Struct git_status_vars::ShellWriter

source · 
pub struct ShellWriter<W: Write> { /* private fields */ }
Expand description

A writer of var=value pairs.

See ShellWriter::new().

Implementations§

Create a new ShellWriter. The prefix will be prepended anytime a var is outputted, e.g. prefixvar=value.

Generally, you will want to use this like:

use git_status_vars::ShellWriter;
ShellWriter::default().group("group").write_var("var", "value");
// or...
let mut buffer: Vec<u8> = vec![];
ShellWriter::new(&mut buffer, "").group("group").write_var("var", "value");
assert_eq!(buffer, b"group_var=value\n");
Examples found in repository?
src/shell_writer.rs (line 91)
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    pub fn with_prefix(prefix: String) -> Self {
        Self::new(io::stdout(), prefix)
    }
}

impl Default for ShellWriter<io::Stdout> {
    /// Create a new `ShellWriter` for [`io::stdout()`] and no prefix.
    fn default() -> Self {
        Self::new(io::stdout(), "")
    }

Write var=value. value will be turned into a string, then quoted for safe shell insertion. var will be assumed to be a valid name for a shell variable.

Examples found in repository?
src/lib.rs (line 65)
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    fn write_to_shell<W: io::Write>(&self, out: &ShellWriter<W>) {
        out.write_var("name", &self.name);
        out.write_var("short", self.short());
        out.write_var("kind", &self.kind);
        out.write_var("error", &self.error);
    }
}

/// The trail of a `HEAD` reference.
#[derive(Debug, Default)]
pub struct Head {
    pub trail: Vec<Reference>,
    pub hash: String,
    pub ahead_of_upstream: Option<usize>,
    pub behind_upstream: Option<usize>,
    pub upstream_error: String,
}

impl ShellVars for Head {
    fn write_to_shell<W: io::Write>(&self, out: &ShellWriter<W>) {
        out.write_var("ref_length", self.trail.len() - 1);
        for (i, reference) in self.trail[1..].iter().enumerate() {
            out.group_n("ref", i + 1).write_vars(reference);
        }
        out.write_var("hash", &self.hash);
        out.write_var("ahead", display_option(self.ahead_of_upstream));
        out.write_var("behind", display_option(self.behind_upstream));
        out.write_var("upstream_error", &self.upstream_error);
    }
}

/// Summarize information about a repository.
///
/// This takes the `Result` from one of the `Repository::open()` functions.
///
/// ### Example
///
/// ```no_run
/// use git_status_vars::{summarize_repository, ShellWriter};
/// use git2::Repository;
///
/// summarize_repository(&ShellWriter::default(), Repository::open_from_env());
/// ```
pub fn summarize_repository<W: std::io::Write>(
    out: &ShellWriter<W>,
    opened: Result<Repository, git2::Error>,
) {
    let result = match opened {
        Ok(repository) => summarize_opened_repository(out, repository),
        Err(error)
            if error.code() == ErrorCode::NotFound
                && error.class() == ErrorClass::Repository =>
        {
            out.write_var("repo_state", "NotFound");
            Ok(())
        }
        Err(error) => Err(error),
    };

    if let Err(error) = result {
        out.write_var("repo_state", "Error");
        out.write_var_debug("repo_error", error);
    }
}

/// Summarize information about a successfully opened repository.
///
/// ### Example
///
/// ```no_run
/// use git_status_vars::{summarize_opened_repository, ShellWriter};
/// use git2::Repository;
///
/// summarize_opened_repository(
///     &ShellWriter::default(),
///     Repository::open_from_env().unwrap(),
/// ).unwrap();
/// ```
pub fn summarize_opened_repository<W: std::io::Write>(
    out: &ShellWriter<W>,
    repository: Repository,
) -> Result<(), git2::Error> {
    out.write_var_debug("repo_state", repository.state());
    out.write_var(
        "repo_workdir",
        display_option(repository.workdir().map(|path| path.display())),
    );
    out.write_var("repo_empty", repository.is_empty()?);
    out.write_var("repo_bare", repository.is_bare());
    out.group("head").write_vars(&head_info(&repository)?);
    out.write_vars(&count_changes(&repository)?);

    Ok(())
}

/// Trace the `HEAD` reference for a repository.
pub fn head_info(repository: &Repository) -> Result<Head, git2::Error> {
    let mut current = "HEAD".to_string();
    let mut head = Head::default();
    loop {
        match repository.find_reference(&current) {
            Ok(reference) => match reference.kind() {
                Some(ReferenceType::Direct) => {
                    head.trail.push(Reference::direct(&display_option(
                        reference.name(),
                    )));
                    head.hash = display_option(reference.target());
                    break;
                }
                Some(ReferenceType::Symbolic) => {
                    head.trail.push(Reference::symbolic(&display_option(
                        reference.name(),
                    )));
                    let target = reference
                        .symbolic_target()
                        .expect("Symbolic ref should have symbolic target");
                    current = target.to_string();
                }
                None => {
                    head.trail.push(Reference::new(
                        display_option(reference.name()),
                        "unknown",
                    ));
                    break;
                }
            },
            Err(error) => {
                head.trail
                    .push(Reference::new_with_error(current, "", error));
                break;
            }
        };
    }

    match get_upstream_difference(repository) {
        Ok(Some((ahead, behind))) => {
            head.ahead_of_upstream = Some(ahead);
            head.behind_upstream = Some(behind);
        }
        Ok(None) => {}
        Err(error) => {
            head.upstream_error = format!("{:?}", error);
        }
    }

    Ok(head)
}

/// Get the (ahead, behind) count of HEAD versus its upstream branch.
pub fn get_upstream_difference(
    repository: &Repository,
) -> Result<Option<(usize, usize)>, git2::Error> {
    let local_ref = repository.head()?.resolve()?;
    if let Some(local_oid) = local_ref.target() {
        let upstream_branch = Branch::wrap(local_ref).upstream()?;
        if let Some(upstream_oid) = upstream_branch.get().target() {
            repository
                .graph_ahead_behind(local_oid, upstream_oid)
                .map(Some)
        } else {
            Ok(None)
        }
    } else {
        Ok(None)
    }
}

fn display_option(s: Option<impl fmt::Display>) -> String {
    s.map(|s| s.to_string()).unwrap_or_else(|| "".to_string())
}

/// Track changes in the working tree and index (staged area).
#[derive(Debug, Default)]
pub struct ChangeCounters {
    pub untracked: usize,
    pub unstaged: usize,
    pub staged: usize,
    pub conflicted: usize,
}

impl From<[usize; 4]> for ChangeCounters {
    fn from(array: [usize; 4]) -> Self {
        ChangeCounters {
            untracked: array[0],
            unstaged: array[1],
            staged: array[2],
            conflicted: array[3],
        }
    }
}

impl ShellVars for ChangeCounters {
    // Output the tree change information with a prefix (e.g. "tree_").
    fn write_to_shell<W: io::Write>(&self, out: &ShellWriter<W>) {
        out.write_var("untracked_count", self.untracked);
        out.write_var("unstaged_count", self.unstaged);
        out.write_var("staged_count", self.staged);
        out.write_var("conflicted_count", self.conflicted);
    }

Write var=value. value will be formatted into a string using Debug, then quoted for safe shell insertion. var will be assumed to be a valid name for a shell variable.

Examples found in repository?
src/lib.rs (line 125)
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pub fn summarize_repository<W: std::io::Write>(
    out: &ShellWriter<W>,
    opened: Result<Repository, git2::Error>,
) {
    let result = match opened {
        Ok(repository) => summarize_opened_repository(out, repository),
        Err(error)
            if error.code() == ErrorCode::NotFound
                && error.class() == ErrorClass::Repository =>
        {
            out.write_var("repo_state", "NotFound");
            Ok(())
        }
        Err(error) => Err(error),
    };

    if let Err(error) = result {
        out.write_var("repo_state", "Error");
        out.write_var_debug("repo_error", error);
    }
}

/// Summarize information about a successfully opened repository.
///
/// ### Example
///
/// ```no_run
/// use git_status_vars::{summarize_opened_repository, ShellWriter};
/// use git2::Repository;
///
/// summarize_opened_repository(
///     &ShellWriter::default(),
///     Repository::open_from_env().unwrap(),
/// ).unwrap();
/// ```
pub fn summarize_opened_repository<W: std::io::Write>(
    out: &ShellWriter<W>,
    repository: Repository,
) -> Result<(), git2::Error> {
    out.write_var_debug("repo_state", repository.state());
    out.write_var(
        "repo_workdir",
        display_option(repository.workdir().map(|path| path.display())),
    );
    out.write_var("repo_empty", repository.is_empty()?);
    out.write_var("repo_bare", repository.is_bare());
    out.group("head").write_vars(&head_info(&repository)?);
    out.write_vars(&count_changes(&repository)?);

    Ok(())
}

Write an object with the ShellVars trait. Mostly used with Self::group() and Self::group_n().

Examples found in repository?
src/lib.rs (line 86)
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    fn write_to_shell<W: io::Write>(&self, out: &ShellWriter<W>) {
        out.write_var("ref_length", self.trail.len() - 1);
        for (i, reference) in self.trail[1..].iter().enumerate() {
            out.group_n("ref", i + 1).write_vars(reference);
        }
        out.write_var("hash", &self.hash);
        out.write_var("ahead", display_option(self.ahead_of_upstream));
        out.write_var("behind", display_option(self.behind_upstream));
        out.write_var("upstream_error", &self.upstream_error);
    }
}

/// Summarize information about a repository.
///
/// This takes the `Result` from one of the `Repository::open()` functions.
///
/// ### Example
///
/// ```no_run
/// use git_status_vars::{summarize_repository, ShellWriter};
/// use git2::Repository;
///
/// summarize_repository(&ShellWriter::default(), Repository::open_from_env());
/// ```
pub fn summarize_repository<W: std::io::Write>(
    out: &ShellWriter<W>,
    opened: Result<Repository, git2::Error>,
) {
    let result = match opened {
        Ok(repository) => summarize_opened_repository(out, repository),
        Err(error)
            if error.code() == ErrorCode::NotFound
                && error.class() == ErrorClass::Repository =>
        {
            out.write_var("repo_state", "NotFound");
            Ok(())
        }
        Err(error) => Err(error),
    };

    if let Err(error) = result {
        out.write_var("repo_state", "Error");
        out.write_var_debug("repo_error", error);
    }
}

/// Summarize information about a successfully opened repository.
///
/// ### Example
///
/// ```no_run
/// use git_status_vars::{summarize_opened_repository, ShellWriter};
/// use git2::Repository;
///
/// summarize_opened_repository(
///     &ShellWriter::default(),
///     Repository::open_from_env().unwrap(),
/// ).unwrap();
/// ```
pub fn summarize_opened_repository<W: std::io::Write>(
    out: &ShellWriter<W>,
    repository: Repository,
) -> Result<(), git2::Error> {
    out.write_var_debug("repo_state", repository.state());
    out.write_var(
        "repo_workdir",
        display_option(repository.workdir().map(|path| path.display())),
    );
    out.write_var("repo_empty", repository.is_empty()?);
    out.write_var("repo_bare", repository.is_bare());
    out.group("head").write_vars(&head_info(&repository)?);
    out.write_vars(&count_changes(&repository)?);

    Ok(())
}

Generate a sub-writer with this group name. Example output:

prefix_group_var=value
Examples found in repository?
src/shell_writer.rs (line 84)
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    pub fn group_n(
        &self,
        prefix: impl Display,
        n: impl Display,
    ) -> ShellWriter<W> {
        self.group(format!("{}{}", prefix, n))
    }
More examples
Hide additional examples
src/lib.rs (line 153)
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pub fn summarize_opened_repository<W: std::io::Write>(
    out: &ShellWriter<W>,
    repository: Repository,
) -> Result<(), git2::Error> {
    out.write_var_debug("repo_state", repository.state());
    out.write_var(
        "repo_workdir",
        display_option(repository.workdir().map(|path| path.display())),
    );
    out.write_var("repo_empty", repository.is_empty()?);
    out.write_var("repo_bare", repository.is_bare());
    out.group("head").write_vars(&head_info(&repository)?);
    out.write_vars(&count_changes(&repository)?);

    Ok(())
}

Generate a sub-writer with this group name and number. Example output:

prefix_groupN_var=value
Examples found in repository?
src/lib.rs (line 86)
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    fn write_to_shell<W: io::Write>(&self, out: &ShellWriter<W>) {
        out.write_var("ref_length", self.trail.len() - 1);
        for (i, reference) in self.trail[1..].iter().enumerate() {
            out.group_n("ref", i + 1).write_vars(reference);
        }
        out.write_var("hash", &self.hash);
        out.write_var("ahead", display_option(self.ahead_of_upstream));
        out.write_var("behind", display_option(self.behind_upstream));
        out.write_var("upstream_error", &self.upstream_error);
    }

Create a new ShellWriter for io::stdout() and a prefix.

Trait Implementations§

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more

Create a new ShellWriter for io::stdout() and no prefix.

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.