jshn: refactor _jshn_append to require fewer evals

[project/libubox.git] / sh / jshn.sh

diff --git a/sh/jshn.sh b/sh/jshn.sh
index 110892c..9e7f444 100644 (file)
--- a/sh/jshn.sh
+++ b/sh/jshn.sh
@@ -1,78 +1,71 @@
 # functions for parsing and generating json
 
 _json_get_var() {
-       local ___dest="$1"
-       local ___var="$2"
-       eval "$___dest=\"\$${JSON_PREFIX}$___var\""
+       # dest=$1
+       # var=$2
+       eval "$1=\"\$${JSON_PREFIX}$2\""
 }
 
 _json_set_var() {
-       local ___var="$1"
+       # var=$1
        local ___val="$2"
-       eval "${JSON_PREFIX}$___var=\"\$___val\""
+       eval "${JSON_PREFIX}$1=\"\$___val\""
 }
 
-_jshn_append() {
-       local __var="$1"
-       local __value="$2"
-       local __sep="${3:- }"
-       local __old_val
+__jshn_raw_append() {
+       # var=$1
+       local value="$2"
+       local sep="${3:- }"
 
-       _json_get_var __old_val "$__var"
-       __value="${__old_val:+$__old_val$__sep}$__value"
-       _json_set_var "$__var" "$__value"
+       eval "export -- \"$1=\${$1:+\${$1}\${value:+\$sep}}\$value\""
 }
 
-_json_export() {
-       local __var="${JSON_PREFIX}$1"
-       local __val="$2"
+_jshn_append() {
+       # var=$1
+       local _a_value="$2"
+       local _a_sep="${3:- }"
+       eval "${JSON_PREFIX}$1=\"\${${JSON_PREFIX}$1:+\${${JSON_PREFIX}$1}\${_a_value:+\$_a_sep}}\$_a_value\""
+}
 
-       export -- "$__var=$__val"
-       _jshn_append "JSON_UNSET" "$__var"
+_json_export() {
+       # var=$1
+       # value=$2
+       export -- "${JSON_PREFIX}$1=$2"
 }
 
 _json_add_key() {
-       local table="$1"
-       local var="$2"
-       _jshn_append "KEYS_${table}" "$var"
+       # var=$1
+       # value=$2
+       _jshn_append "KEYS_$1" "$2"
 }
 
 _get_var() {
-       local __dest="$1"
-       local __var="$2"
-       eval "$__dest=\"\$$__var\""
+       # var=$1
+       # value=$2
+       eval "$1=\"\$$2\""
 }
 
 _set_var() {
-       local __var="$1"
+       # var=$1
        local __val="$2"
-       eval "$__var=\"\$__val\""
+       eval "$1=\"\$__val\""
 }
 
 _json_inc() {
-       local _var="$1"
-       local _dest="$2"
+       # var=$1
+       # dest=$2
        local _seq
 
-       _json_get_var _seq "$_var"
+       _json_get_var _seq "$1"
        _seq="$((${_seq:-0} + 1))"
-       _json_set_var "$_var" "$_seq"
-       [ -n "$_dest" ] && _set_var "$_dest" "$_seq"
-}
-
-_json_stack_push() {
-       local new_cur="$1"
-       local cur
-
-       _json_get_var cur JSON_CUR
-       _jshn_append JSON_STACK "$cur"
-       _json_set_var JSON_CUR "$new_cur"
+       _json_set_var "$1" "$_seq"
+       [ -n "$2" ] && _set_var "$2" "$_seq"
 }
 
 _json_add_generic() {
-       local type="$1"
+       # type=$1
        local var="$2"
-       local val="$3"
+       # value=$3
        local cur="$4"
 
        [ -n "$cur" ] || _json_get_var cur JSON_CUR
@@ -85,39 +78,39 @@ _json_add_generic() {
                var="$name"
        fi
 
-       _json_export "${cur}_$var" "$val"
-       _json_export "TYPE_${cur}_$var" "$type"
+       local cur_var=
+       _json_export "${cur}_$var" "$3"
+       _json_export "TYPE_${cur}_$var" "$1"
+       _jshn_append "JSON_UNSET" "${cur}_$var"
        _json_add_key "$cur" "$var"
 }
 
 _json_add_table() {
-       local name="$1"
-       local type="$2"
-       local itype="$3"
-       local cur new_cur
-       local seq
+       # name=$1
+       # type=$2
+       # itype=$3
+       local cur new_cur seq
 
        _json_get_var cur JSON_CUR
        _json_inc JSON_SEQ seq
 
-       local table="JSON_$itype$seq"
-       _json_export "UP_$table" "$cur"
+       local table="JSON_$3$seq"
+       _json_set_var "UP_$table" "$cur"
        _json_export "KEYS_$table" ""
-       [ "$itype" = "ARRAY" ] && _json_export "SEQ_$table" ""
-       _json_stack_push "$table"
+       [ "$itype" = "ARRAY" ] && _json_set_var "SEQ_$table" ""
+       _json_set_var JSON_CUR "$table"
+       _jshn_append "JSON_UNSET" "$table"
 
        _json_get_var new_cur JSON_CUR
-       _json_add_generic "$type" "$1" "$new_cur" "$cur"
+       _json_add_generic "$2" "$1" "$new_cur" "$cur"
 }
 
 _json_close_table() {
-       local stack new_stack
+       local _s_cur _s_new
 
-       _json_get_var stack JSON_STACK
-       _json_set_var JSON_CUR "${stack##* }"
-       new_stack="${stack% *}"
-       [[ "$stack" == "$new_stack" ]] && new_stack=
-       _json_set_var JSON_STACK "$new_stack"
+       _json_get_var _s_cur JSON_CUR
+       _json_get_var _s_new "UP_$_s_cur"
+       _json_set_var JSON_CUR "$_s_new"
 }
 
 json_set_namespace() {
@@ -132,24 +125,27 @@ json_cleanup() {
        local unset
 
        _json_get_var unset JSON_UNSET
-       [ -n "$unset" ] && eval "unset $unset"
+       for tmp in $unset JSON_VAR; do
+               unset \
+                       ${JSON_PREFIX}UP_$tmp \
+                       ${JSON_PREFIX}KEYS_$tmp \
+                       ${JSON_PREFIX}SEQ_$tmp \
+                       ${JSON_PREFIX}TYPE_$tmp \
+                       ${JSON_PREFIX}NAME_$tmp \
+                       ${JSON_PREFIX}$tmp
+       done
 
        unset \
                ${JSON_PREFIX}JSON_SEQ \
-               ${JSON_PREFIX}JSON_STACK \
                ${JSON_PREFIX}JSON_CUR \
-               ${JSON_PREFIX}JSON_UNSET \
-               ${JSON_PREFIX}KEYS_JSON_VAR \
-               ${JSON_PREFIX}TYPE_JSON_VAR
+               ${JSON_PREFIX}JSON_UNSET
 }
 
 json_init() {
        json_cleanup
        export -- \
                ${JSON_PREFIX}JSON_SEQ=0 \
-               ${JSON_PREFIX}JSON_STACK= \
                ${JSON_PREFIX}JSON_CUR="JSON_VAR" \
-               ${JSON_PREFIX}JSON_UNSET="" \
                ${JSON_PREFIX}KEYS_JSON_VAR= \
                ${JSON_PREFIX}TYPE_JSON_VAR=
 }
@@ -209,11 +205,37 @@ json_get_keys() {
        local __dest="$1"
        local _tbl_cur
 
-       json_get_var _tbl_cur "$2"
+       if [ -n "$2" ]; then
+               json_get_var _tbl_cur "$2"
+       else
+               _json_get_var _tbl_cur JSON_CUR
+       fi
        local __var="${JSON_PREFIX}KEYS_${_tbl_cur}"
        eval "export -- \"$__dest=\${$__var}\"; [ -n \"\${$__var+x}\" ]"
 }
 
+json_get_values() {
+       local _v_dest="$1"
+       local _v_keys _v_val _select=
+
+       unset "$_v_dest"
+       [ -n "$2" ] && {
+               json_select "$2"
+               _select=1
+       }
+
+       json_get_keys _v_keys
+       set -- $_v_keys
+       while [ "$#" -gt 0 ]; do
+               json_get_var _v_val "$1"
+               __jshn_raw_append "$_v_dest" "$_v_val"
+               shift
+       done
+       [ -n "$_select" ] && json_select ..
+
+       return 0
+}
+
 json_get_var() {
        local __dest="$1"
        local __cur