Add the ability to select a source image to use in the code.

experimental/webtry/DESIGN.md

Index: experimental/webtry/DESIGN.md
diff --git a/experimental/webtry/DESIGN.md b/experimental/webtry/DESIGN.md
index 0bc214512833beb6c84a2f0c6fc416ccd45d0a44..6def175b823fd6a2c4782634125dca17b75b01cc 100644
--- a/experimental/webtry/DESIGN.md
+++ b/experimental/webtry/DESIGN.md
@@ -136,6 +136,7 @@ Initial setup of the database, the user, and the only table:
     GRANT SELECT, INSERT, UPDATE ON webtry.webtry       TO 'webtry'@'%';
     GRANT SELECT, INSERT, UPDATE ON webtry.workspace    TO 'webtry'@'%';
     GRANT SELECT, INSERT, UPDATE ON webtry.workspacetry TO 'webtry'@'%';
+    GRANT SELECT, INSERT, UPDATE ON webtry.sources      TO 'webtry'@'%';
 
     // If this gets changed also update the sqlite create statement in webtry.go.
 
@@ -143,24 +144,40 @@ Initial setup of the database, the user, and the only table:
       code      TEXT      DEFAULT ''                 NOT NULL,
       create_ts TIMESTAMP DEFAULT CURRENT_TIMESTAMP  NOT NULL,
       hash      CHAR(64)  DEFAULT ''                 NOT NULL,
-      PRIMARY KEY(hash)
+      source    INTEGER   DEFAULT 0                  NOT NULL,

[mtklein, 2014/05/28 17:36:50]

Having both "code" and "source" is a touch confusing.  Is it to late to go to
something like source_image_id and webtry.source_images?

[jcgregorio, 2014/05/28 18:42:59]

Done.

+      PRIMARY KEY(hash),
+
+      FOREIGN KEY (source) REFERENCES sources(id)
     );
 
     CREATE TABLE workspace (
       name      CHAR(64)  DEFAULT ''                 NOT NULL,
       create_ts TIMESTAMP DEFAULT CURRENT_TIMESTAMP  NOT NULL,
-      PRIMARY KEY(name)
+      PRIMARY KEY(name),
     );
 
     CREATE TABLE workspacetry (
       name      CHAR(64)  DEFAULT ''                 NOT NULL,
       create_ts TIMESTAMP DEFAULT CURRENT_TIMESTAMP  NOT NULL,
       hash      CHAR(64)  DEFAULT ''                 NOT NULL,
+      source    INTEGER   DEFAULT 0                  NOT NULL,
       hidden    INTEGER   DEFAULT 0                  NOT NULL,
 
-      FOREIGN KEY (name) REFERENCES workspace(name)
+      FOREIGN KEY (name)   REFERENCES workspace(name),
     );
 
+		CREATE TABLE sources (

[mtklein, 2014/05/28 17:36:50]

Funky indent?

[jcgregorio, 2014/05/28 18:42:59]

Done.

+      id        INTEGER     PRIMARY KEY                NOT NULL,
+      image     MEDIUMBLOB  DEFAULT ''                 NOT NULL,

[mtklein, 2014/05/28 17:36:50]

Can we note somehow how image is encoded?  Is it, the original source file (i.e.
must be sniffed, probably JPG, PNG, etc.) or decoded into some bitmap format
(ARGB8888?)

[jcgregorio, 2014/05/28 18:42:59]

Done.

+      width     INTEGER     DEFAULT 0                  NOT NULL,
+      height    INTEGER     DEFAULT 0                  NOT NULL,
+      create_ts TIMESTAMP   DEFAULT CURRENT_TIMESTAMP  NOT NULL,
+      hidden    INTEGER     DEFAULT 0                  NOT NULL
+    )
+
+    ALTER TABLE webtry       ADD COLUMN source INTEGER DEFAULT 0 NOT NULL AFTER hash;
+    ALTER TABLE workspacetry ADD COLUMN source INTEGER DEFAULT 0 NOT NULL AFTER hash;
+
 Common queries webtry.go will use:
 
     INSERT INTO webtry (code, hash) VALUES('int i = 0;...', 'abcdef...');
@@ -183,6 +200,10 @@ Common queries for workspaces:
 
     SELECT name FROM workspace GROUP BY name;
 
+Common queries for sources:
+
+    SELECT id, image, width, height, create_ts FROM sources ORDER BY create_ts DESC LIMIT 100;
+
 Password for the database will be stored in the metadata instance, if the
 metadata server can't be found, i.e. running locally, then a local sqlite
 database will be used. To see the current password stored in metadata and the
@@ -202,6 +223,26 @@ the metadata server:
 N.B. If you need to change the MySQL password that webtry uses, you must change
 it both in MySQL and the value stored in the metadata server.
 
+Source Images
+-------------
+
+For every try the user can select an optional source image to use as an input.
+The id of the source image is just an integer and is stored in the database
+along with the other try information, such as the code.
+
+The actual image itself is also stored in a separate table, 'sources', in the
+database.  On startup we check that all the images are available in 'inout',
+and write out the images if not. Since they are all written to 'inout' we can
+use the same /i/ image handler to serve them.
+
+The bitmap is available to user code as a module level variable:
+
+    SkBitmap source;
+
+The bitmap is read, decoded and stored in source before the seccomp jail is
+instantiated.
+
+
 Squid
 -----