git-add-test-data

#!/usr/bin/env bash
#===============================================================================
# Adds a content link to a test data file that will be referenced using CMake's
# ExternalData mechanism
# Debug mode can be requested by setting MANTID_GIT_DEBUG=1
#===============================================================================
# Use git supplied helpers
USAGE="<file1> [<file2> <file3> ...]"
OPTIONS_SPEC=
SUBDIRECTORY_OK=Yes
. "$(git --exec-path)/git-sh-setup"

# Hashing algorithm
HASH_ALG="MD5"
# Extension for content link files
CONTENT_LINK_EXTENSION=".md5"
# Output indentation
INDENT="    "

#
# Adds a content link for a single file
#   @param $1 - Path to the test data that will be added
#
add_test_data() {
  content_file=$1
  if [ ! -f $content_file ]; then
    fatal "Cannot find file '$content_file'"
  fi
  debug_msg "Adding data file '$content_file'"

  # Compute hash
  hash=$(hash_code $content_file)
  if [ "$hash" = "" ]; then
    return 1
  fi
  debug_msg "${INDENT}${HASH_ALG} hash: $hash"

  # Create content link if required
  content_link_filename=$(content_link_filename $content_file)
  msgs=$(create_or_check_content_link $content_link_filename $content_file $hash)
  debug_msg $msgs

  git_add $content_link_filename
  debug_msg "${INDENT}$content_link_filename staged for commit"

  renamed_file=$(rename_content $content_file $hash)
  debug_msg "${INDENT}Content location: ${renamed_file}"

  # For capture by caller
  echo ${renamed_file}
}

#
# Computes the hash, using the algorithm defined in HASH_ALG, of the given file.
# Hash code is printed to stdout
#   @param $1 - Path to the file whose hash is computed
#   @return 1 on failure, 0 on success
hash_code() {
  if [ "$HASH_ALG" = "MD5" ]; then
    echo $(md5sum $1)
  else
    echo "Unknown hashing algorithm '$HASH_ALG' requested"
    return 1
  fi
}

#
# Computes the MD5 checksum of the given file.
# MD5 code is printed to stdout
#   @param $1 - Path to the file whose hash is computed
#   @return 1 failure to create md5sum, 0 on success.
md5sum() {
  md5cmd="cmake -E md5sum"
  cmake_output=$($md5cmd $1)
  if [ "$cmake_output" = "" ]; then
    echo "CMake was unable to create the MD5 Sum" 1>&2
    return 1
  fi
  # CMake output is of form: HASH   filename
  md5=$(echo $cmake_output | awk '{print $1}')
  echo $md5
}

#
# Rename a file to the hashed variant: $hash_code
# Path to the new full path is printed to stdout
#   @param $1 - Path to the original file
#   @param $2 - Hash code of the file content
rename_content() {
  directory_name=$(dirname $1)
  original_filename=$(basename $1)
  hash_code=$2
  hashed_filename=$hash_code
  full_path=$directory_name/$hashed_filename
  # Rename the file
  mv $1 $full_path
  # Allow caller to capture the value
  echo $full_path
}

#
# Create a text file containing the hash of the content named filename.ext.hash
# if one does not already exist. If a file exists then verify that the checksum
# is correct
# Path to the new full path is printed to stdout
#   @param $1 - New content link filename
#   @param $2 - Real content filename
#   @param $3 - Hash code of the file content
#   @return 0 indicates content link was created/updated. 10 indicates file existed and was not updated.
create_or_check_content_link() {
  content_link_filename=$1
  content_file=$2
  hash=$3

  # The content link file may already exist. If it does not then it is created.
  # If the file exists then either:
  #   - the hash in the file matches the raw content: nothing is changed.
  #   - the hash in the file is different to the raw content: it is assume the content will be updated
  verb="created"
  if [ -f $content_link_filename ]; then
    hash_in_file=$(cat $content_link_filename)
    if [ "$hash_in_file" = "$hash" ]; then
      echo "${INDENT}${content_file} already referenced as ${content_link_filename}"
      return 10
    fi
    verb="updated"
  fi

  create_content_link $content_link_filename $hash
  echo "${INDENT}Content link ${verb}: ${content_link_filename}"
  return 0
}

#
# Create a text file containing the hash of the content named filename.ext.hash
#   @param $1 - New content link filename
#   @param $2 - Hash code of the file content
create_content_link() {
  content_link_filename=$1
  # Create file
  echo $2 > ${content_link_filename}
}

#
# Create the filename for the content link
#   @param $1 Path to original file
content_link_filename() {
  echo ${1}${CONTENT_LINK_EXTENSION}
}

#
# Adds the given file to git
#   @param $1 - Path to file
#
git_add() {
  git add $1
}

#
# If in debug mode then sends all arguments to echo
debug_msg() {
  if [ "$MANTID_GIT_DEBUG" = "1" ]; then
    echo "$@"
  fi
}

#
# Send a message to stdout
information_msg() {
  echo "$@"
}

#
# Sends a fatal error message to stderr and aborts the script
#   @param $1 Message
fatal() {
  echo "$@" 1>&2
  exit 1
}

#-------------------------------------------------------------------------------

# Check arguments
if [ $# = 0 ]; then
  usage
fi

datafiles=$*
all_hashed_files=""
for datafile in $datafiles; do
  hashed_content=$(add_test_data ${GIT_PREFIX}$datafile)
  if [ "$hashed_content" = "" ]; then
    fatal "Unable to add test data '${GIT_PREFIX}$datafile'"
  fi
  all_hashed_files="$all_hashed_files $hashed_content"
done

information_msg "Please upload the following files to the remote store under the $HASH_ALG directory:"
for file in $all_hashed_files; do
  information_msg "${INDENT}$file"
done