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2020-12-05report-layout: remove vestigial includesVito Caputo
This is derived from report-usage.c, tidy this up.
2020-12-05report-layout: implement rudimentary `jio report layout`Vito Caputo
This writes a .layout file for every opened journal, which describes the sequential object layout for the respective journal. Sample output: ``` Layout for "user-1000.journal" Legend: ? OBJECT_UNUSED d OBJECT_DATA f OBJECT_FIELD e OBJECT_ENTRY D OBJECT_DATA_HASH_TABLE F OBJECT_FIELD_HASH_TABLE A OBJECT_ENTRY_ARRAY T OBJECT_TAG |N| object spans N page boundaries (page size used=4096) | single page boundary +N N bytes of alignment padding + single byte alignment padding F|5344 D|448|1834896 d81+7 f50+6 d74+6 f48 d82+6 f55+ d84+4 f57+7 d80 f50+6 d122+6 f47+ d74+6 f44+4 d73+7 f44+4 d70+2 f44+4 d72 f45+3 d76+4 f44+4 d75+5 f48 d90+6 f54+2 d80 f54+2 d84+4 f55+ d123+5 f55+ d82+6 f56 d87+ f58+6 d93+3 f53+3 d|94+2 f54+2 d91+5 f59+5 d119+ f62+2 d107+5 f66+6 d105+7 f48 d108+4 f51+5 d82+6 f49+7 e480 A56 d80 d104 d74+6 d73+7 d107+5 e480 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 A56 d97+7 d107+5 e|480 A56 A56 A56 d136 d107+5 e480 A56 d74+6 d148+4 d107+5 e480 A88 d107+5 e480 A88 A88 A88 A56 A88 A88 A88 A88 A88 A88 A88 A88 A88 A88 A|88 A88 A88 A88 A88 A88 A88 d80 d74+6 d107+5 e480 A88 A56 d107+5 e480 A56 A56 A56 d107+5 e480 A56 d107+5 e480 A88 A56 A56 d107+5 e|480 d80 d74+6 d107+5 e480 d97+7 d107+5 e480 A232 A88 A56 A56 d142+2 d107+5 e480 A232 A232 A232 A232 A232 A|232 A232 A232 A232 A232 A232 A232 A232 A232 A232 A232 A232 A232 A232 A232 d107+5 e480 d107+5 e|480 d80 d74+6 d107+5 e480 A232 d107+5 e480 A56 A56 d107+5 e480 d107+5 e480 d107+5 e304 d80 d74+6 d107+5 e|480 d107+5 e480 A56 A56 d107+5 e480 A232 d107+5 e480 d107+5 e480 A88 d80 d74+6 d107+5 e480 A88 d107+5 e|480 A56 A56 d107+5 e480 d107+5 e480 A88 A88 ``` This provides insight into the distribution of object types, how much space is spent on alignment padding, how frequently objects land on page boundaries - something preferably avoided especially for small objects near a boundary. In the above example, we can immediately make the observation that early in the journal there are interleaved data and field objects, and this cluster of the initially added data and field objects gets torn by a page boundary. It's possible if they weren't interleaved when adding an entry and its respective data + fields, fitting all the early (common) data objects within a single page might confer some performance gain. The field objects aren't currently used by data object heavy operations, it doesn't make much sense to have them polluting the area of the initially added data objects or really any otherwise clustered data objects.
2020-11-29journals: s/journal_for_each/journal_iter_objects/Vito Caputo
Make naming a bit more descriptive and consistent... journals_for_each() is a simple non-IO-incurring journals array iteration, journal_for_each() generates IO and walks the data objects hash table... they're quite different, and shouldn't have such similar names.
2020-11-25*: explicitly include assert.hVito Caputo
2020-11-25build: introduce rudimentary autotoolsVito Caputo
Now it's easy to build even
2020-11-25src: initial commit of jio WIP sourceVito Caputo
This is a very quick and dirty experimental hack written in some sort of bastard continuation-passing style in C w/io_uring using journal-file introspection and manipulation duty as an excuse for its existence. Consider this unfinished prototype quality code.
2020-11-25upstream: import some hacked systemd headersVito Caputo
This brings journal-file data structures and byte swapping helpers I may as well just reuse. I've had to do some minor messing about to make things workable in isolation out of the systemd tree without pulling in too much. I've also added a new HashedObjectHeader type to encompass the slightly larger common header components of FieldObject and DataObject to facilitate a generic hash table iterator that can operate on just loading HashedObjectHeader when nothing more than the object size is needed for accounting. Basically the HashedObjectHeader is ObjectHeader+hash+next_hash_offset.
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