From: Alex Riesen Date: Thu, 14 Dec 2006 14:49:38 GMT Subject: Re: [PATCH] Avoid accessing a slow working copy during diffcore operations. Message-ID: <81b0412b0612140649i71643aaar847460ca9e4cea48@mail.gmail.com> In-Reply-To: On 12/14/06, Johannes Schindelin wrote: > > > If Git is compiled with NO_FAST_WORKING_DIRECTORY set then we will > > > avoid looking at the working directory when the blob in question > > > is available within a packfile and the caller doesn't need the data > > > unpacked into a temporary file. > > > > Why can't it be useful in generic code? What are the downsides? > > It is usually cheaper to just read the file, especially if it is still > cached, because the alternative means unpacking the loose object, or > worse, unpacking the packed object _along_ with the objects in its delta > chain. But you have to read less, and even that could be in cache as well and unpacking in userspace could be faster than open/write temporary/ read temporary/close/unlink temporary file on a normal system > Not every OS sucks cache-wise, and you should not make others suffer for > Redmond's shortcomings. I'm just do not understand why avoiding temporary file wouldn't help