Improved memory usage while applying patch....

Improved memory usage while applying patch.

Reduced total size of allocations from 520MB to 318MB.
The general technique is to allocate the correct size rather than grow into
the correct size and overshoot.

1. Find file sizes and allocate buffers of that size for the input files.

2. Pre-allocate a buffer for the collected inputs for the final diff.

3. Calculate the size for (2) during compression and include it in the patch
   header.

The courgette.exe command line tool now calls the same ApplyEnsemblePatch
entry point that is called by the installer.  This ensures measurements of
courgette.exe are a better reflection of the installer.

BUG=72459
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=75787

[tommi (sloooow) - chröme, 2011-02-23 06:35:59]

couple of questions/requests

http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc
File courgette/courgette_tool.cc (right):

http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc#...
courgette/courgette_tool.cc:306:
courgette::ApplyEnsemblePatch(old_path.value().c_str(),
would it be simpler to make all ApplyEnsemplePatch functions just use const
FilePath&? (including this one)

http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc#...
courgette/courgette_tool.cc:314: std::string old_buffer = ReadOrFail(old_file,
"'old' input");
remove these calls?

[sra1, 2011-02-23 06:47:23]

On 2011/02/23 06:35:59, tommi wrote:
> couple of questions/requests
> 
> http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc
> File courgette/courgette_tool.cc (right):
> 
>
http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc#...
> courgette/courgette_tool.cc:306:
> courgette::ApplyEnsemblePatch(old_path.value().c_str(),
> would it be simpler to make all ApplyEnsemplePatch functions just use const
> FilePath&? (including this one)
> 
>
http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc#...
> courgette/courgette_tool.cc:314: std::string old_buffer = ReadOrFail(old_file,
> "'old' input");
> remove these calls?

[sra1, 2011-02-23 06:51:59]

http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc
File courgette/courgette_tool.cc (right):

http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc#...
courgette/courgette_tool.cc:306:
courgette::ApplyEnsemblePatch(old_path.value().c_str(),
On 2011/02/23 06:35:59, tommi wrote:
> would it be simpler to make all ApplyEnsemplePatch functions just use const
> FilePath&? (including this one)

I would like to keep the entry point with as simple an interface as possible.

http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc#...
courgette/courgette_tool.cc:314: std::string old_buffer = ReadOrFail(old_file,
"'old' input");
On 2011/02/23 06:35:59, tommi wrote:
> remove these calls?

If the file does not exist, this is what gives the command line tool error. 
This is simpler than testing explicitly, and this command is only used for
testing and development.

[tommi (sloooow) - chröme, 2011-02-23 06:53:36]

Sounds good.  LGTM.

On 2011/02/23 06:51:59, sra1 wrote:
> http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc
> File courgette/courgette_tool.cc (right):
> 
>
http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc#...
> courgette/courgette_tool.cc:306:
> courgette::ApplyEnsemblePatch(old_path.value().c_str(),
> On 2011/02/23 06:35:59, tommi wrote:
> > would it be simpler to make all ApplyEnsemplePatch functions just use const
> > FilePath&? (including this one)
> 
> I would like to keep the entry point with as simple an interface as possible.
> 
>
http://codereview.chromium.org/6546008/diff/1008/courgette/courgette_tool.cc#...
> courgette/courgette_tool.cc:314: std::string old_buffer = ReadOrFail(old_file,
> "'old' input");
> On 2011/02/23 06:35:59, tommi wrote:
> > remove these calls?
> 
> If the file does not exist, this is what gives the command line tool error. 
> This is simpler than testing explicitly, and this command is only used for
> testing and development.