Export WPILOGs in timestamp order

src/hub/dataSources/wpilog/WPILOGEncoder.ts

@@ -169,6 +169,11 @@ export class WPILOGEncoderRecord {
     return array;
   }
 
+  /** Returns the timestamp in microseconds. */
+  getTimestamp() {
+    return this.timestamp;
+  }
+
   /** Encodes the full contents of this record and returns the result. */
   getEncoded(): Uint8Array {
     // Generate length bitfield
@@ -207,9 +212,10 @@ export class WPILOGEncoder {
   }
 
   /** Encodes the full data log. */
-  getEncoded(): Uint8Array {
+  getEncoded(sortByTimestamp = false): Uint8Array {
     // Encode all records and header data
-    let encodedRecords = this.records.map((record) => record.getEncoded());
+    let records = sortByTimestamp ? this.records.sort((a, b) => a.getTimestamp() - b.getTimestamp()) : this.records;
+    let encodedRecords = records.map((record) => record.getEncoded());
     let totalRecordLength = encodedRecords.reduce((previous, current) => previous + current.length, 0);
     let encodedHeader = TEXT_ENCODER.encode(HEADER_STRING);
     let encodedExtraHeader = TEXT_ENCODER.encode(this.extraHeader);

src/hub/exportWorker.ts

@@ -203,8 +203,9 @@ function generateWPILOG(log: Log, fields: string[], progress: (progress: number)
         metadata = JSON.stringify(metadataParsed);
       } catch {}
     }
+    let startTimestamp = fieldData.timestamps.length > 0 ? fieldData.timestamps[0] : 0;
     encoder.add(
-      WPILOGEncoderRecord.makeControlStart(0, {
+      WPILOGEncoderRecord.makeControlStart(startTimestamp, {
         entry: entryId, // Entry 0 is reserved
         name: field,
         type: typeStr,
@@ -260,7 +261,7 @@ function generateWPILOG(log: Log, fields: string[], progress: (progress: number)
 
   // Encode full log
   progress(1);
-  return encoder.getEncoded();
+  return encoder.getEncoded(true);
 }
 
 async function generateMCAP(log: Log, fields: string[], progress: (progress: number) => void): Promise<Uint8Array> {