Re: image-size

[Lars Magne Ingebrigtsen]

With this image:

http://www.evo.org/html/scans/BAD0013/BAD0013-1-l.jpg

address@hidden ~/mgnus]$ ls -l 
/home/larsi/Catalogue/html/scans/BAD0013/BAD0011-l.jpg
-rw-r--r-- 1 larsi users 2399848 Feb 25  2007 
/home/larsi/Catalogue/html/scans/BAD0013/BAD0013-1-l.jpg

(benchmark-elapse (image-size (create-image 
"/home/larsi/Catalogue/html/scans/BAD0013/BAD0013-1-l.jpg") nil))
=> 46.614988405

46 seconds to query the size.

With a local X, this is the result:

(benchmark-elapse (image-size (create-image 
"/home/larsi/Catalogue/html/scans/BAD0013/BAD0013-1-l.jpg") nil))
=> 0.572555233


strace shows that this is what Emacs does during that time:

pid 16301]      0.000055 writev(4, [{"H\2\316\362^\0 \4_\0 
\4H\16\21\0\0\0\265\6\0\30 \4", 24}, 
{"\"\"\34\0\"\"\34\0\"\"\34\0\"\"\34\0\r\10\v\0\32\27\25\0\32\27\25\0\32\27\25\0"...,
 248608}, {"", 0}], 3) = 248632
[pid 16301]      0.000055 writev(4, [{"H\2\316\362^\0 \4_\0 
\4H\16\21\0\0\0\306\6\0\30 \4", 24}, 
{"\32\27\25\0\32\27\25\0\32\27\25\0\32\27\25\0\32\27\25\0\32\27\25\0\32\27\25\0\32\27\25\0"...,
 248608}, {"", 0}], 3) = 248632
[pid 16301]      0.000191 writev(4, [{"H\2\316\362^\0 \4_\0 
\4H\16\21\0\0\0\327\6\0\30 \4", 24}, 
{"\32\27\25\0\"\"\34\0\32\27\25\0#$&\0\"\"\34\0\"\"\34\0\32\27\25\0#$&\0"..., 
248608}, {"", 0}], 3) = 248632

fd 4 is the X-over-ssh socket.

address@hidden ~/mgnus]$ grep 248632 /tmp/s | wc -l
214

(* 214 248608)
=> 53202112

So it transferred about 53MB over the net, which is a bit more than
1MB/s, which is about half the size of the connection I have to work.
Which makes sense, since I'm ssh-ing first to work, and then back again.

Proof!!!1!

-- 
(domestic pets only, the antidote for overdose, milk.)
  bloggy blog http://lars.ingebrigtsen.no/