Iterator adaptor for package printing mechanic

This implements a new interface for printing packages from an iterator.
It can be used to implement parallel print-preparation.

The new interface is used in the command implementation of the "find-pkg"
subcommand.

Signed-off-by: Matthias Beyer <matthias.beyer@atos.net>
Tested-by: Matthias Beyer <matthias.beyer@atos.net>

2 files changed, 285 insertions, 1 deletions

diff --git a/src/commands/find_pkg.rs b/src/commands/find_pkg.rs
index d45c946..8982911 100644
--- a/src/commands/find_pkg.rs
+++ b/src/commands/find_pkg.rs
@@ -16,10 +16,13 @@ use anyhow::Context;
 use anyhow::Result;
 use clap::ArgMatches;
 use log::trace;
+use futures::stream::StreamExt;
+use futures::stream::TryStreamExt;
 
 use crate::config::Configuration;
 use crate::package::PackageVersionConstraint;
 use crate::repository::Repository;
+use crate::ui::*;
 
 /// Implementation of the "find_pkg" subcommand
 pub async fn find_pkg(
@@ -85,6 +88,17 @@ pub async fn find_pkg(
         };
 
         let format = config.package_print_format();
-        crate::ui::print_packages(&mut outlock, format, iter, config, &flags)
+        let hb = crate::ui::handlebars_for_package_printing(format)?;
+
+        tokio_stream::iter({
+            iter.enumerate()
+                .map(|(i, p)| p.prepare_print(config, &flags, &hb, i))
+        })
+        .map(|pp| pp.into_displayable())
+        .try_for_each(|p| {
+            let r = writeln!(&mut outlock, "{}", p).map_err(anyhow::Error::from);
+            futures::future::ready(r)
+        })
+        .await
     }
 }
diff --git a/src/ui/package.rs b/src/ui/package.rs
new file mode 100644
index 0000000..7794b05
--- /dev/null
+++ b/src/ui/package.rs
@@ -0,0 +1,270 @@
+use std::borrow::Borrow;
+use std::collections::BTreeMap;
+use std::io::Write;
+
+use anyhow::anyhow;
+use anyhow::Context;
+use anyhow::Error;
+use anyhow::Result;
+use handlebars::Handlebars;
+
+use crate::config::Configuration;
+use crate::package::Package;
+use crate::package::ScriptBuilder;
+use crate::package::Shebang;
+
+pub struct PackagePrintFlags {
+    pub print_all: bool,
+    pub print_runtime_deps: bool,
+    pub print_build_deps: bool,
+    pub print_sources: bool,
+    pub print_dependencies: bool,
+    pub print_patches: bool,
+    pub print_env: bool,
+    pub print_flags: bool,
+    pub print_allowed_images: bool,
+    pub print_denied_images: bool,
+    pub print_phases: bool,
+    pub print_script: bool,
+    pub script_line_numbers: bool,
+    pub script_highlighting: bool,
+}
+
+impl PackagePrintFlags {
+    // Helper to check whether any of the CLI args requested one of these flags.
+    //
+    // The print_build_deps and print_runtime_deps as well as the script_highlighting and
+    // script_line_numbers is not included, because these only modify what to print and not whether
+    // to print.
+    fn print_any(&self) -> bool {
+        self.print_all || {
+            self.print_sources
+                || self.print_dependencies
+                || self.print_patches
+                || self.print_env
+                || self.print_flags
+                || self.print_allowed_images
+                || self.print_denied_images
+                || self.print_phases
+                || self.print_script
+        }
+    }
+}
+
+
+pub trait PreparePrintable<'a>
+    where Self: Borrow<Package> + Sized
+{
+    fn prepare_print(self, config: &'a Configuration, flags: &'a PackagePrintFlags, handlebars: &'a Handlebars<'a>, i: usize) -> PreparePrintPackage<'a, Self>;
+}
+
+impl<'a, P> PreparePrintable<'a> for P
+    where P: Borrow<Package>
+{
+    fn prepare_print(self, config: &'a Configuration, flags: &'a PackagePrintFlags, handlebars: &'a Handlebars<'a>, i: usize) -> PreparePrintPackage<'a, P> {
+        PreparePrintPackage {
+            package: self,
+            config,
+            flags,
+            handlebars,
+            i,
+        }
+    }
+}
+
+pub struct PreparePrintPackage<'a, P: Borrow<Package>> {
+    package: P,
+    config: &'a Configuration,
+    flags: &'a PackagePrintFlags,
+    handlebars: &'a Handlebars<'a>,
+    i: usize,
+}
+
+
+pub fn handlebars_for_package_printing(format: &str) -> Result<Handlebars> {
+    let mut hb = Handlebars::new();
+    hb.register_escape_fn(handlebars::no_escape);
+    hb.register_template_string("package", format)?;
+    Ok(hb)
+}
+
+impl<'a, P: Borrow<Package>> PreparePrintPackage<'a, P> {
+    pub fn into_displayable(self) -> Result<PrintablePackage> {
+        let script = ScriptBuilder::new(&Shebang::from(self.config.shebang().clone())).build(
+            self.package.borrow(),
+            self.config.available_phases(),
+            *self.config.strict_script_interpolation(),
+        ).context("Rendering script for printing it failed")?;
+
+        let script = crate::ui::script_to_printable(
+            &script,
+            self.flags.script_highlighting,
+            self.config
+                .script_highlight_theme()
+                .as_ref()
+                .ok_or_else(|| anyhow!("Highlighting for script enabled, but no theme configured"))?,
+            self.flags.script_line_numbers,
+        )?;
+
+        let mut data = BTreeMap::new();
+        data.insert("i", serde_json::Value::Number(serde_json::Number::from(self.i)));
+        data.insert("p", serde_json::to_value(self.package.borrow())?);
+        data.insert("script", serde_json::Value::String(script));
+        data.insert("print_any", serde_json::Value::Bool(self.flags.print_any()));
+        data.insert(
+            "print_runtime_deps",
+            serde_json::Value::Bool(self.flags.print_runtime_deps),
+        );
+        data.insert(
+            "print_build_deps",
+            serde_json::Value::Bool(self.flags.print_build_deps),
+        );
+
+        data.insert(
+            "print_sources",
+            serde_json::Value::Bool(self.flags.print_all || self.flags.print_sources),
+        );
+        data.insert(
+            "print_dependencies",
+            serde_json::Value::Bool(self.flags.print_all || self.flags.print_dependencies),
+        );
+        data.insert(
+            "print_patches",
+            serde_json::Value::Bool(self.flags.print_all || self.flags.print_patches),
+        );
+        data.insert(
+            "print_env",
+            serde_json::Value::Bool(self.flags.print_all || self.flags.print_env),
+        );
+        data.insert(
+            "print_flags",
+            serde_json::Value::Bool(self.flags.print_all || self.flags.print_flags),
+        );
+        data.insert(
+            "print_allowed_images",
+            serde_json::Value::Bool(self.flags.print_all || self.flags.print_allowed_images),
+        );
+        data.insert(
+            "print_denied_images",
+            serde_json::Value::Bool(self.flags.print_all || self.flags.print_denied_images),
+        );
+        data.insert(
+            "print_phases",
+            serde_json::Value::Bool(self.flags.print_all || self.flags.print_phases),
+        );
+        data.insert(
+            "print_script",
+            serde_json::Value::Bool(self.flags.print_all || self.flags.print_script),
+        );
+
+        let string = self.handlebars.render("package", &data)?;
+        Ok(PrintablePackage { string })
+    }
+}
+
+pub struct PrintablePackage { string: String }
+
+impl std::fmt::Display for PrintablePackage {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.string)
+    }
+}
+
+
+pub fn print_packages<'a, I>(
+    out: &mut dyn Write,
+    format: &str,
+    iter: I,
+    config: &Configuration,
+    flags: &PackagePrintFlags,
+) -> Result<()>
+where
+    I: Iterator<Item = &'a Package>,
+{
+    let mut hb = Handlebars::new();
+    hb.register_escape_fn(handlebars::no_escape);
+    hb.register_template_string("package", format)?;
+
+    iter.enumerate()
+        .try_for_each(|(i, package)| print_package(out, &hb, i, package, config, flags))
+}
+
+fn print_package(
+    out: &mut dyn Write,
+    hb: &Handlebars,
+    i: usize,
+    package: &Package,
+    config: &Configuration,
+    flags: &PackagePrintFlags,
+) -> Result<()> {
+    let script = ScriptBuilder::new(&Shebang::from(config.shebang().clone())).build(
+        package,
+        config.available_phases(),
+        *config.strict_script_interpolation(),
+    ).context("Rendering script for printing it failed")?;
+
+    let script = crate::ui::script_to_printable(
+        &script,
+        flags.script_highlighting,
+        config
+            .script_highlight_theme()
+            .as_ref()
+            .ok_or_else(|| anyhow!("Highlighting for script enabled, but no theme configured"))?,
+        flags.script_line_numbers,
+    )?;
+
+    let mut data = BTreeMap::new();
+    data.insert("i", serde_json::Value::Number(serde_json::Number::from(i)));
+    data.insert("p", serde_json::to_value(package)?);
+    data.insert("script", serde_json::Value::String(script));
+    data.insert("print_any", serde_json::Value::Bool(flags.print_any()));
+    data.insert(
+        "print_runtime_deps",
+        serde_json::Value::Bool(flags.print_runtime_deps),
+    );
+    data.insert(
+        "print_build_deps",
+        serde_json::Value::Bool(flags.print_build_deps),
+    );
+
+    data.insert(
+        "print_sources",
+        serde_json::Value::Bool(flags.print_all || flags.print_sources),
+    );
+    data.insert(
+        "print_dependencies",
+        serde_json::Value::Bool(flags.print_all || flags.print_dependencies),
+    );
+    data.insert(
+        "print_patches",
+        serde_json::Value::Bool(flags.print_all || flags.print_patches),
+    );
+    data.insert(
+        "print_env",
+        serde_json::Value::Bool(flags.print_all || flags.print_env),
+    );
+    data.insert(
+        "print_flags",
+        serde_json::Value::Bool(flags.print_all || flags.print_flags),
+    );
+    data.insert(
+        "print_allowed_images",
+        serde_json::Value::Bool(flags.print_all || flags.print_allowed_images),
+    );
+    data.insert(
+        "print_denied_images",
+        serde_json::Value::Bool(flags.print_all || flags.print_denied_images),
+    );
+    data.insert(
+        "print_phases",
+        serde_json::Value::Bool(flags.print_all || flags.print_phases),
+    );
+    data.insert(
+        "print_script",
+        serde_json::Value::Bool(flags.print_all || flags.print_script),
+    );
+
+    hb.render("package", &data)
+        .map_err(Error::from)
+        .and_then(|r| writeln!(out, "{}", r).map_err(Error::from))
+}