overleaf/services/track-changes/app/coffee/RedisManager.js

80 lines
3.1 KiB
JavaScript

Settings = require "settings-sharelatex"
redis = require("redis-sharelatex")
rclient = redis.createClient(Settings.redis.history)
Keys = Settings.redis.history.key_schema
async = require "async"
module.exports = RedisManager =
getOldestDocUpdates: (doc_id, batchSize, callback = (error, jsonUpdates) ->) ->
key = Keys.uncompressedHistoryOps({doc_id})
rclient.lrange key, 0, batchSize - 1, callback
expandDocUpdates: (jsonUpdates, callback = (error, rawUpdates) ->) ->
try
rawUpdates = ( JSON.parse(update) for update in jsonUpdates or [] )
catch e
return callback(e)
callback null, rawUpdates
deleteAppliedDocUpdates: (project_id, doc_id, docUpdates, callback = (error) ->) ->
multi = rclient.multi()
# Delete all the updates which have been applied (exact match)
for update in docUpdates or []
multi.lrem Keys.uncompressedHistoryOps({doc_id}), 1, update
multi.exec (error, results) ->
return callback(error) if error?
# It's ok to delete the doc_id from the set here. Even though the list
# of updates may not be empty, we will continue to process it until it is.
rclient.srem Keys.docsWithHistoryOps({project_id}), doc_id, (error) ->
return callback(error) if error?
callback null
getDocIdsWithHistoryOps: (project_id, callback = (error, doc_ids) ->) ->
rclient.smembers Keys.docsWithHistoryOps({project_id}), callback
# iterate over keys asynchronously using redis scan (non-blocking)
# handle all the cluster nodes or single redis server
_getKeys: (pattern, callback) ->
nodes = rclient.nodes?('master') || [ rclient ];
doKeyLookupForNode = (node, cb) ->
RedisManager._getKeysFromNode node, pattern, cb
async.concatSeries nodes, doKeyLookupForNode, callback
_getKeysFromNode: (node, pattern, callback) ->
cursor = 0 # redis iterator
keySet = {} # use hash to avoid duplicate results
# scan over all keys looking for pattern
doIteration = (cb) ->
node.scan cursor, "MATCH", pattern, "COUNT", 1000, (error, reply) ->
return callback(error) if error?
[cursor, keys] = reply
for key in keys
keySet[key] = true
if cursor == '0' # note redis returns string result not numeric
return callback(null, Object.keys(keySet))
else
doIteration()
doIteration()
# extract ids from keys like DocsWithHistoryOps:57fd0b1f53a8396d22b2c24b
# or DocsWithHistoryOps:{57fd0b1f53a8396d22b2c24b} (for redis cluster)
_extractIds: (keyList) ->
ids = for key in keyList
m = key.match(/:\{?([0-9a-f]{24})\}?/) # extract object id
m[1]
return ids
getProjectIdsWithHistoryOps: (callback = (error, project_ids) ->) ->
RedisManager._getKeys Keys.docsWithHistoryOps({project_id:"*"}), (error, project_keys) ->
return callback(error) if error?
project_ids = RedisManager._extractIds project_keys
callback(error, project_ids)
getAllDocIdsWithHistoryOps: (callback = (error, doc_ids) ->) ->
# return all the docids, to find dangling history entries after
# everything is flushed.
RedisManager._getKeys Keys.uncompressedHistoryOps({doc_id:"*"}), (error, doc_keys) ->
return callback(error) if error?
doc_ids = RedisManager._extractIds doc_keys
callback(error, doc_ids)