reorganize filesv2.1.0

1 files changed, 308 insertions, 0 deletions

diff --git a/lib/db.sh b/lib/db.sh
new file mode 100644
index 0000000..ae96487
--- /dev/null
+++ b/lib/db.sh
@@ -0,0 +1,308 @@
+# Copyright (c) 2016 Egor Tensin <egor@tensin.name>
+# This file is part of the "Config file sharing" project.
+# For details, see https://github.com/egor-tensin/config-links.
+# Distributed under the MIT License.
+
+# Shared directory settings
+
+shared_root_dir="$( pwd )/"
+
+update_shared_dir() {
+    if [ "$#" -ne 1 ]; then
+        echo "usage: ${FUNCNAME[0]} DIR" >&2
+        return 1
+    fi
+
+    local new_shared_dir
+    new_shared_dir="$( traverse_path --exist --directory -- "$1" )"
+
+    [ "$new_shared_dir" = / ] || new_shared_dir="$new_shared_dir/"
+
+    [ "$db_path" = "$shared_root_dir$default_db_name" ] \
+        && db_path="$new_shared_dir$default_db_name"
+
+    shared_root_dir="$new_shared_dir"
+}
+
+# Database maintenance
+
+readonly default_db_name='links.bin'
+db_path="$shared_root_dir$default_db_name"
+declare -A database=()
+declare -A shared_paths=()
+declare -A symlink_paths=()
+
+update_database_path() {
+    if [ "$#" -ne 1 ]; then
+        echo "usage: ${FUNCNAME[0]} PATH" >&2
+        return 1
+    fi
+
+    db_path="$( traverse_path --file -- "$1" )"
+
+    local db_dir
+    db_dir="$( dirname -- "$db_path" )"
+    mkdir -p -- "$db_dir"
+}
+
+add_entry() {
+    local entry
+    for entry; do
+        dump "entry: $entry"
+
+        local var_name
+        var_name="$( extract_variable_name "$entry" )"
+        cache_variable "$var_name"
+
+        local shared_var_dir="$shared_root_dir%$var_name%"
+        local symlink_var_dir
+        symlink_var_dir="$( resolve_variable "$var_name" )"
+        local subpath="${entry#%"$var_name"%/}"
+
+        local shared_path="$shared_var_dir"
+        [ "$shared_var_dir" != / ] && shared_path="$shared_path/"
+        shared_path="$shared_path$subpath"
+
+        local symlink_path="$symlink_var_dir"
+        [ "$symlink_var_dir" != / ] && symlink_path="$symlink_path/"
+        symlink_path="$symlink_path$subpath"
+
+        dump "    shared file path: $shared_path"
+        dump "    symlink path: $symlink_path"
+
+        database[$entry]="$var_name"
+        shared_paths[$entry]="$shared_path"
+        symlink_paths[$entry]="$symlink_path"
+    done
+}
+
+remove_entry() {
+    local entry
+    for entry; do
+        unset -v 'database[$entry]'
+        unset -v 'shared_paths[$entry]'
+        unset -v 'symlink_paths[$entry]'
+    done
+}
+
+read_database() {
+    [ ! -r "$db_path" ] && return 0
+
+    local entry
+    while IFS= read -d '' -r entry; do
+        add_entry "$entry"
+    done < "$db_path"
+}
+
+write_database() {
+    is_dry_run && return 0
+
+    [ "${#database[@]}" -eq 0 ] && rm -f -- "$db_path" && return 0
+
+    > "$db_path"
+
+    local entry
+    for entry in "${!database[@]}"; do
+        printf -- '%s\0' "$entry" >> "$db_path"
+    done
+}
+
+link_entry() {
+    local entry
+    for entry; do
+        local shared_path="${shared_paths[$entry]}"
+        local symlink_path="${symlink_paths[$entry]}"
+
+        local symlink_dir
+        symlink_dir="$( dirname -- "$symlink_path" )"
+        mkdir -p -- "$symlink_dir"
+        ln -f -s --no-target-directory -- "$shared_path" "$symlink_path"
+    done
+}
+
+delete_obsolete_dirs() {
+    if [ "$#" -ne 2 ]; then
+        echo "usage: ${FUNCNAME[0]} BASE_DIR DIR" >&2
+        return 1
+    fi
+
+    local base_dir="$1"
+    local dir="$2"
+
+    base_dir="$( traverse_path --exist --directory -- "$base_dir" )"
+    dir="$( traverse_path --exist --directory -- "$dir" )"
+
+    [ "$base_dir" = "$dir" ] && return 0
+
+    local subpath="${dir##"$base_dir"/}"
+
+    if [ "$subpath" = "$dir" ]; then
+        dump "base directory: $base_dir"    >&2
+        dump "... is not a parent of: $dir" >&2
+        return 1
+    fi
+
+    ( cd -- "$base_dir/" && rmdir -p --ignore-fail-on-non-empty -- "$subpath" )
+}
+
+unlink_entry() {
+    local entry
+    for entry; do
+        local shared_path="${shared_paths[$entry]}"
+        local symlink_path="${symlink_paths[$entry]}"
+
+        rm -f -- "$symlink_path"
+
+        local symlink_dir
+        symlink_dir="$( dirname -- "$symlink_path" )"
+        local var_name="${database[$entry]}"
+        local symlink_var_dir
+        symlink_var_dir="$( resolve_variable "$var_name" )"
+        delete_obsolete_dirs "$symlink_var_dir" "$symlink_dir" || true
+    done
+}
+
+symlink_present() {
+    local entry
+    for entry; do
+        local symlink_path="${symlink_paths[$entry]}"
+        test -L "$symlink_path" -o -e "$symlink_path"
+    done
+}
+
+symlink_points_to_shared_file() {
+    symlink_present "$@"
+    local entry
+    for entry; do
+        local shared_path="${shared_paths[$entry]}"
+        shared_path="$( traverse_path -- "$shared_path" )"
+        local symlink_path="${symlink_paths[$entry]}"
+        local target_path
+        target_path="$( traverse_path -- "$symlink_path" )"
+        test "$target_path" = "$shared_path"
+    done
+}
+
+shared_file_present() {
+    local entry
+    for entry; do
+        local shared_path="${shared_paths[$entry]}"
+        test -L "$shared_path" -o -e "$shared_path"
+    done
+}
+
+link_all_entries() {
+    local -a shared_var_dirs=()
+    local shared_var_dir
+
+    find "$shared_root_dir" \
+        -mindepth 1 -maxdepth 1 \
+        -\( -type d -o -type l -\) \
+        -regextype posix-basic \
+        -regex ".*/$var_name_regex\$" \
+        -printf '%P\0' |
+    while IFS= read -d '' -r shared_var_dir; do
+        shared_var_dirs+=("$shared_var_dir")
+    done
+
+    for shared_var_dir in ${shared_var_dirs[@]+"${shared_var_dirs[@]}"}; do
+        dump "shared directory: $shared_root_dir$shared_var_dir"
+        local shared_path
+
+        find "$shared_root_dir$shared_var_dir/" -\( -type f -o -type l -\) -print0 |
+        while IFS= read -d '' -r shared_path; do
+            dump "    shared file path: $shared_path"
+            local entry="${shared_path:${#shared_root_dir}}"
+            add_entry "$entry" > /dev/null
+            dump "    symlink path: ${symlink_paths[$entry]}"
+
+            if symlink_present "$entry"; then
+                if symlink_points_to_shared_file "$entry"; then
+                    dump '    ... up-to-date'
+                else
+                    dump "    ... not a symlink or doesn't point to the shared file, adding a symlink"
+                    is_dry_run || link_entry "$entry"
+                fi
+            else
+                dump '    ... adding a symlink'
+                is_dry_run || link_entry "$entry"
+            fi
+        done
+    done
+}
+
+unlink_all_entries() {
+    local entry
+    for entry in "${!database[@]}"; do
+        dump "entry: $entry"
+        local shared_path="${shared_paths[$entry]}"
+        local symlink_path="${symlink_paths[$entry]}"
+        dump "    shared file path: $shared_path"
+        dump "    symlink path: $symlink_path"
+
+        if symlink_points_to_shared_file "$entry"; then
+            dump '    ... removing the symlink'
+            is_dry_run || unlink_entry "$entry"
+            remove_entry "$entry"
+        else
+            dump "    ... not a symlink or doesn't point to the shared file"
+            remove_entry "$entry"
+        fi
+    done
+}
+
+unlink_obsolete_entries() {
+    local entry
+    for entry in "${!database[@]}"; do
+        dump "entry: $entry"
+        local shared_path="${shared_paths[$entry]}"
+        local symlink_path="${symlink_paths[$entry]}"
+        dump "    shared file path: $shared_path"
+        dump "    symlink path: $symlink_path"
+
+        if symlink_points_to_shared_file "$entry"; then
+            if shared_file_present "$entry"; then
+                dump '    ... up-to-date'
+            else
+                dump '    ... obsolete'
+                is_dry_run || unlink_entry "$entry"
+                remove_entry "$entry"
+            fi
+        else
+            dump "    ... not a symlink or doesn't point to the shared file"
+            remove_entry "$entry"
+        fi
+    done
+}
+
+parse_mode() {
+    if [ "$#" -ne 1 ]; then
+        echo "usage: ${FUNCNAME[0]} MODE" >&2
+        return 1
+    fi
+
+    local mode="$1"
+    shift
+
+    if [ -z "$mode" ]; then
+        dump "mode cannot be empty" >&2
+        return 1
+    fi
+
+    echo "$mode"
+}
+
+chmod_entries() {
+    if [ "$#" -ne 1 ]; then
+        echo "usage: ${FUNCNAME[0]} MODE" >&2
+        return 1
+    fi
+
+    local mode="$1"
+    shift
+
+    dump "applying mode $mode to shared files..."
+    if [ "${#shared_paths[@]}" -ne 0 ]; then
+        is_dry_run || chmod -- "$mode" ${shared_paths[@]+"${shared_paths[@]}"}
+    fi
+}