jshn: optimize the shell code some more
[project/libubox.git] / sh / jshn.sh
1 # functions for parsing and generating json
2
3 _json_get_var() {
4 # dest=$1
5 # var=$2
6 eval "$1=\"\$${JSON_PREFIX}$2\""
7 }
8
9 _json_set_var() {
10 # var=$1
11 local ___val="$2"
12 eval "${JSON_PREFIX}$1=\"\$___val\""
13 }
14
15 __jshn_raw_append() {
16 # var=$1
17 local value="$2"
18 local sep="${3:- }"
19
20 eval "export -- \"$1=\${$1:+\${$1}\${value:+\$sep}}\$value\""
21 }
22
23 _jshn_append() {
24 # var=$1
25 local _a_value="$2"
26 eval "${JSON_PREFIX}$1=\"\${${JSON_PREFIX}$1} \$_a_value\""
27 }
28
29 _get_var() {
30 # var=$1
31 # value=$2
32 eval "$1=\"\$$2\""
33 }
34
35 _set_var() {
36 # var=$1
37 local __val="$2"
38 eval "$1=\"\$__val\""
39 }
40
41 _json_inc() {
42 # var=$1
43 # dest=$2
44
45 eval "${JSON_PREFIX}$1=\$(( \${${JSON_PREFIX}$1:-0} + 1))${2:+; $2=\"\$${JSON_PREFIX}$1\"}"
46 }
47
48 _json_add_generic() {
49 # type=$1
50 # name=$2
51 # value=$3
52 # cur=$4
53
54 local var
55 if [ "${4%%[0-9]*}" = "JSON_ARRAY" ]; then
56 _json_inc "SEQ_$4" var
57 else
58 local name="${2//[^a-zA-Z0-9_]/_}"
59 [[ "$name" == "$2" ]] || export -- "${JSON_PREFIX}NAME_${4}_${name}=$2"
60 var="$name"
61 fi
62
63 local cur_var=
64 export -- \
65 "${JSON_PREFIX}${4}_$var=$3" \
66 "${JSON_PREFIX}TYPE_${4}_$var=$1"
67 _jshn_append "JSON_UNSET" "${4}_$var"
68 _jshn_append "KEYS_$4" "$var"
69 }
70
71 _json_add_table() {
72 # name=$1
73 # type=$2
74 # itype=$3
75 local cur seq
76
77 _json_get_var cur JSON_CUR
78 _json_inc JSON_SEQ seq
79
80 local table="JSON_$3$seq"
81 _json_set_var "UP_$table" "$cur"
82 export -- "${JSON_PREFIX}KEYS_$table="
83 unset "${JSON_PREFIX}SEQ_$table"
84 _json_set_var JSON_CUR "$table"
85 _jshn_append "JSON_UNSET" "$table"
86
87 _json_add_generic "$2" "$1" "$table" "$cur"
88 }
89
90 _json_close_table() {
91 local _s_cur
92
93 _json_get_var _s_cur JSON_CUR
94 _json_get_var "${JSON_PREFIX}JSON_CUR" "UP_$_s_cur"
95 }
96
97 json_set_namespace() {
98 local _new="$1"
99 local _old="$2"
100
101 [ -n "$_old" ] && _set_var "$_old" "$JSON_PREFIX"
102 JSON_PREFIX="$_new"
103 }
104
105 json_cleanup() {
106 local unset
107
108 _json_get_var unset JSON_UNSET
109 for tmp in $unset JSON_VAR; do
110 unset \
111 ${JSON_PREFIX}UP_$tmp \
112 ${JSON_PREFIX}KEYS_$tmp \
113 ${JSON_PREFIX}SEQ_$tmp \
114 ${JSON_PREFIX}TYPE_$tmp \
115 ${JSON_PREFIX}NAME_$tmp \
116 ${JSON_PREFIX}$tmp
117 done
118
119 unset \
120 ${JSON_PREFIX}JSON_SEQ \
121 ${JSON_PREFIX}JSON_CUR \
122 ${JSON_PREFIX}JSON_UNSET
123 }
124
125 json_init() {
126 json_cleanup
127 export -- \
128 ${JSON_PREFIX}JSON_SEQ=0 \
129 ${JSON_PREFIX}JSON_CUR="JSON_VAR" \
130 ${JSON_PREFIX}KEYS_JSON_VAR= \
131 ${JSON_PREFIX}TYPE_JSON_VAR=
132 }
133
134 json_add_object() {
135 _json_add_table "$1" object TABLE
136 }
137
138 json_close_object() {
139 _json_close_table
140 }
141
142 json_add_array() {
143 _json_add_table "$1" array ARRAY
144 }
145
146 json_close_array() {
147 _json_close_table
148 }
149
150 json_add_string() {
151 local cur
152 _json_get_var cur JSON_CUR
153 _json_add_generic string "$1" "$2" "$cur"
154 }
155
156 json_add_int() {
157 local cur
158 _json_get_var cur JSON_CUR
159 _json_add_generic int "$1" "$2" "$cur"
160 }
161
162 json_add_boolean() {
163 local cur
164 _json_get_var cur JSON_CUR
165 _json_add_generic boolean "$1" "$2" "$cur"
166 }
167
168 json_add_double() {
169 local cur
170 _json_get_var cur JSON_CUR
171 _json_add_generic double "$1" "$2" "$cur"
172 }
173
174 # functions read access to json variables
175
176 json_load() {
177 eval `jshn -r "$1"`
178 }
179
180 json_dump() {
181 jshn "$@" ${JSON_PREFIX:+-p "$JSON_PREFIX"} -w
182 }
183
184 json_get_type() {
185 local __dest="$1"
186 local __cur
187
188 _json_get_var __cur JSON_CUR
189 local __var="${JSON_PREFIX}TYPE_${__cur}_${2//[^a-zA-Z0-9_]/_}"
190 eval "export -- \"$__dest=\${$__var}\"; [ -n \"\${$__var+x}\" ]"
191 }
192
193 json_get_keys() {
194 local __dest="$1"
195 local _tbl_cur
196
197 if [ -n "$2" ]; then
198 json_get_var _tbl_cur "$2"
199 else
200 _json_get_var _tbl_cur JSON_CUR
201 fi
202 local __var="${JSON_PREFIX}KEYS_${_tbl_cur}"
203 eval "export -- \"$__dest=\${$__var}\"; [ -n \"\${$__var+x}\" ]"
204 }
205
206 json_get_values() {
207 local _v_dest="$1"
208 local _v_keys _v_val _select=
209
210 unset "$_v_dest"
211 [ -n "$2" ] && {
212 json_select "$2"
213 _select=1
214 }
215
216 json_get_keys _v_keys
217 set -- $_v_keys
218 while [ "$#" -gt 0 ]; do
219 json_get_var _v_val "$1"
220 __jshn_raw_append "$_v_dest" "$_v_val"
221 shift
222 done
223 [ -n "$_select" ] && json_select ..
224
225 return 0
226 }
227
228 json_get_var() {
229 local __dest="$1"
230 local __cur
231
232 _json_get_var __cur JSON_CUR
233 local __var="${JSON_PREFIX}${__cur}_${2//[^a-zA-Z0-9_]/_}"
234 eval "export -- \"$__dest=\${$__var}\"; [ -n \"\${$__var+x}\" ]"
235 }
236
237 json_get_vars() {
238 while [ "$#" -gt 0 ]; do
239 local _var="$1"; shift
240 json_get_var "$_var" "$_var"
241 done
242 }
243
244 json_select() {
245 local target="$1"
246 local type
247 local cur
248
249 [ -z "$1" ] && {
250 _json_set_var JSON_CUR "JSON_VAR"
251 return 0
252 }
253 [[ "$1" == ".." ]] && {
254 _json_get_var cur JSON_CUR
255 _json_get_var cur "UP_$cur"
256 _json_set_var JSON_CUR "$cur"
257 return 0
258 }
259 json_get_type type "$target"
260 case "$type" in
261 object|array)
262 json_get_var cur "$target"
263 _json_set_var JSON_CUR "$cur"
264 ;;
265 *)
266 echo "WARNING: Variable '$target' does not exist or is not an array/object"
267 return 1
268 ;;
269 esac
270 }
271
272 json_is_a() {
273 local type
274
275 json_get_type type "$1"
276 [ "$type" = "$2" ]
277 }