The Skia Debugger consists of two components, the C++ command-line application that ingests SKPs and analyzes them, and the HTML/CSS/JS front-end to the debugger that is loaded off of https://debugger.skia.org.
The C++ command-line application embeds a web server and provides a web API for inspecting and interacting with an SKP that the front-end consumes.
Normally the skdebugger will be run on the same machine that the browser is run on:
+---------------------+
| |
| debugger.skia.org |
| |
+----+----------------+
^
|
+-----------------------------------------------+
| | |
| Desktop | |
| +-----------+ | |
| | | | +---------+ |
| | Browser +-----+ | | |
| | | | skdebug | |
| | +------> | | |
| +-----------+ +---------+ |
| |
| |
+-----------------------------------------------+
But that ins't a requirement, and the skdebugger could be run on a remove machine, or with port forwarding could be run on an Android device:
+---------------------+
| |
| debugger.skia.org |
| |
+----+----------------+
^
|
+----------------------------------+ +----------------------+
| | | | |
| Desktop | | | Android Device |
| +-----------+ | | | |
| | | | | | +---------+ |
| | Browser +-----+ | | | | |
| | | | | | skdebug | |
| | +---------------------->+ | |
| +-----------+ | | +---------+ |
| | | |
| | | |
+----------------------------------+ +----------------------+
Current Actions:
Future Actions:
Far Future Actions:
Insert command at N.
Delete command N.
Update command N (change both values and/or command).
/new POST /new - Start working on a new SKP. The content is a multipart/form-data with the SKP uploaded as ‘file’.
/info[/N] GET /info - Get general info for the fully rendered SKP (matrix, clip). Get /info/N - Get info about the SKP after rendering to command N (matrix, clip).
/img[/N] Get /img - Get the rendered image from the full SKP. Get /img/N - Get the rendered image up to command N.
/cmd[/N][/toggle] GET /cmd - Returns JSON description of all commands. GET /cmd/N - Returns JSON description of one command. PUT /cmd/N - Update the command at location N. DELETE /cmd/N - Delete command at location N. POST /cmd/N/[0|1] - Toggles command N on or off.
/clipAlpha/[0-255] POST - Change the opacity of the clip overlay.
/break/n/x/y GET - Returns the index of the next op after ‘n’ where the color of the pixel at (x, y) has changed.
/enableGPU/[0|1] POST - Changes the rendering to/from CPU/GPU.
/colorMode/[0|1|2] POST - Changes rendering to Linear 32-bit (0), sRGB (1), or Half-float (2)
A hosted version of the debugger runs on debugger.skia.org.
Each signed in user has a skiaserve that is run in a chroot jail just for them, so these are long running processes. Each on runs on a different port and the skdebugger Go app proxies requests to different skiaserve instances based on the users id.
Every hour the server attempts to build skiaserve at LKGR. When a new skiaserve instance is started it always uses the latest LKGR of skiaserve.
An attached disk will reside at /mnt/pd0 and will be populated as:
/mnt/pd0/container - Image for chroot jail.
/mnt/pd0/depot_tools - A copy of depot_tools.
/mnt/pd0/debugger - $WORK_ROOT
/mnt/pd0/debugger/skia - A checkout of Skia used only for
look up git commit hashes.
/mnt/pd0/debugger/versions/[git hash] - Checkouts of
Skia at various LKGRs.
skia-debugger
+----------------------------------------------------------+
| |
| gyp/ninja |
| WORK_ROOT/versions/<githash>/ +------------> skiaserve |
| |
| |
| systemd-nspawn |
| + |
| | |
| +-> skiaserve (opens TCP/IP port) |
| |
| |
+----------------------------------------------------------+
We could continuously add new builds to /versions/ but each checkout and build is ~1.3GB. So we‘ll fill up our 1TB disk in under a year. So we need to keep around older builds, but can’t keep them all. Having finer-grained history for recent builds is also important, while we can tolerate gaps in older builds. I.e. we don't really need a build from 30 days ago, and 30 days and 1 hr ago, but we would like to have almost all of the last weeks worth of commits available. So we end up with a decimation strategy that is simple but also accomplishes the above goals. For example: