| | | 176 | | { |
| | 11592 | 177 | | lock (_lock) |
| | | 178 | | { |
| | 11592 | 179 | | var items = _items; |
| | 11592 | 180 | | if (items != null) |
| | | 181 | | { |
| | 8952 | 182 | | if (_index != null) |
| | | 183 | | { |
| | 7515 | 184 | | if (_index.TryGetValue(name, out var slot)) |
| | | 185 | | { |
| | 39 | 186 | | items[slot] = child; |
| | 39 | 187 | | UpdateIndexKeyLocked(name, child.Name, slot); |
| | 39 | 188 | | return; |
| | | 189 | | } |
| | | 190 | | } |
| | | 191 | | else |
| | | 192 | | { |
| | 5472 | 193 | | for (int i = 0; i < _count; i++) |
| | | 194 | | { |
| | 1572 | 195 | | if (string.Equals(items[i].Name, name, StringComparison.OrdinalIgnoreCase)) |
| | | 196 | | { |
| | 273 | 197 | | items[i] = child; |
| | 273 | 198 | | return; |
| | | 199 | | } |
| | | 200 | | } |
| | | 201 | | } |
| | | 202 | | } |
| | 11280 | 203 | | AppendLocked(child); |
| | 11280 | 204 | | } |
| | 11592 | 205 | | } |
| | | 206 | | |
| | | 207 | | /// <summary> |
| | | 208 | | /// Replaces an existing child by span name (case-insensitive). The only call site — |
| | | 209 | | /// <c>FieldFactory.ProcessDottedSegment</c> — invokes this strictly after a successful |
| | | 210 | | /// <see cref="TryGetValue(ReadOnlySpan{char},out FieldDefinition)"/>, so the entry is |
| | | 211 | | /// guaranteed to exist; below the index threshold the loop simply walks to the position of |
| | | 212 | | /// the known match, and once indexed the index resolves that position directly. |
| | | 213 | | /// </summary> |
| | | 214 | | internal void Set(ReadOnlySpan<char> name, FieldDefinition child) |
| | | 215 | | { |
| | 405 | 216 | | lock (_lock) |
| | | 217 | | { |
| | 405 | 218 | | var items = _items!; |
| | 405 | 219 | | if (_index != null) |
| | | 220 | | { |
| | | 221 | | // Documented precondition (see method summary): name is guaranteed to already be a |
| | | 222 | | // key, so the slot lookup itself never allocates a fallback string. |
| | 9 | 223 | | TryGetIndexSlot(name, out var slot); |
| | 9 | 224 | | items[slot] = child; |
| | 9 | 225 | | UpdateIndexKeyLocked(name, child.Name, slot); |
| | 9 | 226 | | return; |
| | | 227 | | } |
| | | 228 | | |
| | 396 | 229 | | int i = 0; |
| | 996 | 230 | | while (!name.Equals(items[i].Name.AsSpan(), StringComparison.OrdinalIgnoreCase)) i++; |
| | 396 | 231 | | items[i] = child; |
| | 396 | 232 | | } |
| | 405 | 233 | | } |
| | | 234 | | |
| | | 235 | | /// <summary> |
| | | 236 | | /// Probes <see cref="_index"/> by span without allocating a lookup string on .NET 9+ (via |
| | | 237 | | /// <c>Dictionary<TKey,TValue>.GetAlternateLookup<ReadOnlySpan<char>>()</c>, |
| | | 238 | | /// which <see cref="StringComparer.OrdinalIgnoreCase"/> supports as an |
| | | 239 | | /// <c>IAlternateEqualityComparer<ReadOnlySpan<char>, string></c>); falls back to |
| | | 240 | | /// <see cref="ReadOnlySpan{T}.ToString"/> on net8.0, where the alternate-lookup API does not |
| | | 241 | | /// exist. Must be called under <see cref="_lock"/> with <see cref="_index"/> known non-null. |
| | | 242 | | /// The lookup struct itself is a zero-allocation view over the live dictionary — obtained |
| | | 243 | | /// fresh on every call rather than cached, so it can never be used against a stale/rebuilt |
| | | 244 | | /// <see cref="_index"/> instance. |
| | | 245 | | /// </summary> |
| | | 246 | | private bool TryGetIndexSlot(ReadOnlySpan<char> name, out int slot) |
| | | 247 | | { |
| | | 248 | | #if NET9_0_OR_GREATER |
| | 920 | 249 | | return _index!.GetAlternateLookup<ReadOnlySpan<char>>().TryGetValue(name, out slot); |
| | | 250 | | #else |
| | 2960 | 251 | | return _index!.TryGetValue(name.ToString(), out slot); |
| | | 252 | | #endif |
| | | 253 | | } |
| | | 254 | | |
| | | 255 | | /// <summary> |
| | | 256 | | /// Removes a key from <see cref="_index"/> by span, same allocation trade-off as |
| | | 257 | | /// <see cref="TryGetIndexSlot"/>. Must be called under <see cref="_lock"/> with |
| | | 258 | | /// <see cref="_index"/> known non-null. |
| | | 259 | | /// </summary> |
| | | 260 | | private void RemoveIndexKey(ReadOnlySpan<char> name) |
| | | 261 | | { |
| | | 262 | | #if NET9_0_OR_GREATER |
| | 22 | 263 | | _index!.GetAlternateLookup<ReadOnlySpan<char>>().Remove(name); |
| | | 264 | | #else |
| | 11 | 265 | | _index!.Remove(name.ToString()); |
| | | 266 | | #endif |
| | 33 | 267 | | } |
| | | 268 | | |
| | | 269 | | /// <summary> |
| | | 270 | | /// After an in-place replace, keeps <see cref="_index"/> consistent when the replacement's |
| | | 271 | | /// name differs from the looked-up key (e.g. alias/name changes on the field object) — removes |
| | | 272 | | /// the stale key and (re)inserts the new one pointing at the same slot. Must be called under |
| | | 273 | | /// <see cref="_lock"/> with <see cref="_index"/> known non-null. |
| | | 274 | | /// </summary> |
| | | 275 | | private void UpdateIndexKeyLocked(ReadOnlySpan<char> oldKey, string newKey, int slot) |
| | | 276 | | { |
| | 57 | 277 | | if (!oldKey.Equals(newKey.AsSpan(), StringComparison.OrdinalIgnoreCase)) |
| | | 278 | | { |
| | 33 | 279 | | RemoveIndexKey(oldKey); |
| | | 280 | | } |
| | 57 | 281 | | _index![newKey] = slot; |
| | 57 | 282 | | } |
| | | 283 | | |
| | | 284 | | /// <summary> |
| | | 285 | | /// Replaces <paramref name="oldChild"/> with <paramref name="newChild"/> in the exact slot |
| | | 286 | | /// <paramref name="oldChild"/> occupies, identified by REFERENCE — never by name. Name-keyed |
| | | 287 | | /// lookup/replace cannot disambiguate two children that legitimately share a |
| | | 288 | | /// <see cref="FieldDefinition.Name"/> but differ by alias (distinct GraphQL response keys); a |
| | | 289 | | /// caller that already holds the exact matched instance (e.g. after an alias-aware scan) uses |
| | | 290 | | /// this to guarantee the replace lands on that instance's own slot, preserving both its |
| | | 291 | | /// position (render order) and every OTHER same-named sibling untouched. |
| | | 292 | | /// </summary> |
| | | 293 | | /// <remarks> |
| | | 294 | | /// Common case is O(1): <see cref="_index"/> is keyed by <see cref="FieldDefinition.Name"/>, and |
| | | 295 | | /// its remembered slot for <paramref name="oldChild"/>'s name almost always already holds |
| | | 296 | | /// <paramref name="oldChild"/> itself, since a caller only reaches here after a same-name hit. |
| | | 297 | | /// Only when that slot no longer holds <paramref name="oldChild"/> (a genuine same-name/ |
| | | 298 | | /// different-alias collision, where the index can remember only one of the colliding slots) does |
| | | 299 | | /// this fall back to a linear scan by reference — exactly the same rare case that already forces |
| | | 300 | | /// a linear scan in <see cref="NGql.Core.Extensions.Helpers.FindExistingField(FieldChildren, FieldDefinition)"/>'s |
| | | 301 | | /// slow path. |
| | | 302 | | /// </remarks> |
| | | 303 | | internal void ReplaceReference(FieldDefinition oldChild, FieldDefinition newChild) |
| | | 304 | | { |
| | 495 | 305 | | lock (_lock) |
| | | 306 | | { |
| | 495 | 307 | | var items = _items!; |
| | | 308 | | |
| | 495 | 309 | | if (_index != null && _index.TryGetValue(oldChild.Name, out var hintSlot) |
| | 495 | 310 | | && ReferenceEquals(items[hintSlot], oldChild)) |
| | | 311 | | { |
| | 6 | 312 | | items[hintSlot] = newChild; |
| | 6 | 313 | | UpdateIndexKeyLocked(oldChild.Name.AsSpan(), newChild.Name, hintSlot); |
| | 6 | 314 | | return; |
| | | 315 | | } |
| | | 316 | | |
| | 1506 | 317 | | for (int i = 0; i < _count; i++) |
| | | 318 | | { |
| | 750 | 319 | | if (ReferenceEquals(items[i], oldChild)) |
| | | 320 | | { |
| | 486 | 321 | | items[i] = newChild; |
| | 486 | 322 | | if (_index != null) |
| | | 323 | | { |
| | 3 | 324 | | UpdateIndexKeyLocked(oldChild.Name.AsSpan(), newChild.Name, i); |
| | | 325 | | } |
| | 486 | 326 | | return; |
| | | 327 | | } |
| | | 328 | | } |
| | 3 | 329 | | } |
| | 495 | 330 | | } |
| | | 331 | | |
| | | 332 | | /// <summary> |
| | | 333 | | /// Supports collection initializer syntax: <c>new FieldChildren { new FieldDefinition("x") }</c>. |
| | | 334 | | /// Delegates to <see cref="Append"/>. |
| | | 335 | | /// </summary> |
| | 51 | 336 | | internal void Add(FieldDefinition child) => Append(child); |
| | | 337 | | |
| | | 338 | | // ── Private helpers ─────────────────────────────────────────────────────── |
| | | 339 | | |
| | | 340 | | /// <summary> |
| | | 341 | | /// Append logic used within locked sections. Publishes the new slot before bumping |
| | | 342 | | /// <see cref="_count"/> so concurrent readers always see fully-initialized data. |
| | | 343 | | /// </summary> |
| | | 344 | | private void AppendLocked(FieldDefinition child) |
| | | 345 | | { |
| | 185631 | 346 | | var items = _items; |
| | 185631 | 347 | | if (items == null) |
| | | 348 | | { |
| | 146382 | 349 | | items = new FieldDefinition[InitialCapacity]; |
| | 146382 | 350 | | Volatile.Write(ref _items, items); |
| | | 351 | | } |
| | 39249 | 352 | | else if (_count == items.Length) |
| | | 353 | | { |
| | | 354 | | // Grow: allocate a new array, copy, then publish. Concurrent readers either see the old |
| | | 355 | | // array (with their bounded count) or the new array — both are coherent snapshots. |
| | 420 | 356 | | var grown = new FieldDefinition[items.Length * 2]; |
| | 420 | 357 | | Array.Copy(items, grown, _count); |
| | 420 | 358 | | items = grown; |
| | 420 | 359 | | Volatile.Write(ref _items, items); |
| | | 360 | | } |
| | | 361 | | |
| | 185631 | 362 | | var newSlot = _count; |
| | 185631 | 363 | | items[newSlot] = child; |
| | | 364 | | // Release-store the new count last so any reader that observes it also sees the slot above. |
| | 185631 | 365 | | Volatile.Write(ref _count, newSlot + 1); |
| | | 366 | | |
| | 185631 | 367 | | if (_index != null) |
| | | 368 | | { |
| | 23112 | 369 | | _index[child.Name] = newSlot; |
| | | 370 | | } |
| | 162519 | 371 | | else if (_count >= IndexThreshold) |
| | | 372 | | { |
| | 99 | 373 | | BuildIndexLocked(); |
| | | 374 | | } |
| | 162519 | 375 | | } |
| | | 376 | | |
| | | 377 | | private void BuildIndexLocked() |
| | | 378 | | { |
| | 99 | 379 | | var built = new Dictionary<string, int>(_count, StringComparer.OrdinalIgnoreCase); |
| | 3366 | 380 | | for (int i = 0; i < _count; i++) |
| | 1584 | 381 | | built[_items![i].Name] = i; |
| | | 382 | | // Publish the index pointer last so readers that observe non-null _index see a fully populated dict. |
| | 99 | 383 | | Volatile.Write(ref _index, built); |
| | 99 | 384 | | } |
| | | 385 | | |
| | | 386 | | // ── IReadOnlyDictionary (Keys / Values / Enumerator) ───────────────────── |
| | | 387 | | |
| | | 388 | | IEnumerable<string> IReadOnlyDictionary<string, FieldDefinition>.Keys |
| | | 389 | | { |
| | | 390 | | get |
| | | 391 | | { |
| | 33 | 392 | | var count = Volatile.Read(ref _count); |
| | 33 | 393 | | var items = Volatile.Read(ref _items); |
| | 36 | 394 | | if (items == null) return []; |
| | 30 | 395 | | var keys = new List<string>(count); |
| | 186 | 396 | | for (int i = 0; i < count; i++) |
| | 63 | 397 | | keys.Add(items[i].Name); |
| | 30 | 398 | | return keys; |
| | | 399 | | } |
| | | 400 | | } |
| | | 401 | | |
| | | 402 | | IEnumerable<FieldDefinition> IReadOnlyDictionary<string, FieldDefinition>.Values |
| | | 403 | | { |
| | | 404 | | get |
| | | 405 | | { |
| | 6 | 406 | | var count = Volatile.Read(ref _count); |
| | 6 | 407 | | var items = Volatile.Read(ref _items); |
| | 9 | 408 | | if (items == null) return []; |
| | 3 | 409 | | var values = new List<FieldDefinition>(count); |
| | 18 | 410 | | for (int i = 0; i < count; i++) |
| | 6 | 411 | | values.Add(items[i]); |
| | 3 | 412 | | return values; |
| | | 413 | | } |
| | | 414 | | } |
| | | 415 | | |
| | | 416 | | /// <summary> |
| | | 417 | | /// Returns a zero-alloc struct enumerator over a snapshot of this collection. |
| | | 418 | | /// </summary> |
| | | 419 | | public FieldChildrenEnumerator GetEnumerator() |
| | | 420 | | { |
| | 1068 | 421 | | var count = Volatile.Read(ref _count); |
| | 1068 | 422 | | var items = Volatile.Read(ref _items); |
| | 1068 | 423 | | return new FieldChildrenEnumerator(items, count); |
| | | 424 | | } |
| | | 425 | | |
| | | 426 | | // Explicit interface implementation — provides fallback for code that uses IEnumerable<T> directly |
| | | 427 | | IEnumerator<KeyValuePair<string, FieldDefinition>> IEnumerable<KeyValuePair<string, FieldDefinition>>.GetEnumerator( |
| | 1041 | 428 | | => GetEnumerator(); |
| | | 429 | | |
| | | 430 | | IEnumerator IEnumerable.GetEnumerator() |
| | 9 | 431 | | => GetEnumerator(); |
| | | 432 | | } |
| | | 433 | | |
| | | 434 | | /// <summary> |
| | | 435 | | /// Zero-allocation struct enumerator for <see cref="FieldChildren"/>. |
| | | 436 | | /// Operates on a snapshot taken at construction time, so concurrent appends do not |
| | | 437 | | /// affect an in-flight enumeration. |
| | | 438 | | /// </summary> |
| | | 439 | | internal struct FieldChildrenEnumerator : IEnumerator<KeyValuePair<string, FieldDefinition>> |
| | | 440 | | { |
| | | 441 | | private readonly FieldDefinition[]? _snapshot; |
| | | 442 | | private readonly int _count; |
| | | 443 | | private int _index; |
| | | 444 | | |
| | | 445 | | internal FieldChildrenEnumerator(FieldDefinition[]? snapshot, int count) |
| | | 446 | | { |
| | | 447 | | _snapshot = snapshot; |
| | | 448 | | _count = count; |
| | | 449 | | _index = -1; |
| | | 450 | | } |
| | | 451 | | |
| | | 452 | | public KeyValuePair<string, FieldDefinition> Current |
| | | 453 | | { |
| | | 454 | | get |
| | | 455 | | { |
| | | 456 | | if (_snapshot == null || _index < 0 || _index >= _count) |
| | | 457 | | throw new InvalidOperationException("Enumeration has not started or has ended."); |
| | | 458 | | var item = _snapshot[_index]; |
| | | 459 | | return new KeyValuePair<string, FieldDefinition>(item.Name, item); |
| | | 460 | | } |
| | | 461 | | } |
| | | 462 | | |
| | | 463 | | object System.Collections.IEnumerator.Current => Current; |
| | | 464 | | |
| | | 465 | | public bool MoveNext() |
| | | 466 | | { |
| | | 467 | | if (_snapshot == null) return false; |
| | | 468 | | _index++; |
| | | 469 | | return _index < _count; |
| | | 470 | | } |
| | | 471 | | |
| | | 472 | | public void Reset() => _index = -1; |
| | | 473 | | |
| | | 474 | | public void Dispose() { } |
| | | 475 | | } |