Create a message queue

The create command creates a new message queue with support of the
typical parameters `mode`, `capacity` and `msgsize`. This command also
supports the global argument `verbose`.
This commit is contained in:
finga 2021-06-14 03:06:23 +02:00
parent 2b96bcc562
commit fdacba1eec
5 changed files with 101 additions and 3 deletions

17
Cargo.lock generated
View file

@ -1,5 +1,11 @@
# This file is automatically @generated by Cargo. # This file is automatically @generated by Cargo.
# It is not intended for manual editing. # It is not intended for manual editing.
[[package]]
name = "anyhow"
version = "1.0.41"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "15af2628f6890fe2609a3b91bef4c83450512802e59489f9c1cb1fa5df064a61"
[[package]] [[package]]
name = "atty" name = "atty"
version = "0.2.14" version = "0.2.14"
@ -105,7 +111,9 @@ checksum = "12b8adadd720df158f4d70dfe7ccc6adb0472d7c55ca83445f6a5ab3e36f8fb6"
name = "mqrs" name = "mqrs"
version = "0.1.0-dev" version = "0.1.0-dev"
dependencies = [ dependencies = [
"anyhow",
"clap", "clap",
"posixmq",
] ]
[[package]] [[package]]
@ -114,6 +122,15 @@ version = "2.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "afb2e1c3ee07430c2cf76151675e583e0f19985fa6efae47d6848a3e2c824f85" checksum = "afb2e1c3ee07430c2cf76151675e583e0f19985fa6efae47d6848a3e2c824f85"
[[package]]
name = "posixmq"
version = "1.0.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e5e01860c5a0b0c823066268fb7950019bac142c1cb8919e774823fe510e697a"
dependencies = [
"libc",
]
[[package]] [[package]]
name = "proc-macro-error" name = "proc-macro-error"
version = "1.0.4" version = "1.0.4"

View file

@ -8,4 +8,6 @@ readme = "README.md"
description = "A CLI program for interacting Posix Message Queues" description = "A CLI program for interacting Posix Message Queues"
[dependencies] [dependencies]
anyhow = "1.0"
clap = "3.0.0-beta.2" clap = "3.0.0-beta.2"
posixmq = "1.0"

View file

@ -1,3 +1,4 @@
use crate::create::Create;
use clap::{crate_authors, crate_version, AppSettings, Clap}; use clap::{crate_authors, crate_version, AppSettings, Clap};
#[derive(Clap, Debug)] #[derive(Clap, Debug)]
@ -12,4 +13,11 @@ pub struct Opts {
/// Produce verbose output /// Produce verbose output
#[clap(short, long, global = true)] #[clap(short, long, global = true)]
pub verbose: bool, pub verbose: bool,
#[clap(subcommand)]
pub command: Command,
}
#[derive(Clap, Debug)]
pub enum Command {
Create(Create),
} }

63
src/create.rs Normal file
View file

@ -0,0 +1,63 @@
use anyhow::Result;
use clap::Clap;
use posixmq::PosixMq;
use std::fs;
/// Create a POSIX message queue
#[derive(Clap, Debug)]
pub struct Create {
/// Permissions (octal) to create the queue with
#[clap(short = 'p', long)]
mode: Option<String>,
/// Maximum number of messages in the queue
#[clap(short, long)]
capacity: Option<usize>,
/// Message size in bytes
#[clap(short = 's', long)]
msgsize: Option<usize>,
/// Name of the queue
#[clap(value_name = "QNAME")]
queue: String,
}
fn msgsize_default() -> usize {
match fs::read_to_string("/proc/sys/fs/mqueue/msgsize_default") {
Ok(m) => m.trim().parse::<usize>().unwrap(), // should never fail
_ => 8192,
}
}
fn msg_default() -> usize {
match fs::read_to_string("/proc/sys/fs/mqueue/msg_default") {
Ok(m) => m.trim().parse::<usize>().unwrap(), // should never fail
_ => 10,
}
}
impl Create {
pub fn run(&self, verbose: bool) -> Result<()> {
let mq = &mut posixmq::OpenOptions::readonly();
if let Some(m) = &self.mode {
mq.mode(u32::from_str_radix(&m, 8)?);
}
mq.max_msg_len(self.msgsize.unwrap_or_else(msgsize_default))
.capacity(self.capacity.unwrap_or_else(msg_default))
.create_new()
.open(&self.queue)?;
if verbose {
let mq = PosixMq::open(&self.queue)?;
let attributes = mq.attributes()?;
println!("Created message queue: {} with attributes msgsize: {}, capacity: {}, current_messages: {}",
&self.queue,
&attributes.max_msg_len,
&attributes.capacity,
&attributes.current_messages);
}
Ok(())
}
}

View file

@ -1,9 +1,17 @@
use anyhow::Result;
use clap::Clap; use clap::Clap;
mod cli; mod cli;
mod create;
use cli::Opts; use cli::{Command, Opts};
fn main() { fn main() -> Result<()> {
Opts::parse(); let opts: Opts = Opts::parse();
match opts.command {
Command::Create(c) => c.run(opts.verbose)?,
}
Ok(())
} }