view rust/rhg/src/blackbox.rs @ 51602:68929cf3c0c6

match: avoid rust fast path if the matcher was tampered with

Otherwise the fast path does not respect the modifications made
by the extension (concretely largefiles, but other extensions can
start using that too)

//! Logging for repository events, including commands run in the repository.

use crate::CliInvocation;
use format_bytes::format_bytes;
use hg::errors::HgError;
use hg::repo::Repo;
use hg::utils::{files::get_bytes_from_os_str, shell_quote};
use std::ffi::OsString;

// Python does not support %.3f, only %f
const DEFAULT_DATE_FORMAT: &str = "%Y-%m-%d %H:%M:%S%.3f";

type DateTime = chrono::DateTime<chrono::Local>;

pub struct ProcessStartTime {
    /// For measuring duration
    monotonic_clock: std::time::Instant,
    /// For formatting with year, month, day, etc.
    calendar_based: DateTime,
}

impl ProcessStartTime {
    pub fn now() -> Self {
        Self {
            monotonic_clock: std::time::Instant::now(),
            calendar_based: chrono::Local::now(),
        }
    }
}

pub struct Blackbox<'a> {
    process_start_time: &'a ProcessStartTime,
    /// Do nothing if this is `None`
    configured: Option<ConfiguredBlackbox<'a>>,
}

struct ConfiguredBlackbox<'a> {
    repo: &'a Repo,
    max_size: u64,
    max_files: u32,
    date_format: &'a str,
}

impl<'a> Blackbox<'a> {
    pub fn new(
        invocation: &'a CliInvocation<'a>,
        process_start_time: &'a ProcessStartTime,
    ) -> Result<Self, HgError> {
        let configured = if let Ok(repo) = invocation.repo {
            if !invocation.config.is_extension_enabled(b"blackbox") {
                None
            } else {
                Some(ConfiguredBlackbox {
                    repo,
                    max_size: invocation
                        .config
                        .get_byte_size(b"blackbox", b"maxsize")?
                        .expect(
                            "blackbox.maxsize should have a default value",
                        ),
                    max_files: invocation
                        .config
                        .get_u32(b"blackbox", b"maxfiles")?
                        .expect(
                            "blackbox.maxfiles should have a default value",
                        ),
                    date_format: invocation
                        .config
                        .get_str(b"blackbox", b"date-format")?
                        .map(|f| {
                            if f.is_empty() {
                                DEFAULT_DATE_FORMAT
                            } else {
                                f
                            }
                        })
                        .expect(
                            "blackbox.date-format should have a default value",
                        ),
                })
            }
        } else {
            // Without a local repository there’s no `.hg/blackbox.log` to
            // write to.
            None
        };
        Ok(Self {
            process_start_time,
            configured,
        })
    }

    pub fn log_command_start<'arg>(
        &self,
        argv: impl Iterator<Item = &'arg OsString>,
    ) {
        if let Some(configured) = &self.configured {
            let message = format_bytes!(b"(rust) {}", format_cli_args(argv));
            configured.log(&self.process_start_time.calendar_based, &message);
        }
    }

    pub fn log_command_end<'arg>(
        &self,
        argv: impl Iterator<Item = &'arg OsString>,
        exit_code: i32,
    ) {
        if let Some(configured) = &self.configured {
            let now = chrono::Local::now();
            let duration = self
                .process_start_time
                .monotonic_clock
                .elapsed()
                .as_secs_f64();
            let message = format_bytes!(
                b"(rust) {} exited {} after {} seconds",
                format_cli_args(argv),
                exit_code,
                format_bytes::Utf8(format_args!("{:.03}", duration))
            );
            configured.log(&now, &message);
        }
    }
}

impl ConfiguredBlackbox<'_> {
    fn log(&self, date_time: &DateTime, message: &[u8]) {
        let date = format_bytes::Utf8(date_time.format(self.date_format));
        let user = get_bytes_from_os_str(whoami::username_os());
        let rev = format_bytes::Utf8(match self.repo.dirstate_parents() {
            Ok(parents) if parents.p2 == hg::revlog::node::NULL_NODE => {
                format!("{:x}", parents.p1)
            }
            Ok(parents) => format!("{:x}+{:x}", parents.p1, parents.p2),
            Err(_dirstate_corruption_error) => {
                // TODO: log a non-fatal warning to stderr
                "???".to_owned()
            }
        });
        let pid = std::process::id();
        let line = format_bytes!(
            b"{} {} @{} ({})> {}\n",
            date,
            user,
            rev,
            pid,
            message
        );
        let result =
            hg::logging::LogFile::new(self.repo.hg_vfs(), "blackbox.log")
                .max_size(Some(self.max_size))
                .max_files(self.max_files)
                .write(&line);
        match result {
            Ok(()) => {}
            Err(_io_error) => {
                // TODO: log a non-fatal warning to stderr
            }
        }
    }
}

fn format_cli_args<'a>(
    mut args: impl Iterator<Item = &'a OsString>,
) -> Vec<u8> {
    let _ = args.next(); // Skip the first (or zeroth) arg, the name of the `rhg` executable
    let mut args = args.map(|arg| shell_quote(&get_bytes_from_os_str(arg)));
    let mut formatted = Vec::new();
    if let Some(arg) = args.next() {
        formatted.extend(arg)
    }
    for arg in args {
        formatted.push(b' ');
        formatted.extend(arg)
    }
    formatted
}