[JCS] Re: JCS Key Length Issue -- limited to 256 characters long?

2012-01-05 Thread Thomas Vandahl
First of all: Please use user@commons.apache.org for questions regarding
JCS.

On 04.01.12 18:12, Chopin hu wrote:
 I have a program to download files from remote sites.   Once downloaded a 
 data file, I use the URL as a key and put it to the cache so that I don't 
 have to download it again if the url is found to exist in the cache.   
 However, I found sometimes the caching would fail -- no caching is put to the 
 file system ( I am using Disk File Cache).   the url is working fine for 
 downloading.   After debugging, it turns out that the URL string is too long. 
   When the url string exceeds 256 characters, JCS won't accept it as a proper 
 key.   
 
 So my questions are:
 1.) is a JCS cache key limited to 256 chars long?   is there a way to 
 increase its length?
 2.) If can not get around the cache key length limitation, what could be the 
 possible ways to make a long URL string short enough but still unique enough 
 to serve as a key?  I tried to use the last 256 characters from the url 
 string, but some query string is so long that it could not guarantee a key's 
 uniqueness.

I guess the FileDiskCache is the issue here. The key of the item in
FileDiskCache is directly used as a file name. So what you experience is
a limit of file name length rather than key length.

You should better use another disk cache implementation such as
IndexedDiskCache which does not have such limits.

Bye, Thomas.

-
To unsubscribe, e-mail: user-unsubscr...@commons.apache.org
For additional commands, e-mail: user-h...@commons.apache.org



Re: [JCS] Re: JCS Key Length Issue -- limited to 256 characters long?

2012-01-05 Thread Chopin hu
good point.   too focused on jcs not realizing it is a file system issue.

--- On Thu, 1/5/12, Thomas Vandahl t...@apache.org wrote:

From: Thomas Vandahl t...@apache.org
Subject: [JCS] Re: JCS Key Length Issue -- limited to 256 characters long?
To: user@commons.apache.org
Cc: JCS Users List jcs-us...@jakarta.apache.org
Date: Thursday, January 5, 2012, 4:48 AM

First of all: Please use user@commons.apache.org for questions regarding
JCS.

On 04.01.12 18:12, Chopin hu wrote:
 I have a program to download files from remote sites.   Once downloaded a 
 data file, I use the URL as a key and put it to the cache so that I don't 
 have to download it again if the url is found to exist in the 
 cache.   However, I found sometimes the caching would fail -- no caching is 
 put to the file system ( I am using Disk File Cache).   the url is working 
 fine for downloading.   After debugging, it turns out that the URL string is 
 too long.   When the url string exceeds 256 characters, JCS won't accept it 
 as a proper key.   
 
 So my questions are:
 1.) is a JCS cache key limited to 256 chars long?   is there a way to 
 increase its length?
 2.) If can not get around the cache key length limitation, what could be the 
 possible ways to make a long URL string short enough but still unique enough 
 to serve as a key?  I tried to use the last 256 characters from the url 
 string, but some query string is so long that it could not guarantee a key's 
 uniqueness.

I guess the FileDiskCache is the issue here. The key of the item in
FileDiskCache is directly used as a file name. So what you experience is
a limit of file name length rather than key length.

You should better use another disk cache implementation such as
IndexedDiskCache which does not have such limits.

Bye, Thomas.

-
To unsubscribe, e-mail: jcs-users-unsubscr...@jakarta.apache.org
For additional commands, e-mail: jcs-users-h...@jakarta.apache.org