Package org.exoplatform.caldav.utils

Class ForeignWriterSummary

java.lang.Object

org.exoplatform.caldav.utils.ForeignWriterSummary

public class ForeignWriterSummary
extends Object

How the deployments seen writing into a server's accounts are held on the server's own row (EXO-89824).

One bounded string, for the reason the quirk summary gives. It survives a restart, because an empty section after one is an empty section exactly when somebody is investigating; it stays cheap, because it is one short column per server rather than a row per copy; and it costs no extra query, because the drawer already fetches the registration. It is also the only shape that works on more than one node — the detection happens on whichever node ran the pass, and the drawer is served by whichever node took the request.

Format: authority@day, entries separated by ;, the day an epoch day. ai-contribution-ft.meeds.io@20342;host:8080@20339. The day is what lets the list forget: a deployment moved to another account stops appearing, and its entry ages out rather than accusing an administrator for ever of something they have already fixed.

See Also:

• the sibling this follows

Method Summary

Modifier and Type	Method	Description
static String	format(Map<String,Long> writers)	Writes a summary back to the shape the column holds.
static Map<String,Long>	parse(String summary)	Reads a stored summary.
static Map<String,Long>	record(Map<String,Long> stored, String authority, long today, long retentionDays)	Records that a deployment was seen writing here today, forgetting what has not been seen for long enough.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

parse

public static Map<String,Long> parse(String summary)

Reads a stored summary.

Never throws on a malformed string. The column is evidence written by a background pass and read by a drawer; a row a hand-edit or an older version left unreadable must cost an administrator an entry, never the page. An entry without a day, or with one that is not a number, is dropped rather than guessed at — a wrong date here would age out a live finding or keep a dead one.

Parameters:

summary - the stored value, possibly null or empty

Returns:

the deployments and the epoch day each was last seen, most recently seen first, never null

record

public static Map<String,Long> record(Map<String,Long> stored,
 String authority,
 long today,
 long retentionDays)

Records that a deployment was seen writing here today, forgetting what has not been seen for long enough.

Parameters:

stored - what the row holds, as parse(java.lang.String) read it

authority - the deployment just seen, or null to age the list without adding to it

today - the current epoch day

retentionDays - how long an unseen deployment stays on the list

Returns:

the new list, most recently seen first, bounded to 5

format

public static String format(Map<String,Long> writers)

Writes a summary back to the shape the column holds.

Bounded to the column: the least recently seen entries are left out until the rest fits, so a write never fails on length.

Parameters:

writers - the deployments and the epoch day each was last seen

Returns:

the value to store, or null when there is nothing to say — null rather than an empty string, so a server that has never seen one reads the same as a server whose last entry has just aged out