From cafda577105794dd00a414a879b0b25475e53abb Mon Sep 17 00:00:00 2001
From: Brian Gough <bjg@network-theory.co.uk>
Date: Fri, 13 Feb 2015 16:23:36 +0000
Subject: [PATCH] command-line packing script

---
 services/track-changes/pack.coffee | 72 ++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 services/track-changes/pack.coffee

diff --git a/services/track-changes/pack.coffee b/services/track-changes/pack.coffee
new file mode 100644
index 0000000000..4bc10c829d
--- /dev/null
+++ b/services/track-changes/pack.coffee
@@ -0,0 +1,72 @@
+mongojs = require "mongojs"
+async = require "async"
+db = mongojs.connect("localhost/sharelatex", ["docHistory"])
+BSON=db.bson.BSON
+util = require 'util'
+_ = require 'underscore'
+MAX_SIZE = 1024*1024
+MAX_COUNT = 1024
+
+packOps = (doc_id, callback) ->
+	console.log 'packing', doc_id
+	db.docHistory.find({doc_id:mongojs.ObjectId(doc_id),pack:{$exists:false}}).sort {v:1}, (err, docs) ->
+		packs = []
+		top = null
+		if docs.length < 100
+			console.log 'only', docs.length, 'ops, skipping'
+			return
+		docs.forEach (d,i) ->
+			sz = BSON.calculateObjectSize(d)
+			if top?	&& top.pack.length < MAX_COUNT && top.sz + sz < MAX_SIZE
+				top.pack = top.pack.concat {v: d.v, meta: d.meta,  op: d.op, _id: d._id}
+				top.sz += sz
+				top.v_end = d.v
+				top.meta.end_ts = d.meta.end_ts
+				return
+			else
+				# create a new pack
+				top = _.clone(d)
+				top.pack = [ {v: d.v, meta: d.meta,  op: d.op, _id: d._id} ]
+				top.meta = { start_ts: d.meta.start_ts, end_ts: d.meta.end_ts }
+				top.sz = sz
+				delete top.op
+				delete top._id
+				packs.push top
+		# never store the last pack, keep some unpacked ops
+		packs.pop()
+		#
+		if packs.length > docs.length
+			console.log 'not enough compression', packs.length, 'vs', docs.length, 'skipping'
+			return
+
+		console.log 'docs', docs.length, 'packs', packs.length
+		tasks = []
+		for pack, i in packs
+			console.log 'storing pack', i
+			do (pack) ->
+				task = (cb) ->
+					bulk = db.docHistory.initializeOrderedBulkOp();
+					console.log 'insert', pack
+					bulk.insert pack
+					pack.pack.forEach (op) ->
+						console.log 'will remove', op._id
+						bulk.find({_id:op._id}).removeOne()
+					bulk.execute (err, result) ->
+						console.log 'ok?', result.ok, 'nInserted', result.nInserted, 'nRemoved', result.nRemoved
+						cb(err, result)
+				tasks.push task
+
+		async.series tasks, (err, result) ->
+			console.log 'writing packs', err, result.length
+			callback err, result
+
+packOpsTask = (doc_id) ->
+	return (callback) ->
+		packOps doc_id, callback
+
+tasks = (packOpsTask id for id in process.argv.slice(2))
+
+async.series tasks, (err, results) ->
+	console.log 'closing db'
+	#console.log util.inspect(results,{depth:null})
+	db.close()