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On Thursday 12 June 2003 02:56 am, Seemant Kulleen wrote: |
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> Anyway, the current approach keeps it simple in that the md5sum is off the |
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> *item(s) that is/are downloaded*. The first reason I can see is what I |
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> stated above. There are other reasons I can see as well. You know, |
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> immediately upon fetching the set of source items that they are bad. So, |
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> no disk i/o or cpu cycles are spent in the unpacking; and no potentially |
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> nasty code is even untarred on the system, yet. |
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Well, I can think of a way to address this part of the issue, anyway. |
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* The portage tree still has MD5 digests for the item(s) which is/are |
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downloaded. |
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* After downloading, emerge executes a (user specified?) program on the newly |
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downloaded file. This program applies some transform to the file; maybe it |
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decompresses whatever format the file is in and re-compresses it with bzip2, |
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or maybe it only format-shifts files which are over a certain size threshold, |
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whatever. |
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* Next, emerge adds a new record to a database (text, one record per line, for |
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example) somewhere in /var. This database has the original name of the |
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downloaded file, the original MD5 digest, the new name, and the new MD5 |
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digest. |
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* When emerge wants a new file, it checks the database to see if the desired |
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file has been mapped to a new transformed name and MD5. |
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You'd probably want to make the digest file readable only by the portage user |
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or something. |
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With infrastructure like this you could even add more interesting |
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functionality to portage pretty easily. Like maybe the transform program |
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uploads the file to the corporate internal FTP mirror, and the database maps |
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the original name to the URI which locates it. |
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Or, if emerge exported sufficient context to the transform program, you could |
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fix the case where a particular braindead package is available only as |
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package.tar.gz, not package-version.tar.gz. The transform program would add |
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the version to the filename, and the database would be allowed to have |
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multiple entries for each original file name (provided they had different MD5 |
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digests). Then emerge would just pick the record with both the desired |
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original name and the desired original MD5 digest. |
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Evan |
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-- |
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