private async Task <SearchResult> SearchImpl(SearchOptions searchOptions, bool historySearch, CancellationToken cancellationToken)
{
Expression searchExpression = searchOptions.Expression;
// AND in the continuation token
if (!string.IsNullOrWhiteSpace(searchOptions.ContinuationToken) && !searchOptions.CountOnly)
{
var continuationToken = ContinuationToken.FromString(searchOptions.ContinuationToken);
if (continuationToken != null)
{
// in case it's a _lastUpdated sort optimization
if (string.IsNullOrEmpty(continuationToken.SortValue))
{
(SearchParameterInfo searchParamInfo, SortOrder sortOrder) = searchOptions.GetFirstSupportedSortParam();
Expression lastUpdatedExpression = sortOrder == SortOrder.Ascending ? Expression.GreaterThan(SqlFieldName.ResourceSurrogateId, null, continuationToken.ResourceSurrogateId)
: Expression.LessThan(SqlFieldName.ResourceSurrogateId, null, continuationToken.ResourceSurrogateId);
var tokenExpression = Expression.SearchParameter(SqlSearchParameters.ResourceSurrogateIdParameter, lastUpdatedExpression);
searchExpression = searchExpression == null ? tokenExpression : (Expression)Expression.And(tokenExpression, searchExpression);
}
}
else
{
throw new BadRequestException(Resources.InvalidContinuationToken);
}
}
if (searchOptions.CountOnly)
{
// if we're only returning a count, discard any _include parameters since included resources are not counted.
searchExpression = searchExpression?.AcceptVisitor(RemoveIncludesRewriter.Instance);
}
SqlRootExpression expression = (SqlRootExpression)searchExpression
?.AcceptVisitor(LastUpdatedToResourceSurrogateIdRewriter.Instance)
.AcceptVisitor(DateTimeEqualityRewriter.Instance)
.AcceptVisitor(FlatteningRewriter.Instance)
.AcceptVisitor(_sqlRootExpressionRewriter)
.AcceptVisitor(_sortRewriter, searchOptions)
.AcceptVisitor(DenormalizedPredicateRewriter.Instance)
.AcceptVisitor(NormalizedPredicateReorderer.Instance)
.AcceptVisitor(_chainFlatteningRewriter)
.AcceptVisitor(DateTimeBoundedRangeRewriter.Instance)
.AcceptVisitor(_stringOverflowRewriter)
.AcceptVisitor(NumericRangeRewriter.Instance)
.AcceptVisitor(MissingSearchParamVisitor.Instance)
.AcceptVisitor(IncludeDenormalizedRewriter.Instance)
.AcceptVisitor(TopRewriter.Instance, searchOptions)
.AcceptVisitor(IncludeRewriter.Instance)
?? SqlRootExpression.WithDenormalizedExpressions();
using (SqlConnectionWrapper sqlConnectionWrapper = _sqlConnectionWrapperFactory.ObtainSqlConnectionWrapper(true))
using (SqlCommandWrapper sqlCommandWrapper = sqlConnectionWrapper.CreateSqlCommand())
{
var stringBuilder = new IndentedStringBuilder(new StringBuilder());
EnableTimeAndIoMessageLogging(stringBuilder, sqlConnectionWrapper);
var queryGenerator = new SqlQueryGenerator(stringBuilder, new SqlQueryParameterManager(sqlCommandWrapper.Parameters), _model, historySearch, _schemaInformation);
expression.AcceptVisitor(queryGenerator, searchOptions);
sqlCommandWrapper.CommandText = stringBuilder.ToString();
LogSqlCommand(sqlCommandWrapper);
using (var reader = await sqlCommandWrapper.ExecuteReaderAsync(CommandBehavior.SequentialAccess, cancellationToken))
{
if (searchOptions.CountOnly)
{
await reader.ReadAsync(cancellationToken);
return(new SearchResult(reader.GetInt32(0), searchOptions.UnsupportedSearchParams));
}
var resources = new List <SearchResultEntry>(searchOptions.MaxItemCount);
long?newContinuationId = null;
bool moreResults = false;
int matchCount = 0;
// Currently we support only date time sort type.
DateTime?sortValue = null;
while (await reader.ReadAsync(cancellationToken))
{
(short resourceTypeId, string resourceId, int version, bool isDeleted, long resourceSurrogateId, string requestMethod, bool isMatch, bool isPartialEntry, bool isRawResourceMetaSet, Stream rawResourceStream) = reader.ReadRow(
VLatest.Resource.ResourceTypeId,
VLatest.Resource.ResourceId,
VLatest.Resource.Version,
VLatest.Resource.IsDeleted,
VLatest.Resource.ResourceSurrogateId,
VLatest.Resource.RequestMethod,
_isMatch,
_isPartial,
VLatest.Resource.IsRawResourceMetaSet,
VLatest.Resource.RawResource);
// If we get to this point, we know there are more results so we need a continuation token
// Additionally, this resource shouldn't be included in the results
if (matchCount >= searchOptions.MaxItemCount && isMatch)
{
moreResults = true;
// At this point we are at the last row.
// if we have more columns, it means sort expressions were added.
if (reader.FieldCount > 10)
{
sortValue = reader.GetValue(SortValueColumnName) as DateTime?;
}
continue;
}
// See if this resource is a continuation token candidate and increase the count
if (isMatch)
{
newContinuationId = resourceSurrogateId;
matchCount++;
}
string rawResource;
using (rawResourceStream)
using (var gzipStream = new GZipStream(rawResourceStream, CompressionMode.Decompress))
using (var streamReader = new StreamReader(gzipStream, SqlServerFhirDataStore.ResourceEncoding))
{
rawResource = await streamReader.ReadToEndAsync();
}
// as long as at least one entry was marked as partial, this resultset
// should be marked as partial
_isResultPartial = _isResultPartial || isPartialEntry;
resources.Add(new SearchResultEntry(
new ResourceWrapper(
resourceId,
version.ToString(CultureInfo.InvariantCulture),
_model.GetResourceTypeName(resourceTypeId),
new RawResource(rawResource, FhirResourceFormat.Json, isMetaSet: isRawResourceMetaSet),
new ResourceRequest(requestMethod),
new DateTimeOffset(ResourceSurrogateIdHelper.ResourceSurrogateIdToLastUpdated(resourceSurrogateId), TimeSpan.Zero),
isDeleted,
null,
null,
null),
isMatch ? SearchEntryMode.Match : SearchEntryMode.Include));
}
// call NextResultAsync to get the info messages
await reader.NextResultAsync(cancellationToken);
IReadOnlyList <(string parameterName, string reason)> unsupportedSortingParameters;
if (searchOptions.Sort?.Count > 0)
{
unsupportedSortingParameters = searchOptions
.UnsupportedSortingParams
.Concat(searchOptions.Sort
.Where(x => !x.searchParameterInfo.IsSortSupported())
.Select(s => (s.searchParameterInfo.Name, Core.Resources.SortNotSupported))).ToList();
}
else
{
unsupportedSortingParameters = searchOptions.UnsupportedSortingParams;
}
// Continuation token prep
ContinuationToken continuationToken = null;
if (moreResults)
{
if (sortValue.HasValue)
{
continuationToken = new ContinuationToken(new object[]
{
sortValue.Value.ToString("o"),
newContinuationId ?? 0,
});
}
else
{
continuationToken = new ContinuationToken(new object[]
{
newContinuationId ?? 0,
});
}
}
return(new SearchResult(resources, searchOptions.UnsupportedSearchParams, unsupportedSortingParameters, continuationToken?.ToJson(), _isResultPartial));
}
}
}