Adds a new method ReadUntilComplete to FileStream which ensure that a...

Add a new method ReadUntilComplete to FileStream which ensures that all requested bytes are read from the file in one call, assuming no errors occurr or EOF is reached.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=9803

[James Hawkins, 2009-02-13 21:48:40]

sheesh, I forgot to port it to posix.  Also a lint error.

[rvargas (doing something else), 2009-02-13 22:20:50]

http://codereview.chromium.org/21363/diff/8/9
File net/base/file_stream_win.cc (right):

http://codereview.chromium.org/21363/diff/8/9#newcode242
Line 242: bytes_read = Read(buf, to_read, NULL);
nit: declare bytes_read here

http://codereview.chromium.org/21363/diff/8/9#newcode244
Line 244: return bytes_read;
returning 0 after reading x bytes and reaching eof is not what you really want.
You should return what you have received so far.

http://codereview.chromium.org/21363/diff/8/9#newcode247
Line 247: buf += bytes_read;
don't you want to decrease to_read before the next iteration?

http://codereview.chromium.org/21363/diff/14/1007
File net/base/file_stream.h (right):

http://codereview.chromium.org/21363/diff/14/1007#newcode87
Line 87: // the operation could not be performed.
nit: Does this means that the last read will fail unless I'm  exactly at eof or
that it will be a partial read?

http://codereview.chromium.org/21363/diff/14/1007#newcode114
Line 114: int WriteUntilComplete(const char *buf, int buf_len);
I don't really think that we need this one. I'm not positive, but I don't
believe that the underlying write will return success if it cannot write the
whole buffer.

[rvargas (doing something else), 2009-02-13 22:45:52]

Ignore the nits that are already fixed :(

http://codereview.chromium.org/21363/diff/1010/1012
File net/base/file_stream.h (right):

http://codereview.chromium.org/21363/diff/1010/1012#newcode87
Line 87: // the operation could not be performed.
Still the comment is not clear to me (see previous comment)

http://codereview.chromium.org/21363/diff/1010/1013
File net/base/file_stream_posix.cc (right):

http://codereview.chromium.org/21363/diff/1010/1013#newcode162
Line 162: bytes_read = Read(buf, to_read, NULL);
nit: int bytes_read = Read()

http://codereview.chromium.org/21363/diff/1010/1013#newcode164
Line 164: {
nit: if () {

[rvargas (doing something else), 2009-02-13 23:08:26]

LGTM