view rust/rhg/src/error.rs @ 48409:005ae1a343f8

rhg: add support for narrow clones and sparse checkouts

This adds a minimal support that can be implemented without parsing the narrowspec.
We can parse the narrowspec and add support for more operations later.

The reason we need so few code changes is as follows:

Most operations need no special treatment of sparse because
some of them only read dirstate (`rhg files` without `-r`),
which bakes in the filtering,
some of them only read store (`rhg files -r`, `rhg cat`),
and some of them read no data at all (`rhg root`, `rhg debugrequirements`).

`status` is the command that might care about sparse, so we just disable
rhg on it.

For narrow clones, `rhg files` clearly needs the narrowspec to work
correctly, so we fall back.
`rhg cat` seems to work consistently with `hg cat` if the file exists.
If the file is hidden by narrow spec, the error message is different and confusing, so
that's something that we should improve in follow-up patches.

Differential Revision: https://phab.mercurial-scm.org/D11764

use crate::ui::utf8_to_local;
use crate::ui::UiError;
use crate::NoRepoInCwdError;
use format_bytes::format_bytes;
use hg::config::{ConfigError, ConfigParseError, ConfigValueParseError};
use hg::dirstate_tree::on_disk::DirstateV2ParseError;
use hg::errors::HgError;
use hg::exit_codes;
use hg::repo::RepoError;
use hg::revlog::revlog::RevlogError;
use hg::utils::files::get_bytes_from_path;
use hg::{DirstateError, DirstateMapError, StatusError};
use std::convert::From;

/// The kind of command error
#[derive(Debug)]
pub enum CommandError {
    /// Exit with an error message and "standard" failure exit code.
    Abort {
        message: Vec<u8>,
        detailed_exit_code: exit_codes::ExitCode,
    },

    /// Exit with a failure exit code but no message.
    Unsuccessful,

    /// Encountered something (such as a CLI argument, repository layout, …)
    /// not supported by this version of `rhg`. Depending on configuration
    /// `rhg` may attempt to silently fall back to Python-based `hg`, which
    /// may or may not support this feature.
    UnsupportedFeature { message: Vec<u8> },
}

impl CommandError {
    pub fn abort(message: impl AsRef<str>) -> Self {
        CommandError::abort_with_exit_code(message, exit_codes::ABORT)
    }

    pub fn abort_with_exit_code(
        message: impl AsRef<str>,
        detailed_exit_code: exit_codes::ExitCode,
    ) -> Self {
        CommandError::Abort {
            // TODO: bytes-based (instead of Unicode-based) formatting
            // of error messages to handle non-UTF-8 filenames etc:
            // https://www.mercurial-scm.org/wiki/EncodingStrategy#Mixing_output
            message: utf8_to_local(message.as_ref()).into(),
            detailed_exit_code: detailed_exit_code,
        }
    }

    pub fn unsupported(message: impl AsRef<str>) -> Self {
        CommandError::UnsupportedFeature {
            message: utf8_to_local(message.as_ref()).into(),
        }
    }
}

/// For now we don’t differenciate between invalid CLI args and valid for `hg`
/// but not supported yet by `rhg`.
impl From<clap::Error> for CommandError {
    fn from(error: clap::Error) -> Self {
        CommandError::unsupported(error.to_string())
    }
}

impl From<HgError> for CommandError {
    fn from(error: HgError) -> Self {
        match error {
            HgError::UnsupportedFeature(message) => {
                CommandError::unsupported(message)
            }
            HgError::Abort {
                message,
                detailed_exit_code,
            } => {
                CommandError::abort_with_exit_code(message, detailed_exit_code)
            }
            _ => CommandError::abort(error.to_string()),
        }
    }
}

impl From<ConfigValueParseError> for CommandError {
    fn from(error: ConfigValueParseError) -> Self {
        CommandError::abort_with_exit_code(
            error.to_string(),
            exit_codes::CONFIG_ERROR_ABORT,
        )
    }
}

impl From<UiError> for CommandError {
    fn from(_error: UiError) -> Self {
        // If we already failed writing to stdout or stderr,
        // writing an error message to stderr about it would be likely to fail
        // too.
        CommandError::abort("")
    }
}

impl From<RepoError> for CommandError {
    fn from(error: RepoError) -> Self {
        match error {
            RepoError::NotFound { at } => CommandError::Abort {
                message: format_bytes!(
                    b"abort: repository {} not found",
                    get_bytes_from_path(at)
                ),
                detailed_exit_code: exit_codes::ABORT,
            },
            RepoError::ConfigParseError(error) => error.into(),
            RepoError::Other(error) => error.into(),
        }
    }
}

impl<'a> From<&'a NoRepoInCwdError> for CommandError {
    fn from(error: &'a NoRepoInCwdError) -> Self {
        let NoRepoInCwdError { cwd } = error;
        CommandError::Abort {
            message: format_bytes!(
                b"abort: no repository found in '{}' (.hg not found)!",
                get_bytes_from_path(cwd)
            ),
            detailed_exit_code: exit_codes::ABORT,
        }
    }
}

impl From<ConfigError> for CommandError {
    fn from(error: ConfigError) -> Self {
        match error {
            ConfigError::Parse(error) => error.into(),
            ConfigError::Other(error) => error.into(),
        }
    }
}

impl From<ConfigParseError> for CommandError {
    fn from(error: ConfigParseError) -> Self {
        let ConfigParseError {
            origin,
            line,
            message,
        } = error;
        let line_message = if let Some(line_number) = line {
            format_bytes!(b":{}", line_number.to_string().into_bytes())
        } else {
            Vec::new()
        };
        CommandError::Abort {
            message: format_bytes!(
                b"config error at {}{}: {}",
                origin,
                line_message,
                message
            ),
            detailed_exit_code: exit_codes::CONFIG_ERROR_ABORT,
        }
    }
}

impl From<(RevlogError, &str)> for CommandError {
    fn from((err, rev): (RevlogError, &str)) -> CommandError {
        match err {
            RevlogError::WDirUnsupported => CommandError::abort(
                "abort: working directory revision cannot be specified",
            ),
            RevlogError::InvalidRevision => CommandError::abort(format!(
                "abort: invalid revision identifier: {}",
                rev
            )),
            RevlogError::AmbiguousPrefix => CommandError::abort(format!(
                "abort: ambiguous revision identifier: {}",
                rev
            )),
            RevlogError::Other(error) => error.into(),
        }
    }
}

impl From<StatusError> for CommandError {
    fn from(error: StatusError) -> Self {
        CommandError::abort(format!("{}", error))
    }
}

impl From<DirstateMapError> for CommandError {
    fn from(error: DirstateMapError) -> Self {
        CommandError::abort(format!("{}", error))
    }
}

impl From<DirstateError> for CommandError {
    fn from(error: DirstateError) -> Self {
        match error {
            DirstateError::Common(error) => error.into(),
            DirstateError::Map(error) => error.into(),
        }
    }
}

impl From<DirstateV2ParseError> for CommandError {
    fn from(error: DirstateV2ParseError) -> Self {
        HgError::from(error).into()
    }
}