116 lines
2.7 KiB
Bash
116 lines
2.7 KiB
Bash
#!/usr/bin/env bash
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FILE=$1
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# Sparse sequence
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read -r -a SPARSE_ARRAY <<< "$(
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INDEX=0
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FILE_ID=0
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while read -r CHAR
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do
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if [[ $(( INDEX % 2 )) -eq 0 ]]
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then
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for (( i=1; i<=CHAR; i++ )) do printf "%s " "$FILE_ID"
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done
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(( FILE_ID++ ))
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else
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for (( i=1; i<=CHAR; i++ ))
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do
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printf "%s " '-1'
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done
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fi
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(( INDEX++ ))
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done <<< "$( sed -E 's/(.)/\1\n/g' "$FILE" | grep -v '^$' )"
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)"
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printf "%s" "${SPARSE_ARRAY[@]}" | fold -w 100
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printf "\n"
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printf "Sparse array len: %s\n" "${#SPARSE_ARRAY[@]}"
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SHADOW_ARRAY=( "${SPARSE_ARRAY[@]}" )
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# Start by working backwards
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j=$(( ${#SPARSE_ARRAY[@]} - 1 )) # Moveable index since file blocks jump
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k=0 # SHADOW_ARRAY cursor
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LAST_SKIP=9999
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while [[ $j -ge 0 ]]
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do
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# Find a file
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if [[ ${SPARSE_ARRAY[j]} -eq -1 ]]
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then
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# Not a file
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(( j-- ))
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continue
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fi
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# Get file size
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# j moved to index before file head
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FILE_SIZE=0
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ID=${SPARSE_ARRAY[j]}
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while [[ ${SPARSE_ARRAY[j]} == "$ID" ]]
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do
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(( FILE_SIZE++ ))
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(( j-- ))
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done
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#printf "File ID: %s, File size: %s\n" "$ID" "$FILE_SIZE" 2>&1
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# Since search space is constantly decreasing
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# Contiguous space can only keep getting smaller
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if [[ $FILE_SIZE -ge $LAST_SKIP ]]
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then
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printf "File %s size %s skipped. Last skip: %s\n" "$ID" "$FILE_SIZE" "$LAST_SKIP"
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continue
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fi
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# Search for available contiguous space
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# Search from start until the file itself
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k=0
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while [[ $k -le $j ]] && [[ $k -le ${#SHADOW_ARRAY[@]} ]]
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do
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CONT_SPACE=0
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# Skip ahead until first match of space
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while [[ ${SHADOW_ARRAY[k]} -ne -1 ]] && [[ $k -le ${#SHADOW_ARRAY[@]} ]]
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do
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(( k++ ))
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done
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# Space found, now get contiguous length
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while [[ ${SHADOW_ARRAY[k]} -eq -1 ]] && [[ $k -le ${#SHADOW_ARRAY[@]} ]]
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do
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(( CONT_SPACE++ ))
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(( k++ ))
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done
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# Space length is ok, can proceed
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if [[ $FILE_SIZE -le $CONT_SPACE ]] ;then break; fi
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done
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# Space length ok, can proceed
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if [[ $FILE_SIZE -le $CONT_SPACE ]]
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then
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# Move the file to head of contiguous space
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(( k-= CONT_SPACE ))
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while [[ $FILE_SIZE -gt 0 ]] && \
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[[ ${SHADOW_ARRAY[k]} -eq -1 ]] && \
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[[ ${SHADOW_ARRAY[j+FILE_SIZE]} -ne -1 ]]
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do
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SHADOW_ARRAY[k]=$ID
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SHADOW_ARRAY[j+FILE_SIZE]=-1
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(( k++ ))
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(( FILE_SIZE-- ))
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done
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else
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LAST_SKIP=$FILE_SIZE
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printf "File %s skipped. File size: %s\n" "$ID" "$FILE_SIZE"
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continue
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fi
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done
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printf "%s " "${SHADOW_ARRAY[@]}" | fold -w 100 | tee final-result | cat
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printf "\n"
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# Generate checksum for shadow array
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CHECKSUM=0
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for (( i=0; i<${#SHADOW_ARRAY[@]}; i++ ))
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do
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if [[ ${SHADOW_ARRAY[i]} -ne -1 ]] ;then (( CHECKSUM += i * SHADOW_ARRAY[i] )); fi
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done
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printf "%s\n" "$CHECKSUM"
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