json-splitter.sh

#!/bin/bash
#
# <pre>
#
#   Copyright (c) 2016 Louis Jeng <[email protected]>
# 
#   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.
#
# </pre>
#
# <p>Split Parse.com exported json file
# to the size of 2G bytes.</p>
# 
# prerequisite:
# <code>
#   $ sudo apt-get install jq pv
# </code>
#
# @author Louis Jeng <[email protected]>
# @since  2016-01-20
#


if test -z "$1"; then
    echo "Usage: $0 <source_file> [ <size_limit> ]"
    exit 1
fi

size_padding="13"
size_limit=$(echo "2*2^30" | bc)
source_file="$1"
split_prefix="split-${source_file%.json}"

if test -n "$2"; then
    if test "$2" -gt "0"; then
        size_limit="$2"
        if test -n "$3" -a "$3" = "line"; then
            line_limit="yes"
            size_padding="0"
        fi
    fi
fi

if test ! -f "${source_file}"; then
    echo "${source_file} not found"
    exit 1
fi

rm -fv ${split_prefix}.*.json 2>/dev/null
rm -fv ${source_file%.json}.*.json 2>/dev/null

echo "> [ step 0 ] processing ${source_file}"
echo "> limit size = ${size_limit}"
if test -n "${line_limit}"; then echo "> limit in line"; fi
pv "${source_file}" \
    | sed '1s/^{ "results": \[//' | sed '$s/\] }$//' \
    | sed 's/^    },$/    }/g' \
    | sed 's/^  *//g' | sed 's/": /":/g' \
    | tr -d "\n" | jq -c . \
    | split "$(if test -n "${line_limit}"; then echo "-l"; else echo "-C"; fi)" \
            "$(echo "${size_limit} - ${size_padding}" | bc)" \
            -d -a 3 -u --verbose --additional-suffix=".json" - "${split_prefix}."

steps=$(ls -1 ${split_prefix}.*.json 2>/dev/null | wc -l)
if test "$steps" -gt "0"; then
    for i in $(seq 0 $(echo "${steps} - 1" | bc)); do
        split_file="${split_prefix}.$(printf "%03d" $i).json"
        echo "> [ $(echo "$i + 1" | bc) of ${steps} ] processing ${split_file}"
        if test -f "${split_file}"; then
            pv "${split_file}" | tr "\n" "," \
                | sed "s/^/{\"results\":[/" \
                | sed "s/,$/]}/g" > ${split_file#split-}
        fi
    done
fi