Make dmprof handle long runs better

Make dmprof handle long runs better

Read the dump files one by one as they are processed instead of reading
them all into memory at the start of the program, to reduce peak memory
consumption.  This makes it possible to process larger data sets.

Also restructure a few sub-command implementations to avoid iterating
over the list of dumps more than once and to avoid accessing any given
dump (typically the first) more than once.

BUG=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=248458

[Jens Widell, 2014-01-31 14:50:21]

Please take a look.  This aims to improve the usability of the dmprof program on
larger data-sets.

[Dai Mikurube (NOT FULLTIME), 2014-02-03 07:00:24]

lgtm with a nit. Thanks for working on it!

https://codereview.chromium.org/141563014/diff/1/tools/deep_memory_profiler/l...
File tools/deep_memory_profiler/lib/dump.py (right):

https://codereview.chromium.org/141563014/diff/1/tools/deep_memory_profiler/l...
tools/deep_memory_profiler/lib/dump.py:410: """Represents a sequence of heap
profile dumps."""
Could you add some comments that describes
* It loads dumped files lazily.
* It may read the same file again when __getitem__ is called again for the same
index.

[Jens Widell, 2014-02-03 07:29:57]

https://codereview.chromium.org/141563014/diff/1/tools/deep_memory_profiler/l...
File tools/deep_memory_profiler/lib/dump.py (right):

https://codereview.chromium.org/141563014/diff/1/tools/deep_memory_profiler/l...
tools/deep_memory_profiler/lib/dump.py:410: """Represents a sequence of heap
profile dumps."""
On 2014/02/03 07:00:24, Dai Mikurube wrote:
> Could you add some comments that describes
> * It loads dumped files lazily.
> * It may read the same file again when __getitem__ is called again for the
same
> index.

Some notes to that effect added.

[Dai Mikurube (NOT FULLTIME), 2014-02-03 07:31:06]

Still lgtm. Thanks!

[Jens Widell, 2014-02-03 07:33:27]

The CQ bit was checked by jl@opera.com

[commit-bot: I haz the power, 2014-02-03 07:33:36]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jl@opera.com/141563014/60001

[Jens Widell, 2014-02-03 07:33:41]

On 2014/02/03 07:31:06, Dai Mikurube wrote:
> Still lgtm. Thanks!

Thanks for reviewing!

[commit-bot: I haz the power, 2014-02-03 09:14:15]

Change committed as 248458

[commit-bot: I haz the power, 2014-02-03 09:14:15]

CQ bit was unchecked on CL. Ignoring.

[commit-bot: I haz the power, 2014-02-03 09:14:17]

CQ bit was unchecked on CL. Ignoring.