diff --git a/README.md b/README.md
index 38153d37b766f7239b930286733fd6b7fad2f971..debe2d53d0b0fa81e80aa4935c11d3de05dcd69c 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,12 @@ Below is a description of the config file's properties:
* `cameraSlots`: The camera slots available for this room. Defaults to `4`.
+* `notifyPath`: A path to a file which the camera server will append messages to.
+ This is used to notify the controller (usually PULT).
+ The path can either be absolute or relative to the config file but must not start with a tilde.
+
+ If this property is emitted or an empty string is provided, the notify feature will not be used.
+
## Stdin-Interface
The camera server is controlled by PULT via its stdin. One could also implement the interface in any other program to manage the CVH-Camera.
@@ -68,6 +74,20 @@ The current state of the camera feeds is saved in the server's memory and will b
| `hide` | Hides the feed of the provided slot. <br/> Note that the feed will still be transmitted to the viewer but is just hidden. By doing that, the feed can be shown again with a very low latency. <br/><br/> **Usage**: `hide <slot>`
| `show` | Shows the feed of the provided slot in case it was hidden. <br/><br/> **Usage**: `show <slot>`
+## Notify-Interface
+
+The camera server can notify its controller (usually PULT) by writing to a file which is provided in the config.
+The controller can then read the file and process the messages.
+
+In the case of PULT this file is a named pipe (mkfifo), which works perfectly fine.
+
+This is a list of all sent messages. Note that a newline character `\n` is appended to every message.
+
+| Message | Description
+| ---------------------------------- | -----------
+| `new_feed <slot>` | Sent after a sender on a slot has started transmitting a feed.
+| `remove_feed <slot>` | Sent after a sender on a slot has stopped transmitting a feed or the slot is deactivated (which also removes the feed).
+
## Socket Traffic
This section describes the socket traffic and the socket.io events that are used.
diff --git a/camera-server/example-config.json b/camera-server/example-config.json
index da5cef680e2d8f5ebc8c688afdc7201c71bfdf07..21696d58dbd4b344a42bc2451e9874d1536f77e5 100644
--- a/camera-server/example-config.json
+++ b/camera-server/example-config.json
@@ -1,4 +1,5 @@
{
"port": 5000,
- "cameraSlots": 4
+ "cameraSlots": 4,
+ "notifyPath": "./path-relative-to-config/or-absolute-path/camera-server-output"
}
diff --git a/camera-server/src/config/config.ts b/camera-server/src/config/config.ts
index 84ecd9df53d3936dfb407df5272e6964a17a79e9..5863a51c6053f410438ceac1384f4be875b994ee 100644
--- a/camera-server/src/config/config.ts
+++ b/camera-server/src/config/config.ts
@@ -4,13 +4,13 @@ import * as path from 'path';
interface Config {
port: number;
cameraSlots: number;
+ notifyPath: string;
}
// Required to access config with config[key]
// But only an object of type Config should be returned
interface IndexableConfig extends Config {
- // Change type once non-number values are added
- [key: string]: number;
+ [key: string]: number | string;
}
let configPath = process.env.CONFIG_PATH;
@@ -22,7 +22,7 @@ if (configPath) {
fileContent = fs.readFileSync(configPath).toString();
} catch (err) {
console.log(
- `Could not read config at ${path.resolve(configPath)}:`,
+ `Error: Could not read config at ${path.resolve(configPath)}:`,
err
);
console.log('Using default values');
@@ -33,7 +33,8 @@ if (configPath) {
const indexableConfig: IndexableConfig = {
port: 5000,
- cameraSlots: 4
+ cameraSlots: 4,
+ notifyPath: ''
};
if (fileContent) {
@@ -59,12 +60,12 @@ if (fileContent) {
);
}
} else {
- console.log(`Unknown property ${key} in config`);
+ console.log(`Error: Unknown property ${key} in config`);
}
});
} else {
console.log(
- `Config at ${path.resolve(
+ `Error: Config at ${path.resolve(
configPath!
)} is malformed - using default values`
);
@@ -72,6 +73,12 @@ if (fileContent) {
}
const config = indexableConfig as Config;
+if (config.notifyPath && !path.isAbsolute(config.notifyPath) && configPath) {
+ config.notifyPath = path.resolve(
+ path.dirname(configPath),
+ config.notifyPath
+ );
+}
console.log('Using config:', config);
diff --git a/camera-server/src/io-interface/handlers/output-handlers.ts b/camera-server/src/io-interface/handlers/output-handlers.ts
new file mode 100644
index 0000000000000000000000000000000000000000..ad81cd3374ec004ca949404efef8f950ae654b08
--- /dev/null
+++ b/camera-server/src/io-interface/handlers/output-handlers.ts
@@ -0,0 +1,55 @@
+import * as fs from 'fs';
+
+import { config } from '../../config/config';
+
+// Saves the amount of blocking append calls
+// in case the named pipe is not read by PULT
+let blockingAppendCalls = 0;
+
+const timeoutTime = 5000;
+
+const printTimeoutMessage = (notifyPath: string) => {
+ console.log(
+ `Error: Controller did not read file at path '${notifyPath}' for ${timeoutTime}ms`
+ );
+};
+
+const notifyController = (message: string) => {
+ const { notifyPath } = config;
+ if (notifyPath) {
+ if (fs.existsSync(notifyPath)) {
+ const timeoutId = setTimeout(
+ printTimeoutMessage.bind(null, notifyPath),
+ timeoutTime
+ );
+ console.log(
+ `Notifying controller about message '${message}' using file at path '${notifyPath}'`
+ );
+ blockingAppendCalls += 1;
+ fs.appendFile(notifyPath, message + '\n', (err) => {
+ if (err) {
+ console.log(
+ `Error: Tried to notify controller about message '${message}' but could not write to path '${notifyPath}' - Error:`,
+ err
+ );
+ }
+ blockingAppendCalls -= 1;
+ clearTimeout(timeoutId);
+ });
+ } else {
+ console.log(
+ `Error: Tried to notify controller about message '${message}' using file at path '${notifyPath}' which does not exist`
+ );
+ }
+ }
+};
+
+export const isBlocking = () => blockingAppendCalls !== 0;
+
+export const notifyNewFeed = (slot: number) => {
+ notifyController(`new_feed ${slot}`);
+};
+
+export const notifyRemoveFeed = (slot: number) => {
+ notifyController(`remove_feed ${slot}`);
+};
diff --git a/camera-server/src/socket-io/handlers/common-handlers.ts b/camera-server/src/socket-io/handlers/common-handlers.ts
index d3b56691f50c5f2502530aaa2afca3a841b9470b..39d4e5386c0ff9fb7bedf2204d272cc1a6f8490b 100644
--- a/camera-server/src/socket-io/handlers/common-handlers.ts
+++ b/camera-server/src/socket-io/handlers/common-handlers.ts
@@ -1,19 +1,25 @@
import { socketIO } from '../socket-io';
import { cameraSlotState } from '../../state/camera-slot-state';
import { CommandDescriptor } from '../../models/command-descriptor';
+import {
+ notifyNewFeed,
+ notifyRemoveFeed
+} from '../../io-interface/handlers/output-handlers';
export const emitNewFeed = (slot: number) => {
- const cameraState = cameraSlotState[slot];
+ const slotState = cameraSlotState[slot];
socketIO.emit('new_feed', {
slot,
- feedId: cameraState.feedId,
- visibility: cameraState.visibility,
- geometry: cameraState.geometry
+ feedId: slotState.feedId,
+ visibility: slotState.visibility,
+ geometry: slotState.geometry
});
+ notifyNewFeed(slot);
};
export const emitRemoveFeed = (slot: number) => {
socketIO.emit('remove_feed', { slot });
+ notifyRemoveFeed(slot);
};
export const handleQueryState = (fn: Function) => {
@@ -26,12 +32,12 @@ export const handleQueryState = (fn: Function) => {
};
} = {};
for (let i = 0; i < cameraSlotState.length; i++) {
- const cameraState = cameraSlotState[i];
- if (cameraState.feedActive) {
+ const slotState = cameraSlotState[i];
+ if (slotState.feedActive) {
response[i] = {
- feedId: cameraState.feedId,
- visibility: cameraState.visibility,
- geometry: cameraState.geometry
+ feedId: slotState.feedId,
+ visibility: slotState.visibility,
+ geometry: slotState.geometry
};
}
}
diff --git a/camera-server/src/util/cleanup.ts b/camera-server/src/util/cleanup.ts
index 5cc867a4fff2a245f63c13f0d2357f968917c951..0a78da277e82507dc1291fe4700d9944b376a5ae 100644
--- a/camera-server/src/util/cleanup.ts
+++ b/camera-server/src/util/cleanup.ts
@@ -1,19 +1,29 @@
import { socketIO } from '../socket-io/socket-io';
+import { isBlocking } from '../io-interface/handlers/output-handlers';
interface ExitHandlerOptions {
cleanup?: boolean;
exit?: boolean;
}
-const cleanup = () => {
- console.log('cleanup');
- socketIO.emit('remove_all_feeds');
-};
-
-const exitHandler = (options: ExitHandlerOptions, exitCode: number) => {
- if (options.cleanup) cleanup();
- if (exitCode || exitCode === 0) console.log(exitCode);
- if (options.exit) process.exit();
+const exitHandler = (
+ options: ExitHandlerOptions,
+ exitCode: string | number
+) => {
+ if (options.cleanup) {
+ console.log('cleanup');
+ socketIO.emit('remove_all_feeds');
+ }
+ if (exitCode || exitCode === 0) {
+ console.log('Exit code:', exitCode);
+ if (exitCode === 0 && isBlocking()) {
+ console.log('Aborting process due to blocking file append');
+ process.abort();
+ }
+ }
+ if (options.exit) {
+ process.exit();
+ }
};
export const registerCleanupLogic = () => {