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krh@1
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- keep history of installed packages/journal of package transaction,
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krh@1
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2 |
so we can roll back to yesterday, or see what got installed in the
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krh@1
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3 |
latest yum update.
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krh@1
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4 |
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krh@1
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5 |
- we build a cache of the currently installed set to service
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krh@1
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6 |
dependency inquiries fast:
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krh@1
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7 |
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krh@1
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8 |
map from property to pkg (as hash) providing it
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krh@1
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9 |
map from property to pkgs requiring it
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krh@1
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10 |
map from pkg name to manifest
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krh@1
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11 |
map from string to string pool index
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krh@1
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12 |
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krh@1
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13 |
no implicit provides? not even pkgname?
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krh@1
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14 |
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krh@1
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15 |
- properties are strings, stored in a string table
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krh@1
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16 |
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krh@1
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17 |
- on disk maps are binary files of (string table index, hash) pairs
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krh@1
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18 |
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krh@1
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19 |
- at run time, we mmap the map, and keep changes in memory in a splay
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krh@1
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20 |
tree or similar. if searching the splay tree fails we punt to the
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krh@1
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mmap. once the transaction is done, we merge the map and the splay
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krh@1
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22 |
tree and write it back out.
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krh@1
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23 |
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krh@1
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24 |
- the on-disk string pool is sorted and we keep a list of indices into
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krh@1
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the string pool in sorted order so we can bsearch the list with a
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krh@1
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string to get its string pool index. maybe a hash table is better,
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krh@1
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27 |
less I/O as we will expect to find the string within the block we
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krh@1
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28 |
look up with the hash function.
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krh@1
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29 |
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krh@5
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30 |
- represent all files as a breadth first traversal of the tree of all
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krh@5
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files. each entry has its name (string pool index), the number of
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krh@5
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immediate children, total number of children, and owning package.
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krh@5
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for files both these numbers are zero. a file is identified by its
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krh@5
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index in this flattened tree.
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krh@5
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krh@5
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to get the file name from an index, we search through the list. by
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krh@5
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summing up the number of children, we know when to skip a directory
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krh@5
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38 |
and when to descend into one. as we go we accumulate the path
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krh@5
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elements.
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krh@5
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40 |
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krh@5
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41 |
hmm, dropping number of immediate children and using a sentinel drops
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krh@5
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a word from every entry.
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krh@5
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43 |
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krh@1
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44 |
- signed pkgs
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krh@8
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45 |
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krh@8
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46 |
- gzip repository of look-aside pkg xml files somehow?
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krh@8
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47 |
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krh@8
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48 |
- transactions, proper recovery, make sure we don't poop our package
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krh@8
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49 |
database (no more rm /var/lib/rpm/__cache*).
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krh@8
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50 |
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krh@8
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51 |
- no external dependencies, forget about bdb, sqlite. It's *simple*
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krh@8
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52 |
and we need to control the on-disk format for these tools.
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krh@8
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53 |
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krh@8
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54 |
- 20740 requires, 2246 unique... hmm.
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