Fix abort on inverted time travel query

libtiledbvcf/src/dataset/tiledbvcfdataset.cc

@@ -29,6 +29,7 @@
 #include <cstdlib>
 #include <future>
 #include <map>
+#include <optional>
 #include <string>
 #include <vector>
 
@@ -571,12 +572,12 @@ void TileDBVCFDataset::open(
   // 'vcf.end_timestamp' in tiledb_config. If either timestamp is provided,
   // reopen the arrays.
   bool reopen = false;
+  std::optional<uint64_t> start_timestamp;
+  std::optional<uint64_t> end_timestamp;
 
   try {
-    auto start_timestamp = std::stoull(cfg_.get("vcf.start_timestamp"));
-    data_array_->set_open_timestamp_start(start_timestamp);
-    vcf_header_array_->set_open_timestamp_start(start_timestamp);
-    LOG_INFO("Using vcf.start_timestamp from config: {}", start_timestamp);
+    start_timestamp = std::stoull(cfg_.get("vcf.start_timestamp"));
+    LOG_INFO("Using vcf.start_timestamp from config: {}", *start_timestamp);
     reopen = true;
   } catch (const tiledb::TileDBError& ex) {
     LOG_TRACE("'vcf.start_timestamp' not specified in config, using default");
@@ -587,10 +588,8 @@ void TileDBVCFDataset::open(
   }
 
   try {
-    auto end_timestamp = std::stoull(cfg_.get("vcf.end_timestamp"));
-    data_array_->set_open_timestamp_end(end_timestamp);
-    vcf_header_array_->set_open_timestamp_end(end_timestamp);
-    LOG_INFO("Using vcf.end_timestamp from config: {}", end_timestamp);
+    end_timestamp = std::stoull(cfg_.get("vcf.end_timestamp"));
+    LOG_INFO("Using vcf.end_timestamp from config: {}", *end_timestamp);
     reopen = true;
   } catch (const tiledb::TileDBError& ex) {
     LOG_TRACE("'vcf.end_timestamp' not specified in config, using default");
@@ -600,6 +599,29 @@ void TileDBVCFDataset::open(
         cfg_.get("vcf.end_timestamp"));
   }
 
+  // If the user supplied an inverted range (start > end), short-circuit:
+  // mark the dataset as having an empty time range and skip the reopen.
+  // Calling reopen() with start > end would surface as an uncaught
+  // "Range is empty" exception in some TileDB versions and abort the process.
+  if (start_timestamp && end_timestamp && *start_timestamp > *end_timestamp) {
+    LOG_INFO(
+        "vcf.start_timestamp ({}) > vcf.end_timestamp ({}); treating as "
+        "empty time range",
+        *start_timestamp,
+        *end_timestamp);
+    empty_time_range_ = true;
+    reopen = false;
+  } else {
+    if (start_timestamp) {
+      data_array_->set_open_timestamp_start(*start_timestamp);
+      vcf_header_array_->set_open_timestamp_start(*start_timestamp);
+    }
+    if (end_timestamp) {
+      data_array_->set_open_timestamp_end(*end_timestamp);
+      vcf_header_array_->set_open_timestamp_end(*end_timestamp);
+    }
+  }
+
   if (reopen) {
     data_array_->reopen();
     vcf_header_array_->reopen();

libtiledbvcf/src/dataset/tiledbvcfdataset.h

@@ -812,6 +812,16 @@ class TileDBVCFDataset {
   /** Returns true if the dataset is tiledb cloud URI. */
   bool tiledb_cloud_dataset() const;
 
+  /**
+   * Returns true if the user requested an inverted time-travel range
+   * (vcf.start_timestamp > vcf.end_timestamp). In that case the arrays were
+   * never reopened with the inverted range, and callers should treat reads
+   * as producing zero results.
+   */
+  bool empty_time_range() const {
+    return empty_time_range_;
+  }
+
   /**
    * Gets the datatype of a particular exportable attribute that is not fmt or
    * info
@@ -881,6 +891,11 @@ class TileDBVCFDataset {
   /** Set to true when the dataset is opened. */
   bool open_;
 
+  /** Set to true when open() was called with an inverted time-travel range
+   * (start_timestamp > end_timestamp). When true, reads should short-circuit
+   * to zero results without consulting the underlying arrays. */
+  bool empty_time_range_ = false;
+
   /** The dataset's general metadata (does not contain sample header data). */
   Metadata metadata_;
 

libtiledbvcf/src/read/reader.cc

@@ -365,6 +365,12 @@ void Reader::read() {
     throw std::runtime_error(
         "Error exporting records; reader has not been initialized.");
 
+  if (dataset_->empty_time_range()) {
+    read_state_.status = ReadStatus::COMPLETED;
+    buffers_a.reset(nullptr);
+    return;
+  }
+
   bool pending_work = true;
   switch (read_state_.status) {
     case ReadStatus::COMPLETED:
@@ -2587,6 +2593,10 @@ void Reader::info_attribute_count(int32_t* count) {
 void Reader::sample_count(int32_t* count) {
   if (count == nullptr)
     throw std::runtime_error("Error getting sample count");
+  if (dataset_->empty_time_range()) {
+    *count = 0;
+    return;
+  }
   *count = dataset_->sample_names().size();
 }