| | | 1 | | using AsyncResponse; |
| | | 2 | | using AsyncResponse.DurableFlows.Internal; |
| | | 3 | | using AsyncResponse.DurableFlows.Cosmos; |
| | | 4 | | using Microsoft.Azure.Cosmos; |
| | | 5 | | using Microsoft.Extensions.DependencyInjection.Extensions; |
| | | 6 | | using Microsoft.Extensions.Options; |
| | | 7 | | using Newtonsoft.Json; |
| | | 8 | | using System.Buffers; |
| | | 9 | | using System.Net; |
| | | 10 | | using System.Text; |
| | | 11 | | |
| | | 12 | | namespace Microsoft.Extensions.DependencyInjection |
| | | 13 | | { |
| | | 14 | | /// <summary>DI registration for the Azure Cosmos DB durable-flow state store.</summary> |
| | | 15 | | public static class CosmosDurableFlowServiceCollectionExtensions |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Stores durable-flow state in Azure Cosmos DB. Hosts may either register a |
| | | 19 | | /// <see cref="CosmosClient"/> singleton or set connection options here. |
| | | 20 | | /// </summary> |
| | | 21 | | public static AsyncResponseRegistrationBuilder WithCosmosDurableFlows( |
| | | 22 | | this AsyncResponseRegistrationBuilder builder, |
| | | 23 | | Action<CosmosDurableFlowOptions>? configure = null) |
| | | 24 | | { |
| | | 25 | | // Singleton on purpose: database/container provisioning is cached per store instance |
| | | 26 | | // and Cosmos metadata operations are RU-charged and rate-limited — a scoped store would |
| | | 27 | | // re-issue them on every flow execution. A host-registered CosmosClient is reused when |
| | | 28 | | // present; otherwise the store creates and owns one from ConnectionString. Nothing is |
| | | 29 | | // registered as a bare CosmosClient service, so unrelated resolutions of that type are |
| | | 30 | | // never answered — or broken — by this package. |
| | 204 | 31 | | builder.Services.TryAddSingleton(provider => |
| | 204 | 32 | | { |
| | 204 | 33 | | var options = provider.GetRequiredService<IOptions<CosmosDurableFlowOptions>>(); |
| | 204 | 34 | | |
| | 204 | 35 | | var shared = provider.GetService<CosmosClient>(); |
| | 204 | 36 | | if (shared is not null) |
| | 200 | 37 | | return new CosmosFlowStateStore(shared, options); |
| | 204 | 38 | | |
| | 4 | 39 | | if (string.IsNullOrWhiteSpace(options.Value.ConnectionString)) |
| | 2 | 40 | | throw new InvalidOperationException($"{nameof(CosmosDurableFlowOptions)}.{nameof(CosmosDurableFlowOp |
| | 2 | 41 | | return new CosmosFlowStateStore(new CosmosClient(options.Value.ConnectionString), options, ownsClient: t |
| | 204 | 42 | | }); |
| | 204 | 43 | | return builder.WithDurableFlows<CosmosFlowStateStore, CosmosDurableFlowOptions>(configure); |
| | | 44 | | } |
| | | 45 | | } |
| | | 46 | | } |
| | | 47 | | |
| | | 48 | | namespace AsyncResponse.DurableFlows.Cosmos |
| | | 49 | | { |
| | | 50 | | /// <summary>Options for the Azure Cosmos DB durable-flow state store.</summary> |
| | | 51 | | public sealed class CosmosDurableFlowOptions : DurableFlowOptions |
| | | 52 | | { |
| | | 53 | | /// <summary>Optional Cosmos DB connection string used when no <see cref="CosmosClient"/> is registered.</summary> |
| | | 54 | | public string? ConnectionString { get; set; } |
| | | 55 | | |
| | | 56 | | /// <summary>Cosmos database name. Required.</summary> |
| | | 57 | | public string? DatabaseName { get; set; } |
| | | 58 | | |
| | | 59 | | /// <summary>Container storing one durable-flow ledger document per flow id.</summary> |
| | | 60 | | public string ContainerName { get; set; } = "asyncresponse_flow_state"; |
| | | 61 | | |
| | | 62 | | /// <summary>Partition-key path for the container. Default: <c>/flowId</c>.</summary> |
| | | 63 | | public string PartitionKeyPath { get; set; } = "/flowId"; |
| | | 64 | | |
| | | 65 | | /// <summary>Creates the database and container on first use.</summary> |
| | | 66 | | public bool AutoCreateContainer { get; set; } = true; |
| | | 67 | | |
| | | 68 | | /// <summary>Optional throughput used when auto-creating the container.</summary> |
| | | 69 | | public int? Throughput { get; set; } |
| | | 70 | | |
| | | 71 | | /// <summary> |
| | | 72 | | /// Maximum size in bytes of the COMPLETE ledger document accepted by writes — the item as it |
| | | 73 | | /// is serialized for Cosmos, with the ledger JSON embedded (and therefore escaped a second |
| | | 74 | | /// time) as its <c>stateJson</c> string and the sibling fields beside it. Cosmos caps the item |
| | | 75 | | /// as a whole at 2 MB, not the ledger inside it: a ledger whose own JSON is well under the |
| | | 76 | | /// budget can escape into a document over it, so the budget is enforced on what is actually |
| | | 77 | | /// sent. Oversized ledgers fail fast with an actionable error instead of the raw Cosmos 413 |
| | | 78 | | /// the executor would retry into the dead-letter queue. Default: 1.9 MB (headroom under the |
| | | 79 | | /// item cap); <c>null</c> disables the guard. |
| | | 80 | | /// </summary> |
| | | 81 | | public long? MaxStateBytes { get; set; } = 1_900_000; |
| | | 82 | | |
| | | 83 | | /// <summary>Validates option values and throws on misconfiguration.</summary> |
| | | 84 | | public void Validate() |
| | | 85 | | { |
| | | 86 | | if (string.IsNullOrWhiteSpace(DatabaseName)) |
| | | 87 | | throw new InvalidOperationException($"{nameof(CosmosDurableFlowOptions)}.{nameof(DatabaseName)} must be conf |
| | | 88 | | if (string.IsNullOrWhiteSpace(ContainerName)) |
| | | 89 | | throw new InvalidOperationException($"{nameof(CosmosDurableFlowOptions)}.{nameof(ContainerName)} must be con |
| | | 90 | | if (string.IsNullOrWhiteSpace(PartitionKeyPath) || !PartitionKeyPath.StartsWith("/", StringComparison.Ordinal)) |
| | | 91 | | throw new InvalidOperationException($"{nameof(CosmosDurableFlowOptions)}.{nameof(PartitionKeyPath)} must sta |
| | | 92 | | // Every store operation addresses documents with new PartitionKey(flowId), and the ledger |
| | | 93 | | // document only carries the flow id under 'id' and 'flowId' — any other partition-key path |
| | | 94 | | // would make every write fail with a Cosmos partition-key-mismatch error at runtime, so |
| | | 95 | | // reject it up front instead of letting validation pass on a doomed configuration. |
| | | 96 | | if (!string.Equals(PartitionKeyPath, "/flowId", StringComparison.Ordinal) |
| | | 97 | | && !string.Equals(PartitionKeyPath, "/id", StringComparison.Ordinal)) |
| | | 98 | | { |
| | | 99 | | throw new InvalidOperationException( |
| | | 100 | | $"{nameof(CosmosDurableFlowOptions)}.{nameof(PartitionKeyPath)} must be '/flowId' or '/id': the store " |
| | | 101 | | "partitions every operation by the flow id, and the ledger document carries no other property to " + |
| | | 102 | | $"satisfy a container partitioned on '{PartitionKeyPath}'."); |
| | | 103 | | } |
| | | 104 | | if (Throughput is <= 0) |
| | | 105 | | throw new InvalidOperationException($"{nameof(CosmosDurableFlowOptions)}.{nameof(Throughput)} must be positi |
| | | 106 | | DurableFlowStoreShared.ValidateMaxStateBytes(MaxStateBytes, nameof(CosmosDurableFlowOptions)); |
| | | 107 | | } |
| | | 108 | | } |
| | | 109 | | |
| | | 110 | | /// <summary>Azure Cosmos DB implementation of <see cref="IFlowStateStore"/>.</summary> |
| | | 111 | | public sealed class CosmosFlowStateStore : IFlowStateStore, IDisposable |
| | | 112 | | { |
| | | 113 | | // Time authority: this store keeps the app clock (DateTime.UtcNow) for expiry and lease |
| | | 114 | | // comparisons. Cosmos conditional writes (ETag preconditions) evaluate client-supplied |
| | | 115 | | // values only — there is no server-clock expression usable inside a point write — so the |
| | | 116 | | // read-check-replace cycles below compare against the app clock and rely on the ETag fence |
| | | 117 | | // for atomicity. Multi-node deployments should keep worker clocks synchronized well inside |
| | | 118 | | // the lease window. (The server's own TTL sweep, by contrast, runs on the service clock.) |
| | | 119 | | private readonly CosmosClient _client; |
| | | 120 | | private readonly CosmosDurableFlowOptions _options; |
| | | 121 | | private readonly SemaphoreSlim _ensureGate = new(1, 1); |
| | | 122 | | private readonly bool _ownsClient; |
| | | 123 | | private volatile bool _created; |
| | | 124 | | |
| | | 125 | | public CosmosFlowStateStore(CosmosClient client, IOptions<CosmosDurableFlowOptions> options, bool ownsClient = false |
| | | 126 | | { |
| | | 127 | | _client = client; |
| | | 128 | | _options = options.Value; |
| | | 129 | | _options.Validate(); |
| | | 130 | | _ownsClient = ownsClient; |
| | | 131 | | } |
| | | 132 | | |
| | | 133 | | public async Task<FlowState?> LoadAsync(string flowId, CancellationToken cancellationToken = default) |
| | | 134 | | { |
| | | 135 | | ArgumentException.ThrowIfNullOrWhiteSpace(flowId); |
| | | 136 | | var container = await GetContainerAsync(cancellationToken).ConfigureAwait(false); |
| | | 137 | | |
| | | 138 | | // Point reads have no predicate, so the expiry check happens client-side on the app |
| | | 139 | | // clock — see the time-authority note on this class. |
| | | 140 | | var document = await ReadDocumentAsync(container, flowId, cancellationToken).ConfigureAwait(false); |
| | | 141 | | if (document is null || document.ExpiresAtUtc <= DateTime.UtcNow) |
| | | 142 | | { |
| | | 143 | | // Callers acknowledge the wake-up on null, so "absent" must not come from a read |
| | | 144 | | // alone. Session consistency is read-your-writes for the client that WROTE: a |
| | | 145 | | // different process never received the writer's session token, so its read may be |
| | | 146 | | // served by a replica that has not applied the create yet (a plain 404, sub-status 0 |
| | | 147 | | // — 1002 only answers a token the replica cannot satisfy) or by one still holding an |
| | | 148 | | // older version whose expiry has since been extended. Inside that replication lag a |
| | | 149 | | // live run's only wake-up was acknowledged as "no state". The write path answers |
| | | 150 | | // authoritatively, and its 412 brings this client's session token up to the write |
| | | 151 | | // region's, so the re-read below is current. |
| | | 152 | | for (var attempt = 0; ; attempt++) |
| | | 153 | | { |
| | | 154 | | if (!await ExistsOnWritePathAsync(container, flowId, cancellationToken).ConfigureAwait(false)) |
| | | 155 | | return null; |
| | | 156 | | |
| | | 157 | | document = await ReadDocumentAsync(container, flowId, cancellationToken).ConfigureAwait(false); |
| | | 158 | | if (document is not null) |
| | | 159 | | break; |
| | | 160 | | |
| | | 161 | | // Present for writes and absent for reads, repeatedly: a delete can win that race |
| | | 162 | | // once, not every time. This client's reads are not session-consistent with its |
| | | 163 | | // writes (an Eventual or Consistent Prefix account or client), so nothing it |
| | | 164 | | // reads can prove the run is gone. |
| | | 165 | | if (attempt == MaxAbsenceConfirmations - 1) |
| | | 166 | | { |
| | | 167 | | throw new FlowStateUnreadableException( |
| | | 168 | | flowId, |
| | | 169 | | "the container's write path reports its document present while reads keep answering 404; the " + |
| | | 170 | | "CosmosClient's reads are not session-consistent with its writes (the store needs Session consis |
| | | 171 | | } |
| | | 172 | | } |
| | | 173 | | |
| | | 174 | | if (document.ExpiresAtUtc <= DateTime.UtcNow) |
| | | 175 | | return null; |
| | | 176 | | } |
| | | 177 | | |
| | | 178 | | // The document exists, so a missing required field is an unreadable ledger, not an |
| | | 179 | | // absent one. Reporting it as absent let the executor ack the only wake-up of a run that |
| | | 180 | | // is still sitting in the container. |
| | | 181 | | if (document.Revision is not { } revision) |
| | | 182 | | throw new FlowStateUnreadableException(flowId, "its stored document has no revision"); |
| | | 183 | | |
| | | 184 | | if (string.IsNullOrEmpty(document.StateJson)) |
| | | 185 | | throw new FlowStateUnreadableException(flowId, "its stored document has no state JSON"); |
| | | 186 | | |
| | | 187 | | return DurableFlowStoreShared.ReadState(flowId, document.StateJson, revision); |
| | | 188 | | } |
| | | 189 | | |
| | | 190 | | private static async Task<CosmosFlowStateDocument?> ReadDocumentAsync(Container container, string flowId, Cancellati |
| | | 191 | | { |
| | | 192 | | try |
| | | 193 | | { |
| | | 194 | | var response = await container.ReadItemAsync<CosmosFlowStateDocument>( |
| | | 195 | | flowId, |
| | | 196 | | new PartitionKey(flowId), |
| | | 197 | | cancellationToken: cancellationToken).ConfigureAwait(false); |
| | | 198 | | return response.Resource; |
| | | 199 | | } |
| | | 200 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.NotFound && ex.SubStatusCode == 0) |
| | | 201 | | { |
| | | 202 | | // Sub-status 0 is the only 404 that CAN mean "no such item". Cosmos also answers 404 |
| | | 203 | | // for conditions where the ledger still exists — 1002 ReadSessionNotAvailable (the |
| | | 204 | | // replicas in reach are behind the session token this client already holds, surfaced |
| | | 205 | | // once the SDK's session retries exhaust) and 1003/1004 (container/database |
| | | 206 | | // recreated). Mapping those to null silently dropped a live run's only wake-up; |
| | | 207 | | // letting them throw routes the delivery through retry/dead-letter instead. Sub-status |
| | | 208 | | // 0 is still only what one replica says, which is why LoadAsync confirms it on the |
| | | 209 | | // write path. (DynamoDB pins this contract point with ConsistentRead and MongoDB with |
| | | 210 | | // primary reads; Cosmos cannot strengthen a read per request.) |
| | | 211 | | return null; |
| | | 212 | | } |
| | | 213 | | } |
| | | 214 | | |
| | | 215 | | /// <inheritdoc /> |
| | | 216 | | public void ValidateCreate(string flowId, FlowState state, TimeSpan ttl) |
| | | 217 | | { |
| | | 218 | | DurableFlowStoreShared.ValidateCreate(flowId, state, ttl); |
| | | 219 | | var stateJson = DurableFlowStoreShared.SerializeBounded(flowId, state, _options.MaxStateBytes, "Cosmos DB"); |
| | | 220 | | ThrowIfDocumentTooLarge(flowId, CreateDocument(flowId, stateJson, state.Revision, ttl, DateTime.UtcNow)); |
| | | 221 | | } |
| | | 222 | | |
| | | 223 | | public async Task<bool> TryCreateAsync(string flowId, FlowState state, TimeSpan ttl, CancellationToken cancellationT |
| | | 224 | | { |
| | | 225 | | DurableFlowStoreShared.ValidateCreate(flowId, state, ttl); |
| | | 226 | | var stateJson = DurableFlowStoreShared.SerializeBounded(flowId, state, _options.MaxStateBytes, "Cosmos DB"); |
| | | 227 | | var container = await GetContainerAsync(cancellationToken).ConfigureAwait(false); |
| | | 228 | | |
| | | 229 | | // Bounded retry: documents carry native Cosmos TTL alongside the logical ExpiresAtUtc, so |
| | | 230 | | // the server's TTL sweep can physically purge an expired document between our create's |
| | | 231 | | // 409 and the follow-up read (or the conditional replace). A vanished conflicting |
| | | 232 | | // document means the slot is free — create again — not that a live competitor won. |
| | | 233 | | // The short growing delay lets one purge cycle finish instead of burning all attempts |
| | | 234 | | // inside the same inconsistency window (the Linux emulator is markedly worse here than |
| | | 235 | | // the service, but the race itself is real on both). |
| | | 236 | | for (var attempt = 0; attempt < 4; attempt++) |
| | | 237 | | { |
| | | 238 | | if (attempt > 0) |
| | | 239 | | await Task.Delay(TimeSpan.FromMilliseconds(50 * attempt), cancellationToken).ConfigureAwait(false); |
| | | 240 | | |
| | | 241 | | var now = DateTime.UtcNow; |
| | | 242 | | var document = CreateDocument(flowId, stateJson, state.Revision, ttl, now); |
| | | 243 | | if (attempt == 0) |
| | | 244 | | ThrowIfDocumentTooLarge(flowId, document); |
| | | 245 | | try |
| | | 246 | | { |
| | | 247 | | await container.CreateItemAsync(document, new PartitionKey(flowId), cancellationToken: cancellationToken |
| | | 248 | | return true; |
| | | 249 | | } |
| | | 250 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.Conflict) |
| | | 251 | | { |
| | | 252 | | try |
| | | 253 | | { |
| | | 254 | | var current = await container.ReadItemAsync<CosmosFlowStateDocument>( |
| | | 255 | | flowId, |
| | | 256 | | new PartitionKey(flowId), |
| | | 257 | | cancellationToken: cancellationToken).ConfigureAwait(false); |
| | | 258 | | if (current.Resource.ExpiresAtUtc > now) |
| | | 259 | | return false; |
| | | 260 | | |
| | | 261 | | await container.ReplaceItemAsync( |
| | | 262 | | document, |
| | | 263 | | flowId, |
| | | 264 | | new PartitionKey(flowId), |
| | | 265 | | new ItemRequestOptions { IfMatchEtag = current.ETag }, |
| | | 266 | | cancellationToken).ConfigureAwait(false); |
| | | 267 | | return true; |
| | | 268 | | } |
| | | 269 | | catch (CosmosException retryEx) when (retryEx.StatusCode == HttpStatusCode.PreconditionFailed) |
| | | 270 | | { |
| | | 271 | | // The ETag moved under us. That is either a live writer winning the id or the |
| | | 272 | | // TTL purge touching the expired document; only the next read can tell them |
| | | 273 | | // apart, so retry instead of conceding — a live occupant surfaces as an |
| | | 274 | | // unexpired read (false) on the next attempt, a purged one as a clean create. |
| | | 275 | | continue; |
| | | 276 | | } |
| | | 277 | | catch (CosmosException retryEx) when (retryEx.StatusCode == HttpStatusCode.NotFound) |
| | | 278 | | { |
| | | 279 | | // The expired document was TTL-purged after our 409 — the id is free again. |
| | | 280 | | continue; |
| | | 281 | | } |
| | | 282 | | } |
| | | 283 | | } |
| | | 284 | | |
| | | 285 | | return false; |
| | | 286 | | } |
| | | 287 | | |
| | | 288 | | public async Task<bool> TryUpdateAsync( |
| | | 289 | | string flowId, |
| | | 290 | | FlowState state, |
| | | 291 | | long expectedRevision, |
| | | 292 | | TimeSpan ttl, |
| | | 293 | | string? leaseId = null, |
| | | 294 | | CancellationToken cancellationToken = default) |
| | | 295 | | { |
| | | 296 | | DurableFlowStoreShared.ValidateUpdate(flowId, state, expectedRevision, ttl); |
| | | 297 | | var stateJson = DurableFlowStoreShared.SerializeBounded(flowId, state, _options.MaxStateBytes, "Cosmos DB"); |
| | | 298 | | var container = await GetContainerAsync(cancellationToken).ConfigureAwait(false); |
| | | 299 | | for (var attempt = 0; attempt < 4; attempt++) |
| | | 300 | | { |
| | | 301 | | var now = DateTime.UtcNow; |
| | | 302 | | try |
| | | 303 | | { |
| | | 304 | | var current = await container.ReadItemAsync<CosmosFlowStateDocument>( |
| | | 305 | | flowId, |
| | | 306 | | new PartitionKey(flowId), |
| | | 307 | | cancellationToken: cancellationToken).ConfigureAwait(false); |
| | | 308 | | var document = current.Resource; |
| | | 309 | | if (document.ExpiresAtUtc <= now || document.Revision != expectedRevision) |
| | | 310 | | return false; |
| | | 311 | | // Positive form (SQL-sibling parity: `lease_id = @lease_id AND lease_expires_at_utc > now()` |
| | | 312 | | // is false for NULL). The negated `LeaseExpiresAtUtc <= now` was ALSO false for a |
| | | 313 | | // null deadline, so a document with a lease id and no expiry passed the fence. |
| | | 314 | | if (leaseId is not null && !(document.LeaseId == leaseId && document.LeaseExpiresAtUtc > now)) |
| | | 315 | | return false; |
| | | 316 | | |
| | | 317 | | document.StateJson = stateJson; |
| | | 318 | | document.ExpiresAtUtc = DurableFlowStoreShared.AddSaturating(now, ttl); |
| | | 319 | | document.UpdatedAtUtc = now; |
| | | 320 | | document.Revision = state.Revision; |
| | | 321 | | document.Ttl = CosmosTtlSeconds(ttl); |
| | | 322 | | ThrowIfDocumentTooLarge(flowId, document); |
| | | 323 | | await container.ReplaceItemAsync( |
| | | 324 | | document, |
| | | 325 | | flowId, |
| | | 326 | | new PartitionKey(flowId), |
| | | 327 | | new ItemRequestOptions { IfMatchEtag = current.ETag }, |
| | | 328 | | cancellationToken).ConfigureAwait(false); |
| | | 329 | | return true; |
| | | 330 | | } |
| | | 331 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.NotFound && ex.SubStatusCode == 0) |
| | | 332 | | { |
| | | 333 | | // Sub-status 0 only (LoadAsync's discriminator, for the same reason): a 404/1002 |
| | | 334 | | // ReadSessionNotAvailable from a lagging replica names a ledger that still exists. |
| | | 335 | | // Reporting it as "gone" made the lease mark itself lost, the delivery redeliver, |
| | | 336 | | // and the step's already-performed side effect run a second time. Letting the |
| | | 337 | | // other sub-statuses throw routes the delivery through retry instead. |
| | | 338 | | return false; |
| | | 339 | | } |
| | | 340 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.PreconditionFailed) |
| | | 341 | | { |
| | | 342 | | // Lease acquire/renew/release patch the document's lease fields and change its |
| | | 343 | | // ETag without changing the ledger revision. Re-read and retry so that benign |
| | | 344 | | // race is not reported as a lost execution lease; a real state race fails the |
| | | 345 | | // revision check above. |
| | | 346 | | } |
| | | 347 | | } |
| | | 348 | | |
| | | 349 | | return false; |
| | | 350 | | } |
| | | 351 | | |
| | | 352 | | public Task<bool> TryAcquireLeaseAsync(string flowId, string leaseId, TimeSpan leaseDuration, CancellationToken canc |
| | | 353 | | => UpdateLeaseAsync(flowId, leaseId, leaseDuration, acquire: true, cancellationToken); |
| | | 354 | | |
| | | 355 | | public Task<bool> TryRenewLeaseAsync(string flowId, string leaseId, TimeSpan leaseDuration, CancellationToken cancel |
| | | 356 | | => UpdateLeaseAsync(flowId, leaseId, leaseDuration, acquire: false, cancellationToken); |
| | | 357 | | |
| | | 358 | | public async Task ReleaseLeaseAsync(string flowId, string leaseId, CancellationToken cancellationToken = default) |
| | | 359 | | { |
| | | 360 | | var container = await GetContainerAsync(cancellationToken).ConfigureAwait(false); |
| | | 361 | | for (var attempt = 0; attempt < 4; attempt++) |
| | | 362 | | { |
| | | 363 | | try |
| | | 364 | | { |
| | | 365 | | var current = await ReadLeaseAsync(container, flowId, cancellationToken).ConfigureAwait(false); |
| | | 366 | | if (current is null || current.LeaseId != leaseId) |
| | | 367 | | return; |
| | | 368 | | |
| | | 369 | | // Every write refreshes _ts — the anchor the server-side TTL counts from — so |
| | | 370 | | // re-persisting the stored full-window ttl would restart the physical-retention |
| | | 371 | | // countdown and decouple it from the logical ExpiresAtUtc. Rewrite it from the |
| | | 372 | | // remaining logical window instead. (Checkpoints recompute both together in |
| | | 373 | | // TryUpdateAsync; only the lease paths write without moving ExpiresAtUtc.) |
| | | 374 | | await PatchLeaseAsync( |
| | | 375 | | container, |
| | | 376 | | flowId, |
| | | 377 | | current.ETag, |
| | | 378 | | [ |
| | | 379 | | PatchOperation.Set<string?>(LeaseIdPath, null), |
| | | 380 | | PatchOperation.Set<DateTime?>(LeaseExpiresAtPath, null), |
| | | 381 | | PatchOperation.Set(TtlPath, CosmosTtlSeconds(current.ExpiresAtUtc, DateTime.UtcNow)) |
| | | 382 | | ], |
| | | 383 | | cancellationToken).ConfigureAwait(false); |
| | | 384 | | return; |
| | | 385 | | } |
| | | 386 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.NotFound && ex.SubStatusCode == 0) |
| | | 387 | | { |
| | | 388 | | return; |
| | | 389 | | } |
| | | 390 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.PreconditionFailed) |
| | | 391 | | { |
| | | 392 | | } |
| | | 393 | | } |
| | | 394 | | } |
| | | 395 | | |
| | | 396 | | /// <inheritdoc /> |
| | | 397 | | public async Task<FlowLeaseObservation?> ObserveLeaseAsync(string flowId, CancellationToken cancellationToken = defa |
| | | 398 | | { |
| | | 399 | | ArgumentException.ThrowIfNullOrWhiteSpace(flowId); |
| | | 400 | | var container = await GetContainerAsync(cancellationToken).ConfigureAwait(false); |
| | | 401 | | |
| | | 402 | | // The same projecting point query the lease writes read through, so stateJson never |
| | | 403 | | // crosses the wire — and, unlike them, nothing here is compared with a clock: an expired |
| | | 404 | | // lease nobody has taken over must keep reading as the same lease, because the engine's |
| | | 405 | | // proof of a live holder is that two observations DIFFER. Whether it has lapsed stays |
| | | 406 | | // UpdateLeaseAsync's call. |
| | | 407 | | // |
| | | 408 | | // That proof only holds when each observation is at least as new as the moment it was |
| | | 409 | | // asked for. A waiting delivery runs in a process that never received the holder's |
| | | 410 | | // session token, so a bare query may be served by a lagging replica: a baseline older |
| | | 411 | | // than the wait makes a renewal written BEFORE the delivery arrived look like one written |
| | | 412 | | // while it waited, and the delivery is acknowledged as a duplicate of a holder that may |
| | | 413 | | // already be dead. The write-path round trip first pins the query to the write region's |
| | | 414 | | // progress as of now (and answers absence authoritatively, without the query). |
| | | 415 | | if (!await ExistsOnWritePathAsync(container, flowId, cancellationToken).ConfigureAwait(false)) |
| | | 416 | | return FlowLeaseObservation.Unheld; |
| | | 417 | | |
| | | 418 | | try |
| | | 419 | | { |
| | | 420 | | var current = await ReadLeaseAsync(container, flowId, cancellationToken).ConfigureAwait(false); |
| | | 421 | | return DurableFlowStoreShared.LeaseObservation(current?.LeaseId, current?.LeaseExpiresAtUtc); |
| | | 422 | | } |
| | | 423 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.NotFound && ex.SubStatusCode == 0) |
| | | 424 | | { |
| | | 425 | | return FlowLeaseObservation.Unheld; |
| | | 426 | | } |
| | | 427 | | } |
| | | 428 | | |
| | | 429 | | /// <summary> |
| | | 430 | | /// How often <see cref="LoadAsync"/> re-asks the write path when it reports the ledger present |
| | | 431 | | /// and the follow-up read still answers 404, before it gives up proving absence. |
| | | 432 | | /// </summary> |
| | | 433 | | private const int MaxAbsenceConfirmations = 3; |
| | | 434 | | |
| | | 435 | | /// <summary> |
| | | 436 | | /// An <c>If-Match</c> value no document can carry (service ETags are quoted GUIDs, and the |
| | | 437 | | /// wildcard is <c>*</c>), so the conditional patch below can never apply. |
| | | 438 | | /// </summary> |
| | | 439 | | internal const string NeverMatchingEtag = "\"asyncresponse-consistency-barrier\""; |
| | | 440 | | |
| | | 441 | | // Inert even if it could apply: no reader or writer of the ledger document knows this path. |
| | | 442 | | private const string BarrierPath = "/consistencyBarrier"; |
| | | 443 | | |
| | | 444 | | /// <summary> |
| | | 445 | | /// Asks the container's WRITE path whether the ledger document exists, with a conditional |
| | | 446 | | /// patch whose precondition cannot hold. Writes are served by the partition's write-region |
| | | 447 | | /// primary, never by a lagging read replica: 404 (sub-status 0) there is an authoritative |
| | | 448 | | /// "no such item", and 412 means the document exists. Nothing is ever written. |
| | | 449 | | /// <para> |
| | | 450 | | /// The 412 has a second effect the callers depend on. The SDK records the session token of a |
| | | 451 | | /// 412/409/404 response exactly as it does a successful one (StoreClient and |
| | | 452 | | /// GatewayStoreModel both capture it), so after this call the client's session token for the |
| | | 453 | | /// partition is at least the write region's progress as of now, and under Session consistency |
| | | 454 | | /// the NEXT read from this client cannot be served by a replica behind it — it is current, or |
| | | 455 | | /// it fails with 404/1002, which every path here lets throw. |
| | | 456 | | /// </para> |
| | | 457 | | /// <para> |
| | | 458 | | /// What that guarantees, by the client's effective consistency level: Strong reads, and |
| | | 459 | | /// Bounded Staleness reads served from the write region, were already current; Session (the |
| | | 460 | | /// account default) is made current by the token; Bounded Staleness read from another |
| | | 461 | | /// region, Consistent Prefix and Eventual send no session token on reads, so only the absence |
| | | 462 | | /// answer is authoritative there and the following read can still lag. An account with |
| | | 463 | | /// multiple WRITE regions has no single authoritative write path (it already lets two regions |
| | | 464 | | /// win the same ETag-fenced lease write and resolves them last-writer-wins), so none of this |
| | | 465 | | /// holds on one. The cost is one extra bodiless request, on the two decision paths only — |
| | | 466 | | /// never on a load that found its document. |
| | | 467 | | /// </para> |
| | | 468 | | /// </summary> |
| | | 469 | | private static async Task<bool> ExistsOnWritePathAsync(Container container, string flowId, CancellationToken cancell |
| | | 470 | | { |
| | | 471 | | try |
| | | 472 | | { |
| | | 473 | | await container.PatchItemAsync<CosmosFlowStateDocument>( |
| | | 474 | | flowId, |
| | | 475 | | new PartitionKey(flowId), |
| | | 476 | | [PatchOperation.Set(BarrierPath, 0)], |
| | | 477 | | new PatchItemRequestOptions { IfMatchEtag = NeverMatchingEtag, EnableContentResponseOnWrite = false }, |
| | | 478 | | cancellationToken).ConfigureAwait(false); |
| | | 479 | | // Unreachable against the service; a patch that applied still proves the document exists. |
| | | 480 | | return true; |
| | | 481 | | } |
| | | 482 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.PreconditionFailed) |
| | | 483 | | { |
| | | 484 | | return true; |
| | | 485 | | } |
| | | 486 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.NotFound && ex.SubStatusCode == 0) |
| | | 487 | | { |
| | | 488 | | return false; |
| | | 489 | | } |
| | | 490 | | } |
| | | 491 | | |
| | | 492 | | // JSON-pointer paths of the lease fields, matching CosmosFlowStateDocument's property names. |
| | | 493 | | private const string LeaseIdPath = "/leaseId"; |
| | | 494 | | private const string LeaseExpiresAtPath = "/leaseExpiresAtUtc"; |
| | | 495 | | private const string TtlPath = "/ttl"; |
| | | 496 | | |
| | | 497 | | /// <summary> |
| | | 498 | | /// The lease-relevant slice of one ledger document, read with a projecting point query so a |
| | | 499 | | /// lease acquire, heartbeat, or release never transfers <c>stateJson</c>. A point read has no |
| | | 500 | | /// projection — it returned the whole document, StateJson included, and the follow-up |
| | | 501 | | /// ReplaceItemAsync sent it all back — so an idle execution's every renewal (default: each |
| | | 502 | | /// 20 seconds) moved and re-serialized the full ledger twice, proportional to its size. |
| | | 503 | | /// Together with the conditional patches below, lease maintenance now costs O(lease fields) |
| | | 504 | | /// on the wire regardless of ledger size. RU cost still depends on the service's accounting |
| | | 505 | | /// for the loaded document; measure it (docs/durable-flow-state-stores.md). |
| | | 506 | | /// <para> |
| | | 507 | | /// Only the SQL text is shared. A <see cref="QueryDefinition"/> is a mutable parameter bag — |
| | | 508 | | /// <c>WithParameter</c> replaces the named parameter in place and returns the same instance — |
| | | 509 | | /// so one static definition parameterized per call handed concurrent lease operations each |
| | | 510 | | /// other's ids: flow A's query could execute with <c>@id = B</c> under A's partition key, |
| | | 511 | | /// return no document, and fail a healthy renewal (which abandons and replays the run). Every |
| | | 512 | | /// call builds its own definition. |
| | | 513 | | /// </para> |
| | | 514 | | /// </summary> |
| | | 515 | | private const string LeaseProjectionSql = |
| | | 516 | | "SELECT c.id, c._etag, c.expiresAtUtc, c.revision, c.leaseId, c.leaseExpiresAtUtc FROM c WHERE c.id = @id"; |
| | | 517 | | |
| | | 518 | | private static async Task<CosmosLeaseProjection?> ReadLeaseAsync(Container container, string flowId, CancellationTok |
| | | 519 | | { |
| | | 520 | | using var iterator = container.GetItemQueryIterator<CosmosLeaseProjection>( |
| | | 521 | | new QueryDefinition(LeaseProjectionSql).WithParameter("@id", flowId), |
| | | 522 | | requestOptions: new QueryRequestOptions { PartitionKey = new PartitionKey(flowId), MaxItemCount = 1 }); |
| | | 523 | | while (iterator.HasMoreResults) |
| | | 524 | | { |
| | | 525 | | var page = await iterator.ReadNextAsync(cancellationToken).ConfigureAwait(false); |
| | | 526 | | foreach (var projection in page) |
| | | 527 | | { |
| | | 528 | | if (string.IsNullOrEmpty(projection.ETag)) |
| | | 529 | | { |
| | | 530 | | // The fence for every lease write. A projection without it cannot be acted |
| | | 531 | | // on safely, and silently treating it as "not held" would let the executor |
| | | 532 | | // acknowledge a wake-up as a duplicate against a run nobody holds. |
| | | 533 | | throw new InvalidOperationException( |
| | | 534 | | $"The Cosmos DB durable-flow store's lease query for '{flowId}' returned no _etag; the registere |
| | | 535 | | } |
| | | 536 | | |
| | | 537 | | return projection; |
| | | 538 | | } |
| | | 539 | | } |
| | | 540 | | |
| | | 541 | | return null; |
| | | 542 | | } |
| | | 543 | | |
| | | 544 | | /// <summary> |
| | | 545 | | /// A conditional partial update of the lease fields: fenced by the projection's ETag exactly |
| | | 546 | | /// as the replace was, with no document content in the response (there is nothing the |
| | | 547 | | /// caller reads back). |
| | | 548 | | /// </summary> |
| | | 549 | | private static Task PatchLeaseAsync( |
| | | 550 | | Container container, |
| | | 551 | | string flowId, |
| | | 552 | | string etag, |
| | | 553 | | IReadOnlyList<PatchOperation> operations, |
| | | 554 | | CancellationToken cancellationToken) |
| | | 555 | | => container.PatchItemAsync<CosmosFlowStateDocument>( |
| | | 556 | | flowId, |
| | | 557 | | new PartitionKey(flowId), |
| | | 558 | | operations, |
| | | 559 | | new PatchItemRequestOptions { IfMatchEtag = etag, EnableContentResponseOnWrite = false }, |
| | | 560 | | cancellationToken); |
| | | 561 | | |
| | | 562 | | public async Task<bool> TryDeleteAsync(string flowId, CancellationToken cancellationToken = default) |
| | | 563 | | { |
| | | 564 | | ArgumentException.ThrowIfNullOrWhiteSpace(flowId); |
| | | 565 | | var container = await GetContainerAsync(cancellationToken).ConfigureAwait(false); |
| | | 566 | | |
| | | 567 | | try |
| | | 568 | | { |
| | | 569 | | await container.DeleteItemAsync<CosmosFlowStateDocument>( |
| | | 570 | | flowId, |
| | | 571 | | new PartitionKey(flowId), |
| | | 572 | | cancellationToken: cancellationToken).ConfigureAwait(false); |
| | | 573 | | return true; |
| | | 574 | | } |
| | | 575 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.NotFound && ex.SubStatusCode == 0) |
| | | 576 | | { |
| | | 577 | | return false; |
| | | 578 | | } |
| | | 579 | | } |
| | | 580 | | |
| | | 581 | | private async Task<Container> GetContainerAsync(CancellationToken cancellationToken) |
| | | 582 | | { |
| | | 583 | | if (!_created) |
| | | 584 | | await EnsureCreatedAsync(cancellationToken).ConfigureAwait(false); |
| | | 585 | | |
| | | 586 | | return _client.GetContainer(_options.DatabaseName, _options.ContainerName); |
| | | 587 | | } |
| | | 588 | | |
| | | 589 | | private async Task EnsureCreatedAsync(CancellationToken cancellationToken) |
| | | 590 | | { |
| | | 591 | | if (_created) |
| | | 592 | | return; |
| | | 593 | | |
| | | 594 | | await _ensureGate.WaitAsync(cancellationToken).ConfigureAwait(false); |
| | | 595 | | try |
| | | 596 | | { |
| | | 597 | | if (_created) |
| | | 598 | | return; |
| | | 599 | | |
| | | 600 | | ContainerResponse container; |
| | | 601 | | if (_options.AutoCreateContainer) |
| | | 602 | | { |
| | | 603 | | var database = await _client.CreateDatabaseIfNotExistsAsync( |
| | | 604 | | _options.DatabaseName, |
| | | 605 | | cancellationToken: cancellationToken).ConfigureAwait(false); |
| | | 606 | | |
| | | 607 | | // DefaultTimeToLive = -1 enables per-item TTL without a container-wide default. |
| | | 608 | | var properties = new ContainerProperties(_options.ContainerName, _options.PartitionKeyPath) |
| | | 609 | | { |
| | | 610 | | DefaultTimeToLive = -1 |
| | | 611 | | }; |
| | | 612 | | container = await database.Database.CreateContainerIfNotExistsAsync( |
| | | 613 | | properties, |
| | | 614 | | _options.Throughput, |
| | | 615 | | cancellationToken: cancellationToken).ConfigureAwait(false); |
| | | 616 | | } |
| | | 617 | | else |
| | | 618 | | { |
| | | 619 | | container = await _client |
| | | 620 | | .GetContainer(_options.DatabaseName, _options.ContainerName) |
| | | 621 | | .ReadContainerAsync(cancellationToken: cancellationToken) |
| | | 622 | | .ConfigureAwait(false); |
| | | 623 | | } |
| | | 624 | | |
| | | 625 | | if (!string.Equals(container.Resource.PartitionKeyPath, _options.PartitionKeyPath, StringComparison.Ordinal) |
| | | 626 | | throw new InvalidOperationException( |
| | | 627 | | $"Cosmos container '{_options.ContainerName}' uses partition key '{container.Resource.PartitionKeyPa |
| | | 628 | | $"but '{_options.PartitionKeyPath}' is required."); |
| | | 629 | | if (container.Resource.DefaultTimeToLive is null) |
| | | 630 | | throw new InvalidOperationException( |
| | | 631 | | $"Cosmos container '{_options.ContainerName}' does not have TTL enabled. " + |
| | | 632 | | "Enable container TTL (DefaultTimeToLive = -1) before using it for durable flows."); |
| | | 633 | | |
| | | 634 | | ValidateHostSerializer(); |
| | | 635 | | _created = true; |
| | | 636 | | } |
| | | 637 | | finally |
| | | 638 | | { |
| | | 639 | | _ensureGate.Release(); |
| | | 640 | | } |
| | | 641 | | } |
| | | 642 | | |
| | | 643 | | /// <summary> |
| | | 644 | | /// Fails provisioning fast when a host-registered <see cref="CosmosClient"/> carries a custom |
| | | 645 | | /// serializer that does not honor the flow-state document's JSON property names. |
| | | 646 | | /// <see cref="CosmosFlowStateDocument"/> is attributed for both Newtonsoft.Json |
| | | 647 | | /// (<c>[JsonProperty]</c>) and System.Text.Json (<c>[JsonPropertyName]</c>), so the SDK's |
| | | 648 | | /// default serializer and STJ-based serializers both map correctly; a serializer honoring |
| | | 649 | | /// neither would write documents whose <c>id</c> Cosmos rejects — or, worse, whose fields |
| | | 650 | | /// silently round-trip as nulls. The probe serializes a sentinel document through the host's |
| | | 651 | | /// serializer and verifies the wire property names survive. |
| | | 652 | | /// </summary> |
| | | 653 | | private void ValidateHostSerializer() |
| | | 654 | | { |
| | | 655 | | if (_client.ClientOptions?.Serializer is not { } serializer) |
| | | 656 | | return; // The SDK default serializer honors [JsonProperty]; nothing to probe. |
| | | 657 | | |
| | | 658 | | var now = DateTime.UtcNow; |
| | | 659 | | using var stream = serializer.ToStream(new CosmosFlowStateDocument |
| | | 660 | | { |
| | | 661 | | Id = "asyncresponse-serializer-probe", |
| | | 662 | | FlowId = "asyncresponse-serializer-probe", |
| | | 663 | | StateJson = "{}", |
| | | 664 | | ExpiresAtUtc = now, |
| | | 665 | | UpdatedAtUtc = now, |
| | | 666 | | Revision = 0, |
| | | 667 | | LeaseId = "probe", |
| | | 668 | | LeaseExpiresAtUtc = now, |
| | | 669 | | Ttl = 1 |
| | | 670 | | }); |
| | | 671 | | using var probe = System.Text.Json.JsonDocument.Parse(stream); |
| | | 672 | | if (!probe.RootElement.TryGetProperty("id", out _) || !probe.RootElement.TryGetProperty("leaseExpiresAtUtc", out |
| | | 673 | | { |
| | | 674 | | throw new InvalidOperationException( |
| | | 675 | | $"The registered CosmosClient's serializer ({serializer.GetType().Name}) does not honor the durable-flow |
| | | 676 | | "JSON property names ('id', 'flowId', 'leaseExpiresAtUtc', ...). Flow-state documents would be written w |
| | | 677 | | "property names and could not be read back. Configure the serializer to honor Newtonsoft.Json [JsonPrope |
| | | 678 | | "System.Text.Json [JsonPropertyName] attributes, or let the SDK use its default serializer."); |
| | | 679 | | } |
| | | 680 | | } |
| | | 681 | | |
| | | 682 | | private async Task<bool> UpdateLeaseAsync( |
| | | 683 | | string flowId, |
| | | 684 | | string leaseId, |
| | | 685 | | TimeSpan leaseDuration, |
| | | 686 | | bool acquire, |
| | | 687 | | CancellationToken cancellationToken) |
| | | 688 | | { |
| | | 689 | | DurableFlowStoreShared.ValidateLeaseArgs(flowId, leaseId, leaseDuration); |
| | | 690 | | |
| | | 691 | | var container = await GetContainerAsync(cancellationToken).ConfigureAwait(false); |
| | | 692 | | for (var attempt = 0; attempt < 4; attempt++) |
| | | 693 | | { |
| | | 694 | | var now = DateTime.UtcNow; |
| | | 695 | | try |
| | | 696 | | { |
| | | 697 | | var document = await ReadLeaseAsync(container, flowId, cancellationToken).ConfigureAwait(false); |
| | | 698 | | if (document is null || document.ExpiresAtUtc <= now || document.Revision is null) |
| | | 699 | | return false; |
| | | 700 | | if (acquire) |
| | | 701 | | { |
| | | 702 | | if (document.LeaseId is not null && document.LeaseId != leaseId && document.LeaseExpiresAtUtc > now) |
| | | 703 | | return false; |
| | | 704 | | } |
| | | 705 | | else if (!(document.LeaseId == leaseId && document.LeaseExpiresAtUtc > now)) |
| | | 706 | | { |
| | | 707 | | // Positive form: a renewal needs a live deadline, and a null one is not live. |
| | | 708 | | return false; |
| | | 709 | | } |
| | | 710 | | |
| | | 711 | | // Same _ts realignment as ReleaseLeaseAsync: a lease heartbeat writes the |
| | | 712 | | // document without moving ExpiresAtUtc, so it must not restart the server TTL's |
| | | 713 | | // full retention window. |
| | | 714 | | await PatchLeaseAsync( |
| | | 715 | | container, |
| | | 716 | | flowId, |
| | | 717 | | document.ETag, |
| | | 718 | | [ |
| | | 719 | | PatchOperation.Set(LeaseIdPath, leaseId), |
| | | 720 | | PatchOperation.Set(LeaseExpiresAtPath, DurableFlowStoreShared.AddSaturating(now, leaseDuration)) |
| | | 721 | | PatchOperation.Set(TtlPath, CosmosTtlSeconds(document.ExpiresAtUtc, now)) |
| | | 722 | | ], |
| | | 723 | | cancellationToken).ConfigureAwait(false); |
| | | 724 | | return true; |
| | | 725 | | } |
| | | 726 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.NotFound && ex.SubStatusCode == 0) |
| | | 727 | | { |
| | | 728 | | return false; |
| | | 729 | | } |
| | | 730 | | catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.PreconditionFailed) |
| | | 731 | | { |
| | | 732 | | } |
| | | 733 | | } |
| | | 734 | | |
| | | 735 | | return false; |
| | | 736 | | } |
| | | 737 | | |
| | | 738 | | /// <summary> |
| | | 739 | | /// Enforces <see cref="CosmosDurableFlowOptions.MaxStateBytes"/> on the document as Cosmos |
| | | 740 | | /// will receive it. <see cref="DurableFlowStoreShared.SerializeBounded"/> already refused a |
| | | 741 | | /// ledger whose own JSON is over the budget — a cheap first check, since the document can only |
| | | 742 | | /// be larger — but the ledger travels inside the document as a string value, so every quote |
| | | 743 | | /// and backslash in it is escaped again: a 1.2 MB ledger made of escaped quotes is a 2.4 MB |
| | | 744 | | /// document, accepted by the inner check and refused by Cosmos's 2 MB item cap on every |
| | | 745 | | /// retry. Measured through the host's own serializer when one is registered (its escaping |
| | | 746 | | /// and property naming are what go on the wire), else through the SDK default's |
| | | 747 | | /// Newtonsoft-based shape. |
| | | 748 | | /// </summary> |
| | | 749 | | private void ThrowIfDocumentTooLarge(string flowId, CosmosFlowStateDocument document) |
| | | 750 | | { |
| | | 751 | | if (_options.MaxStateBytes is not { } limit) |
| | | 752 | | return; |
| | | 753 | | |
| | | 754 | | var size = MeasureDocumentBytes(document); |
| | | 755 | | if (size > limit) |
| | | 756 | | throw new FlowStateTooLargeException(flowId, size, limit, "Cosmos DB"); |
| | | 757 | | } |
| | | 758 | | |
| | | 759 | | private long MeasureDocumentBytes(CosmosFlowStateDocument document) |
| | | 760 | | { |
| | | 761 | | if (_client.ClientOptions?.Serializer is { } serializer) |
| | | 762 | | { |
| | | 763 | | using var stream = serializer.ToStream(document); |
| | | 764 | | if (stream.CanSeek) |
| | | 765 | | return stream.Length; |
| | | 766 | | |
| | | 767 | | long total = 0; |
| | | 768 | | var buffer = ArrayPool<byte>.Shared.Rent(16 * 1024); |
| | | 769 | | try |
| | | 770 | | { |
| | | 771 | | int read; |
| | | 772 | | while ((read = stream.Read(buffer, 0, buffer.Length)) > 0) |
| | | 773 | | total += read; |
| | | 774 | | } |
| | | 775 | | finally |
| | | 776 | | { |
| | | 777 | | ArrayPool<byte>.Shared.Return(buffer); |
| | | 778 | | } |
| | | 779 | | |
| | | 780 | | return total; |
| | | 781 | | } |
| | | 782 | | |
| | | 783 | | return MeasureDefaultDocumentBytes(document, _client.ClientOptions?.SerializerOptions); |
| | | 784 | | } |
| | | 785 | | |
| | | 786 | | // The SDK's default wire shape, written as scalars rather than by reflecting over the |
| | | 787 | | // document. JsonTextWriter preserves Newtonsoft's escaping/date rules without IL2026/3050. |
| | | 788 | | internal static long MeasureDefaultDocumentBytes(CosmosFlowStateDocument document, CosmosSerializationOptions? optio |
| | | 789 | | { |
| | | 790 | | using var text = new StringWriter(System.Globalization.CultureInfo.InvariantCulture); |
| | | 791 | | using var writer = new JsonTextWriter(text) { Formatting = options?.Indented == true ? Formatting.Indented : For |
| | | 792 | | writer.WriteStartObject(); |
| | | 793 | | writer.WritePropertyName("id"); writer.WriteValue(document.Id); |
| | | 794 | | writer.WritePropertyName("flowId"); writer.WriteValue(document.FlowId); |
| | | 795 | | writer.WritePropertyName("stateJson"); writer.WriteValue(document.StateJson); |
| | | 796 | | writer.WritePropertyName("expiresAtUtc"); writer.WriteValue(document.ExpiresAtUtc); |
| | | 797 | | writer.WritePropertyName("updatedAtUtc"); writer.WriteValue(document.UpdatedAtUtc); |
| | | 798 | | if (document.Revision is not null || options?.IgnoreNullValues != true) |
| | | 799 | | { |
| | | 800 | | writer.WritePropertyName("revision"); writer.WriteValue(document.Revision); |
| | | 801 | | } |
| | | 802 | | if (document.LeaseId is not null) |
| | | 803 | | { |
| | | 804 | | writer.WritePropertyName("leaseId"); writer.WriteValue(document.LeaseId); |
| | | 805 | | } |
| | | 806 | | if (document.LeaseExpiresAtUtc is not null) |
| | | 807 | | { |
| | | 808 | | writer.WritePropertyName("leaseExpiresAtUtc"); writer.WriteValue(document.LeaseExpiresAtUtc); |
| | | 809 | | } |
| | | 810 | | if (document.Ttl is not null) |
| | | 811 | | { |
| | | 812 | | writer.WritePropertyName("ttl"); writer.WriteValue(document.Ttl); |
| | | 813 | | } |
| | | 814 | | writer.WriteEndObject(); |
| | | 815 | | writer.Flush(); |
| | | 816 | | return Encoding.UTF8.GetByteCount(text.ToString()); |
| | | 817 | | } |
| | | 818 | | |
| | | 819 | | private static CosmosFlowStateDocument CreateDocument(string flowId, string stateJson, long revision, TimeSpan ttl, |
| | | 820 | | => new() |
| | | 821 | | { |
| | | 822 | | Id = flowId, |
| | | 823 | | FlowId = flowId, |
| | | 824 | | StateJson = stateJson, |
| | | 825 | | ExpiresAtUtc = DurableFlowStoreShared.AddSaturating(now, ttl), |
| | | 826 | | UpdatedAtUtc = now, |
| | | 827 | | Revision = revision, |
| | | 828 | | // Cosmos reaps the item itself once container TTL is enabled. Ceiling keeps the |
| | | 829 | | // server-side TTL from being shorter than the requested duration. |
| | | 830 | | Ttl = CosmosTtlSeconds(ttl) |
| | | 831 | | }; |
| | | 832 | | |
| | | 833 | | /// <summary>Per-item TTL in whole seconds, rounded up and saturated at int.MaxValue (~68 years) for absurd expiries |
| | | 834 | | private static int CosmosTtlSeconds(TimeSpan ttl) |
| | | 835 | | => (int)Math.Min(Math.Ceiling(ttl.TotalSeconds), int.MaxValue); |
| | | 836 | | |
| | | 837 | | /// <summary> |
| | | 838 | | /// Remaining per-item TTL in whole seconds until <paramref name="expiresAtUtc"/>, rounded up |
| | | 839 | | /// and floored at 1 (Cosmos rejects 0). Used by replaces that keep the logical expiry in place: |
| | | 840 | | /// an already-due document collapses to the shortest legal TTL so the next sweep purges it |
| | | 841 | | /// instead of the replace granting it a fresh retention window. |
| | | 842 | | /// </summary> |
| | | 843 | | private static int CosmosTtlSeconds(DateTime expiresAtUtc, DateTime now) |
| | | 844 | | => (int)Math.Min(Math.Max(Math.Ceiling((expiresAtUtc - now).TotalSeconds), 1), int.MaxValue); |
| | | 845 | | |
| | | 846 | | /// <summary>Disposes the Cosmos client when the store created (and therefore owns) it.</summary> |
| | | 847 | | public void Dispose() |
| | | 848 | | { |
| | | 849 | | _ensureGate.Dispose(); |
| | | 850 | | if (_ownsClient) |
| | | 851 | | _client.Dispose(); |
| | | 852 | | } |
| | | 853 | | } |
| | | 854 | | |
| | | 855 | | /// <summary> |
| | | 856 | | /// One durable-flow ledger document. Attributed for BOTH Newtonsoft.Json and System.Text.Json: |
| | | 857 | | /// the Cosmos SDK's default serializer is Newtonsoft-based, but hosts may register a |
| | | 858 | | /// <see cref="CosmosClient"/> with an STJ-based serializer — with single-stack attributes such a |
| | | 859 | | /// client would silently write PascalCase property names (breaking <c>id</c> and every read |
| | | 860 | | /// back). <see cref="CosmosFlowStateStore"/> additionally probes custom serializers at |
| | | 861 | | /// provisioning time and fails fast when neither attribute set is honored. |
| | | 862 | | /// </summary> |
| | | 863 | | internal sealed class CosmosFlowStateDocument |
| | | 864 | | { |
| | | 865 | | [JsonProperty("id")] |
| | | 866 | | [System.Text.Json.Serialization.JsonPropertyName("id")] |
| | | 867 | | public string Id { get; set; } = ""; |
| | | 868 | | |
| | | 869 | | [JsonProperty("flowId")] |
| | | 870 | | [System.Text.Json.Serialization.JsonPropertyName("flowId")] |
| | | 871 | | public string FlowId { get; set; } = ""; |
| | | 872 | | |
| | | 873 | | [JsonProperty("stateJson")] |
| | | 874 | | [System.Text.Json.Serialization.JsonPropertyName("stateJson")] |
| | | 875 | | public string StateJson { get; set; } = ""; |
| | | 876 | | |
| | | 877 | | [JsonProperty("expiresAtUtc")] |
| | | 878 | | [System.Text.Json.Serialization.JsonPropertyName("expiresAtUtc")] |
| | | 879 | | public DateTime ExpiresAtUtc { get; set; } |
| | | 880 | | |
| | | 881 | | [JsonProperty("updatedAtUtc")] |
| | | 882 | | [System.Text.Json.Serialization.JsonPropertyName("updatedAtUtc")] |
| | | 883 | | public DateTime UpdatedAtUtc { get; set; } |
| | | 884 | | |
| | | 885 | | [JsonProperty("revision")] |
| | | 886 | | [System.Text.Json.Serialization.JsonPropertyName("revision")] |
| | | 887 | | public long? Revision { get; set; } |
| | | 888 | | |
| | | 889 | | [JsonProperty("leaseId", NullValueHandling = NullValueHandling.Ignore)] |
| | | 890 | | [System.Text.Json.Serialization.JsonPropertyName("leaseId")] |
| | | 891 | | [System.Text.Json.Serialization.JsonIgnore(Condition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritin |
| | | 892 | | public string? LeaseId { get; set; } |
| | | 893 | | |
| | | 894 | | [JsonProperty("leaseExpiresAtUtc", NullValueHandling = NullValueHandling.Ignore)] |
| | | 895 | | [System.Text.Json.Serialization.JsonPropertyName("leaseExpiresAtUtc")] |
| | | 896 | | [System.Text.Json.Serialization.JsonIgnore(Condition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritin |
| | | 897 | | public DateTime? LeaseExpiresAtUtc { get; set; } |
| | | 898 | | |
| | | 899 | | /// <summary>Cosmos per-item TTL in seconds; honored once the container enables TTL.</summary> |
| | | 900 | | [JsonProperty("ttl", NullValueHandling = NullValueHandling.Ignore)] |
| | | 901 | | [System.Text.Json.Serialization.JsonPropertyName("ttl")] |
| | | 902 | | [System.Text.Json.Serialization.JsonIgnore(Condition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritin |
| | | 903 | | public int? Ttl { get; set; } |
| | | 904 | | } |
| | | 905 | | |
| | | 906 | | /// <summary> |
| | | 907 | | /// The lease slice of <see cref="CosmosFlowStateDocument"/> plus the document's <c>_etag</c>, as |
| | | 908 | | /// returned by the store's projecting lease query — everything a lease acquire, renewal, or |
| | | 909 | | /// release decides on and fences with, and nothing else (no <c>stateJson</c>). Attributed for |
| | | 910 | | /// both serializer stacks for the same reason the document is. |
| | | 911 | | /// </summary> |
| | | 912 | | internal sealed class CosmosLeaseProjection |
| | | 913 | | { |
| | | 914 | | [JsonProperty("id")] |
| | | 915 | | [System.Text.Json.Serialization.JsonPropertyName("id")] |
| | | 916 | | public string Id { get; set; } = ""; |
| | | 917 | | |
| | | 918 | | /// <summary>The fence for every lease write; the store refuses to act on a projection without one.</summary> |
| | | 919 | | [JsonProperty("_etag")] |
| | | 920 | | [System.Text.Json.Serialization.JsonPropertyName("_etag")] |
| | | 921 | | public string ETag { get; set; } = ""; |
| | | 922 | | |
| | | 923 | | [JsonProperty("expiresAtUtc")] |
| | | 924 | | [System.Text.Json.Serialization.JsonPropertyName("expiresAtUtc")] |
| | | 925 | | public DateTime ExpiresAtUtc { get; set; } |
| | | 926 | | |
| | | 927 | | [JsonProperty("revision")] |
| | | 928 | | [System.Text.Json.Serialization.JsonPropertyName("revision")] |
| | | 929 | | public long? Revision { get; set; } |
| | | 930 | | |
| | | 931 | | [JsonProperty("leaseId")] |
| | | 932 | | [System.Text.Json.Serialization.JsonPropertyName("leaseId")] |
| | | 933 | | public string? LeaseId { get; set; } |
| | | 934 | | |
| | | 935 | | [JsonProperty("leaseExpiresAtUtc")] |
| | | 936 | | [System.Text.Json.Serialization.JsonPropertyName("leaseExpiresAtUtc")] |
| | | 937 | | public DateTime? LeaseExpiresAtUtc { get; set; } |
| | | 938 | | } |
| | | 939 | | } |