From 18b34d1bcbe11c654fe419b0fe138c5952d2dc59 Mon Sep 17 00:00:00 2001
From: Brian Gough <bjg@network-theory.co.uk>
Date: Fri, 13 Feb 2015 17:01:37 +0000
Subject: [PATCH] clean up packing script

---
 services/track-changes/pack.coffee | 78 +++++++++++++++---------------
 1 file changed, 38 insertions(+), 40 deletions(-)

diff --git a/services/track-changes/pack.coffee b/services/track-changes/pack.coffee
index 4bc10c829d..aa0c079261 100644
--- a/services/track-changes/pack.coffee
+++ b/services/track-changes/pack.coffee
@@ -6,15 +6,31 @@ util = require 'util'
 _ = require 'underscore'
 MAX_SIZE = 1024*1024
 MAX_COUNT = 1024
+MIN_COUNT = 100
+KEEP_OPS = 100
 
-packOps = (doc_id, callback) ->
-	console.log 'packing', doc_id
+insertPack = (packObj, callback) ->
+	bulk = db.docHistory.initializeOrderedBulkOp();
+	expect_nInserted = 1
+	expect_nRemoved = packObj.pack.length
+	console.log 'inserting', expect_nInserted, 'pack, will remove', expect_nRemoved, 'ops'
+	bulk.insert packObj
+	packObj.pack.forEach (op) ->
+		bulk.find({_id:op._id}).removeOne()
+	bulk.execute (err, result) ->
+		if err? or result.nInserted != expect_nInserted or result.nRemoved != expect_nRemoved
+			console.log err, result
+			console.log 'nInserted', result.nInserted, 'nRemoved', result.nRemoved
+		callback(err, result)
+
+packDocHistory = (doc_id, callback) ->
+	console.log 'packing doc_id', 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
+		origDocs = docs.length
+		# keep the last KEEP_OPS as individual ops
+		docs = docs.slice(0,-KEEP_OPS)
 		docs.forEach (d,i) ->
 			sz = BSON.calculateObjectSize(d)
 			if top?	&& top.pack.length < MAX_COUNT && top.sz + sz < MAX_SIZE
@@ -23,7 +39,7 @@ packOps = (doc_id, callback) ->
 				top.v_end = d.v
 				top.meta.end_ts = d.meta.end_ts
 				return
-			else
+			else if sz < MAX_SIZE
 				# create a new pack
 				top = _.clone(d)
 				top.pack = [ {v: d.v, meta: d.meta,  op: d.op, _id: d._id} ]
@@ -32,41 +48,23 @@ packOps = (doc_id, callback) ->
 				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
+			else
+				# keep the op
+				console.log 'keeping large op unchanged'
 
-		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
+		# only store packs with a sufficient number of ops, discard others
+		packs = packs.filter (packObj) ->
+			packObj.pack.length > MIN_COUNT
 
-		async.series tasks, (err, result) ->
-			console.log 'writing packs', err, result.length
+		console.log 'docs', origDocs, 'packs', packs.length
+		async.each packs, insertPack, (err, result) ->
+			if err?
+				console.log 'err', err
+			console.log 'done writing packs'
 			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()
+async.each process.argv.slice(2),	(doc_id, callback) ->
+		packDocHistory(doc_id, callback)
+	, (err, results) ->
+		console.log 'closing db'
+		db.close()