Начать. Это бесплатно
или регистрация c помощью Вашего email-адреса
Google IO 2013 создатель Mind Map: Google IO 2013

1. Web Languages and VMs: Why fast code is always in fashion

1.1. Same guys wrote the V8 vm/engine that is writing the Dart vm.

1.1.1. worked together for 12 years on vms

1.1.1.1. smalltalk, hotspot, crankshaft, cldc, jvm, v8, self, Dart

1.1.2. Lars Bak & Kasper Lund

1.2. Where is time spent in the V8 vm

1.2.1. gmail, google docs, google search etc

1.2.1.1. 50-70% V8

1.2.1.2. 30-50% Blink

1.2.2. twitter, facebook, youtube

1.2.2.1. 20-40% V8

1.2.2.2. 60-80% Blink

1.3. Moden JavaScript Engine

1.3.1. general process

1.3.1.1. parser

1.3.1.1.1. multi-teir adaptive compilation

1.3.2. Identify 'hot' heavily used functoinas, attempt to optimize, but if it does dumb js stuff, fallback to the conventional way

1.3.3. Converts prototypes to classes

1.3.4. Didn't invent this

1.3.4.1. 60's

1.3.4.1.1. lisp

1.3.4.2. 70's-80's

1.3.4.2.1. small talk

1.3.4.3. 90's

1.3.4.3.1. self

1.3.4.4. They just added all of them up to v8

1.3.5. Garbage Collection

1.3.5.1. Using generational was new to a browser

1.3.5.2. Has many problems that java has

1.3.5.2.1. many due to how js nodes is cleaned up with tracing while the dom nodes are cleaned up with a number of references pointer

1.3.6. BUT

1.3.6.1. It's still js...

1.3.6.2. v8 started at 100,000 lines, now almost 500,000 lines....

1.4. Welcome to the Dart Side

1.4.1. Why Dart is inately faster than js

1.4.1.1. real objects

1.4.1.2. straightforward language semantics makes it clear the intent and the VM does not have to interrogate an entire block of code to determine its use

1.4.1.3. fewer special corner cases

1.4.1.4. Prototype methods can be overridden in js... not dart

1.4.1.5. less generated code (minify etc)

1.5. Benchmarks

1.5.1. Richards & DeltaBlue benchmark

1.5.2. Richards

1.5.2.1. Dart 1.7x faster than v8

1.5.2.2. dar2js slightly behind v8

1.5.3. DeltaBlue

1.5.3.1. Dart 2x faster than v8

1.5.3.2. dart2js slightly better than v8 --- booyah

1.6. What's next?

1.6.1. Project OilPan

1.6.1.1. re-write the browser garbage collection

1.6.1.2. do all tracing removals so gc doesn't freeze as much and can be smarter

1.6.1.3. Entire web application can be serialized

1.6.1.4. Concurrent manipulation of the DOM

2. Cognitive Science and Design

2.1. Lost my notes

2.2. Mostly referenced some books that designers should read

2.3. Things like our peripheral vision can identify change faster than our direct vision

2.4. Make changes across the board

2.4.1. Don't just change a language, change it to go from right to left, change the back button to be on the right, reverse icons

3. Upgrading to a Chrome Packaged App

3.1. Lots of api's available for chromeos type environments

3.2. very new apis, very specific

3.3. lots of js and other stuff is actually disabled for security

3.4. sounds like a pain in the butt and just not worth it right now

4. Get Unstuck - Gamestorming Not Brainstorming

4.1. Book - Must Read

4.2. Brainwriting

4.2.1. everyone individually writes ideas, one per note card

4.2.1.1. for a few minutes

4.2.2. next part pass the cards to the right and everyone elaborate on the previous card

4.2.2.1. after writing down an additional idea, pass it again to the right until time is up

4.2.2.2. for ~5+ minutes

4.2.3. Review cards

4.3. 6-8-5

4.3.1. Fold a single sheet of paper in half 3 times

4.3.1.1. produces 8 squares

4.3.2. Everyone individually elaborates on an idea

4.3.2.1. adds one idea per box

4.3.2.2. can be a single word

4.3.2.3. a picture

4.3.2.4. a phrase

4.3.3. Goal is to get 6-8 ideas within 5 minutes

4.4. $100 investment

4.4.1. All ideas are place don the wall

4.4.2. Everyone writes down $ amounts that would add up to $100 and invest in certain ideas

4.4.3. This is to reduce ideas and get a feel for where people are leaning toward on the team

4.5. Gamestorming Cheat Sheet

4.5.1. bit.ly/gamestorming-cheatsheet

5. Google Visualization API

5.1. What

5.1.1. javascript charting api

5.1.2. timeline is new and looks pretty useful

5.1.3. Scatter chart

5.1.4. Bubble Chart

5.1.5. Geo / Map chart

5.1.5.1. differet projections

5.2. Why?

5.2.1. unsure of why, there are a lot of charting apis in js

5.2.2. the timeline one looks like the only real needed one

6. Feature Detection in the Real World

6.1. Basically walks us through a year of her trying to develop for the cutting edge and all the difficulties she had

6.1.1. lots of examples of checking for a feature is not enough, sometimes a feature is only halfway implemented

6.1.2. checking all the api calls needed to do it's job before ever needing them because it's the only safe way

6.2. Ultimate takeaway is don't live on teh chrome (or others) cutting edge for a real serious, money making product

6.2.1. only do it for the experimental and prototype projects needing to help stay ahead of the curve but not super reliable

6.3. Big Expectations

6.3.1. Do NOT assume it's going to be easy

6.3.2. Do NOT just copy the first stackoverflow answer

6.3.3. DO use tried and true techniques

6.3.4. DO try feature detection first

6.3.5. Mix & Match - modernizr, blacklist etc

7. Automating Performance Best Practices with PageSpeed

7.1. Lost my notes =(

7.2. Google released an apache mod and something else to do this many years ago

7.2.1. really no reason not to do this

7.2.2. ngx_pagespeed also

7.3. PageSpeed chrome extension

7.4. LOTS of very smart automations

7.4.1. Hacks the outgoing html to reference exact image sizes, of compressed versions of the image

7.4.1.1. photos/800x450wawesome_cat.png.pagespeed.ic.HASH.webp

7.4.2. Minify JS

7.4.3. Concatenate css files into one

7.4.3.1. yellow.css+blue.css+big.css+bold.css.pagespeed.cc.HASH.css

7.4.3.2. cc = combined css

7.4.3.3. hash = date modified hashing (or smarter)

7.4.4. 40+ optimizations

7.4.4.1. configurable

7.5. Google API services

7.5.1. can route your own website through google servers and control all the settings from a google dashboard

7.5.2. live demo, freaking awesome, freaking smart

7.5.3. first request when the mod enabled does nothing, because it doesn't want to slow down the first request

7.5.3.1. but it will concatenate and cache things for the next requests now that it knows how the page works

7.5.3.2. second page load had all the benefits

7.5.4. Showed a 3 image page example going from ~3MB to 300kb

7.5.5. developers.google.com/speed/pagespeed/service

8. WebM VP9

8.1. VP8 was getting finalized and now VP9 is new

8.1.1. yah, but it's better

8.2. Uses source frames throughout the video for reuse throughout the video

8.2.1. The source frame is highly optimized

8.2.1.1. vp8's source frame was the basis for WebP the new image format

8.3. Goal is 4th Quarter 2013 to integrate production ready software versions

8.3.1. hardware accelerated will be primary focus after release

9. Instant Mobile Websites

9.1. Bandwidth is not the problem - it's latency

9.2. Load required css in the initial html response to give the user a response right away before the leave

9.3. 14kb is of html before another round trip (even if it's one html file) so keep it less than that

9.3.1. prioritize visible content from there

10. True Grit: Debugging CSS & Render Performance

10.1. Chelsea Derric - Senior software engineer on gmail

10.2. Fast is better than slow - google 10 things philosophy

10.2.1. http://www.google.com/about/company/philosophy/

10.3. Use the Chrome Dev Tools timeline

10.3.1. it shows where rendering time is being spent

10.3.2. The Rendering Cycle

10.3.2.1. Build the DOM

10.3.2.2. Calculate CSS property values

10.3.2.3. Build the rendering tree

10.3.2.3.1. Boxes vs Elements

10.3.2.4. Calculate Layout

10.3.2.4.1. tall, wide, top left corner

10.3.2.4.2. height, width, padding, border-width, margin- coordinates (top, right, bottom left)

10.3.2.5. Paint

10.3.2.5.1. Transparency can be expensive, especially anti-aliased text

10.3.2.5.2. layers are painted individually

10.3.2.6. Compositing

10.3.2.6.1. layer bitmaps are transferred to the gpu, combined (composited) and drawn on the screen

10.3.2.6.2. opacity, transform etc

10.3.3. Timeline shows what stages are happening

10.4. Many animations etc cause calculate layout and painting which take a long time and make things look choppy

10.4.1. tricks can be used to do layouting early and only do compositing which is very light weight

10.4.2. transform translate3d 0,0,0

11. Never leaving the DevTools

11.1. Paul Irish

11.2. Workspaces

11.2.1. editing in dev tools can change the source also

11.2.2. And vice versa

11.3. SASS (css toolkit) support

11.4. ADB Extension to chrome dev tools for android

11.5. Lot of cool stuff, need to keep up on this because it would save lots of time

11.5.1. much of what was shown was in canary build so hopefully stable soon enough

12. WebP - enabling faster, smaller and more beautiful web

12.1. Why WebP is needed

12.1.1. 60 % of desktop sites are images

12.1.2. 59% of mobile sites are images

12.1.3. Screens are getting higher dpi (retina, pixel etc)

12.2. WebP is

12.2.1. Improved data compression

12.2.2. Lossy and lossless modes

12.2.3. Alpha channel, animation ...

12.2.4. Derived from VP8 keyframe (not vp9)

12.2.5. open-source, royalty free formats

12.3. Achievements

12.3.1. On average 30% smaller than PNG for lessless compression

12.3.1.1. Even better for slightly lossy

12.4. Encoding and Decoding

12.4.1. Encoding 5-10x slower than JPEG

12.4.1.1. only bad use case is dynamic imagery... like AFWWEBS

12.4.2. Decoding ~1.3x slower than JPEG

12.4.3. Bandwidth saving vs extra CPU time

12.4.3.1. Most encoding is done upfront, rarely dynamically

12.4.4. Lots of tools support this

12.5. Facebook trial

12.5.1. worked great - FB loved it

12.5.2. People could save a picture but not open it

12.5.2.1. chrome updated so that it will be an app that can open webp images

12.5.3. People would send a url from chrome to a friend using IE, they can't see webp

12.5.3.1. make urls extension agnostic and pick off user agent

12.5.3.1.1. requires 2 versions or a dynamic parser on the fly but it's a way to transition

12.6. Google Is Moving Toward it

12.6.1. google maps

12.6.2. docs

12.6.3. gmail

12.6.4. chrome

12.6.5. youtube

12.6.6. g+

12.6.6.1. on android already - got 50% bytes savings

12.6.7. google play

12.6.8. google image search