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RavenDB LastInWinsReplicationConflictResolver
using System;
using System.Linq;
using NLog;
using Raven.Abstractions.Data;
using Raven.Bundles.Replication;
using Raven.Bundles.Replication.Plugins;
using Raven.Json.Linq;
namespace MyRavenReplicationBundle
{
public class LastInWinsReplicationConflictResolver
: AbstractDocumentReplicationConflictResolver
{
private readonly Logger log = LogManager.GetCurrentClassLogger();
public override bool TryResolve(
string id,
RavenJObject metadata,
RavenJObject document,
JsonDocument existingDoc)
{
if (this.ExistingDocShouldWin(metadata, existingDoc))
{
this.ReplaceValues(metadata, existingDoc.Metadata);
this.ReplaceValues(document, existingDoc.DataAsJson);
log.Debug("Replication conflict for '{0}' resolved by choosing existing document.", id);
}
else
{
log.Debug("Replication conflict for '{0}' resolved by choosing inbound document.", id);
}
return true;
}
private bool ExistingDocShouldWin(RavenJObject newMetadata, JsonDocument existingDoc)
{
if (existingDoc == null ||
this.ExistingDocHasConflict(existingDoc) ||
this.ExistingDocIsOlder(newMetadata, existingDoc))
{
return false;
}
return true;
}
private bool ExistingDocHasConflict(JsonDocument existingDoc)
{
return existingDoc.Metadata[ReplicationConstants.RavenReplicationConflict] != null;
}
private bool ExistingDocIsOlder(RavenJObject newMetadata, JsonDocument existingDoc)
{
var newLastModified = this.GetLastModified(newMetadata);
if (!existingDoc.LastModified.HasValue ||
newLastModified.HasValue &&
existingDoc.LastModified <= newLastModified)
{
return true;
}
return false;
}
private DateTime? GetLastModified(RavenJObject metadata)
{
var lastModified = metadata[Constants.LastModified];
return (lastModified == null) ?
new DateTime?() :
lastModified.Value<DateTime?>();
}
private void ReplaceValues(RavenJObject target, RavenJObject source)
{
var targetKeys = target.Keys.ToArray();
foreach (var key in targetKeys)
{
target.Remove(key);
}
foreach (var key in source.Keys)
{
target.Add(key, source[key]);
}
}
}
}
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