throw exception if empty chunk idx has non-zero start and end times

foxglove · Jan 8, 2025 · b5ddcaf · b5ddcaf
1 parent e5c9da3
commit b5ddcaf
Showing 1 changed file with 11 additions and 0 deletions.
diff --git a/typescript/core/src/ChunkCursor.ts b/typescript/core/src/ChunkCursor.ts
@@ -103,6 +103,17 @@ export class ChunkCursor {
     const reverse = this.#reverse;
     let messageIndexStartOffset: bigint | undefined;
     let relevantMessageIndexStartOffset: bigint | undefined;
+
+    if (this.chunkIndex.messageIndexLength === 0n) {
+      // Chunk has no message indexes.
+      // We only allow that if the chunk has no messages and the start and end times are 0.
+      if (this.chunkIndex.messageStartTime !== 0n || this.chunkIndex.messageEndTime !== 0n) {
+        throw new Error(
+          `Encountered a chunk index without message indexes and non-zero start and end times`,
+        );
+      }
+    }
+
     for (const [channelId, offset] of this.chunkIndex.messageIndexOffsets) {
       if (messageIndexStartOffset == undefined || offset < messageIndexStartOffset) {
         messageIndexStartOffset = offset;