Integrate linenoise with web server #162

vax-r · 2024-02-29T11:29:08Z

Summary

In the previous version of console implementation, we tried to integrate tiny-web-server to enable the ability of processing commands from web requests. As the result, the package linenoise which is responsible for
command-line auto-complete needs to be disabled during the running time of tiny-web-server. Because the line_edit() function in linenoise.c doesn't have the ability to handle web requests correctly.

When we start the web server, we use cmd_select in console.c and use select system call to monitor web socket file descriptor and stdin_fd at the same time, however, this ability should present in the line_edit function in linenoise.c so we can process commands from command-line and from web requests at the same time.

That's the reason I re-design the linenoise implementation and make some modification to put select() system call in line_edit so we can have the full ability to use web server and linenoise package in command-line at the same time.

linenoise.h

jserv

Refine the subject of git commit messages: make it compliant with https://cbea.ms/git-commit/

linenoise.c

jserv · 2024-03-01T12:39:18Z

Remove "Successfully" from the subject of git commit messages. Make it informative.

jserv · 2024-03-01T13:27:04Z

linenoise.c

@@ -927,6 +928,11 @@ static int line_edit(int stdin_fd,

    if (write(l.ofd, prompt, l.plen) == -1)
        return -1;
+
+    int result = web_select(l.buf, l.ifd);


The proposed change lacks refinement, as it tightly integrates web server operations with the linenoise package. Linenoise is intended to be a streamlined and functional package, offering basic command line editing capabilities universally. Therefore, it's advisable to incorporate the function hook within the main loop of linenoise. This strategy will enable a standard method for callback registration, allowing web server interactions to be executed alongside linenoise's main loop, thus achieving a more decoupled approach.

My understanding is that the main loop of linenoise is the same as the function linenoise() in linenoise.c , can I say that ?

My understanding is that the main loop of linenoise is the same as the function linenoise() in linenoise.c , can I say that ?

No, the main loop of linenoise package appears in line_edit function, and you check the callbacks such as completion_callback for the execution of user-defined functions. Always program in an elegant way.

linenoise.c

jserv

Avoid using backtick in git commit message for the sake of maximum editor compatibility. You can use (double) quotation marks instead.

linenoise.c

web.h

jserv · 2024-03-02T06:01:40Z

linenoise.c

@@ -472,6 +473,14 @@ void line_set_free_hints_callback(line_free_hints_callback_t *fn)
    free_hints_callback = fn;
 }

+/* Register a function to perform I/O multiplexing to monitor multiple file


Improve the descriptions by explaining the functionality of this callback invoked inside the main loop of linenoise. You should discuss the use case for example.

jserv

Refine the subject "Integrate linenoise package with web server," which is a bit misleading. In fact, web server has been integrated into the whole project, and the proposed change is not exactly referred as the integration effort. Instead, it was meant to inject the main loop of line editing by introducing an extra callback which can interoperate with the web server.

web.c

In the previous version of console implementation, we tried to integrate tiny-web-server to enable the ability of processing commands from web requests. As the result, the package linenoise which is responsible for command-line auto-complete needs to be disabled during the running time of tiny-web-server. Because the main loop in "line_edit()" function in linenoise doesn't have the ability to handle web requests correctly. When we start the web server, we use "cmd_select" in console.c and use "select" function to monitor web socket file descriptor and stdin_fd at the same time. I re-design the control flow of web request and command-line input by implement the function "web_eventmux()", and register it as a hook function of type "line_eventmux_callback_t" inside linenoise package. As the result, we can utilize function inside the main loop of linenoise which is located inside the function "line_edit()". "web_eventmux()" is a function which use the function "select()" to monitor both input file descriptor and web file descriptor and modify "line_edit()" to use "eventmux_callback()" so we can process command-line input as normal and provide the command-line auto-complete feature alongside with the abitlity to deal with inputs from different input sources, such as web request. One may wonder why don't we simply modify the function "line_edit()", the reason is that linenoise is an upstream package so we only want to do the miminal changes to this package.

jserv · 2024-03-02T06:46:55Z

Can I mention this PR in my homework-1 note ? or I should refine my commit in my personal repository and mentioned it instead ?

Go ahead. Don't go off-topic here.

jserv · 2024-03-04T03:26:52Z

Thank @vax-r for contributing!

vax-r force-pushed the Integrate_linenoise_web branch 2 times, most recently from 4fb6f1d to ee46154 Compare February 29, 2024 12:43

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jserv requested a review from eecheng87 February 29, 2024 13:38

jserv reviewed Feb 29, 2024

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vax-r force-pushed the Integrate_linenoise_web branch from ee46154 to 39cfd90 Compare March 1, 2024 02:05

vax-r requested a review from jserv March 1, 2024 02:06

jserv requested changes Mar 1, 2024

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