tree d604045e5f2cf778b7702fbb9d055f2961c29895
parent a606550743b0f909ce5ce52839fc83dc166d6208
author Jason Ling <jasonling@google.com> 1603507997 -0700
committer Jason Ling <jasonling@google.com> 1603821542 +0000

extend file_handler to support reads

Problem: the upcomming version handler will need to read from files.
Currently file hander (image handler) does not support reads.

Solution: Add read support by providing an optional mode parameter.

Tests added:
FileHanderTest added to
- Test out open for reads
- Test out reading out bytes and verifying size and content
- Test out trying to read beyond EOF
- Test out offset reads that go beyond EOF

Tested:
Existing unit tests pass
New unit tests for reading all pass

Signed-off-by: Jason Ling <jasonling@google.com>
Change-Id: Ie416a6b4b452d8d04fa158bd55989d07a891896f