ustream: prevent recursive calls to the read callback
[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=$2
44
45 let "${JSON_PREFIX}$1 += 1" "$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]*}" = "J_A" ]; then
56 _json_inc "S_$4" var
57 else
58 var="${2//[^a-zA-Z0-9_]/_}"
59 [[ "$var" == "$2" ]] || export -- "${JSON_PREFIX}N_${4}_${var}=$2"
60 fi
61
62 export -- \
63 "${JSON_PREFIX}${4}_$var=$3" \
64 "${JSON_PREFIX}T_${4}_$var=$1"
65 _jshn_append "JSON_UNSET" "${4}_$var"
66 _jshn_append "K_$4" "$var"
67 }
68
69 _json_add_table() {
70 # name=$1
71 # type=$2
72 # itype=$3
73 local cur seq
74
75 _json_get_var cur JSON_CUR
76 _json_inc JSON_SEQ seq
77
78 local table="J_$3$seq"
79 _json_set_var "U_$table" "$cur"
80 export -- "${JSON_PREFIX}K_$table="
81 unset "${JSON_PREFIX}S_$table"
82 _json_set_var JSON_CUR "$table"
83 _jshn_append "JSON_UNSET" "$table"
84
85 _json_add_generic "$2" "$1" "$table" "$cur"
86 }
87
88 _json_close_table() {
89 local _s_cur
90
91 _json_get_var _s_cur JSON_CUR
92 _json_get_var "${JSON_PREFIX}JSON_CUR" "U_$_s_cur"
93 }
94
95 json_set_namespace() {
96 local _new="$1"
97 local _old="$2"
98
99 [ -n "$_old" ] && _set_var "$_old" "$JSON_PREFIX"
100 JSON_PREFIX="$_new"
101 }
102
103 json_cleanup() {
104 local unset tmp
105
106 _json_get_var unset JSON_UNSET
107 for tmp in $unset J_V; do
108 unset \
109 ${JSON_PREFIX}U_$tmp \
110 ${JSON_PREFIX}K_$tmp \
111 ${JSON_PREFIX}S_$tmp \
112 ${JSON_PREFIX}T_$tmp \
113 ${JSON_PREFIX}N_$tmp \
114 ${JSON_PREFIX}$tmp
115 done
116
117 unset \
118 ${JSON_PREFIX}JSON_SEQ \
119 ${JSON_PREFIX}JSON_CUR \
120 ${JSON_PREFIX}JSON_UNSET
121 }
122
123 json_init() {
124 json_cleanup
125 export -n ${JSON_PREFIX}JSON_SEQ=0
126 export -- \
127 ${JSON_PREFIX}JSON_CUR="J_V" \
128 ${JSON_PREFIX}K_J_V=
129 }
130
131 json_add_object() {
132 _json_add_table "$1" object T
133 }
134
135 json_close_object() {
136 _json_close_table
137 }
138
139 json_add_array() {
140 _json_add_table "$1" array A
141 }
142
143 json_close_array() {
144 _json_close_table
145 }
146
147 json_add_string() {
148 local cur
149 _json_get_var cur JSON_CUR
150 _json_add_generic string "$1" "$2" "$cur"
151 }
152
153 json_add_int() {
154 local cur
155 _json_get_var cur JSON_CUR
156 _json_add_generic int "$1" "$2" "$cur"
157 }
158
159 json_add_boolean() {
160 local cur
161 _json_get_var cur JSON_CUR
162 _json_add_generic boolean "$1" "$2" "$cur"
163 }
164
165 json_add_double() {
166 local cur
167 _json_get_var cur JSON_CUR
168 _json_add_generic double "$1" "$2" "$cur"
169 }
170
171 json_add_null() {
172 local cur
173 _json_get_var cur JSON_CUR
174 _json_add_generic null "$1" "" "$cur"
175 }
176
177 json_add_fields() {
178 while [ "$#" -gt 0 ]; do
179 local field="$1"
180 shift
181
182 local name="${field%%=*}"
183 local val="${field#*=}"
184 [ "$name" != "$val" ] || val=""
185
186 local type="${name#*:}"
187 [ "$type" != "$name" ] || type=string
188 name="${name%%:*}"
189
190 case "$type" in
191 string|int|boolean|double)
192 local cur
193 _json_get_var cur JSON_CUR
194 _json_add_generic "$type" "$name" "$val" "$cur"
195 ;;
196 esac
197 done
198 }
199
200 # functions read access to json variables
201
202 json_compact() {
203 JSON_NONEWLINE=1
204 JSON_INDENT=
205 }
206
207 json_pretty() {
208 JSON_NONEWLINE=
209 JSON_INDENT=1
210 }
211
212 json_load() {
213 eval "`jshn -r "$1"`"
214 }
215
216 json_load_file() {
217 eval "`jshn -R "$1"`"
218 }
219
220 json_dump() {
221 jshn "$@" ${JSON_PREFIX:+-p "$JSON_PREFIX"} ${JSON_NONEWLINE:+-n} ${JSON_INDENT:+-i} -w
222 }
223
224 json_get_type() {
225 local __dest="$1"
226 local __cur
227
228 _json_get_var __cur JSON_CUR
229 local __var="${JSON_PREFIX}T_${__cur}_${2//[^a-zA-Z0-9_]/_}"
230 eval "export -- \"$__dest=\${$__var}\"; [ -n \"\${$__var+x}\" ]"
231 }
232
233 json_get_keys() {
234 local __dest="$1"
235 local _tbl_cur
236
237 if [ -n "$2" ]; then
238 json_get_var _tbl_cur "$2"
239 else
240 _json_get_var _tbl_cur JSON_CUR
241 fi
242 local __var="${JSON_PREFIX}K_${_tbl_cur}"
243 eval "export -- \"$__dest=\${$__var}\"; [ -n \"\${$__var+x}\" ]"
244 }
245
246 json_get_values() {
247 local _v_dest="$1"
248 local _v_keys _v_val _select=
249 local _json_no_warning=1
250
251 unset "$_v_dest"
252 [ -n "$2" ] && {
253 json_select "$2" || return 1
254 _select=1
255 }
256
257 json_get_keys _v_keys
258 set -- $_v_keys
259 while [ "$#" -gt 0 ]; do
260 json_get_var _v_val "$1"
261 __jshn_raw_append "$_v_dest" "$_v_val"
262 shift
263 done
264 [ -n "$_select" ] && json_select ..
265
266 return 0
267 }
268
269 json_get_var() {
270 local __dest="$1"
271 local __cur
272
273 _json_get_var __cur JSON_CUR
274 local __var="${JSON_PREFIX}${__cur}_${2//[^a-zA-Z0-9_]/_}"
275 eval "export -- \"$__dest=\${$__var:-$3}\"; [ -n \"\${$__var+x}\${3+x}\" ]"
276 }
277
278 json_get_vars() {
279 while [ "$#" -gt 0 ]; do
280 local _var="$1"; shift
281 if [ "$_var" != "${_var#*:}" ]; then
282 json_get_var "${_var%%:*}" "${_var%%:*}" "${_var#*:}"
283 else
284 json_get_var "$_var" "$_var"
285 fi
286 done
287 }
288
289 json_select() {
290 local target="$1"
291 local type
292 local cur
293
294 [ -z "$1" ] && {
295 _json_set_var JSON_CUR "J_V"
296 return 0
297 }
298 [[ "$1" == ".." ]] && {
299 _json_get_var cur JSON_CUR
300 _json_get_var cur "U_$cur"
301 _json_set_var JSON_CUR "$cur"
302 return 0
303 }
304 json_get_type type "$target"
305 case "$type" in
306 object|array)
307 json_get_var cur "$target"
308 _json_set_var JSON_CUR "$cur"
309 ;;
310 *)
311 [ -n "$_json_no_warning" ] || \
312 echo "WARNING: Variable '$target' does not exist or is not an array/object"
313 return 1
314 ;;
315 esac
316 }
317
318 json_is_a() {
319 local type
320
321 json_get_type type "$1"
322 [ "$type" = "$2" ]
323 }
324
325 json_for_each_item() {
326 [ "$#" -ge 2 ] || return 0
327 local function="$1"; shift
328 local target="$1"; shift
329 local type val
330
331 json_get_type type "$target"
332 case "$type" in
333 object|array)
334 local keys key
335 json_select "$target"
336 json_get_keys keys
337 for key in $keys; do
338 json_get_var val "$key"
339 eval "$function \"\$val\" \"\$key\" \"\$@\""
340 done
341 json_select ..
342 ;;
343 *)
344 json_get_var val "$target"
345 eval "$function \"\$val\" \"\" \"\$@\""
346 ;;
347 esac
348 }