Can't graph unified gc log w/o uptime

[pburka]

In Java 11, if you collect GC logs with time, but not uptime (e.g. -Xlog:gc*=info:gclog:time,tags -XX:+UseParallelGC), GCViewer seems to parse the logs successfully, but it can't graph them. All of the lines are bunched up against the left hand side of the graph, and throughput calculation is completely wrong (i.e. a large negative number).

[2019-07-18T18:29:11.553+0000][gc,heap,coops] Heap address: 0x000000048f400000, size: 14092 MB, Compressed Oops mode: Zero based, Oop shift amount: 3
[2019-07-18T18:29:12.220+0000][gc,start     ] GC(0) Pause Young (Allocation Failure)
[2019-07-18T18:29:12.289+0000][gc,heap      ] GC(0) PSYoungGen: 196401K->3104K(263680K)
[2019-07-18T18:29:12.289+0000][gc,heap      ] GC(0) ParOldGen: 0K->68341K(602112K)
[2019-07-18T18:29:12.289+0000][gc,metaspace ] GC(0) Metaspace: 14973K->14973K(1062912K)
[2019-07-18T18:29:12.289+0000][gc           ] GC(0) Pause Young (Allocation Failure) 191M->69M(845M) 69.243ms
[2019-07-18T18:29:12.289+0000][gc,cpu       ] GC(0) User=0.33s Sys=0.08s Real=0.07s
[2019-07-18T18:29:12.341+0000][gc,start     ] GC(1) Pause Young (Allocation Failure)
[2019-07-18T18:29:12.391+0000][gc,heap      ] GC(1) PSYoungGen: 223402K->3040K(489984K)
...

[chewiebug]

Yes - as documented in the readme, uptime currently is required. for GCViewer to work

Minimum tags required: -Xlog:gc=info:file="path-to-file":tags,uptime,level

I might change this in the future.