[PATCHv2 0/3] Travis CI: skip commits with successfully built and tested trees

["SZEDER Gábor" <szeder.dev@gmail.com>]

This is the second iteration of 'sg/travis-skip-identical-test',
addressing the comments of Lars and Jonathan:

  - Colorize the "Tip of $TRAVIS_BRANCH is exactly at $TAG" message
    in the new patch 1/3.

  - Create the cache directory at the beginning of the build process
    (patch 2/3).

  - Limit the the cached good trees file size to 1000 records, to
    prevent it from growing too large for git/git's forever living
    integration branches (patch 3/3).

  - Colorize the first line of the "skip build job because this tree has
    been tested".  Green it is (3/3).

  - Removed stray whitespace (3/3).

  - Updated an in-code comment, to make clear which code path deals with
    a non-existing good trees file (3/3).

SZEDER Gábor (3):
  travis-ci: print the "tip of branch is exactly at tag" message in
    color
  travis-ci: create the cache directory early in the build process
  travis-ci: record and skip successfully built trees

 ci/lib-travisci.sh        | 51 ++++++++++++++++++++++++++++++++++++++++++++++-
 ci/run-linux32-docker.sh  |  2 ++
 ci/run-static-analysis.sh |  2 ++
 ci/run-tests.sh           |  3 ++-
 ci/run-windows-build.sh   |  2 ++
 ci/test-documentation.sh  |  2 ++
 6 files changed, 60 insertions(+), 2 deletions(-)

-- 
2.16.0.rc0.67.g3a46dbca7


diff --git a/ci/lib-travisci.sh b/ci/lib-travisci.sh
index 05e73123f..bade71617 100755
--- a/ci/lib-travisci.sh
+++ b/ci/lib-travisci.sh
@@ -16,7 +16,7 @@ skip_branch_tip_with_tag () {
 	if TAG=$(git describe --exact-match "$TRAVIS_BRANCH" 2>/dev/null) &&
 		test "$TAG" != "$TRAVIS_BRANCH"
 	then
-		echo "Tip of $TRAVIS_BRANCH is exactly at $TAG"
+		echo "$(tput setaf 2)Tip of $TRAVIS_BRANCH is exactly at $TAG$(tput sgr0)"
 		exit 0
 	fi
 }
@@ -28,6 +28,9 @@ good_trees_file="$HOME/travis-cache/good-trees"
 # message.
 save_good_tree () {
 	echo "$(git rev-parse $TRAVIS_COMMIT^{tree}) $TRAVIS_COMMIT $TRAVIS_JOB_NUMBER $TRAVIS_JOB_ID" >>"$good_trees_file"
+	# limit the file size
+	tail -1000 "$good_trees_file" >"$good_trees_file".tmp
+	mv "$good_trees_file".tmp "$good_trees_file"
 }
 
 # Skip the build job if the same tree has already been built and tested
@@ -36,23 +39,24 @@ save_good_tree () {
 skip_good_tree () {
 	if ! good_tree_info="$(grep "^$(git rev-parse $TRAVIS_COMMIT^{tree}) " "$good_trees_file")"
 	then
-		# haven't seen this tree yet; continue the build job
+		# Haven't seen this tree yet, or no cached good trees file yet.
+		# Continue the build job.
 		return
 	fi
 
 	echo "$good_tree_info" | {
 		read tree prev_good_commit prev_good_job_number prev_good_job_id
 
-		if test "$TRAVIS_JOB_ID" =  "$prev_good_job_id"
+		if test "$TRAVIS_JOB_ID" = "$prev_good_job_id"
 		then
 			cat <<-EOF
-			Skipping build job for commit $TRAVIS_COMMIT.
+			$(tput setaf 2)Skipping build job for commit $TRAVIS_COMMIT.$(tput sgr0)
 			This commit has already been built and tested successfully by this build job.
 			To force a re-build delete the branch's cache and then hit 'Restart job'.
 			EOF
 		else
 			cat <<-EOF
-			Skipping build job for commit $TRAVIS_COMMIT.
+			$(tput setaf 2)Skipping build job for commit $TRAVIS_COMMIT.$(tput sgr0)
 			This commit's tree has already been built and tested successfully in build job $prev_good_job_number for commit $prev_good_commit.
 			The log of that build job is available at https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$prev_good_job_id
 			To force a re-build delete the branch's cache and then hit 'Restart job'.
@@ -69,6 +73,8 @@ skip_good_tree () {
 # and installing dependencies.
 set -ex
 
+mkdir -p "$HOME/travis-cache"
+
 skip_branch_tip_with_tag
 skip_good_tree