From d2f423521ec76406944ad83098ec33afe20c692b Mon Sep 17 00:00:00 2001
From: Kim Altintop <kim@eagain.io>
Date: Mon, 9 Jan 2023 13:18:33 +0100
Subject: This is it

Squashed commit of all the exploration history. Development starts here.

Signed-off-by: Kim Altintop <kim@eagain.io>
---
 src/cmd/topic/unbundle.rs | 174 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 174 insertions(+)
 create mode 100644 src/cmd/topic/unbundle.rs

(limited to 'src/cmd/topic/unbundle.rs')

diff --git a/src/cmd/topic/unbundle.rs b/src/cmd/topic/unbundle.rs
new file mode 100644
index 0000000..3aab54b
--- /dev/null
+++ b/src/cmd/topic/unbundle.rs
@@ -0,0 +1,174 @@
+// Copyright © 2022 Kim Altintop <kim@eagain.io>
+// SPDX-License-Identifier: GPL-2.0-only WITH openvpn-openssl-exception
+
+use std::{
+    collections::{
+        BTreeMap,
+        BTreeSet,
+    },
+    path::PathBuf,
+};
+
+use anyhow::anyhow;
+use clap::ValueHint;
+
+use super::Common;
+use crate::{
+    cmd::{
+        self,
+        ui::{
+            debug,
+            info,
+            warn,
+        },
+        Aborted,
+    },
+    git::{
+        self,
+        if_not_found_none,
+        refs,
+        Refname,
+    },
+    metadata::{
+        self,
+        git::FromGit,
+    },
+    patches::{
+        self,
+        iter::dropped,
+        Bundle,
+        Record,
+        Topic,
+        REF_IT_BUNDLES,
+        REF_IT_PATCHES,
+        TOPIC_MERGES,
+        TOPIC_SNAPSHOTS,
+    },
+    paths,
+};
+
+// TODO:
+//
+// - don't require patch bundle to be present on-disk when snapshots would do
+
+#[derive(Debug, clap::Args)]
+pub struct Unbundle {
+    #[clap(flatten)]
+    common: Common,
+    /// The directory where to write the bundle to
+    ///
+    /// Unless this is an absolute path, it is treated as relative to $GIT_DIR.
+    #[clap(
+        long,
+        value_parser,
+        value_name = "DIR",
+        default_value_os_t = paths::bundles().to_owned(),
+        value_hint = ValueHint::DirPath,
+    )]
+    bundle_dir: PathBuf,
+    /// The topic to unbundle
+    #[clap(value_parser)]
+    topic: Topic,
+    /// The drop history to find the topic in
+    #[clap(value_parser)]
+    drop: Option<String>,
+}
+
+#[derive(serde::Serialize)]
+pub struct Output {
+    updated: BTreeMap<Refname, git::serde::oid::Oid>,
+}
+
+pub fn unbundle(args: Unbundle) -> cmd::Result<Output> {
+    let repo = git::repo::open(&args.common.git_dir)?;
+    let bundle_dir = if args.bundle_dir.is_relative() {
+        repo.path().join(args.bundle_dir)
+    } else {
+        args.bundle_dir
+    };
+    let drop = match args.drop {
+        Some(rev) => if_not_found_none(repo.resolve_reference_from_short_name(&rev))?
+            .ok_or_else(|| anyhow!("no ref matching {rev} found"))?
+            .name()
+            .ok_or_else(|| anyhow!("invalid drop"))?
+            .to_owned(),
+        None => REF_IT_PATCHES.to_owned(),
+    };
+
+    let filter = [&args.topic, &TOPIC_MERGES, &TOPIC_SNAPSHOTS];
+    let mut on_topic: Vec<Record> = Vec::new();
+    let mut checkpoints: Vec<Record> = Vec::new();
+    for row in dropped::topics(&repo, &drop) {
+        let (t, id) = row?;
+
+        if filter.into_iter().any(|f| f == &t) {
+            let commit = repo.find_commit(id)?;
+            let record = Record::from_commit(&repo, &commit)?;
+            if t == args.topic {
+                on_topic.push(record);
+                continue;
+            }
+
+            // Skip checkpoint which came after the most recent record on the topic
+            if !on_topic.is_empty() {
+                checkpoints.push(record);
+            }
+        }
+    }
+
+    let odb = repo.odb()?;
+
+    info!("Indexing checkpoints...");
+    for rec in checkpoints.into_iter().rev() {
+        Bundle::from_stored(&bundle_dir, rec.bundle_info().as_expect())?
+            .packdata()?
+            .index(&odb)?
+    }
+
+    let mut missing = BTreeSet::new();
+    for oid in on_topic
+        .iter()
+        .flat_map(|rec| &rec.bundle_info().prerequisites)
+    {
+        let oid = git2::Oid::try_from(oid)?;
+        if !odb.exists(oid) {
+            missing.insert(oid);
+        }
+    }
+
+    if !missing.is_empty() {
+        warn!("Unable to satisfy all prerequisites");
+        info!("The following prerequisite commits are missing:\n");
+        for oid in missing {
+            info!("{oid}");
+        }
+        info!("\nYou may try to unbundle the entire drop history");
+        cmd::abort!();
+    }
+
+    info!("Unbundling topic records...");
+    let mut tx = refs::Transaction::new(&repo)?;
+    let topic_ref = tx.lock_ref(args.topic.as_refname())?;
+    let mut up = BTreeMap::new();
+    for rec in on_topic.into_iter().rev() {
+        let hash = rec.bundle_hash();
+        let bundle = Bundle::from_stored(&bundle_dir, rec.bundle_info().as_expect())?;
+        if bundle.is_encrypted() {
+            warn!("Skipping encrypted bundle {hash}");
+            continue;
+        }
+        bundle.packdata()?.index(&odb)?;
+        debug!("{hash}: unbundle");
+        let updated = patches::unbundle(&odb, &mut tx, REF_IT_BUNDLES, &rec)?;
+        for (name, oid) in updated {
+            up.insert(name, oid.into());
+        }
+        debug!("{hash}: merge notes");
+        let submitter = metadata::Identity::from_content_hash(&repo, &rec.meta.signature.signer)?
+            .verified(metadata::git::find_parent(&repo))?;
+        patches::merge_notes(&repo, &submitter, &topic_ref, &rec)?;
+    }
+    tx.commit()?;
+
+    Ok(Output { updated: up })
+}
-- 
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