qmvn

qmvn

#!/usr/bin/env bash
# qmvn (quick maven)
#
# Maven wrapper script to accelerate the build of multi-module projects
# This script detects which modules have been modified since the last build, and executes maven in `-amd -pl ...` mode.
# This means only modules with changes to source code or their POMs, or which depend on a changed module, get built.
# See this page for details of how these flags accelerate the build:
#   http://blog.sonatype.com/2009/10/maven-tips-and-tricks-advanced-reactor-options/
#
# Authors:
#  - Richard North (https://rnorth.org)
#
# Usage:
#  qmvn <goal>, e.g. ./qmvn install
#
# Licence:
#   The MIT License (MIT)
#
#   Copyright (c) 2016 Richard North <rich.north@gmail.com>
#
#   Permission is hereby granted, free of charge, to any person obtaining a copy
#   of this software and associated documentation files (the "Software"), to deal
#   in the Software without restriction, including without limitation the rights
#   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#   copies of the Software, and to permit persons to whom the Software is
#   furnished to do so, subject to the following conditions:
#
#   The above copyright notice and this permission notice shall be included in all
#   copies or substantial portions of the Software.
#
#   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
#   SOFTWARE.

set -o errexit
set -o nounset
set -o pipefail
#set -x

# Discover all modules in the project - only done once
if [[ ! -f .qmvn.modules ]]; then
    echo "Discovering modules..."
    mvn exec:exec -Dexec.executable=echo -Dexec.args="qmvn_module: \${basedir}" | grep "^qmvn_module:" | cut -d\  -f2 | sed "s#${PWD}##" | sed -e "s/^/./" > .qmvn.modules
fi

MODULES=($(cat .qmvn.modules ))

# Array to collect which modules have changed
CHANGED_MODULES=()
# We need to known when the maven command (args to this script) were last run
COMMAND_HASH=$(echo $@ | md5)
# JVM options to make maven run more quickly
export MAVEN_OPTS="-XX:+TieredCompilation -XX:TieredStopAtLevel=1"

# Iterate over all the modules to detect changes
for MODULE in ${MODULES[@]}; do

    GUARDFILE="${MODULE}/target/.lastchange.${COMMAND_HASH}"

    if [[ ! -f ${GUARDFILE} ]]; then
        mkdir -p ${GUARDFILE} && rm -rf ${GUARDFILE}
        touch -t "$(date -r 0 +%Y%m%d%H%M.%S)" ${GUARDFILE}
    fi

    # Specifically ignore changes the to target and src/generated directories
    CHANGES=$(find ${MODULE} -newer ${GUARDFILE} \
        \( -path "${MODULE}/src/*" -or \
           -wholename "${MODULE}/pom.xml" \) -and \
        -not -path "${MODULE}/target/*" -prune -and \
        -not -path "${MODULE}/src/generated/*" -prune -and \
        -not -name "\.*" -prune
        )

    CHANGE_COUNT=$(echo $CHANGES | sed "/^\s*$/d" | wc -l | xargs)

    if [[ $CHANGE_COUNT > 0 ]]; then
        echo "$MODULE has change(s) since the last invocation of mvn $@"
        echo "  Changes:"
        echo ${CHANGES} | sed -e "s/^/    /"
        CHANGED_MODULES+=($MODULE)
    fi
done

# Exit right away if nothing has changed
if [[ ${#CHANGED_MODULES[@]} == 0 ]]; then
    echo "No changes"
    exit 0
fi

# Create a comma-separated list of changed modules
function join { local IFS="$1"; shift; echo "$*"; }
PL_LIST=$(join "," ${CHANGED_MODULES[@]})

# Execute maven such that just the changed modules, and modules that depend on them, get built
mvn $@ -pl ${PL_LIST} -amd

# Finally, assuming successful invocation of maven, update our guardfiles so that future changes are detected from now onwards
for MODULE in ${MODULES[@]}; do
    GUARDFILE="${MODULE}/target/.lastchange.${COMMAND_HASH}"
    touch ${GUARDFILE}
done

Nice! Does this work if you change your maven args between builds?