Fix performance regression in heap dump parsing.
The previous change to support large heap dumps significantly regressed
parsing performance. On an example heap dump, it increased the
'Reading Hprof...' time from 2 seconds to 46 seconds.
Read data from the file into the buffer in bigger chunks to make heap
dump parsing performance reasonable again: around 3 seconds on the
example heap dump.
Test: atest --host ahat-tests; manually measure performance on sample heap dump
Flag: TEST_ONLY
Bug: 413418793
Change-Id: Ib5548f2a9db9559c7654010f10b780d06c2a8ba5
1 file changed
