From 9ea4ed087adfcfd6a3a232758b43cb4f91e8b87e Mon Sep 17 00:00:00 2001
From: Louis Royer <louis.royer@univ-tlse3.fr>
Date: Tue, 14 Apr 2020 18:02:46 +0200
Subject: [PATCH] Add sequence diagrams

---
 doc/download_sequence_diagram.drawio | 1 +
 doc/download_sequence_diagram.svg    | 3 +++
 2 files changed, 4 insertions(+)
 create mode 100644 doc/download_sequence_diagram.drawio
 create mode 100644 doc/download_sequence_diagram.svg

diff --git a/doc/download_sequence_diagram.drawio b/doc/download_sequence_diagram.drawio
new file mode 100644
index 0000000..33e679b
--- /dev/null
+++ b/doc/download_sequence_diagram.drawio
@@ -0,0 +1 @@
+<mxfile host="app.diagrams.net" modified="2020-04-14T16:00:28.147Z" agent="5.0 (X11)" etag="tqTRW0GmAMdtYaH70H5-" version="12.9.12" type="device"><diagram name="Page-1" id="13e1069c-82ec-6db2-03f1-153e76fe0fe0">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</diagram></mxfile>
\ No newline at end of file
diff --git a/doc/download_sequence_diagram.svg b/doc/download_sequence_diagram.svg
new file mode 100644
index 0000000..3d39924
--- /dev/null
+++ b/doc/download_sequence_diagram.svg
@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg xmlns="http://www.w3.org/2000/svg" style="background-color: rgb(255, 255, 255);" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="635px" height="981px" viewBox="-0.5 -0.5 635 981" content="&lt;mxfile host=&quot;app.diagrams.net&quot; modified=&quot;2020-04-14T16:01:54.378Z&quot; agent=&quot;5.0 (X11)&quot; etag=&quot;gZXlR6-bOW7SQzcn2Lk7&quot; version=&quot;12.9.12&quot; type=&quot;device&quot;&gt;&lt;diagram name=&quot;Page-1&quot; id=&quot;13e1069c-82ec-6db2-03f1-153e76fe0fe0&quot;&gt;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&lt;/diagram&gt;&lt;/mxfile&gt;"><defs/><g><rect x="170" y="0" width="100" height="40" rx="6" ry="6" fill="#ffffff" stroke="#000000" pointer-events="all"/><path d="M 220 40 L 220 980" fill="none" stroke="#000000" stroke-miterlimit="10" stroke-dasharray="3 3" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 20px; margin-left: 171px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Verdana; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Application2</div></div></div></foreignObject><text x="220" y="24" fill="#000000" font-family="Verdana" font-size="12px" text-anchor="middle">Application2</text></switch></g><rect x="0" y="0" width="100" height="40" rx="6" ry="6" fill="#ffffff" stroke="#000000" pointer-events="all"/><path d="M 50 40 L 50 940" fill="none" stroke="#000000" stroke-miterlimit="10" stroke-dasharray="3 3" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 20px; margin-left: 1px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Verdana; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Application1</div></div></div></foreignObject><text x="50" y="24" fill="#000000" font-family="Verdana" font-size="12px" text-anchor="middle">Application1</text></switch></g><rect x="350" y="0" width="100" height="40" rx="6" ry="6" fill="#ffffff" stroke="#000000" pointer-events="all"/><path d="M 400 40 L 400 870" fill="none" stroke="#000000" stroke-miterlimit="10" stroke-dasharray="3 3" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 20px; margin-left: 351px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Verdana; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Application3</div></div></div></foreignObject><text x="400" y="24" fill="#000000" font-family="Verdana" font-size="12px" text-anchor="middle">Application3</text></switch></g><rect x="520" y="0" width="100" height="40" rx="6" ry="6" fill="#ffffff" stroke="#000000" pointer-events="all"/><path d="M 570 40 L 570 960" fill="none" stroke="#000000" stroke-miterlimit="10" stroke-dasharray="3 3" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 20px; margin-left: 521px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Verdana; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Tracker</div></div></div></foreignObject><text x="570" y="24" fill="#000000" font-family="Verdana" font-size="12px" text-anchor="middle">Tracker</text></switch></g><path d="M 49.5 110 L 300 110 Q 310 110 320 110 L 561.38 110" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 568.38 110 L 561.38 113.5 L 561.38 106.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 97px; margin-left: 330px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">DISCOVER REQUEST(file1)</div></div></div></foreignObject><text x="330" y="97" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">DISCOVER REQUES...</text></switch></g><path d="M 569.5 150 L 320 150 Q 310 150 300 150 L 57.62 150" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 50.62 150 L 57.62 146.5 L 57.62 153.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 147px; margin-left: 310px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">DISCOVER RESPONSE (file1, Application2, Application3)</div></div></div></foreignObject><text x="310" y="147" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">DISCOVER RESPON...</text></switch></g><path d="M 30 50 L 596 50 L 610 64 L 610 80 L 30 80 L 30 50 Z" fill="#ffffff" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><path d="M 596 50 L 596 64 L 610 64" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-start; justify-content: unsafe center; width: 578px; height: 1px; padding-top: 51px; margin-left: 31px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><div align="center">Applications are all already registered successfully into tracker.</div><div align="center">Lets start a download of file1 from Application1.</div></div></div></div></foreignObject><text x="320" y="63" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Applications are all already registered successfully into tracker....</text></switch></g><path d="M 50 210 L 211.38 210" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 218.38 210 L 211.38 213.5 L 211.38 206.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 207px; margin-left: 135px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">SIZE REQUEST(file1)</div></div></div></foreignObject><text x="135" y="207" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">SIZE REQUEST(fi...</text></switch></g><path d="M 220 240 L 57.62 240" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 50.62 240 L 57.62 236.5 L 57.62 243.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 237px; margin-left: 135px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">SIZE RESPONSE(file1, sizeof(file1))</div></div></div></foreignObject><text x="135" y="237" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">SIZE RESPONSE(f...</text></switch></g><path d="M 50 280 L 211.38 280" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 218.38 280 L 211.38 283.5 L 211.38 276.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 277px; margin-left: 140px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">HASH REQUEST(file1, "SHA512")</div></div></div></foreignObject><text x="140" y="277" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">HASH REQUEST(fi...</text></switch></g><path d="M 220 310 L 57.62 310" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 50.62 310 L 57.62 306.5 L 57.62 313.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 307px; margin-left: 135px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">HASH RESPONSE(file1, sha512(file1))</div></div></div></foreignObject><text x="135" y="307" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">HASH RESPONSE(f...</text></switch></g><path d="M 50 340 L 391.38 340" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 398.38 340 L 391.38 343.5 L 391.38 336.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 337px; margin-left: 225px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">HASH REQUEST(file1, "SHA512")</div></div></div></foreignObject><text x="225" y="337" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">HASH REQUEST(fi...</text></switch></g><path d="M 400 370 L 57.62 370" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 50.62 370 L 57.62 366.5 L 57.62 373.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 367px; margin-left: 225px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">HASH RESPONSE(file1, sha512(file1))</div></div></div></foreignObject><text x="225" y="367" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">HASH RESPONSE(f...</text></switch></g><path d="M 20 385 L 586 385 L 600 399 L 600 440 L 20 440 L 20 385 Z" fill="#ffffff" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><path d="M 586 385 L 586 399 L 600 399" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-start; justify-content: unsafe center; width: 578px; height: 1px; padding-top: 386px; margin-left: 21px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><div>Application1 is requesting hashsum from each application to ensure applications have</div><div>the same file, but an improvement could be to register this sum in the tracker, and ask only the tracker once instead of asking each application.<br /></div></div></div></div></foreignObject><text x="310" y="398" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Application1 is requesting hashsum from each application to ensure applications have...</text></switch></g><path d="M 50 460 L 211.38 460" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 218.38 460 L 211.38 463.5 L 211.38 456.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 457px; margin-left: 135px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">LOAD PART(0, 512, file1)</div></div></div></foreignObject><text x="135" y="457" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">LOAD PART(0, 51...</text></switch></g><path d="M 220 490 L 561.38 490" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 568.38 490 L 561.38 493.5 L 561.38 486.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 487px; margin-left: 395px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">RATIO REQUEST(Application1)</div></div></div></foreignObject><text x="395" y="487" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">RATIO REQUE...</text></switch></g><path d="M 569.5 520 L 430 520 Q 420 520 410 520 L 227.62 520" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 220.62 520 L 227.62 516.5 L 227.62 523.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 517px; margin-left: 395px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">RATIO RESPONSE(Application1, upratio, downratio)</div></div></div></foreignObject><text x="395" y="517" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">RATIO RESPONSE(...</text></switch></g><path d="M 20 540 L 586 540 L 600 554 L 600 610 L 20 610 L 20 540 Z" fill="#ffffff" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><path d="M 586 540 L 586 554 L 600 554" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-start; justify-content: unsafe center; width: 578px; height: 1px; padding-top: 541px; margin-left: 21px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><div>Application2 will cache the ratio a few seconds, to avoid asking the tracker</div><div>on each LOAD PART.</div><div>Here, based on this ratio, Application2 randomly decide to send a DENY to punish Application1. This filepart will be asked again later, and possibly to an other application.<br /></div></div></div></div></foreignObject><text x="310" y="553" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Application2 will cache the ratio a few seconds, to avoid asking the tracker...</text></switch></g><path d="M 219.5 640 L 120 640 Q 110 640 100 640 L 57.62 640" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 50.62 640 L 57.62 636.5 L 57.62 643.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 637px; margin-left: 141px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">DENY(file1, 0)</div></div></div></foreignObject><text x="141" y="637" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">DENY(file1, 0)</text></switch></g><path d="M 49.5 670 L 170 670 Q 180 670 190 670 L 391.38 670" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 398.38 670 L 391.38 673.5 L 391.38 666.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 667px; margin-left: 225px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">LOAD PART(1024, 512, file1)</div></div></div></foreignObject><text x="225" y="667" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">LOAD PART(1024,...</text></switch></g><path d="M 399.5 680 L 480 680 Q 490 680 500 680 L 561.38 680" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 568.38 680 L 561.38 683.5 L 561.38 676.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 677px; margin-left: 485px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">RATIO REQUEST(Application1)</div></div></div></foreignObject><text x="485" y="677" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">RATIO REQUEST(A...</text></switch></g><path d="M 569.5 700 L 520 700 Q 510 700 500 700 L 407.62 700" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 400.62 700 L 407.62 696.5 L 407.62 703.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 697px; margin-left: 485px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">RATIO RESPONSE(Application1, upratio, downratio)</div></div></div></foreignObject><text x="485" y="697" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">RATIO RESPONSE(...</text></switch></g><path d="M 399.5 740 L 300 740 Q 290 740 280 740 L 57.62 740" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 50.62 740 L 57.62 736.5 L 57.62 743.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 737px; margin-left: 225px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">LOAD RESPONSE(file1, 1024, content(file1,1024, 512))</div></div></div></foreignObject><text x="225" y="737" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">LOAD RESPONSE(f...</text></switch></g><path d="M 40 780 L 606 780 L 620 794 L 620 850 L 40 850 L 40 780 Z" fill="#ffffff" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><path d="M 606 780 L 606 794 L 620 794" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-start; justify-content: unsafe center; width: 578px; height: 1px; padding-top: 781px; margin-left: 41px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><div>Application1 asks for all the missing fileparts (not represented here).</div><div>Application1 compute the hashsum locally and if it matches the received one, send</div><div>UPDATE RATIO to tracker.<br /></div></div></div></div></foreignObject><text x="330" y="793" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Application1 asks for all the missing fileparts (not represented here)....</text></switch></g><path d="M 50 880 L 561.38 880" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 568.38 880 L 561.38 883.5 L 561.38 876.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 877px; margin-left: 310px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">UPDATE RATIO(Application2, &lt;number of bytes sent by Application2&gt;)</div></div></div></foreignObject><text x="310" y="877" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">UPDATE RATIO(Ap...</text></switch></g><path d="M 49.5 910 L 310 910 Q 320 910 330 910 L 561.38 910" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 568.38 910 L 561.38 913.5 L 561.38 906.5 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-end; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 907px; margin-left: 301px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 11px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">UPDATE RATIO(Application3, &lt;number of bytes sent by Application3&gt;)</div></div></div></foreignObject><text x="301" y="907" fill="#000000" font-family="Helvetica" font-size="11px" text-anchor="middle">UPDATE RATIO(Ap...</text></switch></g><path d="M 30 930 L 596 930 L 610 944 L 610 980 L 30 980 L 30 930 Z" fill="#ffffff" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><path d="M 596 930 L 596 944 L 610 944" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe flex-start; justify-content: unsafe center; width: 578px; height: 1px; padding-top: 931px; margin-left: 31px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><div>The download is over. Application1will detect a change in filelist an register the new</div><div>file to the tracker.<br /></div></div></div></div></foreignObject><text x="320" y="943" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">The download is over. Application1will detect a change in filelist an register the new...</text></switch></g></g><switch><g requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"/><a transform="translate(0,-5)" xlink:href="https://desk.draw.io/support/solutions/articles/16000042487" target="_blank"><text text-anchor="middle" font-size="10px" x="50%" y="100%">Viewer does not support full SVG 1.1</text></a></switch></svg>
\ No newline at end of file