ci: Only test commits once in all_commits.azul/untested-commits

- When a commit has been tested we keep track of it by touching
  a file named by the commit sha in tested_commits.

- Before running the tests in all_commits we check if such a file exists.

- We store these files as artifacts and load them before runs on the same branch.

3 files changed, 70 insertions, 19 deletions

diff --git a/.ci/all_commits.sh b/.ci/all_commits.sh
index b44f48c5..821fbadb 100755
--- a/.ci/all_commits.sh
+++ b/.ci/all_commits.sh
@@ -14,11 +14,13 @@ git merge-base --is-ancestor HEAD~ origin/main &&
   echo "All commits tested already" &&
   exit 0
 
+# Copy the current version of the test_commit script
+# so we can use it to test all the previous commits:
+cp .ci/test_commit.sh .
+
 # Leave out the last commit - it has already been checked.
 git checkout HEAD~
-git rebase origin/main \
-           --exec 'echo ===; echo ===; echo ===; git log -n 1;' \
-           --exec 'cargo test -p sequoia-openpgp' &&
+git rebase origin/main --exec './test_commit.sh' &&
   echo "All commits passed tests" &&
   exit 0
 
diff --git a/.ci/test_commit.sh b/.ci/test_commit.sh
new file mode 100755
index 00000000..dde3b5ca
--- /dev/null
+++ b/.ci/test_commit.sh
@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+# Test one commit if it has not been tested yet.
+#
+# We mark tested commits by touching a file named with the commit hash
+# in the tested_commits dir.
+
+COMMIT_DIR=tested_commits
+COMMIT_SHA=$(git rev-list HEAD -1)
+COMMIT_FILE=$COMMIT_DIR/$COMMIT_SHA
+
+mkdir -p $COMMIT_DIR
+
+echo ===; echo ===; echo ===;
+git log -n 1;
+
+if [ ! -f $COMMIT_FILE ]
+then
+  cargo test -p sequoia-openpgp && \
+    echo $CI_JOB_URL >> $COMMIT_FILE
+else
+  echo $COMMIT_SHA has already been tested in this job:
+  cat $COMMIT_FILE
+fi
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 33177c87..a1dff2c4 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -49,22 +49,6 @@ bullseye:
     RUSTFLAGS: -D warnings -A unused-parens
   after_script: []
 
-all_commits:
-  # Test each commit up to main, to facilitate bisecting.
-  stage: test
-  image: registry.gitlab.com/sequoia-pgp/build-docker-image/rust-stable-prebuild:latest
-  needs: ["rust-stable"]
-  except:
-    # Do not run for pushes to the pep-engine branch.
-    - /^pep-engine$/
-  script:
-    - .ci/all_commits.sh
-  variables:
-    CARGO_TARGET_DIR: /target
-    CARGO_HOME: /cargo
-    RUSTFLAGS: -D warnings -A unused-parens
-    GIT_STRATEGY: clone
-
 codespell:
   tags:
     - linux
@@ -84,10 +68,51 @@ rust-stable:
   image: registry.gitlab.com/sequoia-pgp/build-docker-image/rust-stable-prebuild:latest
   script:
     - CARGO_PACKAGES="-p buffered-reader -p sequoia-openpgp -p sequoia-sqv" make test
+    - mkdir -p tested_commits
+    # Mark this commit sha as succesfully run, for all_commits.
+    - echo $CI_JOB_URL >> tested_commits/$CI_COMMIT_SHA
   variables:
     CARGO_TARGET_DIR: /target
     CARGO_HOME: /cargo
     RUSTFLAGS: -D warnings -A unused-parens
+  artifacts:
+    paths:
+      - tested_commits
+    expire_in: 1 week
+
+# Only test commits once in all_commits.
+# When a commit has been tested we keep track of it by touching a file named by
+# the commit sha in tested_commits.
+# Before running the tests we check if such a file exists.
+# We store these files as artifacts and load them before runs on the same branch.
+all_commits:
+  # Test each commit up to main, to facilitate bisecting.
+  stage: test
+  image: registry.gitlab.com/sequoia-pgp/build-docker-image/rust-stable-prebuild:latest
+  needs: ["rust-stable"]
+  except:
+    # Do not run for pushes to the pep-engine branch.
+    - /^pep-engine$/
+    # We have a strict farst-forward-merge policy, all commits have been tested by
+    # this job on the source branche anyway.
+    - master
+  script:
+    - echo $ARTIFACTS
+    - 'curl -sL -o artifacts.zip -H "JOB-TOKEN: $CI_JOB_TOKEN" "$ARTIFACTS"'
+    - unzip -n artifacts.zip || echo "No previous runs found."
+    - if [ -d tested_commits ]; then ls tested_commits; fi
+    - .ci/all_commits.sh
+    - if [ -d tested_commits ]; then ls tested_commits; fi
+  variables:
+    CARGO_TARGET_DIR: /target
+    CARGO_HOME: /cargo
+    RUSTFLAGS: -D warnings -A unused-parens
+    GIT_STRATEGY: clone
+    ARTIFACTS: "$CI_API_V4_URL/projects/$CI_PROJECT_ID/jobs/artifacts/$CI_COMMIT_BRANCH/download?job=all_commits"
+  artifacts:
+    paths:
+      - tested_commits
+    expire_in: 1 week
 
 windows-gnu:
   tags: