#!/bin/bash
#This script was un-gracefully hacked out of http://cvs.sourceforge.net/viewcvs.py/emc/emc_HAL/farm_scripts/run_farm?rev=1.3&view=auto

# This script reads the file "trees" in the current directory.  It
# cd's into each subdirectory listed there, does a cvs up, and if
# any files have changed, it calls "build" in that directory, logging
# its output to "build_log"


# This function is used to log messages to farm_log
function MSG {
    if [ "$TREE" != "" ] ; then
        date -u "+%D %T $TREE $1" >>farm_log
    else
        date -u "+%D %T $1" >>farm_log
    fi
}

# This function attempts to do a "cvs up", saving the results in
# cvs_log.  It does not interpret the results.  It returns 0 if
# the cvs command completes successfully, and 1 if it fails or
# times out.
#
function TRY_CVS {
	rm -f cvs_log
    # invoke the command in the background
    if cvs -q up -dP 1>>cvs_log 2>>cvs_log; then
        echo "CVS_SUCCESS" >>cvs_log
    fi &
    # save the PID of the "if" block above
    BLKPID=$!
    # find the PID of the actual command (not the entire block)
    # (look for parent pid = BLKPID and command = "cvs" )
    CMDPID=`ps o ppid,pid,cmd | awk -- "\\$1 ~ /$BLKPID/ && \\$3 ~ /cvs/ {print \\$2}"`
    # loop until the command ends, if it takes too long, kill it
    TIMEOUT=60
    while ps -p $BLKPID &>/dev/null ; do
        # check for timeout
        if [ $TIMEOUT -eq 0 ] ; then
            # find pids of any children of the command
            CHILDPID=`ps -A o ppid,pid | awk -- "\\$1 ~ /\$CMDPID/ { print \\$2 }"`
            # stop the command
            kill $CMDPID &>/dev/null
            # stop any children
            for CHILDPID in $CHILDPID ; do
                kill $CHILDPID &>/dev/null
            done
            # wait for the "if" block to finish
            wait $BLKPID &>/dev/null
            # log the timeout
            echo "CVS_TIMEOUT" >>cvs_log
        else
            # wait a bit
            sleep 1
            # decrement TIMEOUT
            TIMEOUT=$((${TIMEOUT}-1))
        fi
    done
    if grep -q CVS_SUCCESS cvs_log ; then return 0 ; else return 1 ; fi
}

# This function calls TRY_CVS, retrying several
# times on timeouts or errors.
#
function DO_CVS {
    MSG "cvs up"
    # first remove any old cvs_log file that is laying around
    rm -f cvs_log
    # then try to do a cvs up
    if TRY_CVS ; then
        return 0
    fi
    RETRY=1
    LIMIT=5
    while [ $RETRY -lt $LIMIT ] ; do
        MSG "cvs up retry $RETRY"
        if TRY_CVS ; then
            return 0
        fi
        RETRY=$((${RETRY}+1))
    done
    MSG "cvs up failed ($LIMIT retries)"
    return 1
}

# this function is given the name of a directory tree and
# attempts to do a cvs up and if neccessary a build in that tree

function TEST_CVS {
    # attempt to do CVS update, if it fails, we're done
    if ! DO_CVS ; then
        # save the cvs logfile for troubleshooting
        date +"%D %T" >>cvs_log_fail
        cat cvs_log >>cvs_log_fail
        return 1
    fi
    # parse the file looking for "U" or "P" that indicates modified
    # files.  also look for "A", "R", "M", or "C" that indicates local
    # changes that shouldn't happen.
    RESULT=`cat cvs_log | awk -- \
        'BEGIN { errors=0 ; updates=0 } \
        $1 ~ /^[ARMC]$/ { errors++ } \
        $1 ~ /^[UP]$/ { updates++ } \
        END { result="NOTHING" ; \
              if ( updates > 0 ) { result="UPDATE" } ; \
              if ( errors > 0 ) { result="ERROR" } ; \
              printf ( "%s\n", result )
            }'`

    # decide what is do be done
    if [ "$RESULT" = "ERROR" ] ; then
        MSG "local repository has been modified, something is wrong"
        # save cvs log file for troubleshooting
        date +"%D %T" >cvs_log_fail
        cat cvs_log >>cvs_log_fail
        return 1
    fi
    if [ "$RESULT" = "NOTHING" ] ; then
        MSG "no changes"
        return 0
    fi
    # if we get here, we need to attempt a build
    MSG "starting build"
    # make a header for the build log
    echo >build_log
    date -u +"make tgz started at %D %T" >>build_log
    echo >>build_log
    # make the tarball
    if $(cd emc2/src/ ; make tgz) 1>>build_log 2>>build_log; then
        # succeeded
        echo >>build_log
        date -u +"make tgz completed successfully at %D %T" >>build_log
        echo >>build_log
        MSG "make tgz succeeded"
        STAMP=`date -u +" %D %T "`
        STATUS=PASSED
    else
        # failed
        echo >>build_log
        date -u +"make tgz failed at %D %T" >>build_log
        echo >>build_log
        MSG "build failed"
        STAMP=`date -u +" %D %T "`
        STATUS=FAILED
    fi
    # append an entry to the history log
    echo "`date -u +" %D %T "`${STATUS}" >>history_log
    return 0
}

#now we actually do something

TREE=./emc2/
cd $TREE
TEST_CVS