From b83c35fdbb38721dd2db46c3e6c23706ec60f2b5 Mon Sep 17 00:00:00 2001
From: Eric Mc Sween <eric.mcsween@overleaf.com>
Date: Mon, 16 Aug 2021 08:09:52 -0400
Subject: [PATCH] Merge pull request #4665 from overleaf/bg-zip-manager

add streaming zip export of history (migrated from track-changes#117)

GitOrigin-RevId: 45e6a66332541f463241f148892817725c0be39c
---
 services/track-changes/app.js                 |   2 +
 services/track-changes/app/js/DocIterator.js  |  42 +++++
 .../track-changes/app/js/DocstoreManager.js   |  51 ++++++
 .../app/js/DocumentUpdaterManager.js          |  34 +++-
 .../track-changes/app/js/HttpController.js    |  26 +++
 services/track-changes/app/js/PackManager.js  |  96 +++++++++--
 .../track-changes/app/js/UpdatesManager.js    |   7 +
 services/track-changes/app/js/ZipManager.js   | 162 ++++++++++++++++++
 services/track-changes/package-lock.json      |  45 +++--
 services/track-changes/package.json           |   3 +-
 .../js/HttpController/HttpControllerTests.js  |   1 +
 11 files changed, 439 insertions(+), 30 deletions(-)
 create mode 100644 services/track-changes/app/js/DocIterator.js
 create mode 100644 services/track-changes/app/js/DocstoreManager.js
 create mode 100644 services/track-changes/app/js/ZipManager.js

diff --git a/services/track-changes/app.js b/services/track-changes/app.js
index a009431de0..fd0893e1ce 100644
--- a/services/track-changes/app.js
+++ b/services/track-changes/app.js
@@ -66,6 +66,8 @@ app.get('/project/:project_id/doc/:doc_id/check', HttpController.checkDoc)
 app.get('/project/:project_id/updates', HttpController.getUpdates)
 app.get('/project/:project_id/export', HttpController.exportProject)
 
+app.get('/project/:project_id/zip', HttpController.zipProject)
+
 app.post('/project/:project_id/flush', HttpController.flushProject)
 
 app.post(
diff --git a/services/track-changes/app/js/DocIterator.js b/services/track-changes/app/js/DocIterator.js
new file mode 100644
index 0000000000..d78cf02b65
--- /dev/null
+++ b/services/track-changes/app/js/DocIterator.js
@@ -0,0 +1,42 @@
+module.exports = class DocIterator {
+  constructor(packs, getPackByIdFn) {
+    this.getPackByIdFn = getPackByIdFn
+    // sort packs in descending order by version (i.e. most recent first)
+    const byVersion = (a, b) => b.v - a.v
+    this.packs = packs.slice().sort(byVersion)
+    this.queue = []
+  }
+
+  next(callback) {
+    const update = this.queue.shift()
+    if (update) {
+      return callback(null, update)
+    }
+    if (!this.packs.length) {
+      this._done = true
+      return callback(null)
+    }
+    const nextPack = this.packs[0]
+    this.getPackByIdFn(
+      nextPack.project_id,
+      nextPack.doc_id,
+      nextPack._id,
+      (err, pack) => {
+        if (err != null) {
+          return callback(err)
+        }
+        this.packs.shift() // have now retrieved this pack, remove it
+        for (const op of pack.pack.reverse()) {
+          op.doc_id = nextPack.doc_id
+          op.project_id = nextPack.project_id
+          this.queue.push(op)
+        }
+        return this.next(callback)
+      }
+    )
+  }
+
+  done() {
+    return this._done
+  }
+}
diff --git a/services/track-changes/app/js/DocstoreManager.js b/services/track-changes/app/js/DocstoreManager.js
new file mode 100644
index 0000000000..0577939342
--- /dev/null
+++ b/services/track-changes/app/js/DocstoreManager.js
@@ -0,0 +1,51 @@
+const request = require('request')
+const logger = require('logger-sharelatex')
+const Settings = require('@overleaf/settings')
+
+function peekDocument(projectId, docId, callback) {
+  const url = `${Settings.apis.docstore.url}/project/${projectId}/doc/${docId}/peek`
+  logger.log(
+    { project_id: projectId, doc_id: docId },
+    'getting doc from docstore'
+  )
+  request.get(url, function (error, res, body) {
+    if (error != null) {
+      return callback(error)
+    }
+    if (res.statusCode >= 200 && res.statusCode < 300) {
+      try {
+        body = JSON.parse(body)
+      } catch (error1) {
+        error = error1
+        return callback(error)
+      }
+      logger.log(
+        { project_id: projectId, doc_id: docId, version: body.version },
+        'got doc from docstore'
+      )
+      return callback(null, body.lines.join('\n'), body.version)
+    } else {
+      return callback(
+        new Error(
+          `docstore returned a non-success status code: ${res.statusCode}`
+        )
+      )
+    }
+  })
+}
+
+module.exports = {
+  promises: {
+    peekDocument: (projectId, docId) => {
+      return new Promise((resolve, reject) => {
+        peekDocument(projectId, docId, (err, content, version) => {
+          if (err) {
+            reject(err)
+          } else {
+            resolve([content, version])
+          }
+        })
+      })
+    },
+  },
+}
diff --git a/services/track-changes/app/js/DocumentUpdaterManager.js b/services/track-changes/app/js/DocumentUpdaterManager.js
index 01cdf9e07c..4173ba328c 100644
--- a/services/track-changes/app/js/DocumentUpdaterManager.js
+++ b/services/track-changes/app/js/DocumentUpdaterManager.js
@@ -17,11 +17,11 @@ const logger = require('logger-sharelatex')
 const Settings = require('@overleaf/settings')
 
 module.exports = DocumentUpdaterManager = {
-  getDocument(project_id, doc_id, callback) {
+  _requestDocument(project_id, doc_id, url, callback) {
     if (callback == null) {
       callback = function (error, content, version) {}
     }
-    const url = `${Settings.apis.documentupdater.url}/project/${project_id}/doc/${doc_id}`
+
     logger.log({ project_id, doc_id }, 'getting doc from document updater')
     return request.get(url, function (error, res, body) {
       if (error != null) {
@@ -52,6 +52,16 @@ module.exports = DocumentUpdaterManager = {
     })
   },
 
+  getDocument(project_id, doc_id, callback) {
+    const url = `${Settings.apis.documentupdater.url}/project/${project_id}/doc/${doc_id}`
+    DocumentUpdaterManager._requestDocument(project_id, doc_id, url, callback)
+  },
+
+  peekDocument(project_id, doc_id, callback) {
+    const url = `${Settings.apis.documentupdater.url}/project/${project_id}/doc/${doc_id}/peek`
+    DocumentUpdaterManager._requestDocument(project_id, doc_id, url, callback)
+  },
+
   setDocument(project_id, doc_id, content, user_id, callback) {
     if (callback == null) {
       callback = function (error) {}
@@ -88,3 +98,23 @@ module.exports = DocumentUpdaterManager = {
     )
   },
 }
+
+module.exports.promises = {
+  // peekDocument returns two arguments so we can't use util.promisify, which only handles a single argument, we need
+  // to treat this it as a special case.
+  peekDocument: (project_id, doc_id) => {
+    return new Promise((resolve, reject) => {
+      DocumentUpdaterManager.peekDocument(
+        project_id,
+        doc_id,
+        (err, content, version) => {
+          if (err) {
+            reject(err)
+          } else {
+            resolve([content, version])
+          }
+        }
+      )
+    })
+  },
+}
diff --git a/services/track-changes/app/js/HttpController.js b/services/track-changes/app/js/HttpController.js
index 8f665682eb..171907689c 100644
--- a/services/track-changes/app/js/HttpController.js
+++ b/services/track-changes/app/js/HttpController.js
@@ -17,9 +17,12 @@ const UpdatesManager = require('./UpdatesManager')
 const DiffManager = require('./DiffManager')
 const PackManager = require('./PackManager')
 const RestoreManager = require('./RestoreManager')
+const ZipManager = require('./ZipManager')
 const logger = require('logger-sharelatex')
 const HealthChecker = require('./HealthChecker')
 const _ = require('underscore')
+const Path = require('path')
+const { pipeline } = require('stream')
 
 module.exports = HttpController = {
   flushDoc(req, res, next) {
@@ -203,6 +206,29 @@ module.exports = HttpController = {
     )
   },
 
+  zipProject(req, res, next) {
+    const { project_id: projectId } = req.params
+    logger.log({ projectId }, 'exporting project history as zip file')
+    ZipManager.makeTempDirectory((err, tmpdir) => {
+      if (err) {
+        return next(err)
+      }
+      const zipFilePath = Path.join(tmpdir, 'export.zip')
+      ZipManager.exportProject(projectId, zipFilePath, err => {
+        if (err) {
+          ZipManager.cleanupTempDirectory(tmpdir)
+          return next(err)
+        }
+        res.download(zipFilePath, `${projectId}-track-changes.zip`, err => {
+          ZipManager.cleanupTempDirectory(tmpdir)
+          if (err && !res.headersSent) {
+            return next(err)
+          }
+        })
+      })
+    })
+  },
+
   exportProject(req, res, next) {
     // The project history can be huge:
     //  - updates can weight MBs for insert/delete of full doc
diff --git a/services/track-changes/app/js/PackManager.js b/services/track-changes/app/js/PackManager.js
index f8efb77f11..fbb363ba4b 100644
--- a/services/track-changes/app/js/PackManager.js
+++ b/services/track-changes/app/js/PackManager.js
@@ -24,7 +24,9 @@ const LockManager = require('./LockManager')
 const MongoAWS = require('./MongoAWS')
 const Metrics = require('@overleaf/metrics')
 const ProjectIterator = require('./ProjectIterator')
+const DocIterator = require('./DocIterator')
 const Settings = require('@overleaf/settings')
+const util = require('util')
 const keys = Settings.redis.lock.key_schema
 
 // Sharejs operations are stored in a 'pack' object
@@ -423,16 +425,59 @@ module.exports = PackManager = {
       })
   },
 
+  findAllDocsInProject(project_id, callback) {
+    const docIdSet = new Set()
+    async.series(
+      [
+        cb => {
+          db.docHistory
+            .find(
+              { project_id: ObjectId(project_id) },
+              { projection: { pack: false } }
+            )
+            .toArray((err, packs) => {
+              packs.forEach(pack => {
+                docIdSet.add(pack.doc_id.toString())
+              })
+              return cb()
+            })
+        },
+        cb => {
+          db.docHistoryIndex
+            .find({ project_id: ObjectId(project_id) })
+            .toArray((err, indexes) => {
+              indexes.forEach(index => {
+                docIdSet.add(index._id.toString())
+              })
+              return cb()
+            })
+        },
+      ],
+      err => {
+        if (err) return callback(err)
+        callback(null, [...docIdSet])
+      }
+    )
+  },
+
+  // rewrite any query using doc_id to use _id instead
+  // (because docHistoryIndex uses the doc_id)
+
+  _rewriteQueryForIndex(query) {
+    const indexQuery = _.omit(query, 'doc_id')
+    if ('doc_id' in query) {
+      indexQuery._id = query.doc_id
+    }
+    return indexQuery
+  },
+
   // Retrieve all changes across a project
 
-  makeProjectIterator(project_id, before, callback) {
+  _findPacks(query, sortKeys, callback) {
     // get all the docHistory Entries
     return db.docHistory
-      .find(
-        { project_id: ObjectId(project_id) },
-        { projection: { pack: false } }
-      )
-      .sort({ 'meta.end_ts': -1 })
+      .find(query, { projection: { pack: false } })
+      .sort(sortKeys)
       .toArray(function (err, packs) {
         let pack
         if (err != null) {
@@ -444,8 +489,9 @@ module.exports = PackManager = {
           allPacks.push(pack)
           seenIds[pack._id] = true
         }
+        const indexQuery = PackManager._rewriteQueryForIndex(query)
         return db.docHistoryIndex
-          .find({ project_id: ObjectId(project_id) })
+          .find(indexQuery)
           .toArray(function (err, indexes) {
             if (err != null) {
               return callback(err)
@@ -461,14 +507,36 @@ module.exports = PackManager = {
                 }
               }
             }
-            return callback(
-              null,
-              new ProjectIterator(allPacks, before, PackManager.getPackById)
-            )
+            return callback(null, allPacks)
           })
       })
   },
 
+  makeProjectIterator(project_id, before, callback) {
+    PackManager._findPacks(
+      { project_id: ObjectId(project_id) },
+      { 'meta.end_ts': -1 },
+      function (err, allPacks) {
+        if (err) return callback(err)
+        callback(
+          null,
+          new ProjectIterator(allPacks, before, PackManager.getPackById)
+        )
+      }
+    )
+  },
+
+  makeDocIterator(doc_id, callback) {
+    PackManager._findPacks(
+      { doc_id: ObjectId(doc_id) },
+      { v: -1 },
+      function (err, allPacks) {
+        if (err) return callback(err)
+        callback(null, new DocIterator(allPacks, PackManager.getPackById))
+      }
+    )
+  },
+
   getPackById(project_id, doc_id, pack_id, callback) {
     return db.docHistory.findOne({ _id: pack_id }, function (err, pack) {
       if (err != null) {
@@ -1165,6 +1233,12 @@ module.exports = PackManager = {
   },
 }
 
+module.exports.promises = {
+  getOpsByVersionRange: util.promisify(PackManager.getOpsByVersionRange),
+  findAllDocsInProject: util.promisify(PackManager.findAllDocsInProject),
+  makeDocIterator: util.promisify(PackManager.makeDocIterator),
+}
+
 //	_getOneDayInFutureWithRandomDelay: ->
 //		thirtyMins = 1000 * 60 * 30
 //		randomThirtyMinMax = Math.ceil(Math.random() * thirtyMins)
diff --git a/services/track-changes/app/js/UpdatesManager.js b/services/track-changes/app/js/UpdatesManager.js
index 26c1104569..574278f1a9 100644
--- a/services/track-changes/app/js/UpdatesManager.js
+++ b/services/track-changes/app/js/UpdatesManager.js
@@ -27,6 +27,7 @@ const async = require('async')
 const _ = require('underscore')
 const Settings = require('@overleaf/settings')
 const keys = Settings.redis.lock.key_schema
+const util = require('util')
 
 module.exports = UpdatesManager = {
   compressAndSaveRawUpdates(
@@ -881,6 +882,12 @@ module.exports = UpdatesManager = {
   },
 }
 
+module.exports.promises = {
+  processUncompressedUpdatesForProject: util.promisify(
+    UpdatesManager.processUncompressedUpdatesForProject
+  ),
+}
+
 function __guard__(value, transform) {
   return typeof value !== 'undefined' && value !== null
     ? transform(value)
diff --git a/services/track-changes/app/js/ZipManager.js b/services/track-changes/app/js/ZipManager.js
new file mode 100644
index 0000000000..b76b81b4bc
--- /dev/null
+++ b/services/track-changes/app/js/ZipManager.js
@@ -0,0 +1,162 @@
+const logger = require('logger-sharelatex')
+const UpdatesManager = require('./UpdatesManager')
+const DiffGenerator = require('./DiffGenerator')
+const DocumentUpdaterManager = require('./DocumentUpdaterManager')
+const DocstoreManager = require('./DocstoreManager')
+const PackManager = require('./PackManager')
+const yazl = require('yazl')
+const util = require('util')
+const stream = require('stream')
+const fs = require('fs')
+const os = require('os')
+const Path = require('path')
+
+const streamPipeline = util.promisify(stream.pipeline)
+
+// look in docstore or docupdater for the latest version of the document
+async function getLatestContent(projectId, docId, lastUpdateVersion) {
+  const [docstoreContent, docstoreVersion] =
+    await DocstoreManager.promises.peekDocument(projectId, docId)
+
+  // if docstore is out of date, check for a newer version in docupdater
+  // and return that instead
+  if (docstoreVersion <= lastUpdateVersion) {
+    const [docupdaterContent, docupdaterVersion] =
+      await DocumentUpdaterManager.promises.peekDocument(projectId, docId)
+    if (docupdaterVersion > docstoreVersion) {
+      return [docupdaterContent, docupdaterVersion]
+    }
+  }
+
+  return [docstoreContent, docstoreVersion]
+}
+
+async function rewindDoc(projectId, docId, zipfile) {
+  logger.log({ projectId, docId }, 'rewinding document')
+
+  // Prepare to rewind content
+
+  const docIterator = await PackManager.promises.makeDocIterator(docId)
+
+  const getUpdate = util.promisify(docIterator.next).bind(docIterator)
+
+  const lastUpdate = await getUpdate()
+  if (!lastUpdate) {
+    return null
+  }
+
+  const lastUpdateVersion = lastUpdate.v
+
+  const [latestContent, version] = await getLatestContent(
+    projectId,
+    docId,
+    lastUpdateVersion
+  )
+
+  const id = docId.toString()
+
+  const contentEndPath = `${id}/content/end/${version}`
+  zipfile.addBuffer(Buffer.from(latestContent), contentEndPath)
+
+  const metadata = {
+    id,
+    version,
+    content: {
+      end: {
+        path: contentEndPath,
+        version,
+      },
+    },
+    updates: [],
+  }
+
+  let content = latestContent
+  let v = version
+  let update = lastUpdate
+
+  while (update) {
+    const updatePath = `${id}/updates/${update.v}`
+
+    zipfile.addBuffer(Buffer.from(JSON.stringify(update)), updatePath, {
+      mtime: new Date(update.meta.start_ts),
+    })
+    try {
+      content = DiffGenerator.rewindUpdate(content, update)
+      v = update.v
+    } catch (e) {
+      e.attempted_update = update // keep a record of the attempted update
+      logger.error({ projectId, docId, err: e }, 'rewind error')
+      break // stop attempting to rewind on error
+    }
+
+    metadata.updates.push({
+      path: updatePath,
+      version: update.v,
+      ts: update.meta.start_ts,
+      doc_length: content.length,
+    })
+    update = await getUpdate()
+  }
+
+  const contentStartPath = `${id}/content/start/${v}`
+  zipfile.addBuffer(Buffer.from(content), contentStartPath)
+
+  metadata.content.start = {
+    path: contentStartPath,
+    version: v,
+  }
+
+  return metadata
+}
+
+async function generateZip(projectId, zipfile) {
+  await UpdatesManager.promises.processUncompressedUpdatesForProject(projectId)
+  const docIds = await PackManager.promises.findAllDocsInProject(projectId)
+  const manifest = { projectId, docs: [] }
+  for (const docId of docIds) {
+    const doc = await rewindDoc(projectId, docId, zipfile)
+    if (doc) {
+      manifest.docs.push(doc)
+    }
+  }
+  zipfile.addBuffer(
+    Buffer.from(JSON.stringify(manifest, null, 2)),
+    'manifest.json'
+  )
+  zipfile.end()
+}
+
+async function exportProject(projectId, zipPath) {
+  const zipfile = new yazl.ZipFile()
+  const pipeline = streamPipeline(
+    zipfile.outputStream,
+    fs.createWriteStream(zipPath)
+  )
+  await generateZip(projectId, zipfile)
+  await pipeline
+}
+
+/**
+ * Create a temporary directory for use with exportProject()
+ */
+async function makeTempDirectory() {
+  const tmpdir = await fs.promises.mkdtemp(
+    (await fs.promises.realpath(os.tmpdir())) + Path.sep
+  )
+  return tmpdir
+}
+
+/**
+ * Clean up a temporary directory made with makeTempDirectory()
+ */
+function cleanupTempDirectory(tmpdir) {
+  fs.promises.rmdir(tmpdir, { recursive: true }).catch(err => {
+    logger.warn({ tmpdir }, 'Failed to clean up temp directory')
+  })
+}
+
+module.exports = {
+  exportProject: util.callbackify(exportProject),
+  makeTempDirectory: util.callbackify(makeTempDirectory),
+  cleanupTempDirectory,
+}
diff --git a/services/track-changes/package-lock.json b/services/track-changes/package-lock.json
index 0cb04e7652..88bce82d6a 100644
--- a/services/track-changes/package-lock.json
+++ b/services/track-changes/package-lock.json
@@ -1344,7 +1344,7 @@
     "bintrees": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/bintrees/-/bintrees-1.0.1.tgz",
-      "integrity": "sha1-DmVcm5wkNeqraL9AJyJtK1WjRSQ="
+      "integrity": "sha512-tbaUB1QpTIj4cKY8c1rvNAvEQXA+ekzHmbe4jzNfW3QWsF9GnnP/BRWyl6/qqS53heoYJ93naaFcm/jooONH8g=="
     },
     "bl": {
       "version": "2.2.1",
@@ -1431,6 +1431,11 @@
         "isarray": "^1.0.0"
       }
     },
+    "buffer-crc32": {
+      "version": "0.2.13",
+      "resolved": "https://registry.npmjs.org/buffer-crc32/-/buffer-crc32-0.2.13.tgz",
+      "integrity": "sha1-DTM+PwDqxQqhRUq9MO+MKl2ackI="
+    },
     "buffer-equal-constant-time": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/buffer-equal-constant-time/-/buffer-equal-constant-time-1.0.1.tgz",
@@ -1738,7 +1743,7 @@
     "d64": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/d64/-/d64-1.0.0.tgz",
-      "integrity": "sha1-QAKofoUMv8n52XBrYPymE6MzbpA="
+      "integrity": "sha512-5eNy3WZziVYnrogqgXhcdEmqcDB2IHurTqLcrgssJsfkMVCUoUaZpK6cJjxxvLV2dUm5SuJMNcYfVGoin9UIRw=="
     },
     "dashdash": {
       "version": "1.14.1",
@@ -2640,7 +2645,7 @@
     "findit2": {
       "version": "2.2.3",
       "resolved": "https://registry.npmjs.org/findit2/-/findit2-2.2.3.tgz",
-      "integrity": "sha1-WKRmaX34piBc39vzlVNri9d3pfY="
+      "integrity": "sha512-lg/Moejf4qXovVutL0Lz4IsaPoNYMuxt4PA0nGqFxnJ1CTTGGlEO2wKgoDpwknhvZ8k4Q2F+eesgkLbG2Mxfog=="
     },
     "flat": {
       "version": "5.0.2",
@@ -3543,12 +3548,12 @@
     "lodash.at": {
       "version": "4.6.0",
       "resolved": "https://registry.npmjs.org/lodash.at/-/lodash.at-4.6.0.tgz",
-      "integrity": "sha1-k83OZk8KGZTqM9181A4jr9EbD/g="
+      "integrity": "sha512-GOTh0SEp+Yosnlpjic+8cl2WM9MykorogkGA9xyIFkkObQ3H3kNZqZ+ohuq4K3FrSVo7hMcZBMataJemrxC3BA=="
     },
     "lodash.camelcase": {
       "version": "4.3.0",
       "resolved": "https://registry.npmjs.org/lodash.camelcase/-/lodash.camelcase-4.3.0.tgz",
-      "integrity": "sha1-soqmKIorn8ZRA1x3EfZathkDMaY="
+      "integrity": "sha512-TwuEnCnxbc3rAvhf/LbG7tJUDzhqXyFnv3dtzLOPgCG/hODL7WFnsbwktkD7yUV0RrreP/l1PALq/YSg6VvjlA=="
     },
     "lodash.clonedeep": {
       "version": "4.5.0",
@@ -3559,12 +3564,12 @@
     "lodash.defaults": {
       "version": "4.2.0",
       "resolved": "https://registry.npmjs.org/lodash.defaults/-/lodash.defaults-4.2.0.tgz",
-      "integrity": "sha1-0JF4cW/+pN3p5ft7N/bwgCJ0WAw="
+      "integrity": "sha512-qjxPLHd3r5DnsdGacqOMU6pb/avJzdh9tFX2ymgoZE27BmjXrNy/y4LoaiTeAb+O3gL8AfpJGtqfX/ae2leYYQ=="
     },
     "lodash.flatten": {
       "version": "4.4.0",
       "resolved": "https://registry.npmjs.org/lodash.flatten/-/lodash.flatten-4.4.0.tgz",
-      "integrity": "sha1-8xwiIlqWMtK7+OSt2+8kCqdlph8="
+      "integrity": "sha512-C5N2Z3DgnnKr0LOpv/hKCgKdb7ZZwafIrsesve6lmzvZIRZRGaZ/l6Q8+2W7NaT+ZwO3fFlSCzCzrDCFdJfZ4g=="
     },
     "lodash.get": {
       "version": "4.4.2",
@@ -3575,7 +3580,7 @@
     "lodash.has": {
       "version": "4.5.2",
       "resolved": "https://registry.npmjs.org/lodash.has/-/lodash.has-4.5.2.tgz",
-      "integrity": "sha1-0Z9NwQlQWMzL4rDN9O4P5Ko3yGI="
+      "integrity": "sha512-rnYUdIo6xRCJnQmbVFEwcxF144erlD+M3YcJUVesflU9paQaE8p+fJDcIQrlMYbxoANFL+AB9hZrzSBBk5PL+g=="
     },
     "lodash.merge": {
       "version": "4.6.2",
@@ -3937,7 +3942,7 @@
     "module-details-from-path": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/module-details-from-path/-/module-details-from-path-1.0.3.tgz",
-      "integrity": "sha1-EUyUlnPiqKNenTV4hSeqN7Z52is="
+      "integrity": "sha512-ySViT69/76t8VhE1xXHK6Ch4NcDd26gx0MzKXLO+F7NOtnqH68d9zF94nT8ZWSxXh8ELOERsnJO/sWt1xZYw5A=="
     },
     "moment": {
       "version": "2.24.0",
@@ -4740,12 +4745,12 @@
     "redis-errors": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/redis-errors/-/redis-errors-1.2.0.tgz",
-      "integrity": "sha1-62LSrbFeTq9GEMBK/hUpOEJQq60="
+      "integrity": "sha512-1qny3OExCf0UvUV/5wpYKf2YwPcOqXzkwKKSmKHiE6ZMQs5heeE/c8eXK+PNllPvmjgAbfnsbpkGZWy8cBpn9w=="
     },
     "redis-parser": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/redis-parser/-/redis-parser-3.0.0.tgz",
-      "integrity": "sha1-tm2CjNyv5rS4pCin3vTGvKwxyLQ=",
+      "integrity": "sha512-DJnGAeenTdpMEH6uAJRK/uiyEIH9WVsUmoLwzudwGJUwZPp80PDBWPHXSAGNPwNvIXAbe7MSUB1zQFugFml66A==",
       "requires": {
         "redis-errors": "^1.0.0"
       }
@@ -5291,7 +5296,7 @@
     "stubs": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/stubs/-/stubs-3.0.0.tgz",
-      "integrity": "sha1-6NK6H6nJBXAwPAMLaQD31fiavls="
+      "integrity": "sha512-PdHt7hHUJKxvTCgbKX9C1V/ftOcjJQgz8BZwNfV5c4B6dcGqlpelTbJ999jBGZ2jYiPAwcX5dP6oBwVlBlUbxw=="
     },
     "supports-color": {
       "version": "5.5.0",
@@ -5352,7 +5357,7 @@
     "tdigest": {
       "version": "0.1.1",
       "resolved": "https://registry.npmjs.org/tdigest/-/tdigest-0.1.1.tgz",
-      "integrity": "sha1-Ljyyw56kSeVdHmzZEReszKRYgCE=",
+      "integrity": "sha512-CXcDY/NIgIbKZPx5H4JJNpq6JwJhU5Z4+yWj4ZghDc7/9nVajiRlPPyMXRePPPlBfcayUqtoCXjo7/Hm82ecUA==",
       "requires": {
         "bintrees": "1.0.1"
       }
@@ -5409,7 +5414,7 @@
     "to-no-case": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/to-no-case/-/to-no-case-1.0.2.tgz",
-      "integrity": "sha1-xyKQcWTvaxeBMsjmmTAhLRtKoWo="
+      "integrity": "sha512-Z3g735FxuZY8rodxV4gH7LxClE4H0hTIyHNIHdk+vpQxjLm0cwnKXq/OFVZ76SOQmto7txVcwSCwkU5kqp+FKg=="
     },
     "to-regex-range": {
       "version": "5.0.1",
@@ -5423,7 +5428,7 @@
     "to-snake-case": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/to-snake-case/-/to-snake-case-1.0.0.tgz",
-      "integrity": "sha1-znRpE4l5RgGah+Yu366upMYIq4w=",
+      "integrity": "sha512-joRpzBAk1Bhi2eGEYBjukEWHOe/IvclOkiJl3DtA91jV6NwQ3MwXA4FHYeqk8BNp/D8bmi9tcNbRu/SozP0jbQ==",
       "requires": {
         "to-space-case": "^1.0.0"
       }
@@ -5431,7 +5436,7 @@
     "to-space-case": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/to-space-case/-/to-space-case-1.0.0.tgz",
-      "integrity": "sha1-sFLar7Gysp3HcM6gFj5ewOvJ/Bc=",
+      "integrity": "sha512-rLdvwXZ39VOn1IxGL3V6ZstoTbwLRckQmn/U8ZDLuWwIXNpuZDhQ3AiRUlhTbOXFVE9C+dR51wM0CBDhk31VcA==",
       "requires": {
         "to-no-case": "^1.0.0"
       }
@@ -5780,6 +5785,14 @@
         "is-plain-obj": "^2.1.0"
       }
     },
+    "yazl": {
+      "version": "2.5.1",
+      "resolved": "https://registry.npmjs.org/yazl/-/yazl-2.5.1.tgz",
+      "integrity": "sha512-phENi2PLiHnHb6QBVot+dJnaAZ0xosj7p3fWl+znIjBDlnMI2PsZCJZ306BPTFOaHf5qdDEI8x5qFrSOBN5vrw==",
+      "requires": {
+        "buffer-crc32": "~0.2.3"
+      }
+    },
     "yn": {
       "version": "3.1.1",
       "resolved": "https://registry.npmjs.org/yn/-/yn-3.1.1.tgz",
diff --git a/services/track-changes/package.json b/services/track-changes/package.json
index d3a2d990db..f8789b16a5 100644
--- a/services/track-changes/package.json
+++ b/services/track-changes/package.json
@@ -40,7 +40,8 @@
     "request": "~2.88.2",
     "requestretry": "^4.1.0",
     "s3-streams": "^0.4.0",
-    "underscore": "~1.13.1"
+    "underscore": "~1.13.1",
+    "yazl": "^2.5.1"
   },
   "devDependencies": {
     "chai": "^4.2.0",
diff --git a/services/track-changes/test/unit/js/HttpController/HttpControllerTests.js b/services/track-changes/test/unit/js/HttpController/HttpControllerTests.js
index 6b82dd2b80..ff28975b30 100644
--- a/services/track-changes/test/unit/js/HttpController/HttpControllerTests.js
+++ b/services/track-changes/test/unit/js/HttpController/HttpControllerTests.js
@@ -25,6 +25,7 @@ describe('HttpController', function () {
         './PackManager': (this.PackManager = {}),
         './DocArchiveManager': (this.DocArchiveManager = {}),
         './HealthChecker': (this.HealthChecker = {}),
+        './ZipManager': (this.ZipManager = {}),
       },
     })
     this.doc_id = 'doc-id-123'