/// <summary>
/// Call this method to handle requests on the server, sent by the client
/// </summary>
public async Task HandleRequestAsync(HttpContext context, Action <RemoteOrchestrator> action, CancellationToken cancellationToken)
{
var httpRequest = context.Request;
var httpResponse = context.Response;
var streamArray = GetBody(httpRequest);
var serAndsizeString = string.Empty;
var converter = string.Empty;
// Get the serialization and batch size format
if (TryGetHeaderValue(context.Request.Headers, "dotmim-sync-serialization-format", out var vs))
{
serAndsizeString = vs.ToLowerInvariant();
}
// Get the serialization and batch size format
if (TryGetHeaderValue(context.Request.Headers, "dotmim-sync-converter", out var cs))
{
converter = cs.ToLowerInvariant();
}
if (!TryGetHeaderValue(context.Request.Headers, "dotmim-sync-session-id", out var sessionId))
{
throw new HttpHeaderMissingExceptiopn("dotmim-sync-session-id");
}
if (!TryGetHeaderValue(context.Request.Headers, "dotmim-sync-step", out string iStep))
{
throw new HttpHeaderMissingExceptiopn("dotmim-sync-step");
}
var step = (HttpStep)Convert.ToInt32(iStep);
try
{
// Create a web server remote orchestrator based on cache values
if (this.WebServerOrchestrator == null)
{
this.WebServerOrchestrator = this.WebServerProperties.CreateWebServerOrchestrator();
}
// try get schema from cache
if (this.Cache.TryGetValue <SyncSet>(WebServerProperties.Key, out var cachedSchema))
{
this.WebServerOrchestrator.Schema = cachedSchema;
}
// try get session cache from current sessionId
if (!this.Cache.TryGetValue <SessionCache>(sessionId, out var sessionCache))
{
sessionCache = new SessionCache();
}
// action from user if available
action?.Invoke(this.WebServerOrchestrator);
// Get the serializer and batchsize
(var clientBatchSize, var clientSerializerFactory) = GetClientSerializer(serAndsizeString, this.WebServerOrchestrator);
// Get converter used by client
// Can be null
var clientConverter = GetClientConverter(converter, this.WebServerOrchestrator);
this.WebServerOrchestrator.ClientConverter = clientConverter;
byte[] binaryData = null;
switch (step)
{
case HttpStep.EnsureScopes:
var m1 = clientSerializerFactory.GetSerializer <HttpMessageEnsureScopesRequest>().Deserialize(streamArray);
var s1 = await this.WebServerOrchestrator.EnsureScopeAsync(m1, sessionCache, cancellationToken).ConfigureAwait(false);
binaryData = clientSerializerFactory.GetSerializer <HttpMessageEnsureScopesResponse>().Serialize(s1);
await this.WebServerOrchestrator.Provider.InterceptAsync(new HttpMessageEnsureScopesResponseArgs(binaryData)).ConfigureAwait(false);
break;
case HttpStep.SendChanges:
var m2 = clientSerializerFactory.GetSerializer <HttpMessageSendChangesRequest>().Deserialize(streamArray);
var s2 = await this.WebServerOrchestrator.ApplyThenGetChangesAsync(m2, sessionCache, clientBatchSize, cancellationToken).ConfigureAwait(false);
binaryData = clientSerializerFactory.GetSerializer <HttpMessageSendChangesResponse>().Serialize(s2);
if (s2.Changes != null && s2.Changes.HasRows)
{
await this.WebServerOrchestrator.Provider.InterceptAsync(new HttpMessageSendChangesResponseArgs(binaryData)).ConfigureAwait(false);
}
break;
case HttpStep.GetChanges:
var m3 = clientSerializerFactory.GetSerializer <HttpMessageGetMoreChangesRequest>().Deserialize(streamArray);
var s3 = this.WebServerOrchestrator.GetMoreChanges(m3, sessionCache, cancellationToken);
binaryData = clientSerializerFactory.GetSerializer <HttpMessageSendChangesResponse>().Serialize(s3);
if (s3.Changes != null && s3.Changes.HasRows)
{
await this.WebServerOrchestrator.Provider.InterceptAsync(new HttpMessageSendChangesResponseArgs(binaryData)).ConfigureAwait(false);
}
break;
case HttpStep.GetSnapshot:
var m4 = clientSerializerFactory.GetSerializer <HttpMessageSendChangesRequest>().Deserialize(streamArray);
var s4 = await this.WebServerOrchestrator.GetSnapshotAsync(m4, sessionCache, cancellationToken);
binaryData = clientSerializerFactory.GetSerializer <HttpMessageSendChangesResponse>().Serialize(s4);
if (s4.Changes != null && s4.Changes.HasRows)
{
await this.WebServerOrchestrator.Provider.InterceptAsync(new HttpMessageSendChangesResponseArgs(binaryData)).ConfigureAwait(false);
}
break;
}
// Save schema to cache with a sliding expiration
this.Cache.Set(WebServerProperties.Key, this.WebServerOrchestrator.Schema, this.WebServerProperties.Options.GetServerCacheOptions());
// Save session client to cache with a sliding expiration
this.Cache.Set(sessionId, sessionCache, this.WebServerProperties.Options.GetClientCacheOptions());
// Adding the serialization format used and session id
httpResponse.Headers.Add("dotmim-sync-session-id", sessionId.ToString());
httpResponse.Headers.Add("dotmim-sync-serialization-format", clientSerializerFactory.Key);
// data to send back, as the response
byte[] data = this.EnsureCompression(httpRequest, httpResponse, binaryData);
await this.GetBody(httpResponse).WriteAsync(data, 0, data.Length).ConfigureAwait(false);
}
catch (Exception ex)
{
await WriteExceptionAsync(httpResponse, ex);
}
finally
{
//if (httpMessage != null && httpMessage.Step == HttpStep.EndSession)
// Cleanup(context.RequestServices.GetService(typeof(IMemoryCache)), syncSessionId);
}
}
/// <summary>
/// Call this method to handle requests on the server, sent by the client
/// </summary>
public async Task HandleRequestAsync(HttpContext context, Action <RemoteOrchestrator> action, CancellationToken cancellationToken, IProgress <ProgressArgs> progress)
{
//this.HttpContext = context;
var httpRequest = context.Request;
var httpResponse = context.Response;
var serAndsizeString = string.Empty;
var cliConverterKey = string.Empty;
// Get the serialization and batch size format
if (TryGetHeaderValue(context.Request.Headers, "dotmim-sync-serialization-format", out var vs))
{
serAndsizeString = vs.ToLowerInvariant();
}
// Get the serialization and batch size format
if (TryGetHeaderValue(context.Request.Headers, "dotmim-sync-converter", out var cs))
{
cliConverterKey = cs.ToLowerInvariant();
}
if (!TryGetHeaderValue(context.Request.Headers, "dotmim-sync-session-id", out var sessionId))
{
throw new HttpHeaderMissingExceptiopn("dotmim-sync-session-id");
}
if (!TryGetHeaderValue(context.Request.Headers, "dotmim-sync-scope-name", out var scopeName))
{
throw new HttpHeaderMissingExceptiopn("dotmim-sync-scope-name");
}
if (!TryGetHeaderValue(context.Request.Headers, "dotmim-sync-step", out string iStep))
{
throw new HttpHeaderMissingExceptiopn("dotmim-sync-step");
}
var step = (HttpStep)Convert.ToInt32(iStep);
var readableStream = new MemoryStream();
try
{
// Copty stream to a readable and seekable stream
// HttpRequest.Body is a HttpRequestStream that is readable but can't be Seek
await httpRequest.Body.CopyToAsync(readableStream);
httpRequest.Body.Close();
httpRequest.Body.Dispose();
// if Hash is present in header, check hash
if (TryGetHeaderValue(context.Request.Headers, "dotmim-sync-hash", out string hashStringRequest))
{
HashAlgorithm.SHA256.EnsureHash(readableStream, hashStringRequest);
}
// try get schema from cache
if (this.Cache.TryGetValue <SyncSet>(scopeName, out var cachedSchema))
{
this.Schema = cachedSchema;
}
// try get session cache from current sessionId
if (!this.Cache.TryGetValue <SessionCache>(sessionId, out var sessionCache))
{
sessionCache = new SessionCache();
}
// action from user if available
action?.Invoke(this);
// Get the serializer and batchsize
(var clientBatchSize, var clientSerializerFactory) = this.GetClientSerializer(serAndsizeString);
// Get converter used by client
// Can be null
var clientConverter = this.GetClientConverter(cliConverterKey);
this.ClientConverter = clientConverter;
byte[] binaryData = null;
switch (step)
{
case HttpStep.EnsureScopes:
var m1 = await clientSerializerFactory.GetSerializer <HttpMessageEnsureScopesRequest>().DeserializeAsync(readableStream);
await this.InterceptAsync(new HttpGettingRequestArgs(context, m1.SyncContext, sessionCache, step), cancellationToken).ConfigureAwait(false);
var s1 = await this.EnsureScopesAsync(m1, sessionCache, cancellationToken, progress).ConfigureAwait(false);
binaryData = await clientSerializerFactory.GetSerializer <HttpMessageEnsureScopesResponse>().SerializeAsync(s1);
break;
case HttpStep.EnsureSchema:
var m11 = await clientSerializerFactory.GetSerializer <HttpMessageEnsureScopesRequest>().DeserializeAsync(readableStream);
await this.InterceptAsync(new HttpGettingRequestArgs(context, m11.SyncContext, sessionCache, step), cancellationToken).ConfigureAwait(false);
var s11 = await this.EnsureSchemaAsync(m11, sessionCache, cancellationToken, progress).ConfigureAwait(false);
binaryData = await clientSerializerFactory.GetSerializer <HttpMessageEnsureSchemaResponse>().SerializeAsync(s11);
break;
case HttpStep.SendChanges:
var m2 = await clientSerializerFactory.GetSerializer <HttpMessageSendChangesRequest>().DeserializeAsync(readableStream);
await this.InterceptAsync(new HttpGettingRequestArgs(context, m2.SyncContext, sessionCache, step), cancellationToken).ConfigureAwait(false);
await this.InterceptAsync(new HttpGettingClientChangesArgs(m2, context.Request.Host.Host, sessionCache), cancellationToken).ConfigureAwait(false);
var s2 = await this.ApplyThenGetChangesAsync(m2, sessionCache, clientBatchSize, cancellationToken, progress).ConfigureAwait(false);
await this.InterceptAsync(new HttpSendingServerChangesArgs(s2, context.Request.Host.Host, sessionCache, false), cancellationToken).ConfigureAwait(false);
binaryData = await clientSerializerFactory.GetSerializer <HttpMessageSendChangesResponse>().SerializeAsync(s2);
break;
case HttpStep.GetChanges:
var m3 = await clientSerializerFactory.GetSerializer <HttpMessageSendChangesRequest>().DeserializeAsync(readableStream);
await this.InterceptAsync(new HttpGettingRequestArgs(context, m3.SyncContext, sessionCache, step), cancellationToken).ConfigureAwait(false);
await this.InterceptAsync(new HttpGettingClientChangesArgs(m3, context.Request.Host.Host, sessionCache), cancellationToken).ConfigureAwait(false);
var s3 = await this.GetChangesAsync(m3, sessionCache, clientBatchSize, cancellationToken, progress);
await this.InterceptAsync(new HttpSendingServerChangesArgs(s3, context.Request.Host.Host, sessionCache, false), cancellationToken).ConfigureAwait(false);
binaryData = await clientSerializerFactory.GetSerializer <HttpMessageSendChangesResponse>().SerializeAsync(s3);
break;
case HttpStep.GetMoreChanges:
var m4 = await clientSerializerFactory.GetSerializer <HttpMessageGetMoreChangesRequest>().DeserializeAsync(readableStream);
await this.InterceptAsync(new HttpGettingRequestArgs(context, m4.SyncContext, sessionCache, step), cancellationToken).ConfigureAwait(false);
var s4 = await this.GetMoreChangesAsync(m4, sessionCache, cancellationToken, progress);
await this.InterceptAsync(new HttpSendingServerChangesArgs(s4, context.Request.Host.Host, sessionCache, false), cancellationToken).ConfigureAwait(false);
binaryData = await clientSerializerFactory.GetSerializer <HttpMessageSendChangesResponse>().SerializeAsync(s4);
break;
case HttpStep.GetSnapshot:
var m5 = await clientSerializerFactory.GetSerializer <HttpMessageSendChangesRequest>().DeserializeAsync(readableStream);
await this.InterceptAsync(new HttpGettingRequestArgs(context, m5.SyncContext, sessionCache, step), cancellationToken).ConfigureAwait(false);
var s5 = await this.GetSnapshotAsync(m5, sessionCache, cancellationToken, progress);
await this.InterceptAsync(new HttpSendingServerChangesArgs(s5, context.Request.Host.Host, sessionCache, true), cancellationToken).ConfigureAwait(false);
binaryData = await clientSerializerFactory.GetSerializer <HttpMessageSendChangesResponse>().SerializeAsync(s5);
break;
case HttpStep.GetEstimatedChangesCount:
var m6 = await clientSerializerFactory.GetSerializer <HttpMessageSendChangesRequest>().DeserializeAsync(readableStream);
await this.InterceptAsync(new HttpGettingRequestArgs(context, m6.SyncContext, sessionCache, step), cancellationToken).ConfigureAwait(false);
var s6 = await this.GetEstimatedChangesCountAsync(m6, cancellationToken, progress);
await this.InterceptAsync(new HttpSendingServerChangesArgs(s6, context.Request.Host.Host, sessionCache, false), cancellationToken).ConfigureAwait(false);
binaryData = await clientSerializerFactory.GetSerializer <HttpMessageSendChangesResponse>().SerializeAsync(s6);
break;
}
// Save schema to cache with a sliding expiration
this.Cache.Set(scopeName, this.Schema, this.WebServerOptions.GetServerCacheOptions());
// Save session client to cache with a sliding expiration
this.Cache.Set(sessionId, sessionCache, this.WebServerOptions.GetClientCacheOptions());
// Adding the serialization format used and session id
httpResponse.Headers.Add("dotmim-sync-session-id", sessionId.ToString());
httpResponse.Headers.Add("dotmim-sync-serialization-format", clientSerializerFactory.Key);
// calculate hash
var hash = HashAlgorithm.SHA256.Create(binaryData);
var hashString = Convert.ToBase64String(hash);
// Add hash to header
httpResponse.Headers.Add("dotmim-sync-hash", hashString);
// data to send back, as the response
byte[] data = this.EnsureCompression(httpRequest, httpResponse, binaryData);
await this.InterceptAsync(new HttpSendingResponseArgs(context, this.GetContext(), sessionCache, data, step), cancellationToken).ConfigureAwait(false);
await httpResponse.Body.WriteAsync(data, 0, data.Length, cancellationToken).ConfigureAwait(false);
}
catch (Exception ex)
{
await WebServerManager.WriteExceptionAsync(httpResponse, ex);
}
finally
{
readableStream.Flush();
readableStream.Close();
readableStream.Dispose();
}
}
/// <summary>
/// Get changes from
/// </summary>
internal async Task <HttpMessageSendChangesResponse> ApplyThenGetChangesAsync(HttpMessageSendChangesRequest httpMessage, SessionCache sessionCache,
int clientBatchSize, CancellationToken cancellationToken = default, IProgress <ProgressArgs> progress = null)
{
// Overriding batch size options value, coming from client
// having changes from server in batch size or not is decided by the client.
// Basically this options is not used on the server, since it's always overriden by the client
this.Options.BatchSize = clientBatchSize;
// Get if we need to serialize data or making everything in memory
var clientWorkInMemory = clientBatchSize == 0;
// Get context from request message
var ctx = httpMessage.SyncContext;
// Set the context coming from the client
this.SetContext(ctx);
// Check schema.
// If client has stored the schema, the EnsureScope will not be called on server.
if (this.Schema == null || !this.Schema.HasTables || !this.Schema.HasColumns)
{
var serverScopeInfo = await this.EnsureSchemaAsync(cancellationToken, progress).ConfigureAwait(false);
this.Schema = serverScopeInfo.Schema;
this.Schema.EnsureSchema();
}
// ------------------------------------------------------------
// FIRST STEP : receive client changes
// ------------------------------------------------------------
// We are receiving changes from client
// BatchInfo containing all BatchPartInfo objects
// Retrieve batchinfo instance if exists
// Get batch info from session cache if exists, otherwise create it
if (sessionCache.ClientBatchInfo == null)
{
sessionCache.ClientBatchInfo = new BatchInfo(clientWorkInMemory, Schema, this.Options.BatchDirectory);
}
// create the in memory changes set
var changesSet = new SyncSet();
foreach (var table in httpMessage.Changes.Tables)
{
DbSyncAdapter.CreateChangesTable(Schema.Tables[table.TableName, table.SchemaName], changesSet);
}
changesSet.ImportContainerSet(httpMessage.Changes, false);
// If client has made a conversion on each line, apply the reverse side of it
if (this.ClientConverter != null && changesSet.HasRows)
{
AfterDeserializedRows(changesSet, this.ClientConverter);
}
// add changes to the batch info
await sessionCache.ClientBatchInfo.AddChangesAsync(changesSet, httpMessage.BatchIndex, httpMessage.IsLastBatch, this);
// Clear the httpMessage set
if (!clientWorkInMemory && httpMessage.Changes != null)
{
httpMessage.Changes.Clear();
}
// Until we don't have received all the batches, wait for more
if (!httpMessage.IsLastBatch)
{
return(new HttpMessageSendChangesResponse(httpMessage.SyncContext)
{
ServerStep = HttpStep.SendChangesInProgress
});
}
// ------------------------------------------------------------
// SECOND STEP : apply then return server changes
// ------------------------------------------------------------
// get changes
var(remoteClientTimestamp, serverBatchInfo, _, clientChangesApplied, serverChangesSelected) =
await this.ApplyThenGetChangesAsync(httpMessage.Scope, sessionCache.ClientBatchInfo, cancellationToken, progress).ConfigureAwait(false);
// Save the server batch info object to cache if not working in memory
if (!clientWorkInMemory)
{
sessionCache.RemoteClientTimestamp = remoteClientTimestamp;
sessionCache.ServerBatchInfo = serverBatchInfo;
sessionCache.ServerChangesSelected = serverChangesSelected;
sessionCache.ClientChangesApplied = clientChangesApplied;
}
// Get the firt response to send back to client
return(await GetChangesResponseAsync(ctx, remoteClientTimestamp, serverBatchInfo, clientChangesApplied, serverChangesSelected, 0));
}
internal async Task <HttpMessageEnsureScopesResponse> EnsureScopesAsync(HttpMessageEnsureScopesRequest httpMessage, SessionCache sessionCache,
CancellationToken cancellationToken, IProgress <ProgressArgs> progress = null)
{
if (httpMessage == null)
{
throw new ArgumentException("EnsureScopesAsync message could not be null");
}
if (this.Setup == null)
{
throw new ArgumentException("You need to set the tables to sync on server side");
}
// Get context from request message
var ctx = httpMessage.SyncContext;
// Set the context coming from the client
this.SetContext(ctx);
// Get schema
var serverScopeInfo = await this.GetServerScopeAsync(default, default, cancellationToken, progress).ConfigureAwait(false);
/// <summary>
/// Get changes from
/// </summary>
internal async Task <HttpMessageSendChangesResponse> GetSnapshotAsync(HttpMessageSendChangesRequest httpMessage, SessionCache sessionCache,
CancellationToken cancellationToken = default, IProgress <ProgressArgs> progress = null)
{
// TODO : check Snapshot with version and scopename
// Check schema.
// If client has stored the schema, the EnsureScope will not be called on server.
if (this.Schema == null || !this.Schema.HasTables || !this.Schema.HasColumns)
{
var serverScopeInfo = await this.EnsureSchemaAsync(cancellationToken, progress).ConfigureAwait(false);
this.Schema = serverScopeInfo.Schema;
this.Schema.EnsureSchema();
}
// Get context from request message
var ctx = httpMessage.SyncContext;
// Set the context coming from the client
this.SetContext(ctx);
// get changes
var snap = await this.GetSnapshotAsync(this.Schema, cancellationToken, progress).ConfigureAwait(false);
// if no snapshot, return empty response
if (snap.ServerBatchInfo == null)
{
var changesResponse = new HttpMessageSendChangesResponse(ctx);
changesResponse.ServerStep = HttpStep.GetSnapshot;
changesResponse.BatchIndex = 0;
changesResponse.IsLastBatch = true;
changesResponse.RemoteClientTimestamp = 0;
changesResponse.Changes = null;
return(changesResponse);
}
sessionCache.RemoteClientTimestamp = snap.RemoteClientTimestamp;
sessionCache.ServerBatchInfo = snap.ServerBatchInfo;
// Get the firt response to send back to client
return(await GetChangesResponseAsync(ctx, snap.RemoteClientTimestamp, snap.ServerBatchInfo, null, null, 0));
}
